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Red beds may form during diagenesis.The key to this mechanism is the intrastratal alteration of ferromagnesian silicates by oxygenated groundwaters during burial. Walker's studies show that the hydrolysis of hornblende and other iron-bearing detritus follows Goldich dissolution series.
The Silurian Bloomsburg Formation is a mapped bedrock unit in Pennsylvania, New Jersey, New York and Maryland. It is named for the town of Bloomsburg, Pennsylvania , in which it was first described. The Bloomsburg marked the first occurrence of red sedimentary rocks in the Appalachian Basin .
The most prolific fossil site in the red beds is the Geraldine Bonebed within the Nocona Formation of the Wichita Group. [6] During the Permian, the bonebed was the site of a freshwater pond. After a catastrophic event this became the burial site for a variety of terrestrial and marine animals. [ 15 ]
Red beds, also referred to as non-marine clastic sequences, which are often red in color, have been found in wells drilled in the Gulf of Mexico which penetrated the Late-Triassic and Early-Jurassic strata, filling the extensional graben features. The Gulf of Mexico basin red beds are specifically named the Eagle Mills formation, located ...
Darton assigned the lower beds of G.K. Gilbert's (since abandoned [6]) Aubrey Group to the Supai Formation, at the same time assigning the overlying gray sandstone beds to the Coconino Sandstone. [3] In 1922, L.F. Noble reassigned the uppermost shale beds of the original Supai Group to the Hermit Shale , based on the disconformity between the ...
A bedding surface is three-dimensional surface, planar or curved, that visibly separates each successive bed (of the same or different lithology) from the preceding or following bed. Where bedding surfaces occur as cross-sections, e.g., in a 2-dimensional vertical cliff face of horizontal strata, are often referred to as bedding contacts .
The Newark Supergroup consists largely of poorly sorted nonmarine sediments; typical rocks are breccia, conglomerate, arkose sandstone, siltstone, and shale. [3] [4] Most of the strata are red beds that feature ripple marks, mud cracks, and even rain drop prints; dinosaur footprints are common, though actual body fossils are very rare. [4]
The Spearfish Formation is a geologic formation, originally described from the Black Hills region of South Dakota, United States, but also recognised in North Dakota, Wyoming, Montana and Nebraska. [2] It is a heterogeneous red bed formation, commonly with siltstone and gypsum low in the formation and sandstone and shale higher up. [3]