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Gold/Mining/Energy : Birch Mountain Resources BMD-ASE -- Ignore unavailable to you. Want to Upgrade?

To: Chuca Marsh who wrote (202)	9/6/1999 10:31:00 AM
From: Chuca Marsh	Read Replies (1) \| Respond to of 402

Happy Labor Day, An Achievement is simply a dream upon which we have labored:( The Dolomite Crystallizations may affect the process in line with a plumbing system, a precipation over geologic time and the Abercrombie Prairie Gold Model for at new enrichment from the PGM flows and Micron/Ionic Metals Process Model used at Birch Mountain and verrified by the Yankee Gold Mine as displayed in Nevada with a Failed Oil Field Model. Heat and Pressure, create change in the chemical compositions. Stability on the size and grains will in time create grams and bulk tonnages of the Largest PM Find ( Precious Metal of Platinum and Palladium ) in our history - all verified by third parties as so declarred in prior BM press releases several times THIS YEAR, next year ... WATCHOUT - WATCHUS FLY! Also, a Limestone Based Deposit is much MORE important to our futures than a Granite Based or Silica Sandstone Based Deposit-Enrichment is the name of the game: uta.edu NONFOLIATED TEXTURES -------------------------------------------------------------------------------- Metamorphic rocks without foliation are termed nonfoliated. Such rocks will appear as massive, structureless units with the exception of occasional lineations created by the elongation of grains or the stretching of beds due to directed pressure or shearing stress. These rocks exhibit a nonfoliated character because the original rock units (usually limestone or sandstone) were composed of largely one mineral (calcite or quartz). When these rocks are metamorphosed, mineral grains tend to grow equally in all directions and form an interlocking, dense, crystalline mosaic. Nonfoliated rock textures are subdivided into three categories on the basis of the grain size (in part a reference to the grain size of original rock) and composition (Table 6-5). Coarse grained fragments of any type rock Conglomerates that have been subjected to sufficient heat, pressure, and stress to stretch, deform, and fuse individual pebbles or cobbles. Because of the size of the pebbles and cobbles, this texture will give the appearance of foliation. The resulting rock is termed a metaconglomerate and the fusion of the pebbles or cobbles is usually so strong that the rock is as likely to fracture through as around a pebble or cobble. Fine to medium grained A texture exhibited by several types of rock. The metamorphic rock, quartzite, is composed principally of mineral grains of quartz from sandstone. Quartz grains are stretched and fused to form a very dense interlocking mosaic. The resulting "sugary" texture may be confused with that of the sedimentary rock dolomite. Marble results from the metamorphism of limestone or dolomite composed principally of calcite or dolomite. The color of marble may be white, pink, blue-gray, brown, or black depending on impurities in the original sedimentary rock. In cases where marble is confused with quartzite, the rocks can be distinguished by the softness of marble and its tendency to effervesce with hydrochloric acid (HCl). Fine grained This texture encompasses two rock types hornfels and coal (Table 6-5). Hornfels is composed of randomly oriented platy or elongate minerals (mostly micas), and is the product of the low-grade contact metamorphism of shales or other argillaceous rocks in the absence of stress. The random growth of minerals prevents the development of foliation. Hornfels is mineralogically like slate. Bituminous and anthracite coals are unique among metamorphic rocks in being composed almost entirely of plant material. Bituminous coal (common coal) develops from the metamorphism of organic matter contained in lignite, a soft, coal-like material common in southeastern Texas. The level of heat required for conversion of lignite to bituminous coal are those associated with the geothermal temperatures generated during the simple burial of sediment. Bituminous coal converts to anthracite (hard coal) during deep and prolonged burial of lignite or bituminous coal from low to moderate regional metamorphism or from high-heat flow produced by igneous intrusions. The process of conversion in either case involves the liberation of hydrogen and oxygen from carbon-rich compounds. The result is a rock (coal) richer in carbon and higher in energy. Anthracite contains more than 90% carbon and bituminous coal contains between 50% and 90% carbon. Both types of coal are found almost exclusively in the regions of former mobile belts. -------------------------------------------------------------------------------- INTERPRETATION OF METAMORPHIC ROCKS -------------------------------------------------------------------------------- Geologists would like to know two things from the study of metamorphic rocks: 1) the temperature and pressure regime (metamorphic environment) in which the rocks formed, and 2) the composition of the original rock. Knowledge of the metamorphic environment allows inferences to be made about the place of formation, such as subduction zone, etc. Knowledge of the composition of the original rock will aid in the reconstruction of the geological history of an area. The answer to these questions is usually straight forward for rocks formed from contact metamorphism. The place contact metamorphism occurred is not in question, and, because the intensity of metamorphism decreases away from the intrusion (usually in a short distance), the original rock type can be directly observed. For rocks formed from regional metamorphism, the problem is considerably more difficult. The place of metamorphism may have been anywhere within the crust of the earth and the magnitude of the metamorphic event was such that none of the original rocks were un-metamorphosed. Fortunately, minerals that form under conditions of regional metamorphism do so in an orderly sequence related to increases in pressure and temperature. The relationship between minerals and the metamorphic grade of the environment in which they formed is outlined in Table 6-3. This relationship is especially good for certain minerals considered as index minerals for particular metamorphic grades (Table 6-3). The presence of one of these minerals in a rock indicates that the temperature and pressure were at least high enough for that mineral to form. Because the temperature/pressure ranges of these minerals overlap, they are grouped in Table 6-3 to define three metamorphic grades, low, medium and high. As shown in Table 6-3, other minerals are commonly associated with certain index minerals but these do not define a particular grade. The rock types which were originally present in a regional metamorphic terrane are determined usually by chemical analysis. While the details of such an analysis are too complicated to be introduced here, the general chemical relationships produced by such an analysis are simplified in Table 6-4. The important thing to remember is that for any mineral to form from metamorphism, the necessary chemical elements must have been present in the original rocks. CLASSIFICATION OF METAMORPHIC ROCKS Metamorphic rocks are classified on the basis of general texture foliated or non-foliated), on details of foliation and grain size (very fine to coarse), and on composition and dominant minerals. This classification scheme is outlined in Table 6-5. -------------------------------------------------------------------------------- PROCEDURE FOR IDENTIFYING METAMORPHIC ROCKS -------------------------------------------------------------------------------- Observe and describe the unknown metamorphic rock samples provided by the instructor. Record the following information on the Metamorphic Rock Lab Form. 1. Relative grain size. 2. Most abundant or diagnostic mineral. 3. General mineral composition. 4. Foliation. 5. Name of protolith (original rock, prior to metamorphism). 6. Record the general metamorphic environment (facies/grade) in which the rock formed, e.g., regional; low-grade; contact; etc 7. Name of metamorphic rock. -------------------------------------------------------------------------------- Table 6-1 Metamorphic Mineral Identification NONMETALLIC LUSTER (LIGHT COLOR) uta.edu Granite- No Changes: Granite Na+, K+,SiO-44, Ca+2, Al+3 Re Crystalized Quartz is another Si0: Quartz Sandstone SiO2 But Limestones ( and sometimes Dolomites are based upon Limestones): Limestone CA+2, Co-2 ___________________Marble_______________> (Crystalline Calcite) Chucka