DIY Flower Basket | DIY Ideas | How To Make A Flower Basket From Plastic Bottles | Waste Utilization.

BEEF logo png vector transparent. Download free BEEF vector logo and icons in PNG, SVG, AI, EPS, CDR formats.

ֺ╮Sᦢft vidᧉo 💭 #Soft #Videos #Food #Japan Cr: for the music edit and the tiktok video ^__^

규현 🐧 조지니 🧞‍♂️❤’s Instagram photo: “اااااااااء الايديت البقره كيوهيون 😭😭😭🤣🤣🤣🤣🤣🤣🤣🤣 Cr : kyu9_oUOb”

#c#i#a#r#a#r#i#l#e#y#w#i#l#s#o#n#ciara#riley#wilson#ciarariley#ciarawilson#ciararileywilson#ciarawilsonriley#c#r#w#cr#cw#crw#cwr#s#e#l#f#i#e#selfie#b#a#t#h#r#o#o#m#bathroomselfie#bathroom#i#n#s#t#a#s#t#o#r#y#instastory#i#n#s#t#a#s#t#o#r#i#e#s#instastories#v#i#a#via#viainstastory#viainstastories#❤ | ("DON'TSAVE/TAKE?!")

Árak és vélemények egy helyen! · Legolcsóbb ár: 1490 Ft · Providence Dubois, a csinos párizsi postáskisasszony számára az élet olyan, mint a titkos atyai recept alapján készült majonéz: ha egyszerű hozzávalókat használunk, és kitartóan keverjük, garantált az eredmény. Providence-nek pedig kitartása és energiája is van bőven: mindig sietős a dolga, s fáradhatatlanul cikázik ide-oda a világban. Most éppen Marokkóba repülne örökbe fogadott, imádott kislányáért. Zahera súlyos beteg, Eiffel-torony nagyságú felhő növekszik a tüdejében, napokon, órákon múlhat az élete. Providence azt ígérte neki, hogy nála lesz, mielőtt felkel a hold. Ám egy izlandi vulkán épp ekkor tör ki, hogy hamufelhővel terítse be az eget, s így földhöz szögezze a repülőket. Ha a gépmadarak nem emelkedhetnek a levegőbe, akkor bizony Providence-nek kell repülnie. Látszólag emberfölötti teljesítmény, de Providence nem ismer lehetetlent: órákat vesz egy versailles-i kolostor tibeti szerzeteseitől, és már ott is áll az Orly reptéren egy szál bikiniben, hogy felszálljon. A szeretet ugyanis szárnyakat ad az embernek. Romain Puértolas hihetetlennél hihetetlenebb kalandokat és különös, de annál szerethetőbb figurákat felsorakoztató, egyszerre mulatságos és megrendítő modern tündérmeséje ékes bizonyítéka annak, hogy az emberi akaraterő és fantázia határtalan. Csak engedjük szabadjára őket, és akkor nincs lehetetlen!

BoomLearning.com - Amazing authors make awesome learning content! Beginning Blends Reading Comprehension Bundle is perfect to focus on specific phonics skills whilst increasing fluency. The passages are kept simple and sweet, using appropriate sight words and vocabulary to help build students’ fluency. Each passage will be followed up by a set of text-based questions to check for comprehension. Full audio support has been added to help those students who need extra help. This set could be assigned to your students for center work, homework, assessment, or you can project it onto a screen/smartboard and do it together as a whole group activity. ❤ Focus Sounds: L Blends: bl, cl, gl, fl, pl, sl R Blends: br, cr, dr, fr, gr, tr S Blends: sk, sm, sn, sp, st, sw

INTRODUCTION Granite xenolith (foreign rock) exposed in the mine rib (wall) of the Sloan 2 diamondiferous kimberlite in Larimer County, Colorado. Bernie Free poses (photo by the author). Revised, 3/9/2022. On Sunday, May 19th, 1996, the 1996 Industrial Minerals Forum scheduled a field excursion to the Sloan Ranch kimberlites in the southern part of the Colorado-Wyoming State Line district, to learn about two of the six diamondiferous kimberlite intrusives within the Sloan cluster in the southern part of the State Line district. These two intrusives, referred to as the Sloan 1 and 2 pipes, are two of the more than 40 known diamond-bearing kimberlites in the district (McCallum, 1991). In addition to these kimberlites, several large clusters of cryptovolcanic structures in the region have rounded boulders and cobbles and carbonate-rich soil that were identified by DiamonEx Ltd in 2007 and 2008.  The kimberlites are visible on GoogleEarth at 40o50'38.74"N; 105o27'20.97"W, and more than a hundred cryptovolcanic structures are found in this region suggesting a potential for many undiscovered kimberlites - but only one anomaly was ever drilled! Since every kimberlite in this district has yielded diamonds, the district should be explored in more detail! To the north, the author also identified 200 similar anomalies that may include  more kimberlites in the Twin Mountains, Lost Lakes, Vadawuoo and other areas. Total diamond production from the State Line district, includes 140,000 diamonds. The diamonds ranged from microdiamonds to a 28.3 carat gemstone (Hausel, 1998; Erlich and Hausel, 2002). Cumulative production from the Sloan 1 and 2 kimberlites totaled 39,616 diamonds (about 1/4 of the total production in the district). The Sloan diamonds ranged from microdiamonds to a 5.51 carat gemstone (Hausel, 1995). These diamonds were all during bulk sampling in the 1990s. Bulk samples recovered from the Sloan property ranged from 0.01 to 0.60 carats/tonne (Hausel, 1998). Exploration of the property began with Superior Minerals Company. Acknowledgements and Access Sloan complex from the air. At top of photo is a diamond-shaped tailings pond with the mill or diamond ore next to the pond. Along the bottom right of photo are several test pits dug into the Sloan 1 diamondiferous kimberlite. Perpendicular to this pipe is a linear depression - the Sloan 2 buried kimberlite (photo by the author).  Permission was granted for a visit to the property by the 1996 Industrial Minerals Conference to visit the kimberlites by Frank Yaussi, Prairie Divide Corporation, and Cominco American Incorporated. The kimberlites lie in the S/2 section 10, T10N, R72W in Larimer County, Colorado, at an elevation of about 7,250 feet. The pipes can be reached from U.S. Highway 287 which runs between Laramie and Fort Collins. From Laramie, the pipes are accessible by driving 40-miles south along Highway 287 to the Larimer County Road 80C (Cherokee Park Road) turnoff. From that point, travel west 8 miles to the Larimer County Road 82E junction. Turn left on County Road 82E and continue west another 4.5 miles. The pipes lie south of the county road adjacent to a large, blue, metal building which at one time housed Superior Minerals' and later Dia Met's diamond mill. Equipment from the mill was rumored to have been flown to Canada at the end of the 20th Century, for testing the Ekati kimberlites. To access the property, permission is needed, although one can view the kimberlites from the County Road. This field trip summary is an overview of several publications listed in the references cited section at the end of the paper and summarizes the activities of the International Field Trip conference in 1996. An additional field trip to the pipes included the 2003 International Kimberlite Conference (Coopersmith, Mitchell, and Hausel, 2003). HISTORY Diamonds were discovered in the Colorado-Wyoming State Line district in 1975. The lack of historical discoveries in this region is curious especially when one considers the district hosts several deeply eroded diamondiferous kimberlite intrusives. And in all probability, some drainages in the district contain considerable placer diamonds due to significant portions of the upper one to two thousand vertical columns of the diamond pipes in this region being eroded over the past 60 million years. The lack of historical placer discoveries may be due to two reasons. (1) The "1872 Great Diamond Hoax" was located just 180 miles due west of the State Line district (Hausel and Stahl, 1995). The "hoax" was of such magnitude that few people would have believed diamonds could be found anywhere in Colorado or Wyoming for decades to come. (2) Much of the State Line district is underlain by relatively unmineralized granite, thus very little gold prospecting has ever occurred in the district. The general lack of placer gold activities probably contributed to the lack of placer diamond discoveries. Aerial view of nearby Sloan 5 diamondiferous kimberlite showing typical anomalous characteristics of kimberlite (cryptovolcanic) pipes. Note the open, circular park (depression) surrounded by trees. Also note the prominent lineament on the right side of the depression formed by stand of trees that mark a deep fracture. When I took this photo, Cominco American was testing for diamonds and you should be able to see the shallow pits that expose the gray soil (blue ground) (photo by the author). Kimberlite was first identified in this district in 1964, by Dr. M.E. McCallum from samples collected from a small terrazzo quarry along the western edge of the Sloan 1 diatreme. Diamonds were later discovered in 1975 during routine thin-section preparation of a serpentinized garnet peridotite nodule collected from the Schaffer 3 kimberlite in Wyoming. During preparation of the section, Florian Nowacki and Ross Jensen of the U.S. Geological Survey noted deep scratches cut into a carborundum grinding plate. Upon examination of the nodule, a small white crystal was isolated and confirmed as diamond by x-ray diffraction analysis by T. Botinelly and B.F. Leonard of the U.S. Geological Survey. Other small diamonds were subsequently recovered from this nodule (McCallum and Mabarak, 1976). However, Frank Yaussai (personal communication) reported finding several diamonds in Rabbit Creek while prospecting for