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Stalagmite paleomagnetic record of a quiet mid-to-late Holocene field activity in central South America

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Jaqueto, Plinio ; Trindade, Ricardo I. F. ; Terra-Nova, Filipe ; Feinberg, Joshua M. ; Novello, Valdir F. ; Strikis, Nicolas M. ; Schroedl, Peter ; Azevedo, Vitor ; Strauss, Beck E. ; Cruz, Francisco W. ; Cheng, Hai ; Edwards, R. Lawrence
Total Authors: 12
Document type: Journal article
Source: NATURE COMMUNICATIONS; v. 13, n. 1, p. 10-pg., 2022-03-15.

Speleothems can provide high-quality continuous records of the direction and relative paleointensity of the geomagnetic field, combining high precision dating (with U-Th method) and rapid lock-in of their detrital magnetic particles during calcite precipitation. Paleomagnetic results for a mid-to-late Holocene stalagmite from Dona Benedita Cave in central Brazil encompass similar to 1900 years (3410 BP to 5310 BP, constrained by 12 U-Th ages) of paleomagnetic record from 58 samples (resolution of similar to 33 years). This dataset reveals angular variations of less than 0.06 degrees yr(-1) and a relatively steady paleointensity record (after calibration with geomagnetic field model) contrasting with the fast variations observed in younger speleothems from the same region under influence of the South Atlantic Anomaly. These results point to a quiescent period of the geomagnetic field during the mid-to-late Holocene in the area now comprised by the South Atlantic Anomaly, suggesting an intermittent or an absent behavior at the multi-millennial timescale. (AU)

FAPESP's process: 16/15807-5 - Paleoclimate and paleoenvironmental reconstructions over the last glacial period in the mid-west Brazil
Grantee:Valdir Felipe Novello
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 18/07410-3 - Persistence of the South Atlantic Anomaly in geomagnetic observations, field models and numerical dynamos
Grantee:Filipe Terra Nova dos Santos
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 19/06709-8 - Speleothem magnetism from the Last Glacial Maximum to the Holocene in South America
Grantee:Plinio Francisco Jaqueto
Support Opportunities: Scholarships abroad - Research Internship - Doctorate
FAPESP's process: 18/15774-5 - Geochronoloy of sedimentary deposits in caves from São Desiderio region: implications for speleogenesis and geomorphological evolution of West Bahia State
Grantee:Ivo Karmann
Support Opportunities: Regular Research Grants
FAPESP's process: 16/24870-2 - Environmental significance of speleothem magnetism
Grantee:Plinio Francisco Jaqueto
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 17/50085-3 - PIRE: climate research education in the Americas using tree-ring speleothem examples (PIRE-CREATE)
Grantee:Francisco William da Cruz Junior
Support Opportunities: Research Projects - Thematic Grants