Stratigraphy and Sedimentary Environments of Lower Cretaceous Rocks, Southern Western Interior
1970; American Association of Petroleum Geologists; Volume: 54; Linguagem: Inglês
10.1306/5d25cbb5-16c1-11d7-8645000102c1865d
ISSN1558-9153
Autores Tópico(s)Water Quality and Resources Studies
ResumoUpper Albian rocks crop out on the southern edge of the Western Interior province in Kansas, Oklahoma, northeastern New Mexico, and southeastern Colorado. Four formations are recognized in the several regions: Cheyenne Sandstone and Kiowa Formation in Kansas and western Oklahoma, Tucumcari Formation in New Mexico, and Purgatoire Formation consisting of the Lytle Sandstone Member and the overlying Glencairn Shale Member in southeastern Colorado and parts of adjacent states. Recognition of four ammonite-bivalve zones indicates that the basal Kiowa and much of the Cheyenne are time equivalents of the uppermost Fredericksburg rocks in Texas. Most of the Kiowa is equivalent to Washita units through the Denton Formation in North Texas. The Tucumcari and Glencairn correlate with upper parts of the Kiowa in southern Kansas. Part of the Lytle is equivalent to lower parts of the Kiowa and part may be older than the basal Kiowa. These rocks record the transgression and regression of the Early Cretaceous sea from the Gulf Coast region of the United States. The sequence consists of coastal-plain, sea-margin, and open-sea deposits. Cross-bedded, conglomeratic sandstones of the Cheyenne and Lytle were deposited by fluviatile processes on a coastal plain; laminated and thin-bedded sandstone and mudstone of the Kiowa, Purgatoire, and Tucumcari that commonly bear marine infaunal and epifaunal mollusks originated in the sublittoral margin of the seaway; and the dark-gray shale of these three formations, locally bearing a fauna of burrowing detritus- and filter-feeding invertebrates, originated as mud in the open seaway.
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