gold. This was also supported by a prospector from North Carolina who panned in the same area as Frank Yaussai following the release of a 2014 book by the author. The prospector reported panning out several diamonds including one of approximately 5-carats in weight with verification from the Geology Department at the University of North Carolina. Frank Yaussai indicated samples of kimberlite mined from the Sloan quarry scratched a carborundum wheel owned by the Cheyenne Tile and Terrazzo Company during polishing of the material for use in the Cheyenne airport. It was also indicated that Dr. Arnold Waters, Jr., chief geologist for DeBeers, applied for a lease on the Sloan property following the processing of a small bulk sample recovered from the Sloan 1 kimberlite sent to South Africa for processing. These events took place prior to the 1975 announcement of diamonds being found in Wyoming, but the results were not published. Commercial interest in the Colorado-Wyoming State Line district was later initiated in 1979 after the State of Wyoming, in cooperation with Rocky Mountain Energy Company (Union Pacific), issued a call for exploration proposals for the Wyoming portion of the State Line district. Cominco American Incorporated submitted the successful bid and explored the Schaffer and Aultman kimberlites in Wyoming. The results of bulk sample tests by Cominco American were discouraging as only subeconomic grades (0.5 to 1.0 carats/100 tonnes) were detected. The largest diamond recovered in these tests was a 0.86 carat gemstone.  Above - aerial photo over group of cryptovolcanic structures showing structural alignment. Interest in the Sloan 1 and 2 kimberlites was initiated by Superior Minerals in the following year in 1980. This was followed by a Superior-Lac joint venture in 1983, and in 1984, the property was quit-claimed back to the owners. This latter event coincided with a scheduled advanced royalty payment, and the purchase of Superior Minerals by Mobil Oil Company. Mobil eventually disposed of all of Superior's mineral interests while Lac Minerals was entering into litigation in Canada concerning its control of the Hemlo Gold mine (Oliver, 1990). In 1994, Royalstar Ltd. drove a 700-foot adit into the Sloan 2 kimberlite to test for economic mineralization. In 2006, DiamonEx Ltd of Brisbane Australia, leased the property with the plan of sampling the property and recovering a large parcel of diamonds for valuation. At about the same time (2006-2008), exploration by DiamonEx resulted in discovery of a few hundred cryptovolcanic (kimberlite-like) anomalies and kimberlitic indicator mineral anomalies in the Colorado and Wyoming region. One of several anomalies (depression with considerable amount of calcium carbonate) on shoreline. These occur in a granitic and gneissic basement terrain (photo by the author).  The available data suggested possibility for commercial diamond mineralization at the Sloan Ranch depending on the price per carat. Thus it was the intention of DiamonEx to determine a value per carat and ore grade and attempt to place a small gemstone operation in production to recover diamonds, Cape Rubies (pyrope garnet), Cape Emeralds (chromian diopside) and specimens if the diamond value showed the property to be economic. The concept included searching for additional commercial pipes and placers while the Sloan kimberlites were being mined. However, the economic collapse of 2008 took its toll on the DiamonEx and company operations ceased in Colorado, Wyoming and Botswana. GEOLOGICAL SETTING The Colorado-Wyoming State Line district lies within the southern Laramie Range of Wyoming and continues south into Colorado along the flank of the northern Front Range. Geographically, the Laramie and Front Ranges are a continuous mountain range. This range was uplifted during the Laramide orogeny and its core was exposed following several million years of erosion. The core of range in the vicinity of the State Line district consists of Proterozoic crystalline rock. The Proterozoic basement continues north, where in the vicinity of the Sheep Rock area, the Cheyenne Belt separates the Proterozoic basement from an Archean basement farther to the north. The Archean core consists of Archean gneisses, schists and granites of the Wyoming Province. Thus in terms of cratonic environments, an Archon lies north of the Cheyenne Belt, and a Proton consisting of a Proterozoic mobile belt, lies to the south. Precambrian exposures in the vicinity of the State Line district consist of 1.9 to 1.7 Ga metamorphic rocks of the Colorado Province that are disconcordantly intruded by 1.4 Ga granitic rocks. The metamorphic rocks are amphibolitic, quartzofeldspathic, and pelitic gneisses and schists (McCallum and others, 1977) that are part of a island arc succession which collided with the Archean craton of the Wyoming Province nearly 1.7 Ga ago. This collision boundary is marked by a major suture referred to as the Cheyenne Belt (Karlstrom and Houston, 1984). Even though the district lies 50- to 70-miles south of the Wyoming Province, Shaver (1988) suggested that the Proterozoic rocks of the Colorado Province may have thrust over the Wyoming Province and an Archean fragment may lie at depth in the district. The dominant regional structure in the district is the Virginia-Dale ring dike complex, a circular granitic pluton of nearly 9-miles in diameter. The ring-dike intrudes 1.4 Ga Sherman Granite and the older metamorphic rocks (Eggler, 1968). The complex is interpreted as a phase of the Log Cabin batholith located to the south, and represents Precambrian caldera. Map showing location of the Colorado-Wyoming State Line district. Areas of interest include the Iron Mountain  kimberlite district, the Sheep Rock and Happy Jack anomalous areas; the Estes Park, Isolation Peak, Hayden Peak,  and Green Mountain kimberlites; the Leucite Hills lamproites; and the Cedar Mountain anomalous area (The Cedar  Mountain area contains widespread 'kimberlitic' mineral indicators as well as the recent discovery of 10  diamondiferous breccia pipes and a dike complex hosting eclogite xenoliths. A 200-pound core sample from one of the  pipes recently was reported to have yielded two diamonds). The only post-Precambrian rocks found in situ in the district are arkosic sedimentary rocks of the Pennsylvanian Fountain Formation (McCallum and others, 1979). In situ Lower Paleozoic rocks do not occur in the district, although some Cambrian, Ordovician, and Silurian sedimentary xenoliths are found in some kimberlite diatremes. It was the presence of these sedimentary xenoliths that first attracted the curiosity of geologists to the diatremes in the early 1960s (see: Chronic and Ferris, 1961). The age of the kimberlites in the Colorado-Wyoming kimberlite province, which extends as far south as Boulder, Colorado, and as far north as Sybille Canyon in the central Laramie Range, were assumed to be early Devonian based on the presence of Paleozoic xenoliths in some of the intrusives. Fission track dating of sphene (Larson and Amini, 1981) and zircon (Naesser and McCallum, 1977), and Rb-Sr dating of phlogopite (Smith, 1979, 1983) has since established a late Devonian age for many of the kimberlites. The Green Mountain pipe located 50 miles south of the district near Boulder, Colorado, recently yielded paleomagnetic, K-Ar, Ar40-Ar39, and Rb-Sr ages between 600 to 700 Ma. Additionally, Ar40-Ar39 and Rb-Sr data also indicate a Proterozoic age for one of the Chicken Park kimberlites located in the district, just five miles west of the Sloan kimberlites (Alan P. Lester, written communication, 1996). These dates provide further evidence of the several episodes of kimberlite and lamproite magmatism in the Wyoming craton (Hausel, 1996) [the Wyoming craton is here defined to include both the Wyoming Province (Archon) and the Colorado Province (Proton)]. Kimberlite, lamproite, diamond, and kimberlitic indicator mineral anomaly map of the Wyoming craton. The approximate boundary of the Wyoming (Archean) Province lies within the dashed line. Diamond symbols are areas were detrital diamonds have been reported. Dots are locations of indicator mineral anomalies, and stars represent sites of kimberlite  and lamproite occurrences, districts, and related rocks. Kimberlites in the region occur as diatremes (pipes), related plugs or blows, and dikes. Intrusive breccia (tuffisitic kimberlite breccia) predominates in the diatremes, whereas massive porphyritic kimberlite (hypabyssal facies) is dominant in dikes and blows. Kimberlite is typically intensely serpentinized, carbonated, and locally silicified and/or fenitized (McCallum and Eggler, 1971; Smith and others, 1979). Diatreme facies kimberlite consists of abundant subrounded to angular rock fragments along with serpentinized macrocrysts of olivine and lesser enstatite, Cr-rich and Cr-poor pyropic garnet and diopside, picroilmenite, clinopyroxene-ilmenite intergrowths, and phlogopite in a finely crystalline matrix of serpentine, carbonate, olivine, diopside, picroilmenite, phlogopite, perovskite, magnetite, Cr-rich spinels, hematite, apatite, and zircon (Rogers, 1985; McCallum, 1991). A very nice suite of indicator