Catalogus

Zoeken

Zoeken kan via de modus 'eenvoudig zoeken' (één veld) of uitgebreid via 'geavanceerd zoeken' (meerdere velden). Zo kan je bv. zoeken op een combinatie van een auteursnaam (auteur), een jaartal (jaar) en een documenttype.

Boekenmand

Nuttige resultaten kan je aanvinken en toevoegen aan een mandje. De inhoud hiervan kan je exporteren of afdrukken (naar bv. PDF).

RSS

Op de hoogte blijven van nieuw toegevoegde publicaties binnen uw interessegebied? Dit kan door een RSS-feed (?) te maken van jouw zoekopdracht.

log in

Publicaties | Kaarten

nieuwe zoekopdracht

[ meld een fout in dit record ]

mandje (0): toevoegen | toon

---

Modelling the joint variability of grain size and chemical composition in sediments Bloemsma, M.R.; Zabel, M.; Stuut, J.B.W.; Tjallingii, R.; Collins, J.A.; Weltje, G.J. (2012). Modelling the joint variability of grain size and chemical composition in sediments. Sediment. Geol. 280: 135-148. dx.doi.org/10.1016/j.sedgeo.2012.04.009 In: Sedimentary Geology. Elsevier: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0037-0738; e-ISSN 1879-0968, meer Is gerelateerd aan: Bloemsma, M.R.; Zabel, M.; Stuut, J.-B.W.; Tjallingii, R.; Collins, J.A.; Weltje, G.J. (2013). Corrigendum to “Modelling the joint variability of grain size and chemical composition in sediments” [Sediment. Geol. 280 (2012) 135–148]. Sediment. Geol. 284-285: 214. http://dx.doi.org/10.1016/j.sedgeo.2012.12.001, meer

---

Beschikbaar in	Auteurs
VLIZ [ aanvragen ]

---

Author keywords

Partial least squares; Multi-proxy analysis; Compositional dataanalysis; Geochemical proxies; Singular value decomposition; Provenance

---

Auteurs		Top
Bloemsma, M.R. Zabel, M. Stuut, J.B.W.	Tjallingii, R. Collins, J.A. Weltje, G.J.

---

Abstract

The geochemical composition of siliciclastic sediments correlates strongly with grain size. Hence, geochemical composition may serve as a grain-size proxy. In the absence of grain-size variations, geochemical data of siliciclastic sediments may be used to characterise size-independent processes, i.e., sediment provenance, weathering, mixing, shape/density sorting and diagenesis. In general, however, geochemical data sets contain both types of information. In order to formalise interpretation of geochemical data, we propose a mathematical method to decompose the total geochemical variability of a series of genetically related specimens into a grain-size dependent (the shared signal) and a grain-size independent part (the residual signal). The former may serve as a proxy for grain size whereas the latter represents geochemical variability that would have been observed if all sediments would have had the same grain-size distribution. The two data sets are jointly decomposed by means of Partial Least Squares (PLS) and orthogonal projection. Subsequently, the presence of significant grain-size independent geochemical variability in the residual signal is determined in a statistically rigorous manner using a chi(2)-test. Using a synthetic example, we show that the residual record effectively reveals an imposed provenance signal which could not have been resolved from the geochemical or grain-size data sets individually. We analysed the relation between grain size and geochemical composition in three Quaternary marine sediment cores located offshore West Africa and South America (GeoB7920-2, GeoB9508-5 and GeoB7139-2). Both sites are characterised by biogenic sediment input, in addition to fluvial and aeolian sediment input from the continent. It was found that all cores show a strong, but different correlation between the mean grain size and the bulk geochemical composition. These results demonstrate that geochemical grain-size proxies are empirical and site-specific. It was also found that the geochemical and grain-size data in cores GeoB7920-2 and GeoB7139-2 do not contain unique information, whereas in core GeoB9508-5 Ti varies independently from the grain size. This residual Ti-signal correlates with the transport mechanism, as demonstrated by statistically different values of aeolian and fluvial-dominated sediments. However, a unique interpretation of this residual signal in terms of the postulated grain-size independent mechanisms could not be provided without additional information. We conclude that the proposed model facilitates identification and validation of different element ratios as grain-size proxies and, more importantly, as proxies for size-independent processes. For this reason, the model paves the way for rigorous analysis of multi-proxy data, which are widely used in palaeoceanographic and palaeoclimatic research.

---

Alle informatie in het Integrated Marine Information System (IMIS) valt onder het VLIZ Privacy beleid

Top | Auteurs