Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Quaternary Research 73 (2010): 507-520, doi:10.1016/j.yqres.2010.02.003.
Description:
Integrated analyses of magnetic, geochemical and textural data on six cores from the
northwestern Iberian continental shelf allowed the reconstruction of the
paleoenvironmental evolution of this area since the last glacial maximum (LGM). Four
sedimentary units were identified, representing a succession from fluvial and subaerial
settings to high and finally low-energy marine deposits subsequent to the post-LGM sea
evel rise. The uppermost unit was deposited during the Holocene and its magnetic
properties were controlled by the interplay between detrital input and early diagenetic
reductive dissolution of magnetic minerals. Identification of a primary steady-state early
diagenetic signal allowed the recognition of periods of increased detrital input bounded
by intervals of lower detrital input and intensified reductive diagenesis related related to
upwelling intensifications in the area. These paleoenvironmental alternations are
consistent with the climatic evolution of the late Holocene. During the Roman Warm
Period (RWP) and Medieval Warm Period (MWP), the combined effect of greater
humidity and intense agricultural and mining activities led to a greater erosion and
transport of detrital sediments to the shelf. In contrast, enhanced diagenetic reduction
intervals, caused by upwelling intensification, were roughly coincident with the colder
Dark Ages (DA) and the Little Ice Age (LIA).
Description:
Contribution to projects CTM2007-61227/MAR and REN2003-02822 funded by the
Spanish MICINN. Partial contribution to projects PGIDIT06TAM31201PR and IN825B
funded by Xunta de Galicia and NACSA 236962 and ANCORIM funded by the EU.
The EU Paleostudies program funded the stay of Kais J. Mohamed in Bremen.
K. J. Mohamed wishes to acknowledge joint funding from the Fulbright Program and the Spanish Ministry of Education and Science and the Marie Curie International Outgoing Fellowships within the 7th European Community Framework Programme.
Keywords:
Environmental magnetism
;
Detrital input
;
Iberian continental shelf
;
Early diagenesis
;
Paleoclimatic evolution
;
Upwelling
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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