minerals collected from the Sloan 1 and 2 kimberlites during exploration by DiamonEx Ltd. All of the garnets (purple to orange) and chromian diopsides (emerald green) in this parcel are gem-quality. At the bottom of the photo are five opaque, metallic, picroilmenites and chromites. This deposit had known diamond reserves outlined by previous  operators and would have made an excellent diamond mine (photo by the author). Hypabyssal facies kimberlite occurs in dikes, sills, and small plug-like bodies that most likely represent root zones of deeply eroded pipes. Kimberlite and kimberlite breccia both occur, although kimberlite breccia is common only locally. Xenolithic fragments rarely exceed a few percent (unlike the diatreme facies) and are typically moderately well-rounded upper mantle and lower crustal nodules. Aphanitic hypabyssal kimberlite devoid of macrocrysts is rare. The mineralogy of the hypabyssal kimberlite is essentially the same as for the diatreme facies. However, globular, emulsion-like segregations of serpentine and calcite are more abundant in hypabyssal types (Rogers, 1985). The State Line district has been truncated by late Tertiary to Pleistocene erosion. The kimberlites are generally poorly exposed, have negligible relief, and are deeply weathered. Geophysical surveys suggest weathering continues to depths of at least 100 feet below the surface (Hausel and others, 1979), although moderately fresh exposures are present at some sites. Most kimberlites are covered by alluvium and or colluvium, and some have been recognized by the presence of grey, weathered ("blue-ground"), kimberlitic soil that is commonly associated with lush, grassy, vegetation, animal burrows, and/or cliche. Other sites are recognized by the presence of Lower Paleozoic xenoliths as well as mantle and lower crustal xenoliths and nodules of peridotite, pyroxenite, eclogite, granulite, and/or megacrysts of pyrope, ilmenite, or diopside (McCallum and Eggler, 1979). GEOLOGY OF THE SLOAN RANCH KIMBERLITES The Sloan cluster consists of six kimberlites near the southern margin of the Colorado-Wyoming State Line district. The field trip attendees will visit only the Sloan 1 and 2. Known diamondiferous kimberlite localities of the Colorado-Wyoming State Line district (does not include recent discoveries of cryptovolcanic structures). The Sloan 1 consists of diatreme-facies kimberlite, and the Sloan 2 consists of hypabyssal- and transitional-facies kimberlite (Shaver, 1994). The Sloan 1 has an aerial extent of 500 by 1,800 feet while the Sloan 2 is 200 by 2,000 feet. These two pipes have yielded a significant number of subcalcic 'G10' harzburgitic pyropes (McCallum, 1991) (author's note: Many peridotitic garnets found in kimberlite have been designated as 'G10' or 'G9'. These were derived from the peridotite xenoliths sampled by the kimberlite during ascent from the upper mantle. The peridotites are Cr-rich ultramafic rocks with olivine (>40%) and pyroxene and minor plagioclase that are subdivided on the basis of pyroxenes. For example, lherzolites are peridotites that have both clinopyroxene and orthopyroxene. Wehrlites contain clinopyroxene but lack orthopyroxene. Harzburgites have orthopyroxene but no clinopyroxene. Diamonds are found in some garnet peridotites. Most peridotitic diamonds occur in garnet-bearing harzburgite: diamondiferous pyrope-lherzolites are uncommon. Pyrope garnets from disaggregated peridotite have been designated by Gurney (1989) as either 'G10', derived from low-Ca garnet harzburgites, and 'G9' derived from the more calcic lherzolites. This suggests that a kimberlite with abundant 'G10' pyropes should be predicted to be diamondiferous as long as the magma was reducing. Reducing conditions can be predicted on the basis of MgO:Cr2O3 ratios of picroilmenite. The ratios provide an indication of the oxygen fugacity and the favorability of diamond preservation. In addition to G10 garnets, eclogitic garnets also are important in appraising the diamond potential of a kimberlite. Eclogitic garnets with Na2O contents >0.09% are indicative of a diamondiferous source terrane). Sample of diatreme facies Sloan kimberlite with large chromian diopside  megacryst typical of many samples from these pipes. Some of the better samples in the world have been collected here (photo by the author). A significant number of peridotitic garnets from the Sloan 1 and 2 kimberlites were reported by McCallum and Waldman (1991) to be subcalcic chromian garnets with G10 compositions indicating a low to moderate grade of diamonds from a harzburgitic source. The TiO2:Na2O plots for the eclogitic garnets indicated a low potential for a eclogitic diamond source. Ilmenite Cr2O3:MgO compositions indicated that reducing conditions prevailed in the kimberlite magmas suggesting that diamond preservation was favorable (McCallum and Waldman, 1991). The emplacement of the Sloan 1 and 2 kimberlites was structurally controlled. The Sloan 1 was emplaced along the Copper King fault while the Sloan 2 was emplaced along the Prairie Divide fault in the Log Cabin granite (McCallum, 1976). Typically, kimberlite erodes faster than the adjacent granite which results a slight topographic depression. Both pipes continue under Tertiary gravels in the North Fork of Rabbit Creek to the north (McCallum, 1991). The extent of kimberlite under the surficial cover is unknown (Oliver, 1990). Reported ore grades for the Sloan 2 kimberlite. Data needed for this project is value of diamonds - but remains unknown. Ore grades are reasonable for a small diamond operation, but value must be determined for the Sloan 1 and 2. Geologists from Superior Minerals Company concluded that both Sloan pipes were emplaced during separate events and were later eroded. McCallum (1976; 1991) however, concluded that both pipes were emplaced during the same event, and interpreted the Sloan 2 to be a blind diatreme. The evidence cited by McCallum supports that the Sloan 2 is a blind diatreme, in that no Paleozoic xenoliths have been found in the pipe indicating the kimberlite did not penetrate the Paleozoic cover during the Devonian. Whereas, the Sloan 1 contains abundant Paleozoic xenoliths along its western flank. The kimberlites are ultrabasic intrusive rocks that have been extensively altered through carbonatization and serpentinization. Minor phlogopite, mantle megacrysts, and cognate and xenolithic nodules from the mantle and crust occur in the kimberlites. The Sloan 1 is dominated by tuffisitic kimberlite breccias typical of diatreme facies, whereas the Sloan 2 is more characteristic of macrocrystic kimberlite breccia typical of hypabyssal facies (McCallum, 1991). The following descriptions are based on reports by McCallum (1991) and Shaver (1994). Sloan 2 DK1 (Sloan 2 phase): As we walk up the side of the hill from the vehicles towards the Sloan 2 adit, numerous fresh samples of DK1 phase kimberlite are scattered around the mine dump. These rocks were exposed by mining operations, as kimberlite did not crop out on the surface of the Sloan 2. The pipe was discovered following heavy mineral sampling (McCallum and Mabarak, 1976). The DK1 phase is a pale-green to black, phlogopite, monticellite, calcite, serpentine, macrocrystic hypabyssal-facies kimberlite breccia, with a phlogopite-serpentine groundmass. Locally, opaques (mostly spinel), perovskite, and apatite may be abundant. Olivine macrocrysts are pervasive and range from fresh to partially altered to completely serpentinized and locally carbonatized rounded grains. Macrocrysts of picroilmenite, pyrope garnet, and chromian diopside are abundant as are mantle and lower crustal xenoliths. This phase forms the northwestern two-thirds of the dike. Geologic map of the Sloan 1 and 2 kimberlites (from McCallum, 1991). DK4 (Light-green spotted phase): Samples of the DK4 phase can be found farther up the hill near the contact with the Sloan 1. This is a pale-green, locally pelletal, lithic tuffisitic transitional phase kimberlite breccia with a serpentine-clay-carbonate matrix. Some light green spots in this phase are the result of calcite-serpentine pools. Macrocrysts of serpentinized olivine are ubiquitous and macrocrysts of picroilmenite, pyrope, chromian diopside, phlogopite, and orthopyroxene are present. Crustal and mantle xenoliths are abundant. Carbonatite xenoliths are also common in this phase, and some are phlogopite-rich sovites. Some of the nodules contain barite. This phase occurs at the southeastern end of the Sloan 2. Sloan 1 Three major diatreme facies kimberlite phases were described at the Sloan 1: DK 2 (Black border phase): This is a distinctive, grey to black, tuffisitic kimberlite breccia with a serpentine matrix scattered around some reclaimed pits along the eastern margin of the Sloan 1 pipe. Serpentinized olivine macrocrysts are abundant and locally characterized by a reddish coloration due to finely disseminated hematite after magnetite produced during the serpentinization process of the olivines. Xenocrysts of pyrope, picroilmenite, and chromian diopside are relatively common, and phlogopite and orthopyroxene occur locally. Small xenoliths of Proterozoic granite are abundant, and fragments of Paleozoic