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| Titel |
Endmember analysis of isothermal and high-temperature magnetization data from ODP 910C, Yermak Plateau, NW Svalbard |
| VerfasserIn |
Karl Fabian, Jochen Knies, Lina Kosareva, Danis Nurgaliev |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250148601
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| Publikation (Nr.) |
 EGU/EGU2017-12870.pdf |
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| Zusammenfassung |
| Room temperature magnetic initial curves, upper hysteresis curves, acquisition curves of
induced remanent magnetization (IRM), and backfield (BF) curves have been measured
between -1.5 T and 1.5 T for more than 430 samples from Ocean Drilling Program (ODP)
Hole 910C. The core was drilled in 556.4 m water depth on the southern Yermak Plateau
(80∘15.896’N, 6∘35.430’E), NW Svalbard. In total, 507.4 m of sediments were cored, and
average recovery was 57%, with 80% between 170 and 504.7 meter below seafloor (mbsf).
For this study, the borehole was re-sampled between 150 mbsf and 504.7 mbsf for
environmental magnetic, inorganic geochemical, and sedimentological analyses (443
samples). The lithology is mainly silty-clay with some enrichments of fine sands
in the lower section (below 400 mbsf). For all samples, a Curie express balance
was used to obtain the temperature dependence of induced magnetization in air
at a heating rate of 100 ∘C/min up to a maximum temperature of 800 ∘C. The
hysteresis curves were used to infer classical hysteresis parameters like saturation
remanence (Mrs), saturation magnetization (Ms), remanence coercivity (Hcr)
or coercivity (Hc). In addition several other parameters, like hysteresis energy,
high-field slope or saturation field have been determined and help to characterize the
down-core variation of the magnetic fractions. Acquisition curves of isothermal
remanent magnetization are decomposed into endmembers using non-negative matrix
factorization. The obtained mixing coefficients decompose hysteresis loops, back-field,
thermomagnetic curves, geochemistry, and sedimentological parameters into their
related endmember components. Down-core variation of the endmembers enables
reconstruction of sediment transport processes and in-situ formation of magnetic mineral
phases. |
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