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Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them. [1] The primary objective of biostratigraphy is correlation , demonstrating that a particular horizon in one geological section represents the same period of time as another ...
A gap or missing strata in the geological record of an area is called a stratigraphic hiatus. This may be the result of a halt in the deposition of sediment. Alternatively, the gap may be due to removal by erosion, in which case it may be called a stratigraphic vacuity. [2] [3] It is called a hiatus because deposition was on hold for a period ...
The Linton Formation is a geologic formation in Indiana.It is the lower formation in the Carbondale Group, and includes six named members, "which, in ascending order, are the Seelyville Coal, Coxville Sandstone, Colchester Coal, Mecca Quarry Shale, Velpen Limestone, and Survant Coal Members, and unnamed units of sandstone, shale, and clay".
A geologic map or geological map is a special-purpose map made to show various geological features. Rock units or geologic strata are shown by color or symbols. Bedding planes and structural features such as faults , folds , are shown with strike and dip or trend and plunge symbols which give three-dimensional orientations features.
A lineage zone, also called a consecutive range zone [1], are biozones which are defined by being a specific segment of an evolutionary lineage. For example, a zone can be bounded by the highest occurrence of the ancestor of a particular of a taxon and the lowest occurrence of its descendant, or between the lowest occurrence of a taxon and the ...
This is a list of Global Boundary Stratotype Sections and Points.Since 1977, Global Boundary Stratotype Sections and Points (abbreviated GSSPs) are internationally agreed upon reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale.
A flute cast, one of many sedimentary structures found in the Book Cliffs. The Book Cliffs are one of the world's best places to study sequence stratigraphy.In the 1980s, Exxon scientists used the Cretaceous strata of the Book Cliffs to develop the science of sequence stratigraphy.
The Dakota is a sedimentary geologic unit name of formation and group rank in Midwestern North America. The Dakota units are generally composed of sandstones, mudstones, clays, and shales deposited in the Mid-Cretaceous opening of the Western Interior Seaway. [7]