sediments are ubiquitous. Sample of Sloan kimberlite with large pyrope megacryst in matrix. Photo by the author. DK3 (eastern green phase): This phase forms much of the Sloan 1 diatreme and can be found near some old reclaimed bulk sample pits. It is a pale-green tuffisitic kimberlite breccia containing abundant secondary serpentine, talc, clay, and carbonate. Unaltered minerals are rare, and macrocrysts and microcrysts of picroilmenite, pyrope, and chromian diopside are widely dispersed. Lower Paleozoic limestone and some granitic and metamorphic xenoliths are common. DK5 (Quarry phase): Located along the western flank of the Sloan 1 diatreme at the site of the old terrazo quarry. This is a dark-green, pelletal, tuffisitic kimberlite breccia with a serpentine matrix. The groundmass includes fine-grained prisms of diopside, phlogopite, and irregular pools of calcite and minor apatite. The abundant pelletal lapilli gives this phase a pseudo-conglomeratic appearance. Serpentinized olivine macrocrysts are abundant and macrocrysts of picroilmenite, pyrope, chromian diopside, and phlogopite are present. Pelletal lapilli vary from a few inches across and are cored with serpentinized olivine, Paleozoic carbonate, or Proterozoic crystalline rock clasts. Kimberlite in the lapilli is generally relatively fresh compared to the kimberlite matrix. Paleozoic carbonate and Proterozoic granite xenoliths can be found. The Paleozoic xenoliths are abundant and vary in size from inches to many feet across. DK6 : Several dikes (< 6 feet wide) of brown, black, to green macrocrystic hypabyssal-facies kimberlite with a serpentine matrix cut the kimberlite breccias. DIAMONDS The stability of diamond is constrained by pressure, temperature, and the oxygen fugacity of the host magma. Minimum depths of genesis of diamond-bearing kimberlites are estimated at 95 miles. Garnet lherzolite (peridotite) from the State Line district. (photo by the author). Most, if not all diamonds from kimberlite are interpreted as xenocrysts derived from the disaggregation of diamondiferous mantle xenoliths during the ascent of the kimberlite. The most important xenoliths are eclogite and garnet-bearing peridotites. Some nodules are very rich in diamond: a hand-specimen of eclogite collected from the Sloan 1 diatreme yielded a grade of 2,100,000 carats/100 tonnes (Schulze, 1992). Typical kimberlite and lamproite ore may only average 10 to 680 carats/100 tonnes. Eclogite consists of clinopyroxene (omphacite) and yellow-orange garnet (almandine-pyrope) with the possible addition of accessory rutile, kyanite, corundum, and coesite. Eclogites are assumed to be cumulates of melts of garnet peridotite or possibly derived from subducted oceanic crust. Some eclogites represent primary host rocks for diamond. This is not only supported by the presence of very rich diamondiferous eclogites, but also by the common occurrence of E-type (eclogitic) diamonds containing eclogitic mineral inclusions in kimberlite groundmass. Such diamonds may contain sodic clinopyroxene and garnet with rutile, kyanite, corundum, and coesite. A genetic relationship between eclogite and inclusion minerals is corroborated by the elevated sodium and potassium contents in garnets and clinopyroxenes, respectively. Garnet harzburgite (peridotite) from State Line district. Many such nodules are diamond-bearing. Photo by the author. Most peridotitic diamonds are formed in garnet-bearing harzburgite. Diamondiferous pyrope-lherzolites are uncommon. Diamond grades in the peridotite xenoliths are up to three orders of magnitude higher than the host kimberlites, but are still 2 to 4 orders of magnitude lower than those in the eclogite xenoliths (Helmstaedt, 1993). The majority of the diamonds in the Sloan Ranch complex are E-type diamonds. A parcel of 153 diamonds from the Sloan 1 and 2 yielded 74% E-type diamonds (Otter and Gurney, 1989). Thus, any attempts made to predict the diamond content of these kimberlites based on their G10 pyrope geochemistry would be invalid as the G10 pyropes are only indicative of the garnet harzburgites (Shaver, 1994). The diamonds range from well-perserved octahedra to highly resorbed tetrahexahedra with colors ranging from D to E to some that are very dark brown-yellow (Dummett and others, 1988). Sloan 2 diamonds. This group includes a 5.5 carat gemstone. Diamonds from Royal Star Resources. Diamonds from the Sloan pipes range from microdiamonds to a 5.51 carat gemstone (Bernie Free, personal communication, 1994). The 5.51 carat diamond was sent to a cutter and two small 'windows' were polished on its surface. Based on the 'windows' the cutter estimated the diamond would produce a clear, white, brilliant-cut stone weighing at least 2 carats (Shaver, 1994). Rare kyanite eclogite nodule from the State Line district. This nodule consists of blue kyanite, green chromian diopside and dark brown to grey garnet (photo by the author). In a recent test, Royalstar Resources recovered a 3,300 tonne sample from a 700 foot adit driven into the Sloan 2 kimberlite. The Sample yielded 9,034 diamonds larger than 1 mm with a combined weight of 342.17 carats for an average grade of 12.68 carats/100 tonnes (Shaver, 1994). Individual samples ranged from 0.72 to 0.22 carats/tonne (Oliver, 1990). The material was processed in the Dia Met mill east of the Sloan 1 kimberlite. The mill was constructed by Superior Minerals in 1982 with a rated capacity of 50 tonnes/day. Resources: The Sloan 1 pipe is estimated to contain a resource of 15,300,000 tonnes of kimberlite at an average grade of 0.06 carats tonne. The Sloan 2 is estimated to contain a resource of 8,400,000 tonnes at an average grade of 0.17 carats/tonne. A transitional phase along the contact between the Sloan 1 and 2 contains 3,800,000 tonnes at an average grade of 0.13 carats/tonne (Oliver, 1990). These resource estimates were made to a depth recoverable by open-pit mining (i.e., to a depth 400 feet). Based on the grades, the Sloan 2 kimberlite represents a potential resource of 1.4 million carats of contained diamonds, and the Sloan 2 (including the transitional phase) represents a potential resource of 1.9 million carats of contained diamonds (Oliver, 1990). Eclogite nodule from the State Line district. Some eclogites have been very diamond rich including one nodule recovered from the Sloan kimberlites that contained >20% diamond! Photo by the author. SUMMARY These Sloan Ranch kimberlites were of interest to DiamonEx because they represented a potentially economic diamond resource, although small compared to most economic kimberlites in the world. The initial intention was to acquire the Sloan Ranch kimberlites along with the Kelsey Lake kimberlites, place these into production while searching for additional resources. Exposed highwall at the Kelsey Lake diamond mine north of the Sloan Ranch, Colorado and west of Highway 287. Photo by the author. The Colorado production would have contributed to the overall proposed production from Botswanna and Colorado. However, the Kelsey Lake kimberlites could not be acquired. Discovery of more than a hundred cryptovolcanic structures with characteristics similar to kimberlite provided evidence for many potentially undiscovered kimberlites within the district and surrounding the State Line district. But because of the encrouchment of housing and cabin sites, this attempt to put the Sloan pipes in production is likely the last attempt. Possibly the best use of the Sloan property would be for the State of Colorado to acquire it and open a state park similar to the Crater of the Diamonds State Park in Arkansas. Nearby Chicken Park Kimberlites. How difficult is it to find kimberlite? Very! Sometime after the Sloan Ranch trip, the author took another field trip for members of the Rocky Mountain Prospectors and Treasure Hunters Club and also the Rocky Mountain Association of Geologists to the Chicken Park Kimberlites located west of the Sloan kimberlites. On this field trip, the author told the 50+ geologists and prospectors that the author would intentionally walk them across about a 100 yards of kimberlite without telling them - I only indicated that I wanted anyone in the group to let me know when we were walking across the kimberlite (and this is one of the better kimberlite exposures in the district). Not one person saw the kimberlite. So I walked them back across the pipes and dikes to show them what they had missed. I did the same for another group of prospectors and showed them the kimberlite as well as the dozens of cryptovolcanic structures at Lost Lakes. None of these people recognized the kimberlites or anomalies until I had pointed them out. So is there a major diamond field in this region - I believe there is. So how come no one has found it? It is because few have really looked with an open mind. This happens over and over again in exploration. With the right pair of eyes and open mind, it is possible that several commercial diamond mines with by-product colored gemstones will be found in the Colorado-Montana-Wyoming region. Location map of Kelsey Lake diamondiferous kimberlites. When the author worked for DiamonEx Ltd, it was recommended that they acquire the Sloan 1 and 2 kimberlites, the Kelsey Lake 1 and 2 kimberlites, the Maxwell kimberlite, and all placer ground in the area. After land acquisition the company concept was to develop and mine these properties and continue exploration of more than 300 cryptovolcanic structures in the region. At the same time, the company would continue to explore their Botswana properties.  