Abstract
The provenance of sediments to the Ionian Sea and western Levantine basin during S-1 sapropel times was studied using 87Sr/86Sr isotopic ratios together with major elements. Measurements were made on sediment profiles from 5 box cores in the Eastern Mediterranean, on Saharan dust and on a core from the Nile delta which included sediment deposited during S-I sapropel times. In the sediment profiles, there was a decrease in 87Sr/86Sr ratio, 1/Sr, Ti/Al, Mg/Al and Si/Al ratio starting at the upper Mn peak and finishing at the base of the organic-rich layer. This showed that there was a major change in the nature of the detrital input during S-1 sapropel times. The timing of the change in detrital input was similar to the change in surface salinity as measured by δ18O. There was linear relationship between 87Sr/86Sr and 1/Sr and for 87Sr/86Sr and Ti/Al for all the sediment samples. The favoured interpretation of this pattern was that the detrital input was a mixture of Saharan dust, similar to that being deposited today on Corsica, and a local riverine sediment source. The data were incompatible with the riverine source to the Ionian Sea and western Levantine basin, being from the river Nile. The minor variations in Sr isotopes, and metal/Al ratios in the Nile delta core was interpreted as due to changes in the proportion of Blue Nile to White Nile inputs brought about by climatic variations. It was calculated that the change in detrital input during S-1 time was caused by a simultaneous increase in riverine input and decrease in Saharan dust input.
Original language | English |
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Pages (from-to) | 45-61 |
Number of pages | 17 |
Journal | Marine Geology |
Volume | 160 |
Issue number | 1-2 |
DOIs | |
State | Published - Aug 1999 |
Externally published | Yes |
Keywords
- Eastern Mediterranean
- Riverine particulate matter
- Saharan dust
- Sapropel
- Sediment sources
- Strontium isotopes
ASJC Scopus subject areas
- Oceanography
- Geology
- Geochemistry and Petrology