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The GSSP assigned to each stage is that stage's lower boundary and oldest point. Ages are given in "million year ago" (mya). They are obtained with different radiometric dating methods depending on the type of rock and its age. Ages that have a tilde (~) prefix are approximate ages for GSSPs that have not been defined or not been accurately dated.
A geologic section has to fulfill a set of criteria to be adapted as a GSSP by the ICS. The following list summarizes the criteria: [2] [3] A GSSP has to define the lower boundary of a geologic stage. The lower boundary has to be defined using a primary marker (usually first appearance datum of a fossil species).
Lower boundary definition: 8.2 kiloyear event: Lower boundary GSSP: NGRIP1 ice core, Greenland: Lower GSSP ratified: 14 June 2018 [1] Upper boundary definition: 4.2 kiloyear event: Upper boundary GSSP: Mawmluh Cave, Meghalaya, India
In the stratigraphy sub-discipline of geology, a Global Standard Stratigraphic Age, abbreviated GSSA, is a chronological reference point and criterion in the geologic record used to define the boundaries (an internationally sanctioned benchmark point) between different geological periods, epochs or ages on the overall geologic time scale in a chronostratigraphically useful rock layer.
The lower boundary of the Greenlandian Age is the GSSP sample from the North Greenland Ice Core Project in central Greenland (75.1000°N 42.3200°W). [6] The Greenlandian GSSP has been correlated with the end of Younger Dryas (from near-glacial to interglacial) and a "shift in deuterium excess values".
The Tremadocian lasted from 486.85 to 477.1 million years ago. The base of the Tremadocian is defined as the first appearance of the conodont species Iapetognathus fluctivagus at the Global Boundary Stratotype Section and Point (GSSP) section on Newfoundland. [7]
The Philippines will not allow China to remove a Philippine military outpost in a fiercely disputed South China Sea shoal, a navy official said Wednesday, a day after four Filipino navy personnel ...
Dob's Linn is important in geology as the location of the Global Boundary Stratotype Section and Point (GSSP) [3] which marks the boundary between the Ordovician and Silurian periods, and marks the base of the Llandovery epoch, on the geologic time scale. Dob's Linn was ratified as the GSSP by the International Union of Geological Sciences in ...