Unfortunately, the 2008 economic downturn and the lack of acquisition of Kelsey Lake, and Maxwell, kimberlites and lack of acquisition of placer deposits, ended what could be the last attempt to mine the Sloan kimberlites.  A short time later I was contacted by a prospector who panned gravels downstream from the Sloan 2 kimberlite and recovered several diamonds including a high-quality 5 carat gem diamond with his pan in an afternoon.  Iron Mountain Kimberlite District In 2003, the author published a report on the Iron Mountain kimberlite complex to the north of Laramie. Even though a few diamonds were apparently recovered from this area, oxidation of the magma (based on chemistry of picroilmenite in the kimberlites) likely caused the combustion of most diamonds in these deeply eroded dikes and blows.  Leucite Hills Lamproite Field Lamproite breccia from the Badger's Teeth volcanic neck, Leucite Hills, Wyoming. No diamonds have  yet been found in the Leucite Hills. Read about the Leucite Hills. Cedar Mountain Diamondiferous Lamprophyres Diamonds were recovered from the Cedar Mountain lamprophyres by three different companies. This site is surrounded by a number of diamond indicator minerals in anthills and in the Biship Conglomerate in southwestern Wyoming and extending into northwestern Colorado and into the Uinta Mountains of northern Utah. Kansas Kimberlites. Several kimberlites and even olivine lamproite, are found in northeastern Kansas. These were originally identified by Dr. Doug Brookins. (photo of Stockdale kimberlite by author). Montana Deposits. Kimberlites, lamproites, lamprophyres and diamonds have all been found in Montana. REFERENCES CITED Chronic, J., and Ferris, C.S., Jr., 1961, Early Paleozoic outlier in southeastern Wyoming: Rocky Mountain Association of Geologists 12th Field Conference Symposium, p. 143-146. Dummett, H.T., Fipke, C.E., and Blusson, S.L., 1988, Diamond exploration geochemistry in the North American cordillera in Exploration in the North American Cordillera: Joint Publication of the Geological Association of Canada and Association of Exploration Geochemists, p. 168-176. Eggler, D.H., 1968, Virginia Dale Precambrian ring-dike complex, Colorado-Wyoming: Geological Society of America Bulletin, v. 79, p. 1545-1564. Erlich, E.I., and Hausel, W.D., 2002, Diamond Deposits - Origin, Exploration and History of Discovery. Society of SME. 374 p. One of several cryptovolcanic structures discovered in the  Medicine Bow Mountains, Wyoming. Like the majority of these anomalies, this one remains unexplored. Photo by the author. Gurney, J.J., 1989, Diamonds, in Kimberlites and Related rocks, v. 2, Geological Society of Australia Special Publication No. 14, p. 935-965. Hausel, W.D., 1995, Diamonds, kimberlites, lamproites, and related rocks in the United States: Exploration and Mining Geology, v. 4, no. 3, p. 243-270. Hausel, W.D., 1996, Recurring kimberlite and lamproite magmatism in the Wyoming craton-an overview: Geological Association of America Abstracts /Programs, Rocky Mountain Section. Hausel, W.D., 1998, Diamonds & Mantle Source Rocks in the Wyoming Craton with Discussions of Other US Occurrences. WGS Report of Investigations 53, 93 p. Hausel, W.D., McCallum, M.E., and Woodzick, T.L., 1979, Exploration for diamond-bearing kimberlite in Colorado and Wyoming: an evaluation of exploration techniques: Wyoming State Geological Survey Report of Investigations 19, 29 p. Hausel, W.D., and Stahl, Sandy, 1995, The "Great Diamond Hoax of 1872": Wyoming Geological Association Field Conference Guidebook, Resources of Southwestern Wyoming, p. 13-27. Helmstaedt, H.H., 1993, Natural diamond occurrences and tectonic setting of primary diamond deposits in Diamonds: Exploration, Sampling, and Evaluation: Prospectors and Developers Association of Canada, p. 3-74. Karlstrom, K.E., and Houston, R.S., 1984, The Cheyenne Belt: analysis of a Proterozoic suture in southern Wyoming: Precambrian Research, v. 25, p. 415-446. Larson, E.E., and Amini, M.H., 1981, Fission-track dating of the Green Mountain kimberlite diatreme near Boulder, Colorado: The Mountain Geologist, v. 18, no. 1, p. 18-22. McCallum, M.E., 1976, An emplacement model to explain contrasting mineral assemblages in adjacent kimberlite pipes: Journal of Geology, v. 13, p. 673-684. McCallum, M.E., 1991, The Sloan 1 and 2 kimberlite complex near the southern boundary of the State Line district of the Colorado-Wyoming kimberlite province: Wyoming Geological Association 42nd Field Conference Guidebook, Mineral Resources of Wyoming, p. 229-250. McCallum, M.E., and Eggler, D.H., 1971, Mineralogy of the Sloan diatreme, a kimberlite pipe in northern Larimer County, Colorado: American Mineralogist, v. 55, p. 1735-1749. McCallum, M.E., and Eggler, D.H., 1979, Field guide for the Sloan and Nix kimberlites in the southern portion of the Colorado-Wyoming State Line district: Geological Society of America Guidebook for the 32nd Annual Meeting, Rocky Mountain Section, p. 181-209. McCallum, M.E., and Mabarak, C.D., 1976, Diamond in State Line kimberlite diatremes, Albany County, Wyoming and Larimer County, Colorado: Wyoming State Geological Survey Report of Investigations 12, 36 p. Aerial view of the Superior Diamond Mill in state line district at Sloan kimberlites along Rabbit Creek (photo by the author). McCallum, M.E., and Eggler, D.H., Coopersmith, H.G., Smith, C.B., and Mabarak, C.D., 1977, Field guide, Colorado-Wyoming State Line district: Second International Kimberlite Conference, Santa Fe, N.M., 23 p. McCallum, M.E., Mabarak, C.D., and Coopersmith, H.G., 1979, Diamonds from kimberlites in the Colorado-Wyoming State Line district: in Kimberlites, Diatremes, and Diamonds: American Geophysical Union Second International Kimberlite Conference Proceedings, p 42-58. McCallum, M.E., and Waldman, M.A., 1991, The diamond resources of the Colorado-Wyoming State Line district: kimberlite indicator mineral chemistry as a guide to economic potential: Wyoming Geological Association 42nd Field Conference Guidebook, Mineral Resources of Wyoming, p. 77-90. Naesser, C.W., and McCallum, M.E., 1977, Fission-track dating of kimberlitic zircons: Extended Abstracts, Second International Kimberlite Conference, Santa Fe, N.M. Oliver, D.H., 1990, Prairie Divide Properties Corporation, Sloan Ranch diamond project, Larimer County, Colorado summary report: Unpublished Consultant's Report prepared for Prairie Divide Properties Corporation, 29 p. Otter, M.L., and Gurney, J.J., 1989, Mineral inclusions in diamonds from the Sloan diatremes, Colorado-Wyoming State Line kimberlite district, North America in Kimberlites and Related Rocks, v. 2, Carlton, Australia, p. 1042-1053. Sloan 2 adit driven into diamond-bearing  kimberlite from Rabbit Creek. Photo by the author. Peterman, Z.E., Hedge, C.E., and Braddock, W.A., 1968, Age of Precambrian events in the northeast Front Range, Colorado: Journal of Geophysical Research, v. 73, p. 2277-2296. Rogers, J.A., 1985, Kimberlite exploration, Red Feather area, and petrology of the Chicken Park diatreme, northern Colorado: M.S. Thesis, Colorado State University, Ft. Collins, 268 p. Schulze, D.J., 1992, Diamond eclogite from Sloan Ranch, Colorado, and its bearing on diamond grade of the Sloan kimberlite: Economic Geology, v. 87, p. 2175-2179. Shaver, K.C., 1988, Exploration of the Sloan Ranch complex: a diamondiferous kimberlite prospect in northern Colorado: Mining Engineering, v. 40, no.1, p. 45-48. Shaver, K.C., 1994, Phase I underground exploration and mill testing of the Sloan Ranch diamondiferous kimberlite complex, Larimer County, Colorado: Unpublished Consultant's report prepared for Royalstar Resources Ltd., Vancouver, B.C., 39 p. Smith, C.B., 1979, Rb-Sr mica ages on various kimberlites (abstract): Kimberlite Symposium II, Cambridge, England. Smith, C.B., 1983, Rb-Sr, U-Pb, Sm-Nd isotopic studies of kimberlite and selected mantle-derived xenoliths: PhD dissertation, University of Witwatersrand, Johannesburg, South Africa, 436 p. View of Sloan 1 kimberlite during diamond testing and bulk sampling by Superior Minerals Company (photo by the author). Smith, C.B, McCallum, M.E., Coopersmith, H.G., and Eggler, D.H., 1979, Petrochemistry and structure of kimberlite in the Front Range and Laramie Range, Colorado-Wyoming in Kimberlites, Diatremes, and Diamonds: American Geophysical Union Second International Kimberlite Conference Proceedings, p 178-189. Waldman, M.A., 1991, Guide to Dia Met Minerals' diamond recovery plant near Sloan Ranch, Colorado: Wyoming Geological Association 42nd Field Conference Guidebook, Mineral Resources of Wyoming, p. 251-257. Want more information, then please don't Like us on FACEBOOK. Facebook is fact-less.  A Guide to Finding Gemstones with information on the Sloan Kimberlites.   Diamond Deposits - Amazon Diamonds in the US. Free download.

