Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution
High-precision Sr isotopic data were obtained on carbonate samples from the Neoproterozoic Shaler Group, Victoria Island (Canada). Results indicate that, between ca. 790 and 850 Ma, the Sr-87/Sr-86 ratio of seawater varied betweeen 0.70676 and 0.70561, with the minimum value at about 830 Ma. A curve...
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1991
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ftnasantrs:oai:casi.ntrs.nasa.gov:19920027931 2023-05-15T18:42:48+02:00 Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution Asmerom, Yemane Jacobsen, Stein B. Knoll, Andrew H. Butterfield, Nicholas J. Swett, Keene Unclassified, Unlimited, Publicly available Oct 1, 1991 http://ntrs.nasa.gov/search.jsp?R=19920027931 unknown http://ntrs.nasa.gov/search.jsp?R=19920027931 Accession ID: 92A10555 Copyright Other Sources 46 Geochimica et Cosmochimica Acta; 55; 2883-289 1991 ftnasantrs 2012-02-15T19:24:35Z High-precision Sr isotopic data were obtained on carbonate samples from the Neoproterozoic Shaler Group, Victoria Island (Canada). Results indicate that, between ca. 790 and 850 Ma, the Sr-87/Sr-86 ratio of seawater varied betweeen 0.70676 and 0.70561, with the minimum value at about 830 Ma. A curve of the Sr-87/Sr-86 seawater ratio vs. age showed that the new data substantially improve the existing isotopic record of Sr in seawater for the period 790-850 Ma. The Sr isotopic system data were coupled with data for the Nd isotopic system to model changes in the seafloor spreading rates (hydrothermal flux) and the continental erosion for the period 500-900 Ma. Results indicate that hydrothermal flux reached a maximum value at ca. 830 Ma, while a maximum in erosion rate occurred at ca. 570 Ma. These peaks are considered to be related to the developments in the Pan-African and related orogenic events. Other/Unknown Material Victoria Island victoria island NASA Technical Reports Server (NTRS) Canada |
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46 |
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46 Asmerom, Yemane Jacobsen, Stein B. Knoll, Andrew H. Butterfield, Nicholas J. Swett, Keene Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution |
topic_facet |
46 |
description |
High-precision Sr isotopic data were obtained on carbonate samples from the Neoproterozoic Shaler Group, Victoria Island (Canada). Results indicate that, between ca. 790 and 850 Ma, the Sr-87/Sr-86 ratio of seawater varied betweeen 0.70676 and 0.70561, with the minimum value at about 830 Ma. A curve of the Sr-87/Sr-86 seawater ratio vs. age showed that the new data substantially improve the existing isotopic record of Sr in seawater for the period 790-850 Ma. The Sr isotopic system data were coupled with data for the Nd isotopic system to model changes in the seafloor spreading rates (hydrothermal flux) and the continental erosion for the period 500-900 Ma. Results indicate that hydrothermal flux reached a maximum value at ca. 830 Ma, while a maximum in erosion rate occurred at ca. 570 Ma. These peaks are considered to be related to the developments in the Pan-African and related orogenic events. |
format |
Other/Unknown Material |
author |
Asmerom, Yemane Jacobsen, Stein B. Knoll, Andrew H. Butterfield, Nicholas J. Swett, Keene |
author_facet |
Asmerom, Yemane Jacobsen, Stein B. Knoll, Andrew H. Butterfield, Nicholas J. Swett, Keene |
author_sort |
Asmerom, Yemane |
title |
Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution |
title_short |
Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution |
title_full |
Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution |
title_fullStr |
Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution |
title_full_unstemmed |
Strontium isotopic variations of Neoproterozoic seawater - Implications for crustal evolution |
title_sort |
strontium isotopic variations of neoproterozoic seawater - implications for crustal evolution |
publishDate |
1991 |
url |
http://ntrs.nasa.gov/search.jsp?R=19920027931 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Victoria Island victoria island |
genre_facet |
Victoria Island victoria island |
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Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19920027931 Accession ID: 92A10555 |
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Copyright |
_version_ |
1766232580976279552 |