首页   按字顺浏览 期刊浏览 卷期浏览 Plio‐Pleistocene sedimentation in Ferrar Fiord, Antarctica
Plio‐Pleistocene sedimentation in Ferrar Fiord, Antarctica

 

作者: P. J. BARRETT,   M. J. HAMBREY,  

 

期刊: Sedimentology  (WILEY Available online 1992)
卷期: Volume 39, issue 1  

页码: 109-123

 

ISSN:0037-0746

 

年代: 1992

 

DOI:10.1111/j.1365-3091.1992.tb01025.x

 

出版商: Blackwell Publishing Ltd

 

数据来源: WILEY

 

摘要:

ABSTRACTA 166 m thick Plio‐Pleistocene sequence of glacial sediments has been cored in Ferrar Fiord in the southwestern corner of the Ross Sea, Antarctica. The core has the following lithofacies: massive diamictite (33% of the core; interpreted as lodgement or waterlain till), weakly stratified diamictite (25%; waterlain till or proximal glaciomarine sediment), well‐stratified diamictite (8%; proximal glaciomarine or glaciolacustrine sediment), sandstone (25%; sand of aeolian or supraglacial origin), mudstone(7%; derived from subglacial debris and transported offshore in suspension), and minor amounts of rhythmite and tuff. The range of facies in this polar setting differs from those normally found in subpolar and temperate glacier fiord settings in the high proportion of aeolian‐derived sand and the low proportion of mudstone facies.The core can be divided into two sequences based on composition and texture. The sequence from 162 to 100 mbsf (metres below the sea floor) comprises alternations of diamictite dominated by basement lithologies and thin marine mudstone beds. It is Pliocene in age (4.9–2.0 Ma) and records several advances and retreats of ice through the Transantarctic Mountains and across the drill site from the west. The sequence from 100 mbsf to the sea floor, of Pleistocene age, consists of alternations of diamictite, interpreted as lodgement and waterlain till, and sandstone of aeolian origin deposited in a glaciolacustrine setting, similar to ice‐covered lakes in the Dry Valleys today. These sediments have a high volcanic component, and hence are thought to have been derived by the grounding and advance of the Ross Ice Shelf from the east past volcanic Ross Island. This change in source is attributed to the rising Transantarctic Mountains increasingly containing East Antarctic ice.The Pleistocene sequence above 100 mbsf clearly represents polar glacial sedimentation, with alternations of till and glaciolacustrine sand. Mudstones from the Pliocene sequence beneath include palynomorphs, indicating times when the landscape was at least partially vegetated, but contain no evidence of meltwater

 

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