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GSSP for Northgrippian


Definition:

The base of the Northgrippian Stage (Middle Holocene Subseries/Subepoch) of the Holocene Series/Epoch is defined in the NGRIP1 ice-core record at a depth of 1228.67 m at a horizon which shows a clear signal of climatic cooling following a period of generally rising temperatures during the Early Holocene. It corresponds to an age of 8236 years b2k (before AD2000).


Location:

The Northgrippian GSSP is located in the borehole NGRIP1 in the central Greenland ice sheet at a latitude of 75.10°N and a longitude of 42.32°W.
GSSP for Northgrippian


Sedimentology:

The NGRIP1 ice core consists almost entirely of glacier ice.


Primary Markers:

The base of the Northgrippian Stage of the Holocene Series/Epoch is defined by a shift in the oxygen isotope record to low 18O/16O and D/H values.

Secondary Markers:

The GSSP is placed in the middle of a double peak in electrical conductivity measurements that marks a volcanic eruption, probably in Iceland. This double peak likely relates to a single eruption, as sulfuric acid often arrives in Greenland in peaks, with several subpeaks 1- 2 years after the eruption. While it has not been linked to a specific eruption, the layer is found in all deep Greenland ice cores.

Correlation Events:

Climatic cooling following a period of generally rising temperatures during the Early Holocene

Other Locations around the World:

A global auxiliary stratotype (latitude of 13°13S, longitude of 44°03W) is placed at 293 - 287 mm level of Speleothem PAD07 (Stalagmite), Gruta do Padre Cave, Brazil at a marked shift of δ18O levels to lighter isotopic values.

References:

Walker, M., Head, M.J., Berkelhammer, M., Björck, S., Cheng, H., Cwynar, L., Fisher, D., Gkinis, V., Long, A., Lowe, j., Newnham, R., Rasmussen, S.O., Weiss, H., 2018. Formal ratification of the subdivision of the Holocene Series/ Epoch (Quaternary System/Period): two new Global Boundary Stratotype Sections and Points (GSSPs) and three new stages/ subseries. Episodes 41/4, 1-11.



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