Search results
Results from the WOW.Com Content Network
Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain thin beds of conglomerate , marl , limestone , or some combination of these sedimentary rocks.
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 ]
This bed form sequence can also be illustrated diagrammatically: Bedforms formed in sand in channels under unidirectional flow. Numbers correspond broadly to increasing flow regime, i.e., increasing water flow velocity. Blue arrows show schematically flow lines in the water above the bed. Flow is always from left to right.
These structures are within sedimentary bedding and can help with the interpretation of depositional environment and paleocurrent directions. They are formed when the sediment is deposited. Cross-bedding Cross-bedding is the layering of beds deposited by wind or water inclined at an angle as much as 35° from the horizontal. [1]
In geology, a bed is a layer of sediment, sedimentary rock, or volcanic rock "bounded above and below by more or less well-defined bedding surfaces". [1] 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.
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 ...
[36] [37] The Rock Point Formation of the Chinle Group preserved large numbers of fossils of Coelophysis, one of the earliest known genera of dinosaurs. [38] [39] The Jurassic was again a time of arid climate. A great dune sea, or erg, spread across northern New Mexico and deposited the sandstone of the Entrada Formation. [40]
In the study of rock and sediment strata, geologists have recognized a number of different types of strata, including bed, flow, band, and key bed. [1] [5] A bed is a single stratum that is lithologically distinguishable from other layers above and below it. In the classification hierarchy of sedimentary lithostratigraphic units, a bed is the ...