Publikationsdatum:
2024-02-02
Beschreibung:
Clay mineral assemblages in a sediment core from the distal Nile discharge plume off Israel have been used to reconstruct the late Quaternary Nile sediment discharge into the Eastern Mediterranean Sea (EMS). The record spans the last ca. 140 ka. Smectite abundances indicate the influence of the Blue Nile and Atbara that have their headwaters in the volcanic rocks of the Ethiopian highlands. Kaolinite abundances indicate the influence of wadis, which contribute periodically to the suspension load of the Nile.
Due to the geographical position, the climate and the sedimentary framework of the EMS is controlled by two climate systems. The long-term climate regime was governed by the African monsoon that caused major humid periods with enhanced sediment discharge at 132 to 〈126 ka (AHP5), 116 to 99 ka (AHP4), and 89 to 77 ka (AHP3). They lasted much longer than the formation of the related sapropel layers S5 (〉2 ka), S4 (3.5 ka) and S3 (5 ka). During the last glacial period (MIS 4-2) the long-term changes of the monsoonal system were superimposed by millennial-scale changes of an intensified mid-latitude glacial system. This climate regime caused short but pronounced drought periods in the Nile catchment, which are linked to Heinrich Events and alternate with more humid interstadials.
The clay mineral record further implies that feedback mechanisms between vegetation cover and sediment discharge of the Nile are detectable but of minor importance for the sedimentary record in the southeastern Mediterranean Sea during the investigated African Humid Periods.
Schlagwort(e):
AGE; Carbon, organic, total; Chlorite; Clay/Silt ratio; Color, L*, lightness; DEPTH, sediment/rock; GeoTu_SL110; Globigerinoides ruber pink, δ18O; Gravity corer (Kiel type); Illite; Kaolinite; Kaolinite/(Illite+Chlorite) ratio; M51/3; M51/3_SL110; Meteor (1986); Palygorskite; Sand; Silt/clay ratio; SL; Smectite; Smectite/(Illite+Chlorite) ratio
Materialart:
Dataset
Format:
text/tab-separated-values, 7312 data points
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