Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland
Peridotitic and highly magnesian pyroxenitic komatiites, thus far known to occur almost exclusively in the Archean (before 2.5 × 10 9 years ago) terranes, are reported from an Ordovician (0.5 × 10 9 years) ophiolite suite in Newfoundland. Their occurrence as pillow lavas or as chilled dikes, their p...
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American Association for the Advancement of Science (AAAS)
1978
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craaas:10.1126/science.202.4373.1192 2024-06-09T07:47:49+00:00 Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland Upadhyay, H. D. 1978 http://dx.doi.org/10.1126/science.202.4373.1192 https://www.science.org/doi/pdf/10.1126/science.202.4373.1192 en eng American Association for the Advancement of Science (AAAS) Science volume 202, issue 4373, page 1192-1195 ISSN 0036-8075 1095-9203 journal-article 1978 craaas https://doi.org/10.1126/science.202.4373.1192 2024-05-16T12:54:32Z Peridotitic and highly magnesian pyroxenitic komatiites, thus far known to occur almost exclusively in the Archean (before 2.5 × 10 9 years ago) terranes, are reported from an Ordovician (0.5 × 10 9 years) ophiolite suite in Newfoundland. Their occurrence as pillow lavas or as chilled dikes, their possession of quench textures and geochemical parameters such as high contents of magnesium oxide, nickel, and chromium and low contents of titanium dioxide and potassium monoxide, low ratios of iron to iron plus magnesium, and values of the ratio of calcium oxide to aluminum oxide of close to unity demonstrate that they were formed through the rapid cooling of a highly mobile komatiitic melt. These features resemble those of many Archean peridotitic-pyroxenitic komatiites and indicate that the Archean-type magmatism did prevail in the younger segments of the earth's history although perhaps in a more erratic manner. Article in Journal/Newspaper Newfoundland AAAS Resource Center (American Association for the Advancement of Science) Science 202 4373 1192 1195 |
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AAAS Resource Center (American Association for the Advancement of Science) |
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English |
description |
Peridotitic and highly magnesian pyroxenitic komatiites, thus far known to occur almost exclusively in the Archean (before 2.5 × 10 9 years ago) terranes, are reported from an Ordovician (0.5 × 10 9 years) ophiolite suite in Newfoundland. Their occurrence as pillow lavas or as chilled dikes, their possession of quench textures and geochemical parameters such as high contents of magnesium oxide, nickel, and chromium and low contents of titanium dioxide and potassium monoxide, low ratios of iron to iron plus magnesium, and values of the ratio of calcium oxide to aluminum oxide of close to unity demonstrate that they were formed through the rapid cooling of a highly mobile komatiitic melt. These features resemble those of many Archean peridotitic-pyroxenitic komatiites and indicate that the Archean-type magmatism did prevail in the younger segments of the earth's history although perhaps in a more erratic manner. |
format |
Article in Journal/Newspaper |
author |
Upadhyay, H. D. |
spellingShingle |
Upadhyay, H. D. Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland |
author_facet |
Upadhyay, H. D. |
author_sort |
Upadhyay, H. D. |
title |
Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland |
title_short |
Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland |
title_full |
Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland |
title_fullStr |
Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland |
title_full_unstemmed |
Phanerozoic Peridotitic and Pyroxenitic Komatiites from Newfoundland |
title_sort |
phanerozoic peridotitic and pyroxenitic komatiites from newfoundland |
publisher |
American Association for the Advancement of Science (AAAS) |
publishDate |
1978 |
url |
http://dx.doi.org/10.1126/science.202.4373.1192 https://www.science.org/doi/pdf/10.1126/science.202.4373.1192 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Science volume 202, issue 4373, page 1192-1195 ISSN 0036-8075 1095-9203 |
op_doi |
https://doi.org/10.1126/science.202.4373.1192 |
container_title |
Science |
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202 |
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4373 |
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1192 |
op_container_end_page |
1195 |
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1801379263133253632 |