2024-03-28T10:37:09Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/183272009-11-04T23:00:00Zcom_10261_91com_10261_8col_10261_344
Marinoni, L.
Setti, M.
Salvi, C.
López-Galindo, A.
2009-11-05T11:08:46Z
2009-11-05T11:08:46Z
2008-06-02
Clay Minerals 43(2): 235-253 (2008)
1993-8616
http://hdl.handle.net/10261/18327
10.1180/claymin.2008.043.2.07
An investigation of bulk-rock and clay-fraction compositions of two sedimentary cores from southern Chile was performed to evaluate the record of temporal climatic changes during the late Quaternary (11 ky and 30 ky BP). The bulk mineralogy shows an abundance of feldspars, mica and quartz, with lesser chlorite, amphibole and pyroxene, and variable amounts of carbonates. The clay fraction consists of illite, chlorite and scarce smectite. Smectite shows platy morphology, an Al-Fe beidellite chemical composition, and is detrital. Smectite, together with biogenic carbonate, increases in levels diagnostic of warmer phases. Increases in smectite are attributed either to the beginning of chemical weathering, allowed by the glacial retreat, or to ice extension and sea-level variations. Warmer climates also favoured the increase of carbonate productivity. Levels diagnostic of colder phases show a large decrease in carbonate, small amounts of smectite and large amounts of chlorite and mica, as the abundance of glaciers reduced the productivity and prevented chemical weathering.
eng
closedAccess
Chile
Strait of megellan
Marine sediments
Palaeoclimate
Provenance
Clay minerals
Smectite
XRD
TEM
Clay minerals in late Quaternary sediments from the south Chilean margin as indicators of provenance and palaeoclimate
artículo