Tab. 1: Geochemical analysis and age dating of Kap Washington Group volcanites and related dykes
Fuente:
PANGAEA
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Dataset Open Access |
| Language: | en |
| Published: |
PANGAEA
2001
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1867167711018090496 |
|---|---|
| author | Estrada, Solveig Höhndorf, Axel Henjes-Kunst, Friedhelm |
| author_facet | Estrada, Solveig Höhndorf, Axel Henjes-Kunst, Friedhelm |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The bimodal, alkaline volcanic suite of the Kap Washington Group (KWG) at the northern coast of Greenland was investigated during the BGR CASE 2 expedition in 1994. Geochemical and Nd and Sr isotopic data are presented for basalts to rhyolites of the KWG and of related basaltic dykes cutting Lower Paleozoic sediments. In the evd(t) vs. (87Sr/86Sr)t diagram, the KWG basalts and rhyolites follow a common mixing trend with increasing crustal contamination from basic to acid volcanites. Assimilation of pre-existing crustal rocks during formation of the rhyolitic melt is documented by Nd model ages of 0.9-1.2 Ga and by different fractionation trends for the basalts and the rhyolites in the Y vs. Zr diagram. Petrographical and geochemical features indicate intra-plate volcanism which was active most probably during a continental rifting phase. A new Rb/Sr whole rock age on rhyolites of 64 ±3 Ma, corresponding to the result of LARSEN (1982), confirms that the volcanic activity lasted until the Cretaceous-Tertiary boundary. 40Ar139Ar dating on amphibol separates from a comendite yielded strongly disturbed age spectra with a minimum age of 37.7 ±0.3 Ma. This age is interpreted to date a hydrothermal overprint of the volcanic rocks related to compressive tectonics which led to the overthrust of basement rocks over the Kap Washington Group. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_107284 |
| institution | PANGAEA |
| language | en |
| publishDate | 2001 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Tab. 1: Geochemical analysis and age dating of Kap Washington Group volcanites and related dykes Estrada, Solveig Höhndorf, Axel Henjes-Kunst, Friedhelm Age, 87Rb/87Sr Rubidium-Strontium; Age, dated; Area/locality; Calculated; Geological sample; GEOS; Inductively coupled plasma atomic emission spectroscope (ICP-AES); kap_washington_group; Lithology/composition/facies; Neodymium; Neodymium-143/Neodymium-144 ratio; Rubidium; Rubidium-87/Strontium-86 ratio; Samarium; Samarium-147/Neodymium-144 ratio; Sample code/label; Smear slide analysis; Strontium; Strontium-87/Strontium-86 ratio; X-ray fluorescence (XRF); ε-Neodymium The bimodal, alkaline volcanic suite of the Kap Washington Group (KWG) at the northern coast of Greenland was investigated during the BGR CASE 2 expedition in 1994. Geochemical and Nd and Sr isotopic data are presented for basalts to rhyolites of the KWG and of related basaltic dykes cutting Lower Paleozoic sediments. In the evd(t) vs. (87Sr/86Sr)t diagram, the KWG basalts and rhyolites follow a common mixing trend with increasing crustal contamination from basic to acid volcanites. Assimilation of pre-existing crustal rocks during formation of the rhyolitic melt is documented by Nd model ages of 0.9-1.2 Ga and by different fractionation trends for the basalts and the rhyolites in the Y vs. Zr diagram. Petrographical and geochemical features indicate intra-plate volcanism which was active most probably during a continental rifting phase. A new Rb/Sr whole rock age on rhyolites of 64 ±3 Ma, corresponding to the result of LARSEN (1982), confirms that the volcanic activity lasted until the Cretaceous-Tertiary boundary. 40Ar139Ar dating on amphibol separates from a comendite yielded strongly disturbed age spectra with a minimum age of 37.7 ±0.3 Ma. This age is interpreted to date a hydrothermal overprint of the volcanic rocks related to compressive tectonics which led to the overthrust of basement rocks over the Kap Washington Group. |
| title | Tab. 1: Geochemical analysis and age dating of Kap Washington Group volcanites and related dykes |
| topic | Age, 87Rb/87Sr Rubidium-Strontium; Age, dated; Area/locality; Calculated; Geological sample; GEOS; Inductively coupled plasma atomic emission spectroscope (ICP-AES); kap_washington_group; Lithology/composition/facies; Neodymium; Neodymium-143/Neodymium-144 ratio; Rubidium; Rubidium-87/Strontium-86 ratio; Samarium; Samarium-147/Neodymium-144 ratio; Sample code/label; Smear slide analysis; Strontium; Strontium-87/Strontium-86 ratio; X-ray fluorescence (XRF); ε-Neodymium |
| url | https://doi.org/10.1594/PANGAEA.107284 |