Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada.
Recent work in the north-central Labrador has identified Paleoproterozoic anorthositic and granitoid rocks that are spatially associated with, yet temporally distinct from, younger Mesoproterozoic intrusions of the Nain Plutonic Suite. The Umiakoviarusek Lake (UL) region of Labrador contains several...
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crcansciencepubl:10.1139/e99-084 2023-12-17T10:33:32+01:00 Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. Piercey, Stephen J Wilton, Derek HC 1999 http://dx.doi.org/10.1139/e99-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e99-084 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 36, issue 12, page 1957-1972 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1999 crcansciencepubl https://doi.org/10.1139/e99-084 2023-11-19T13:39:29Z Recent work in the north-central Labrador has identified Paleoproterozoic anorthositic and granitoid rocks that are spatially associated with, yet temporally distinct from, younger Mesoproterozoic intrusions of the Nain Plutonic Suite. The Umiakoviarusek Lake (UL) region of Labrador contains several of these Paleoproterozoic intrusions and provides an opportunity to study their geochemical and radiogenic isotope (Sr-Nd) characteristics. Geochemically, the anorthositic and granitoid rocks have features consistent with contemporary anorthositic and granitoid rocks from other anorthosite-mangerite-charnockite-granite complexes. The anorthositic rocks contain elevated contents of Al 2 O 3 , CaO, Sr, and Eu with low Ba, Rb, K, Zr, total rare earth elements (REE), and light REE. The granitoid rocks, on the other hand, contain lower concentrations of these elements along with elevated SiO 2 and K 2 O. Isotopic data at 2050 Ma for the anorthositic rocks (I Sr = 0.7048-0.7082; εNd = -4.1 to -15.9) and granitoid rocks (I Sr = 0.7036-0.7094, εNd = -5.1 to -9.7) are consistent with variable crustal and mantle contributions to their genesis. The relatively unradiogenic Sr and slightly evolved Nd isotopic data from the UL granitoid rocks is consistent with a significant juvenile mantle component, possibly derived from an underplating mantle plume; this component may also be present in the anorthositic rocks. The Nd and Sr isotopic data are also consistent with crustal contamination from Archean source materials; however, based on the existing isotopic database for the Nain Province gneisses, it is not possible to delineate a specific gneiss component. Furthermore, it is also quite possible that an Archean source, unlike any described at present, was a crustal source component in the UL intrusive rocks. Article in Journal/Newspaper Nain Canadian Science Publishing (via Crossref) Canada Nain ENVELOPE(-61.695,-61.695,56.542,56.542) Canadian Journal of Earth Sciences 36 12 1957 1972 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Piercey, Stephen J Wilton, Derek HC Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. |
topic_facet |
General Earth and Planetary Sciences |
description |
Recent work in the north-central Labrador has identified Paleoproterozoic anorthositic and granitoid rocks that are spatially associated with, yet temporally distinct from, younger Mesoproterozoic intrusions of the Nain Plutonic Suite. The Umiakoviarusek Lake (UL) region of Labrador contains several of these Paleoproterozoic intrusions and provides an opportunity to study their geochemical and radiogenic isotope (Sr-Nd) characteristics. Geochemically, the anorthositic and granitoid rocks have features consistent with contemporary anorthositic and granitoid rocks from other anorthosite-mangerite-charnockite-granite complexes. The anorthositic rocks contain elevated contents of Al 2 O 3 , CaO, Sr, and Eu with low Ba, Rb, K, Zr, total rare earth elements (REE), and light REE. The granitoid rocks, on the other hand, contain lower concentrations of these elements along with elevated SiO 2 and K 2 O. Isotopic data at 2050 Ma for the anorthositic rocks (I Sr = 0.7048-0.7082; εNd = -4.1 to -15.9) and granitoid rocks (I Sr = 0.7036-0.7094, εNd = -5.1 to -9.7) are consistent with variable crustal and mantle contributions to their genesis. The relatively unradiogenic Sr and slightly evolved Nd isotopic data from the UL granitoid rocks is consistent with a significant juvenile mantle component, possibly derived from an underplating mantle plume; this component may also be present in the anorthositic rocks. The Nd and Sr isotopic data are also consistent with crustal contamination from Archean source materials; however, based on the existing isotopic database for the Nain Province gneisses, it is not possible to delineate a specific gneiss component. Furthermore, it is also quite possible that an Archean source, unlike any described at present, was a crustal source component in the UL intrusive rocks. |
format |
Article in Journal/Newspaper |
author |
Piercey, Stephen J Wilton, Derek HC |
author_facet |
Piercey, Stephen J Wilton, Derek HC |
author_sort |
Piercey, Stephen J |
title |
Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. |
title_short |
Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. |
title_full |
Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. |
title_fullStr |
Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. |
title_full_unstemmed |
Geochemical and radiogenic isotope (Sr-Nd) characteristics of Paleoproterozoic anorthositic and granitoid rocks in the Umiakoviarusek Lake region, Labrador, Canada. |
title_sort |
geochemical and radiogenic isotope (sr-nd) characteristics of paleoproterozoic anorthositic and granitoid rocks in the umiakoviarusek lake region, labrador, canada. |
publisher |
Canadian Science Publishing |
publishDate |
1999 |
url |
http://dx.doi.org/10.1139/e99-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e99-084 |
long_lat |
ENVELOPE(-61.695,-61.695,56.542,56.542) |
geographic |
Canada Nain |
geographic_facet |
Canada Nain |
genre |
Nain |
genre_facet |
Nain |
op_source |
Canadian Journal of Earth Sciences volume 36, issue 12, page 1957-1972 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e99-084 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
36 |
container_issue |
12 |
container_start_page |
1957 |
op_container_end_page |
1972 |
_version_ |
1785587631732555776 |