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Gold/Mining/Energy : MARUM RESOURCES ON ALBERTA -- Ignore unavailable to you. Want to Upgrade?

To: Jesse who wrote (965)	10/24/1998 11:50:00 AM
From: average joe	Respond to of 2514

Such an interesting thread you have here, no substance, but lots of words, no kimberlites, but lots of targets! Talk a about a clever baffle them strategy. Also, for the record there has never been a kimberlite discovery in the Pasquia Hills of Saskatchewan! I really don't know where you dig this stuff up. Every major mining company will drill a properly sized magnetic target, they don't need an esoteric baffle job from Rick, who has never found a kimberlite or anything else diamond bearing. Lighten up on the oolites, OK! over and out - average joe

To: Jesse who wrote (965)	10/25/1998 2:34:00 PM
From: Jesse	Respond to of 2514

Regarding diamond indicator minerals, any who wish to learn more as to the significance in diamond exploration may wish to refer to some of the following links/ info: CSIRO Diamond Exploration syd.dem.csiro.au Geochemical methods of diamond exploration rely on recognizing indicator minerals that formed in the earth's upper mantle, within the diamond stability field, and were entrained in rapidly rising volatile-rich magmas and emplaced in or on the crust (Fig. 1). Diamond is only stable at high pressure. Therefore, diamond exploration commonly targets prospects containing high pressure minerals, such as low-Ca, high-Cr ("G10") garnets and high-Cr chromites, similar to inclusions in diamonds. However, this procedure can be ambiguous; some barren pipes contain abundant "G10" garnets, while such garnets are extremely rare in the Argyle pipe, the world's largest diamond producer. Similarly, high-Cr chromites are shed by a wide variety of barren rock types... / / / -------- Also, NRC -- "Diamond Exploration: Introduction": sts.gsc.emr.ca Diamond exploration in glaciated terrain differs from precious or base metal exploration in that it uses indicator minerals and boulders, instead of till geochemistry, to detect glacial dispersal from a kimberlite. Kimberlites are small (few hundred meters across), circular point sources. They are relatively soft rocks that have been preferentially eroded by preglacial weathering and glacial scouring to deeper levels than the surrounding bedrock surface and as a consequence are covered by lakes or thick glacial sediments. [Except, perhaps, in Alberta, where some kimberlite deposits appear as tho they may remain in tact. Still not known.] Recent discoveries of kimberlite on the Canadian Prairies and in the Northwest Territories have sparked unprecedented levels of diamond exploration in the glaciated Shield terrane of Canada and Finland. Several minerals are useful indicators of kimberlite, and to a certain extent, in evaluation of the diamond potential of kimberlite. These minerals survive glacial transport, are far more abundant in kimberlite than diamond and are visually and chemically distinct. Cr-pyrope, eclogitic garnet, Cr-diopside, Mg-ilmenite, Cr-spinel, and olivine are the most commonly used kimberlite indicator minerals, although in rare cases, diamond is abundant enough to be its own indicator. Kimberlite indicator minerals are recovered from the medium to very coarse sand-sized fraction of glacial sediments, and analyzed by electron microprobe to determine concentrations of major oxides. Kimberlites typically contain large concentrations of garnets from peridotitic rocks and a few from eclogitic rocks. Peridotitic garnets are subdivided on the basis of Ca content into wherlitic (high Ca), lherzolitic and harzburgitic (low Ca) affinities. Most garnet inclusions in diamonds are from low-Ca harzburgite and thus these garnets are sought in diamond exploration. Other chemical criteria include Na2O levels in eclogitic and MgO and Cr2O3 concentrations in ilmenites to determine probability of diamond preservation. Cr-spinel with >60% Cr2O3 and >12% are judged to have a diamond inclusion composition and diopsides with >0.5% Cr2O3 are classified as Cr-diopside. Indicator minerals are most abundant in the 0.25 to 0.5 mm (medium sand) size fraction of glacial sediments. In contrast to unglaciated regions, all kimberlite indicator minerals survive long distance glacial transport and the relative abundances of each mineral in a till sample is a function of the primary mineralogy of individual kimberlite pipes. Surface features and morphology of indicator minerals may provide clues as to the distance and nature (glacial versus fluvial) of their transport. . . / ---- ---- (more at above hotlinks) ---- Here's an extensive "Alphabetical Mineral Reference" with links within the long glossary (eg, links to more info such as 'garnets') geology.wisc.edu -- Also, a "gem database": teleport.com -- "Volcanic and Geologic Terms" page: volcano.und.nodak.edu -- "Carbonates: Textures": science.ubc.ca -- Sedimentary Rocks (excellent photos): hoth.gcn.ou.edu - - - - Cheers, -j :>