Petrologic and Geochemical Composition of the AND-2A Core, ANDRILL Southern McMurdo Sound Project, Antartica

The compositional record of the AND-2A drillcore is examined using petrological, sedimentological, volcanological and geochemical analysis of clasts, sediments and pore waters. Preliminary investigations of basement clasts (granitoids and metasediments) indicate both local and distal sources corresp...

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Main Authors: Panter, K. S., Talarico, F. M., Bassett, K., Del Carlo, P., Field, B., Frank, T., Hoffman, S., Kuhn, G., Reichelt, L., Sandroni, S., Taviani, M., Bracciali, L., Cornamusini, G., von Eynatten, H., Rocchi, R.
Other Authors: Panter, K. S.; Dept. of Geology, Bowling Green State University, Bowling Green, OH, 43403 – USA, Talarico, F. M.; Dipt. di Scienze della Terra, Università di Siena, Siena – Italy, Bassett, K.; Dept. of Geological Science, University of Canterbury, Private Bag 4800, Christchurch - New Zealand, Del Carlo, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia, Field, B.; GNS Science, 1 Fairway Ave, Lower Hutt − New Zealand, Frank, T.; Dept. of Geosciences, University of Nebraska-Lincoln, Lincoln, NE 68588 − USA, Hoffman, S.; Dept. of Sedimentology & Environ., Geology, Geoscience Center Göttingen (GZG), Goldschmidtstr. 3, 37077 Göttingen − Germany, Kuhn, G.; Alfred Wegener Institute for Polar and Marine Research, 27568 Bremerhaven – Germany, Reichelt, L.; Dept. of Sedimentology & Environ., Geology, Geoscience Center Göttingen (GZG), Goldschmidtstr. 3, 37077 Göttingen − Germany, Sandroni, S.; Dipt. di Scienze della Terra, Università di Siena, Siena – Italy, Taviani, M.; ISMAR-CNR, Bologna −Italy, Bracciali, L.; Dipt. di Scienze della Terra, Università di Pisa, Pisa −Italy, Cornamusini, G.; Dipt. di Scienze della Terra, Università di Siena, Siena – Italy; Centro di Geotecnologie, Università di Siena, San Giovanni Val d’Arno, Arezzo – Italy, von Eynatten, H.; Dept. of Sedimentology & Environ., Geology, Geoscience Center Göttingen (GZG), Goldschmidtstr. 3, 37077 Göttingen − Germany, Rocchi, R.; Dipt. di Scienze della Terra, Università di Pisa, Pisa , Italy, Dept. of Geology, Bowling Green State University, Bowling Green, OH, 43403 – USA, Dipt. di Scienze della Terra, Università di Siena, Siena – Italy, Dept. of Geological Science, University of Canterbury, Private Bag 4800, Christchurch - New Zealand, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia, GNS Science, 1 Fairway Ave, Lower Hutt − New Zealand, Dept. of Geosciences, University of Nebraska-Lincoln, Lincoln, NE 68588 − USA, Dept. of Sedimentology & Environ., Geology, Geoscience Center Göttingen (GZG), Goldschmidtstr. 3, 37077 Göttingen − Germany, Alfred Wegener Institute for Polar and Marine Research, 27568 Bremerhaven – Germany, ISMAR-CNR, Bologna −Italy, Dipt. di Scienze della Terra, Università di Pisa, Pisa −Italy, Dipt. di Scienze della Terra, Università di Siena, Siena – Italy; Centro di Geotecnologie, Università di Siena, San Giovanni Val d’Arno, Arezzo – Italy, Dipt. di Scienze della Terra, Università di Pisa, Pisa , Italy
Format: Article in Journal/Newspaper
Language:English
Published: 2009
Subjects:
Online Access:http://hdl.handle.net/2122/5825
http://www.mna.unisi.it/english/Publications/TAP/TA_pdfs/Volume_15/TA_15_01_147_ANDRILL_SMS_Petrology.pdf
Description
Summary:The compositional record of the AND-2A drillcore is examined using petrological, sedimentological, volcanological and geochemical analysis of clasts, sediments and pore waters. Preliminary investigations of basement clasts (granitoids and metasediments) indicate both local and distal sources corresponding to variable ice-volume and ice-flow directions. Low abundance of sedimentary clasts (e.g., arkose, litharenite) suggests reduced contributions from sedimentary covers while intraclasts (e.g., diamictite, conglomerate) attest to intrabasinal reworking. Volcanic material includes pyroclasts (e.g., pumice, scoria), sediments and lava. Primary and reworked tephra layers occur within the Early Miocene interval (1093 to 640 metres below sea floor). The compositions of volcanic clasts reveal a diversity of alkaline types derived from the McMurdo Volcanic Group. Finer-grained sediments (e.g., sandstone, siltstone) show increases in biogenic silica and volcanic glass from 230 to 780 mbsf and higher proportions of terrigenous material ca. 350 to 750 mbsf and below 970 mbsf. Basement clast assemblages suggest a dominant provenance from the Skelton Glacier - Darwin Glacier area and from the Ferrar Glacier - Koettlitz Glacier area. Provenance of sand grains is consistent with clast sources. Thirteen Geochemical Units are established based on compositional trends derived from continuous XRF scanning. High values of Fe and Ti indicate terrigenous and volcanic sources, whereas high Ca values signify either biogenic or diagenic sources. Highly alkaline and saline pore waters were produced by chemical exchange with glass at moderately elevated temperatures. Published 147-192 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici N/A or not JCR open