Changing sediment supply during glacial-interglacial intervals in the North Atlantic revealed by particle size characterization and environmental magnetism

Author(s)

Leone, Stephanie ; Palcu, Dan, V ; Srivastava, Priyeshu ; Bin Hassan, Muhammad ; Muraszko, Joy R. ; Jovane, Luigi

• Document type: Journal article
• Source: GLOBAL AND PLANETARY CHANGE; v. 220, p. 14-pg., 2023-01-05.

Abstract

The Pliocene-Pleistocene transition is characterized by an abundance of Ice-Rafted Debris (IRD) in the North Atlantic basin. One of the regions affected by IRD during this period is the Gardar Drift, where the DSDP Leg 94 Hole 611A is located. This region received sediments from different sources during the glacial and interglacial intervals (e.g., Iceland and Greenland). We analyzed grain size and particle-size specific magnetic properties of sediments for their provenance characterization between-2.64 and 2.52 Ma. Our results show that major proportion of bulk sediments during both glacial and interglacial periods were made up of basaltic-rich Icelandic sediments, whereas only during intense glacial periods (Marine Isotope Stages 100 and 104), a small proportion of non-basaltic sand compositions were identified, possibly sourced from Greenland and other non-basaltic provenance. The non-basaltic sand fractions during the intense glacial periods were likely supplied as IRDs. In addition, a new level of coarse lithics (38 pcs. of >1 mm) composed of different rocks types (e.g., basalt, granite, granodiorite etc.) were identified in DSDP 611A Hole during the end of MIS 104 glacial period. The coarse lithic fragments showed distinctive magnetic properties than rest of the particle sizes and were classified as Iceberg-Rafted Debris (IBRD). Overall, our results show that higher sand percentage was found during the intense glacial episodes, and their magnetic grain size analysis could help in distinguishing their provenance. We elaborate that particle size specific magnetic measurements of sand fractions could help in rapidly characterizing the glacial episodes in the subpolar North Atlantic. (AU)

• FAPESP's process: 18/20733-6 - A paleomagnetic component for a proxy of water stratification and anoxia in the sedimentary archives of oceans and epicontinental seas
• Grantee: Dan Valentin Palcu Rollier
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/04821-0 - Magnetostratigraphic analysis of ferromanganese deposits
• Grantee: Muhammad Bin Hassan
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 19/11364-0 - Investigating ocean acidification during the late Maastrichtian and early Danian from marine sections of Brazil and India: Implications for impact vs. volcanism roles in the Cretaceous-Paleogene boundary mass extinction.
• Grantee: Priyeshu Srivastava
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 16/24946-9 - Sea-level changes and Global Monsoon System: clues from marine cores in Brazil
• Grantee: Luigi Jovane
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants