| OCR Text |
Show 156 The distinqtion Morrison. lithology, particularly can be made with attention to details of the b on asd.s of the cut and fill lenticular channels that characterize the lower MorFison red mudstone The upper contact of the Salt Wash formation with the Basin formation is meratic sandstone. placed This abundant red and green top of a conglomerate, readily recognized by Where the section, the top of the into the fine-grained lag conglomerate is locally uppermost sandstone is used vaiegated contct of the Salt Wash and the overlying the Brushy widespread, lensing conglo- chert, changes laterally scour-fill sandstones. from the at the unt. absent the as of claystone Brushy Basin formation. nitrJbution and_ thickness - The areal distribution and thickness variations of the Salt Wash formation in the lithology of the unit make it are spown on to possible Figure 35. distinguish separate major facies in Colorado baseq primarily on Changes two the ratiQ of sandstone to mudstone. A sandstone and mudstone developed in the Uravan area stratifi.ed fine-grained channel sand$tones and mudstones in about of western A variation of equal proportions. have altered the sandstone to area quartzite. represented by fewer channel sandstones grained claystones, limestones, sandstones less than 25 per comprise stone facies of the Salt Wash Colorado, consists present where the A and of inter- near igneous intrusons secpnd major facies is correspondingly and mudstone. was is tpis f.acies Telluride in the San Juan Mountains facies, typically cent of I In this he deposited n more fine facies, th seetion. The outer rounded clay- margins ., of 'Ghe fan-shaped area of deposition (Fig.35) beyond which the Salt |
