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The Blaine formation is a part of the Pease River group (Upper Guadalupian) and consists of alternating gypsum and anhydrite, carbonate, and fine clastic beds. Carbonates occurring within the Blaine are relatively pure dolomites, closely associated with evaporite deposits.
Petrography, staining methods, chemical analysis, Ca/Mg ratios, X-ray, differential thermal analysis, and stratigraphy were used to interpret the mode of formation and deposition, the sedimentary environments, and the secondary alteration of the Blaine carbonates. The dolomites are predominantly very finely crystalline and are associated with various allochemical elements typical of what has been termed "evaporitic dolomite."
Origin of the carbonate is interpreted to be dolomitization (penecontemporaneous?) of aragonite or calcite allochemical and orthochemical sediments. The homogeneous character, lateral persistency, uniform thickness, and paleogeography suggest deposition in a large lagoon which was probably hypersaline and surrounded by low, arid to semi-arid landmasses. Deposition of carbonate and evaporite sediments occurred similar to configurations noted by Scruton (1953) and Briggs (1958): carbonates and sulphates around the margin and chlorides and sulphates in the center of the basin.
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