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SENT BY:FSP&T, LLC, 02 :11-20- 1 7:32AM <br />l~ <br />Isotopic oxygen signatures than the shales (the oxygen isotopes ate also much more <br />variable). <br />Within the Turonian-Coniacian boundary bed (LS 5), the isotopic oxygen curve <br />from the Wolcott section makes a discernible shift to the lefr of nearly 1.0 ppm (from -6.6 <br />to -7.6). Using the interpretations in Fig. 2-26, one may conclude that water column <br />conditions either became more brackish or that warmer water masses moved in over the <br />area west of the Colorado Front Range. The former pf these is plausible, considering the <br />northern position within the seaway the Wolcott section occupies (near the nonhwestem <br />limit of limestone deposition), hence it's tendency to be effected by cooler temperature <br />variations. Fresh water influences [end to be coupled with decreases in salinity and <br />isotopic oxygen values. The latter explanation (warmer waters) is less likely, especially in <br />light of the relatively small magnitude shifrs in isotopic carbon and isotopic oxygen. The <br />isotopic carbon record from limestone beds at all 3 sampled sections tended to be <br />isotopically lighter than adjacent shale beds. This is in part due to the relatively greater <br />amounts of calcite cement in the limestones, which are though[ to have been lighter in <br />both isotopic carbon and isotopic oxygen even when these cements were still in solution <br />in pore waters within the then uncompacted, unlithified pelagic carbonate sediments of <br />the Fon Hays Limestone. Post-burial diagenetic overprinting and alteration of carbonate <br />carbon is thought to occur quite early after burial and during de-watering (Ricken, 1982). <br />• In conclusion, it is the over 11 pattern(s) of TbC and isotopic carbon values which <br />have the greatest potential contcibutian to a better undzrstanding of Fott Hays <br />geochemistry. The Wagon Mound section has a quite regular, repeated, cyclical isotopic <br />carbonate carbon signature, thought to reflect moderate perturbations of saliniry within <br />stable warm-water paleoceanic conditions. The Wolcott section has a much more erratic <br />isotopic carbon signal, thought to reflect higher (but irregular) burial rates of depleted <br />organic carbon within atemperature-sensitive paleoceanic setting. The Badito section, <br />near the mid-point between These two "extremes", has a more subdued isotopic carbon <br />signature, interpreted to reflect both stable saliniry and temperature conditions in the area <br />of the northern Raton Basin. Alternatively, it is possible that the isotopic perturbations <br />documented in this section are primarily of a diagenetic nature,. and do not reflect <br />paleoenvironmental conditions at the time of deposition. The geochemical data obtained <br />to date from the RGPCC site (Tract "B") is most similar to that of Badito, and would <br />respond well and with minimal co-products to kiln calcining processes. <br />• zooz <br />