A record of Holocene paleoclimatic variability from Neny Fjord, Antarctic Peninsula
Summary Comprehensive analyses of marine sediments recovered from Neny Fjord, Marguerite Bay, yield a high-resolution record of Holocene climate variability. The ~12 m jumbo piston core was collected aboard the Nathanial B Palmer in 2002. The core contains mostly silty, clay-rich, diatomaceous sedim...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.543.6779 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea062.pdf |
| Summary: | Summary Comprehensive analyses of marine sediments recovered from Neny Fjord, Marguerite Bay, yield a high-resolution record of Holocene climate variability. The ~12 m jumbo piston core was collected aboard the Nathanial B Palmer in 2002. The core contains mostly silty, clay-rich, diatomaceous sediments and bioturbated, very fine, sandy, diatomaceous muds with occasional horizons of sand-rich sediments. The chronostratigraphy for the core is derived from radiocarbon-dated foraminifera and shell fragments, collected from several horizons throughout the core. The base of the core, dated to 8,060 14C, reveals an ice-distal facies with high concentration of diatoms, low magnetic susceptibility and sub-rounded grain morphology. This is consistent with an early Holocene warm period, with deglaciation of the fjord having occurred prior to 8,060 14C yrs. Between ~6000 and ~4500 14C yrs climate cooling is indicated by reduced sedimentation rates and increasingly coarse terrigenous flux. The diatom flora suggests a reduced growing season with more variable concentrations in response to episodic deposition associated with the lower sedimentation rates and pulses of coarse-grained material. From ~4500 14C yrs the dates suggest a ~1500 14C yrs sedimentary hiatus occurred during which there is only deposition of fine sand-rich laminae. This is inferred to be a period of ice-shelf or glacial advance over the site. Above the hiatus, the sediments reveal a short lived return to an ice distal setting followed by neoglacial cooling from ~2000 14C yrs. The neoglacial is characterised by a lithological gradation from moderately bioturbated, clay-rich, diatomaceous mud to a well bioturbated, fine-sandy, diatom mud. |
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