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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 .
Because defining a GSSP depends on finding well-preserved geologic sections and identifying key events, this task becomes more difficult as one goes farther back in time. Before 630 million years ago, boundaries on the geologic timescale are defined simply by reference to fixed dates, known as "Global Standard Stratigraphic Ages" (GSSAs).
The first appearance of the graptolite Nemagraptus gracilis defines the boundary. The rock section consists primarily of dark-gray shale and mudstone, except for a phosphorite marker bed 1.4 m above the GSSP, and was probably deposited at a water depth exceeding 100 m. Drill cores have revealed almost identical stratigraphy across an area ...
For younger stages, a Global Boundary Stratotype Section and Point (GSSP), a physical outcrop clearly demonstrates the boundary. For older stages, a Global Standard Stratigraphic Age (GSSA) is an absolute date. The benchmarks will give a much greater certainty that results can be compared with confidence in the date determinations, and such ...
A stratotype or type section in geology is the physical location or outcrop of a particular reference exposure of a stratigraphic sequence or stratigraphic boundary. If the stratigraphic unit is layered, it is called a stratotype, whereas the standard of reference for unlayered rocks is the type locality. [1] Also it can be defined as "The ...
The Global Boundary Stratotype Section and Point of the Dapingian is the Huanghuachang section (), in Huanghuachang, Yichang, It is an outcrop of the Dawan Formation . The lower boundary is defined as the first appearance of the conodont species Baltoniodus triangularis in the type section.
The Global Boundary Stratotype Section and Point (GSSP): overview; Chart of The Global Boundary Stratotype Sections and Points (GSSP): chart; Geotime chart displaying geologic time periods compared to the fossil record – Deals with chronology and classifications for laymen (not GSSPs)
The Brunhes–Matuyama reversal is a marker for the Global Boundary Stratotype Section and Point (GSSP) defining the base of the Chibanian Stage and Middle Pleistocene Subseries at the Chiba section, Japan, which was officially ratified in 2020 by the International Union of Geological Sciences.