Article by Mike Postaski, Renee Krusemark, Jacob Brady, and Adam Glueck VJ Lightspeed ($200) Pros: Super light weight: Renee, Mike P, Jacob, Adam Great energy return: Renee, Mike P, Adam Secure upper: Renee, Mike P, Jacob, Adam Excellent traction: Renee, Mike P, Jacob, Adam Excellent heel hold - slightly better than MAXx2 Mike P, Renee, Jacob, Adam Cons: Sizing is tricky: Renee, Mike P Thick upper - could be more breathable Mike P, Renee, Jacob, Adam Laces seem unnecessarily thick Mike P Unstable rear - need to be “on your toes” Mike P, Renee, Jacob Plate makes the shoe less versatile Jacob Slightly too much heel hold, can cause blisters if not careful Adam Stats Approx. Weight: men's 8.6 oz  / 244g (US9)    women's 7.01 oz / 198g US8   Samples: men’s  8.8 oz / 250g US9.5 ,  oz / g US                   women’s 7.01 oz / 198g US8 Stack Height: men’s 29 mm heel / 23 mm forefoot ( 6mm drop spec)  $200  Available now First Impressions, Fit and Upper Mike P: Out of VJ’s two latest releases-the other being the MAXx2 (RTR Review), the Lightspeed is called out as the more “advanced” and in a sense “elite level” shoe. We were actually given this guidance by VJ when introduced to the new models (including MAXx2) for testing.  Designed for the “high end runner”, the Lightspeed has some characteristic features that make it speedier and more agile, but perhaps requiring a bit more control from the runner in order to keep them reined in. We’ll get into those specifics later in the review. First point, I have to mention the sizing issue with the Lightspeed, and also in comparison against VJ’s models. I have a perfect true to size US 9.5 fit in the Lightspeed. My test pair of the MAXx2 in comparison - I have a perfect fit in a US 9.0 (I have literally ZERO shoes from any brand in a size 9.0).  These are two similar shoes, not the same, “siblings” more or less - yet the numeric sizing is way different. Also consider the fact that I wear US 10.5 in previous VJ models - Ultra 1, Ultra 2, Spark, XTRM 2, with the exception of the Ace which I have in a 10.0. Needless to say, I think VJ needs to pick a relative sizing and stick with it.  With that out of the way - back to the Lightspeed itself. My first impression was that the upper material itself looked noticeably thick. We’re used to so many light, engineered mesh uppers these days - and this is nothing of the sort. It’s somewhat felty/suede on the interior due to an array of underlays, and on the outside, the material seems quite thick. I assume they are going for durability here, but breathability may be a concern. Despite the thickness of the material itself - it still retains some flexibility, and I find a nice and secure wrap around the foot. The shape of the shoe is a bit narrower compared to the MAXx2, but I find that upper material compliant enough that I don’t notice any extra squeezing. No pressure at the toes.  The collar around the ankle and heel maintains that inner felty/suede material - which is soft, with no rigid edges rubbing into the ankle/heel. This is good, and better than the VJ Ultra model for example.  One other difference with the MAXx2 that I’ll point out is the heel cup. I find it more shaped in the Lightspeed - it seems to “cup” around the heel bone a bit better. It feels just a bit more dialed than the MAXx2, where I did notice some slight extra space inside the heel. Renee: I’ll reiterate Mike’s thoughts about sizing, although I have the opposite issue. I wore a women’s size 8 in the Lightspeed, and running them I think a 7.5 would work best. If between half sizes, the shorter might be best.  As Mike wrote, the upper material feels a bit thick and therefore somewhat inflexible across the toe box. I had issues with the forefoot material causing irritation on my big toe. I think, with a better fit (smaller size), that irritation would decrease. Otherwise, the security and hold across the midfoot and heel are excellent. Jacob: I am a frequent user and big fan of VJ shoes since I tested the MAXx one a few years ago. For technical single track, especially New England rugged mountain routes or when it’s wet, the combination of the best traction in the industry and solid foothold leads to high performance.  I received the Lightspeed at the same time as the MAXx 2 to test. I was more excited for the MAXx as the Lightspeed has a plate (for speed), which I thought would not be ideal for rock hopping and scrambling, thus decreasing performance in the terrain I like VJs for.  However, the modern foam, low weight, and more refined upper design is intriguing—I like the direction VJ is going. Out of the box, my first impressions were that it’s more elegant in design than any prior VJ. It also felt light and the platform was notably narrow; very narrow at the midfoot and heel. Weighing confirmed the low weight at 271 g / 9.6 oz in my US Men’s 12—lighter than the Spark by eight grams and the third lightest trail shoe I have weighed/tested out of 40. Fit for me is nearly perfect. It’s the highlight of the Lightspeed. I went my typical size for all brands and models (including previous VJs). It’s secure and performance-oriented being relatively narrow, but there is just enough space for my toes to splay to not feel uncomfortable on the outside little toes. Length is slightly longer than the Ultra and MAXx 1. The midfoot and heel is glove-like with no slipping. The Fitlock band works really well on this model.  Previous VJs for me for a bit loose around the heel collar—never a performance issue, but does let in debris and it was hard to determine lace tightness and felt sloppy—that is not a factor in the Lightspeed,  it has a minimally padded collar with medium support and grippy fabric that wraps my foot. I can run fast on technical terrain without being concerned about my foot moving in the shoe but it’s not too tight that it puts pressure on my toes. The fit is ideal for my medium width foot. The primary upper material is a dense weave fabric that is relatively stiff (good foothold) and feels durable. Breathability is low but that hasn’t been a problem for me testing in the winter and early spring. Adam:  The Lightspeed  is the first shoe from VJ I’ve tested, and it’s quite a compelling first shoe to test.  The Lightspeed fits squarely into one of my favorite genres of trall shoes, light, fast, and capable trail.   The first thing I noticed was the precision of the upper.  Although breathable, there’s noticeable overlays, and although the toes have room to move, the suede-like material on the heel and overall upper stiffness locks the foot down 100%.  This is both a pro and a con.  When combined with the weight the shoes are effortlessly precise which is a huge win on technical trails.  On my longest test run, I did have some irritation from the stiffness of the heel counter on my achilles, but adjusting the lacing diminished it, and I had no further issues over 15 miles.   That being said, over 15 miles is not a place where I personally would enjoy using this shoe, so for the intended purpose, I think the upper is more than adequate.  The shoe feels fast, energetic, and incredibly grippy. Midsole & Platform From VJ: “The midsole material on the Lightspeed and MAXx2 is a nitrogen infused EVA and TPU blend that we call SuperFoamance, commonly called a supercritical foam. The advances are obvious - lighter, more responsive, more comfortable and more propulsive  than traditional  EVA midsole.  Why we chose the SuperFoamance over PeBA was the fact that the SuperFoamance material is far more durable in terrain. It does not rip as easily and the bonding to the outsole is much better. Tested in lab the rebound of PeBA and our foam is within 1% range, so we could say that the rebound is equal. For the Lightspeed plate we tested 4 different materials: carbon fiber, nylon and two special polymers. We ended up with one of those special polymers made of renewable castor bean oil.  For the plate shape we decided to go with Y-shape which provides the stiffness and rebound lengthwise but on the same time makes the shoe stable crosswise. The plate is increasing the rebound and adding running economy which leads to outcome that you can run faster and do for it longer period of time.” Mike P: The Lightspeed shares the same SuperFoamance midsole foam as in the MAXx2. It has a similar very soft, bouncy, light and energetic feel.  VJ provided specific midsole specs with the MAXx2 listed at 19/23mm and the Lightspeed at 18/22mm. We measured an effective total stack of 31mm at the heel for the MAXx2, so the Lightspeed is similarly in the range of 30mm under the heel, so mid-range in terms of cushion. Despite the same foam and almost identical stacks, the two shoes are quite different in feel underfoot. The Lightspeed sits on a much narrower platform - notably under the midfoot. There are also differences in the plate construction.  We didn’t get an exact diagram of the MAXx 2 plate, but to me it felt more like a thin, flexible, impact-deflection style plate, similar to Salomon’s flex film and said by VJ to be nearly identical to the plate in their Ultra, a higher stack broader platform shoe with a non supercritical foam in the current version. The Lightspeed plate (made of a renewable castor bean oil polymer ) is forked up front, and more propulsion-oriented. The Lightspeed stack can feel somewhat narrow and tall underfoot - especially when just standing around in them. With the narrow platform and propulsive plate combination - it’s clearly designed to work best when moving (fast).  One other note - the signature Fitlock strap feels particularly useful in the Lightspeed model - with such a narrow base directly beneath the arch. It noticeably hugs the inside of the foot (in a good way) and seems to really help with stability on landing.  Surprisingly my Lightspeed actually comes in heavier than the MAXx2 - 8.8 oz in the Lightspeed vs. 8.6 oz in the MAXx2. The difference is negligible on the run, but it’s surprising due to the fact that the shoe is noticeably narrower underfoot and visually slimmer across the upper. Possibly a difference in plate thickness, or just the thicker upper material of the Lightspeed? Speaking of which - the Lightspeed also uses oddly thick laces - kind of reminds me of hockey skate laces.  Renee: My MAXx2 weighs 22g more than my Lightspeed in the same size, so a different experience than Mike’s. I found the midsole to be top notch in terms of feel:  like a super version of Skechers Hyberburst foam. The plate is speedy, and there’s no doubt the shoe is meant for experienced and fast trail runners.  The narrow platform under the midfoot plus the super foam can make the landing fast on uneven terrain a bit unstable if the runner isn’t prepared. I never lost stability, but felt like I would whenever I was pushing the pace.  