Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560
Strongly serpentinized peridotites occur at shallow crustal levels at DSDP Sites 556 (35-Ma-old crust), 558 (35-Maold crust), and 560 (12-Ma-old crust) in the North Atlantic. Primary peridotite silicate minerals are preserved only at Sites 556 and 558, but all three sites have primary spinel preserv...
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1985
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.806240 2023-05-15T17:31:18+02:00 Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 Michael, Peter Bonatti, Enrico MEDIAN LATITUDE: 37.916627 * MEDIAN LONGITUDE: -35.743967 * SOUTH-BOUND LATITUDE: 34.722200 * WEST-BOUND LONGITUDE: -38.842700 * NORTH-BOUND LATITUDE: 38.939700 * EAST-BOUND LONGITUDE: -34.685300 * DATE/TIME START: 1981-09-22T00:00:00 * DATE/TIME END: 1981-10-16T00:00:00 1985-01-30 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.806240 https://doi.org/10.1594/PANGAEA.806240 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.806240 https://doi.org/10.1594/PANGAEA.806240 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Michael, Peter; Bonatti, Enrico (1985): Petrology of ultramafic rocks from Sites 556, 558, and 560 in the North Atlantic. In: Bougault, H; Cande, SC; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 82, 523-528, https://doi.org/10.2973/dsdp.proc.82.129.1985 Deep Sea Drilling Project DSDP Dataset 1985 ftpangaea https://doi.org/10.1594/PANGAEA.806240 https://doi.org/10.2973/dsdp.proc.82.129.1985 2023-01-20T07:32:53Z Strongly serpentinized peridotites occur at shallow crustal levels at DSDP Sites 556 (35-Ma-old crust), 558 (35-Maold crust), and 560 (12-Ma-old crust) in the North Atlantic. Primary peridotite silicate minerals are preserved only at Sites 556 and 558, but all three sites have primary spinel preserved. The serpentinites at all three sites were probably spinel harzburgite tectonites, with little or no clinopyroxene. For orthopyroxene from Site 556, Mg/(Mg+Fe) ratios average 0.904, and Al2O3 contents are about 2.0-3.3 wt.%. Compositions of pyroxene-derived bastites from Sites 558 and 560 suggest that the original pyroxenes were probably low-alumina orthopyroxene. Spinels from all three sites have low Fe3+ and TiO2. Spinels from Sites 556 and 560 have high Cr/(Cr+Al) (0.45-0.53). Those from Site 558 have Cr/(Cr+Al) values that are among the highest measured for any plagioclase-free oceanic peridotites (0.55-0.62). Whole-rock chemistry, although affected by serpentinization, suggests that the peridotites had relatively low CaO, TiO2, Al2O3, and Na2O. Mineral and whole-rock chemistry and modal abundances suggest that Leg 82 peridotites are residua from partial melting, and that the extent of partial melting may have been greater in this region than farther south in the North Atlantic, or that the mantle was originally more depleted here. Dataset North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-38.842700,-34.685300,38.939700,34.722200) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Deep Sea Drilling Project DSDP |
spellingShingle |
Deep Sea Drilling Project DSDP Michael, Peter Bonatti, Enrico Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 |
topic_facet |
Deep Sea Drilling Project DSDP |
description |
Strongly serpentinized peridotites occur at shallow crustal levels at DSDP Sites 556 (35-Ma-old crust), 558 (35-Maold crust), and 560 (12-Ma-old crust) in the North Atlantic. Primary peridotite silicate minerals are preserved only at Sites 556 and 558, but all three sites have primary spinel preserved. The serpentinites at all three sites were probably spinel harzburgite tectonites, with little or no clinopyroxene. For orthopyroxene from Site 556, Mg/(Mg+Fe) ratios average 0.904, and Al2O3 contents are about 2.0-3.3 wt.%. Compositions of pyroxene-derived bastites from Sites 558 and 560 suggest that the original pyroxenes were probably low-alumina orthopyroxene. Spinels from all three sites have low Fe3+ and TiO2. Spinels from Sites 556 and 560 have high Cr/(Cr+Al) (0.45-0.53). Those from Site 558 have Cr/(Cr+Al) values that are among the highest measured for any plagioclase-free oceanic peridotites (0.55-0.62). Whole-rock chemistry, although affected by serpentinization, suggests that the peridotites had relatively low CaO, TiO2, Al2O3, and Na2O. Mineral and whole-rock chemistry and modal abundances suggest that Leg 82 peridotites are residua from partial melting, and that the extent of partial melting may have been greater in this region than farther south in the North Atlantic, or that the mantle was originally more depleted here. |
format |
Dataset |
author |
Michael, Peter Bonatti, Enrico |
author_facet |
Michael, Peter Bonatti, Enrico |
author_sort |
Michael, Peter |
title |
Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 |
title_short |
Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 |
title_full |
Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 |
title_fullStr |
Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 |
title_full_unstemmed |
Petrology of ultramafic rocks at DSDP Holes 82-556, 82-558, and 82-560 |
title_sort |
petrology of ultramafic rocks at dsdp holes 82-556, 82-558, and 82-560 |
publisher |
PANGAEA |
publishDate |
1985 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.806240 https://doi.org/10.1594/PANGAEA.806240 |
op_coverage |
MEDIAN LATITUDE: 37.916627 * MEDIAN LONGITUDE: -35.743967 * SOUTH-BOUND LATITUDE: 34.722200 * WEST-BOUND LONGITUDE: -38.842700 * NORTH-BOUND LATITUDE: 38.939700 * EAST-BOUND LONGITUDE: -34.685300 * DATE/TIME START: 1981-09-22T00:00:00 * DATE/TIME END: 1981-10-16T00:00:00 |
long_lat |
ENVELOPE(-38.842700,-34.685300,38.939700,34.722200) |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Supplement to: Michael, Peter; Bonatti, Enrico (1985): Petrology of ultramafic rocks from Sites 556, 558, and 560 in the North Atlantic. In: Bougault, H; Cande, SC; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 82, 523-528, https://doi.org/10.2973/dsdp.proc.82.129.1985 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.806240 https://doi.org/10.1594/PANGAEA.806240 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.806240 https://doi.org/10.2973/dsdp.proc.82.129.1985 |
_version_ |
1766128813137199104 |