Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280, doi:10.1002/2014GC005422. Secondary...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/6936 2023-05-15T13:53:15+02:00 Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica Antibus, Joanne V. Panter, Kurt S. Wilch, Thomas I. Dunbar, Nelia W. McIntosh, William C. Tripati, Aradhna K. Bindeman, Ilya N. Blusztajn, Jerzy S. 2014-08-19 application/pdf application/msword application/vnd.ms-excel https://hdl.handle.net/1912/6936 en_US eng John Wiley & Sons https://doi.org/10.1002/2014GC005422 Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280 https://hdl.handle.net/1912/6936 doi:10.1002/2014GC005422 Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280 doi:10.1002/2014GC005422 Alteration minerals Hyaloclastite Paleoenvironment Isotopes Geochemistry Article 2014 ftwhoas https://doi.org/10.1002/2014GC005422 2022-05-28T22:59:12Z Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280, doi:10.1002/2014GC005422. Secondary minerals in volcaniclastic deposits at Minna Bluff, a 45 km long peninsula in the Ross Sea, are used to infer processes of alteration and environmental conditions in the Late Miocene. Glassy volcaniclastic deposits are altered and contain phillipsite and chabazite, low to high-Mg carbonates, chalcedony, and clay. The δ18O of carbonates and chalcedony is variable, ranging from −0.50 to 21.53‰ and 0.68 to 10.37‰, respectively, and δD for chalcedony is light (−187.8 to −220.6‰), corresponding to Antarctic meteoric water. A mean carbonate 87Sr/86Sr ratio of 0.70327 ± 0.0009 (1σ, n = 12) is comparable to lava and suggests freshwater, as opposed to seawater, caused the alteration. Minerals were precipitated at elevated temperatures (91 and 104°C) based on quartz-calcite equilibrium, carbonate 13C-18C thermometry (Δ47 derived temperature = 5° to 43°C) and stability of zeolites in geothermal systems (>10 to ∼100°C). The alteration was a result of isolated, ephemeral events involving the exchange between heated meteoric water and glass during or soon after the formation of each deposit. Near-surface evaporative distillation can explain 18O-enriched compositions for some Mg-rich carbonates and chalcedony. The δ18Owater calculated for carbonates (−15.8 to −22.9‰) reveals a broad change, becoming heavier between ∼12 and ∼7 Ma, consistent with a warming climate. These findings are independently corroborated by the interpretation of Late Miocene sedimentary sequences recovered from nearby sediment cores. However, in contrast to a cold-based thermal regime proposed for ice flow at core sites, wet-based conditions prevailed at Minna Bluff; a likely consequence of high heat flow associated with an active magma system. This ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Ross Sea Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Antarctic Ross Sea Minna Bluff ENVELOPE(166.417,166.417,-78.517,-78.517) Long Peninsula ENVELOPE(78.250,78.250,-68.467,-68.467) Geochemistry, Geophysics, Geosystems 15 8 3258 3280 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Alteration minerals Hyaloclastite Paleoenvironment Isotopes Geochemistry |
spellingShingle |
Alteration minerals Hyaloclastite Paleoenvironment Isotopes Geochemistry Antibus, Joanne V. Panter, Kurt S. Wilch, Thomas I. Dunbar, Nelia W. McIntosh, William C. Tripati, Aradhna K. Bindeman, Ilya N. Blusztajn, Jerzy S. Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica |
topic_facet |
Alteration minerals Hyaloclastite Paleoenvironment Isotopes Geochemistry |
description |
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280, doi:10.1002/2014GC005422. Secondary minerals in volcaniclastic deposits at Minna Bluff, a 45 km long peninsula in the Ross Sea, are used to infer processes of alteration and environmental conditions in the Late Miocene. Glassy volcaniclastic deposits are altered and contain phillipsite and chabazite, low to high-Mg carbonates, chalcedony, and clay. The δ18O of carbonates and chalcedony is variable, ranging from −0.50 to 21.53‰ and 0.68 to 10.37‰, respectively, and δD for chalcedony is light (−187.8 to −220.6‰), corresponding to Antarctic meteoric water. A mean carbonate 87Sr/86Sr ratio of 0.70327 ± 0.0009 (1σ, n = 12) is comparable to lava and suggests freshwater, as opposed to seawater, caused the alteration. Minerals were precipitated at elevated temperatures (91 and 104°C) based on quartz-calcite equilibrium, carbonate 13C-18C thermometry (Δ47 derived temperature = 5° to 43°C) and stability of zeolites in geothermal systems (>10 to ∼100°C). The alteration was a result of isolated, ephemeral events involving the exchange between heated meteoric water and glass during or soon after the formation of each deposit. Near-surface evaporative distillation can explain 18O-enriched compositions for some Mg-rich carbonates and chalcedony. The δ18Owater calculated for carbonates (−15.8 to −22.9‰) reveals a broad change, becoming heavier between ∼12 and ∼7 Ma, consistent with a warming climate. These findings are independently corroborated by the interpretation of Late Miocene sedimentary sequences recovered from nearby sediment cores. However, in contrast to a cold-based thermal regime proposed for ice flow at core sites, wet-based conditions prevailed at Minna Bluff; a likely consequence of high heat flow associated with an active magma system. This ... |
format |
Article in Journal/Newspaper |
author |
Antibus, Joanne V. Panter, Kurt S. Wilch, Thomas I. Dunbar, Nelia W. McIntosh, William C. Tripati, Aradhna K. Bindeman, Ilya N. Blusztajn, Jerzy S. |
author_facet |
Antibus, Joanne V. Panter, Kurt S. Wilch, Thomas I. Dunbar, Nelia W. McIntosh, William C. Tripati, Aradhna K. Bindeman, Ilya N. Blusztajn, Jerzy S. |
author_sort |
Antibus, Joanne V. |
title |
Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica |
title_short |
Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica |
title_full |
Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica |
title_fullStr |
Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica |
title_full_unstemmed |
Alteration of volcaniclastic deposits at Minna Bluff : geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica |
title_sort |
alteration of volcaniclastic deposits at minna bluff : geochemical insights on mineralizing environment and climate during the late miocene in antarctica |
publisher |
John Wiley & Sons |
publishDate |
2014 |
url |
https://hdl.handle.net/1912/6936 |
long_lat |
ENVELOPE(166.417,166.417,-78.517,-78.517) ENVELOPE(78.250,78.250,-68.467,-68.467) |
geographic |
Antarctic Ross Sea Minna Bluff Long Peninsula |
geographic_facet |
Antarctic Ross Sea Minna Bluff Long Peninsula |
genre |
Antarc* Antarctic Antarctica Ross Sea |
genre_facet |
Antarc* Antarctic Antarctica Ross Sea |
op_source |
Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280 doi:10.1002/2014GC005422 |
op_relation |
https://doi.org/10.1002/2014GC005422 Geochemistry, Geophysics, Geosystems 15 (2014): 3258–3280 https://hdl.handle.net/1912/6936 doi:10.1002/2014GC005422 |
op_doi |
https://doi.org/10.1002/2014GC005422 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
15 |
container_issue |
8 |
container_start_page |
3258 |
op_container_end_page |
3280 |
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1766258252291506176 |