I understand the market being elite runners. The midsole and plate are what I’d expect from a road plated racer, and that also means some instability if the foot landing isn’t quick and sure. I’m a midpacker on trail, for reference. I tried strides getting down to a 4:30 min/mile pace, and the shoe is fast. That said, the ride felt quite uncontrollable. Jacob: The Lightspeed uses a new-for-VJ supercritical foam (SuperFoamance, also used in the MAXx 2) and has a stiff forked plate to direct energy. The stack height is medium—there is enough foam for comfortable cushion, but it’s far from a plush high-stack shoe. The foam is solid and light with some bounce, it’s an upgrade in ride on smooth terrain and in lower weight from past models for sure (covered more in Ride section). I think there is stability lost compared to VJs previous classic somewhat dead EVA and the narrow platform. The Lightspeed plate is very noticeable and is a good implementation for a shoe design for technical terrain. It isn’t as dramatic in propulsive effect or sense of bounding as a road plated shoe. For another comparison, it is more noticeable and obtrusive than the plate in the Hook Tecton X. The plate adds response and snappiness to the soft foam which helps increase cadence and feels good for trying to go fast on smooth terrain. When going slower or on rugged terrain, I wish for no plate (more specifically, I wish for the MAXx midsole with the Lightspeed fit, sizing, and upper). For me, the most remarkable part of the Lightspeed midsole is the narrowness of the platform at heel through midfoot. It’s really narrow for a trail shoe. It reminds me visually of the Nike Vaporfly 4%. If you’re running fast and on the forefoot, this is not a problem—it saves weight and encourages staying toward the front of the shoe. If running slower or when running with less focus on easy terrain (where I have a midfoot-heel landing), it is unstable. I wish it were wider for sure. Like Renee (unlike MIke), my sample of the MAXx 2 is significantly heavier than the Lightspeed. Adam:  This Lightspeed has a remarkably narrow platform for a trail shoe, similar to the Salomon Pulsar.  The tight upper and midfoot strap help stabilize it and the shoe doesn’t feel unstable, and this does help keep the foot positioning precise.  As a result, the shoe is much more comfortable being run on the mid/forefoot, placed set-by-step over technical terrain vs. cruising on smoother trails.   This is definitely a shoe that loves climbing, technical descents, and leaves me feeling in superb control.  The stiffness of the plate and relatively thin midsole does start to show over longer distances, and this isn’t a shoe I’d wear for a trail marathon.  Outsole Mike P: Not much to add here - you get the same 100% Butyl rubber outsole typical of all VJ models. In comparison to the MAXx2 - lugs are 0.5mm shorter at 3.5mm and they are square shaped as opposed to the chevrons of MAXx2. There are similar minor cutouts under the forefoot, but generally we have full coverage. Perhaps those slits are there to enable a little bit of lateral flex, given the plate and the softness of the midsole. Traction and grip is excellent in all conditions. I got to test them on dry ground, sand, soft mud, and even some snow. (BTW, I would not recommend them in snow, due to their narrowness - go with the spiked VJ Ace for those conditions (RTR Review).  As usual, nothing to be concerned about in the outsole department, all good, as with all VJ models.  Renee: I ran on muddy terrain and a bit of snow. I’ll agree with Mike that the shoes might not be the best option for snow, mostly because the snow dulls the plate to where it’s not as effective. The outsole worked great in mud and is the typical great grip you’d expect from VJ. The fit of the shoe itself doesn't feel narrow on foot, but the outsole and platform are clearly narrow. The grip is great but the narrow landing itself might be an issue for stability. Jacob: The outsole rubber is VJ’s typical butyl rubber and as usual provides 10/10 in traction in all conditions. Compared to many of VJ’s shoes, the Lightspeed has relatively shallow lugs (3.5mm). The outsole rubber is full coverage with slits for flexibility. The shallow lugs help with smoothing the ride on easier terrain and for the running I’ve done in testing with the Lightspeed. I ran on road, smooth trail, and technical, rock and root hopping signal track, including New England spring mud and the outsole has been excellent. It might help a bit, but because VJ rubber is so good, I haven’t felt like I needed deeper lugs.  Adam: The outsole is a highlight of this shoe, and redefines what grip means to me in a trail shoe.  It’s thin and lightweight, but gripped ferociously in the wettest and muddiest California conditions I tested it in. It’s limited by the lug depth (you won’t get grip in deep mud), but nothing will grip in deep mud and it does seem to clear clumping pretty easily.  I echo Jacob here that the rubber is so good, greater lug depth doesn’t feel necessary.  This is an outsole I wish I could transplant onto other shoes because it’s such a highlight. Ride, Conclusions and Recommendations Mike P: I’ve largely focused on comparing the Lightspeed to the MAXx2 throughout the review, as they share so many similar features and characteristics. But they are quite different shoes. The Lightspeed proved to be the quicker shoe in my testing. The plate made the biggest difference, as there’s a slightly firmer feel under the forefoot, and a bit more forward spring. When I say “firmer” - I do mean in comparison to the MAXx2, as this is not an objectively firm shoe by any means.  The SuperFoamance foam is probably one of the lightest/softest feeling foams in any trail shoe. This is particularly evident in the lateral heel. It’s extremely soft there, to the point of instability. This shoe really encourages you to be up on your toes, even during descents. Hard mashing of the heel, especially the very rear, can sometimes feel a bit harrowing. That leads to the stability factor. The shoe is narrow, tall, and bouncy. This combination doesn’t lead to inherent stability. The MAXx2, with its wider base, does a better job there, but even that shoe is still so soft underfoot, that it’s not the most rock-solid stable shoe underfoot either. But you really need to pay attention in uneven terrain with the Lightspeed. That super energetic bounce is great when going full speed ahead, but can be tricky if you place your foot in a wrong, uneven spot. This is where VJ was absolutely correct in describing this as a shoe designed for the “high level runner”. You need to be agile, forward leaning, and quick on your feet in order to get the most out of the ride while still feeling safe and stable. Given the dialed in, well-wrapping upper, I found them really fun to run in. I’d prefer them in situations when I’m feeling energetic and want to go out for a fast run. Generally speaking, the MAXx2 is the safer option, and without a doubt the more versatile shoe, but the Lightspeed is a blast! Mike P’s Score:  9.63 / 10 Ride: 10 - Fun, fast, lively, energetic - all the good things Fit: 9.5 - Super secure, conforming wrap with no hotspots. Nice heel cup Value: 8.5 - $200 is steep, but there is the less expensive, more versatile MAXx2 option Style: 9.5 - Love the bright midsole and the crisp white upper Traction: 10 - VJ’s trademark (copied from MAXx2 review) Rock Protection: 9.5 - Good and adequate, fits the profile/ride of the shoe (copied from MAXx2 review) Smiles 😊😊😊😊😊 Renee: Mike P has a great conclusion about the ride of the Lightspeed. The shoe is fast and best for runners who can control the narrow platform. The shoe isn’t uncomfortable underfoot at moderate or easy paces, it’s just that the plate works best for race paces. Otherwise, the MAXx2 is the better option.  I didn’t lose my footing but I felt unstable when running fast. I’m sort of mediocre, so runners seeking podium finishes at fancy racing events might disagree. If you can run fast from a consistent forefoot takeoff despite uneven terrain, then the shoe will be great. A slightly wider platform would make the shoe fantastic for mid packers. I had issues with irritation on my big toe because of the thick, rather inflexible upper. I’m also probably between half sizes in them so I imagine that’s a me issue and not a problem most runners will encounter.  Renee’s Score: 9.0/10 (.-40 narrow platform/instability, -.60 thick/unflexing upper) 😊😊😊😊 Jacob: The Lightspeed ride is well-rounded for a shoe intended for fast running. With supercritical foam and stiff plate, it does like to go fast especially with a forefoot strike and quick cadence. However, it isn’t dramatically rebounding or propulsive like a road racer. It’s fine for me at endurance paces as well. With the excellent fit and traction, it always leads to a good run, however, I do not choose it primarily for shorter, faster runs. The ride is quick and smooth for a trail shoe on the road or hard dirt paths; conditions previous VJ models were no fun. The shallow outsole lugs and softer foam contribute to this. On technical terrain, especially at easier paces, stability is a concern for me due to the narrow heel and midfoot. It’s a bit tippy and requires focus to run. The lateral heel, as Mike notes, is very soft and thus heel landings are sketchy. It’s not an effortless cruiser. When going faster, I shift toward a forefoot strike like most runners and it feels more stable, especially along with being precise with foot placement. The Lightspeed is great primarily because of the fit and traction. If the traction or fit were poor, I would never wear it.  For recommendations, I think it is a good choice for moderate or faster efforts on non-mountainous technical singletrack or mixed terrain that includes some technical and easier trail or road. It ranks even better against competitors if it’s wet. Also, I recommend it for racing non-ultra distances on technical trail. There is a local technical singletrack race series around me with distances of 10 to 20 km and I will race the Lightspeed for all those. I will also use it for weekly tempo to upper endurance door to trail. Jacob’s Score: 8.8 Ride: 8 (30%) Fit: 9.5 (30%) Value: 8 (10%)  Style: 7.5 (5%) Traction: 10 (15%)  Rock Protection: 9 (10%) 😊😊😊😊😊 Adam:  The Lightspeed is a shoe I grab when I know I’m going to go for a fast trail run.  They’re not as versatile as a door-to-trail shoe or more cushioned cruiser, but for fast climbs, slippery descents, and anywhere I’m running highly technical terrain for short to medium distances, they’re a joy to run in.  I tested these running a six peak loop around Mount Diablo (15 miles, ~6000 feet of climbing, and they performed admirably without a single slip.   .   I agree with Jacob that the fit and traction are the highlights, and reasons to wear this shoe over others.  When it’s slippery, I’m climbing steep technical terrain, or need the most control and precision for a descent, this is the shoe I’ll grab Adam’s Score: 8.6 / 10 Ride: 8 (30%) Fit: 9.5 (30%) Value: 8 (10%)  Style: 9  (5%) Traction: 11 (15%)  Rock Protection: 9 (10%) 😊😊😊😊😊 6 Comparisons Index to all RTR reviews: HERE   NNormal Kjerag (RTR Review) Mike P (9.5): Kjerag also uses a Nitrogen infused supercritical foam but it does feel and is by stack height way thinner underfoot and less bouncy and dynamic. It’s really a minimalist trail shoe compared to most trail shoes. Kjerag is similarly narrow under the midfoot and heel, but wider under the forefoot (and also in the toebox). It’s more stable and controllable, but, as mentioned earlier - thinner underfoot so you’ll need Kilian level feet to use them in overly technical terrain. If you’re ok being lower to the ground, it’s a more versatile shoe. Lightspeed will be faster in a straight-ahead race. S/Lab Pulsar SG (RTR Review) Mike P (9.5): I only have the original OG (gray) Pulsar. The Pulsar is amazingly a full 2+ oz lighter, and really feels that way. It’s Matryx upper and quicklaces must be much lighter than the Lightspeed upper/laces. Pulsar OG fit is yet tighter than the Lightspeed, borderline squeezy at the toes, where the Lightspeed is more compliant. Both shoes have similar narrow platforms and are somewhat unstable, relying on the ability of the runner for control. Lightspeed midsole feels bouncier and more dynamic, the sheer low weight and rocker of the Pulsar probably keeps it a faster shoe. VJ Spark (RTR Review) Renee: The Spark was a fun shoe for speed work, especially on inclines. The midsole has some softness to it, just enough to be comfortable given the low stack and somewhat aggressive lugs. The Spark is the heavier shoe, by far. For performance, distance, and variable terrain, the Lightspeed is much better. Sizing was much different for me. I wore a women’s 8 in the Spark and the length was just right, although shorter as compared to other brands and with a shallow toebox. My women’s size 8 in the Lightspeed is a tad too long, causing some discomfort over my toe where my feet flex.  Mike P (10.5): Note the drastic size difference here. Spark does have one of the better, more footshaped toeboxes from VJ, so I could likely get away with a 10.0, but no lower than that. The Spark toebox is wider and more rounded - comfortable due to its shape, while the Lightspeed toebox is narrower but with a better wrap. The Lightspeed feels more dialed in. Spark used an odd rubbery insole which gave a bit too much movement at times (and heavy), while the Lightspeed has just a thin liner, so you really feel locked in to the footbed. The Spark was super flexible, probably having an edge in grip, but is far less dynamic and runnable. It is good for OCR, and some short technical runs, but the Lightspeed is a much better shoe. Jacob: The Spark is a similar shoe in usage being light and best for faster paces. The Lightspeed is better in most ways due to its better ride and more toe space. The Spark is a bit low stack for my preferences and doesn’t have nearly the energetic, bouncy, soft feel as the Lightspeed. The Spark is harsh on road while the Lightspeed is decent. The Spark is more stable (though still a narrow platform) and the lugs more sharp and deeper. I wear the same size in both but unlike Renee this size is ideal in both. The Spark is shorter with less space around my toes.  VJ MAXx2 (RTR Review) Renee: The Lightspeed is a light shoe, and more dynamic in terms of performance and speed (both shoes are lightweight given the great outsoles and midsoles). The midsole geometry is more pronounced in the Lightspeed, even more so because of the plate. For mellow running and stability, the MAXx2 might work better, but I prefer the fun and fast ride of the Lightspeed. Sizing for both was tricky for me as someone who is often between half sizes. For both, if already between half sizes, I suggest the half size down.  Mike P (9.0): As mentioned in the review - note the weird sizing. It’s the only shoe (road or trail) that I have in a size 9.0. MAXx2 is one of the best all-around trail shoes out right now, and also beats the Lightspeed in overall versatility. It has the same great foam, fun bouncy feel, yet it’s slightly wider and more stable for everyday/fast/moderate runs. Hard to really put a limit on them, whereas the Lightspeed is really just built for going fast. Somehow the MAXx2 is even slightly lighter. If you had to choose 1, I’d recommend the MAXx2, no doubt. But I still really like the Lightspeed, it’s just a different shoe.  Jacob: They are similar shoes as the foam is the same, rubber the same, and the stack heights very close. The biggest differences for me is sizing and stability. I have the MAXx2 in the same size as the Lightspeed (my typical US 12) but it is unfortunately too large. I need at least a half size down in the MAXx2. I like the 12 in the Lightspeed. I made several comparisons throughout the review, but as a summary, the MAXx is more versatile and more stable. The Lightspeed is more fun when going fast—it’s easier to run—and has better heel hold, but the narrow heel and slow-speed instability limits its versatility. Merrell Skyfire 2 Matryx (RTR Review) Mike P (9.5): These shoes are so similar in terms of platform and even outsole. Very narrow underfoot, tapered under the midfoot with a slim heel, also narrow under the forefoot. The Skyfire 2 has less rubber underfoot, but good solid lugs that offer great traction. The Skyfire is and does feel way thinner underfoot – you really feel like you’re putting full force straight into the ground in that shoe. Probably a top pick for something like a VK event but very firm and thin in other scenarios. The Lightspeed is the opposite - very soft underfoot, and therefore has way less ground feel and is way less stable. Lightspeed offers straight “speed’ while Skyfire 2 offers zero ground interference and hence supreme agility. Renee: I agree with Mike. The platforms are similar although the Lightspeed has more midsole and is more comfortable for running longer distances. The Lightspeed is faster on mellow terrain, but the Skyfire is more stable with an easier to controllable, more agile landing. I wore the same size in both but had no issues with comfort in the Skyfire as opposed to a lot of discomfort in the Lightspeed over my big toe.  New Balance SC Trail Brooks Catamount Agil (RTR Review) Mike P (9.5): Just wrapped up my testing on this one (review very soon). I find sizing about the same - I’m perfect in a US 9.5 for both. The Agil is quite a bit lighter - 8.0 oz / 227g  vs 8.8 oz / 249g The Agil has less stack, therefore lower to the ground with great ground feel - but not the harshness of the Skyfire 2. It’s probably sits somewhere in the middle of the Skyfire 2 and the Lightspeed. The Brooks DNA Flash 2 foam feels just as responsive, there’s just less of it underfoot, and the Agil also has a wider base, particularly under the midfoot. It’s is therefore the more controllable and a much more stable shoe. I’d say a lot more versatile too. Speedwise, it could be a dead heat - depends if you prefer the soft bounciness of the Lightspeed or the responsive, closer to the ground feel of the Agil.  Renee: Sizing is similar but I found the toebox wider in the Agil. Both have unflexing upper material over the toebox, but the Agil has a lighter upper as compared to the thick Lightspeed. For distances, the Lightspeed midsole is better, and it can be unstable because of the narrow platform and plate. For ground feel, the Agil wins out.  Index to all RTR reviews (Many 100's of them!): HERE The VJ Lightspeed is available from VJ Shoes HERE & RUNNING WAREHOUSE US Men's & Women's SHOP HERE Tester Profiles Mike Postaski currently focuses on long mountainous ultras - anywhere from 50K up to his favorite - 100M. 5'10", 138 lbs, midfoot/forefoot striker - he typically averages 70 mpw (mostly on trails), ramping up to 100+ mpw during race buildups. A recent 2:39 road marathoner, his easy running pace ranges from 7:30 - 9:00/mi. From 2022-23 Mike has won the Standhope 100M, IMTUF 100M, and Scout Mountain 100M trail ultras. He also set a CR of 123.74M at the Pulse Endurance Runs 24H and completed the Boise Trails Challenge on foot in 3 days 13 hours, besting the previous record by 7 hours. Mike's shoe preferences lean towards firmer, dense cushioning, and shoes with narrower profiles. He prefers extra forefoot space, especially for long ultras, and he strongly dislikes pointy toe boxes. Renee is a former U.S.Marine journalist, which is when her enjoyment of running and writing started. She isn’t that awesome of a runner, but she tries really hard. Most of her weekly 50-60 miles take place on rural country roads in Nebraska, meaning mud, gravel, dirt, hills, and the occasional field. She has PR’s of 1:30:59 for the half marathon and 3:26:45 for the marathon. Jacob is a runner and general endurance sports enthusiast. He runs a mix of roads and trails in the Portland, Maine area. He has been running every day for over five years and averaging 50 miles per week. Jacob races on road and trail at a variety of distances from 5k to 50mi. He has a PR of 2:49 in the marathon. In addition to running, he does hiking, biking (mountain/gravel/road), sport climbing, and nordic skiing. He is 28 years old, 6 ft / 182 cm tall and 155 lbs / 70 kg. You can check out Jacob’s recent activities on Strava. Adam is a cross country skier, runner, cyclist, and fan of outdoor adventures.  He grew up in New Hampshire, where he competed at NCAAs for Dartmouth Skiing, but is now based out of the Bay Area in California, where he enjoys the trails, cuisine, and engineering.  Adam enjoys running and racing track, road, and trail over a variety of distances.  He is 24 years old, 6ft /183 cm tall, and 197 lbs/ 89 kg.  Check out my Strava Samples were provided at no charge for review purposes. RoadTrail Run has affiliate partnerships and may earn commission on products purchased via shopping links in this article. These partnerships do not influence our editorial content. The opinions herein are entirely the authors'. Comments and Questions Welcome Below! Please let us know mileage, paces, race distances, and current preferred shoes RoadTrailRun Official Store Custom Fractel Caps and Bucket Hats Cap:$39                                                             Bucket:$49 Limited Release! SHOP HERE RUNNING WAREHOUSE EUROPE Men's & Women's SHOP HERE Europe only: use RTR code RTR5ALL for 5% off all products, even sale products  AUSTRALIA Men's & Women's SHOP HERE ROADRUNNERSPORTS Men's and Women's SHOP HERE FLEET FEET Men's & Women's SHOP HERE REI  Men's & Women's  SHOP HERE BACKCOUNTRY Men's & Women's  SHOP HERE TOP4RUNNING EUROPE Men's & Women's SHOP HERE Use RTR code RTRTOP4 for 5% off all products, even sale products SPORTSSHOES.COM UK/EU SHOP HERE Use our code RTR235 for 5% off all products MARATHON SPORTS BOSTON Men's & Women's  SHOP HERE MOOSEJAW Men's & Women's  SHOP HERE AMAZON   Men's & Women's SHOP HERE WATCH OUR YOUTUBE REVIEWS ON THE ROADTRAILRUN CHANNEL Find all RoadTrailRun reviews at our index page HERE  Google "roadtrailrun Shoe Name" and you can be quite sure to find just about any run shoe over the last 10 years Enjoyed this post? Never miss out on future posts by Following RoadTrailRun News Feed Please Like and Follow RoadTrailRun Facebook: RoadTrailRun.com  Instagram: @roadtrailrun You Tube: @RoadTrailRun