The co-evolution of Black Sea level and composition through the last deglaciation and its paleoclimatic significance

Abstract

The strontium and oxygen isotopic compositions of carbonate shells are a measure of the water delivered to the Black Sea lake since the last glacial maximum. Commencing at ~18 ka BP cal with the arrival of substantial meltwater from the Alpine and northern European ice sheets and overflow via the Caspian Sea from the disintegrating Siberian ice cover, the 87 Sr/ 86 Sr ratio rose rapidly from a glacial minima around 0.7087 to reach a set of peaks near 0.7091 in layers of conspicuous reddish-brown clay with a mineralogy of Eurasian provenance. The 87 Sr/ 86 Sr ratio oscillates between high in the red-brown layers to low in interbedded gray clays with glacial era mineralogy, indicative that the meltwater came in pulses. On the other hand, the rise of the 18 O ratio from glacial low values of -7 per mil was delayed until15.2 ka BP cal, after the last meltwater pulse. Sr composition shifted to that of the global ocean and remained there to the present. Since lake water is significantly depleted in strontium relative to seawater, any earlier leakage from the Mediterranean should have left a corresponding signal.

Taxonomy, distribution and bionomics of Celonites tauricus Kostylev, 1935, stat. n. (Hymenoptera, Vespidae, Masarinae)

“…During the Würm glacial this western costal zone was an extensive refuge harbouring the Mediterranean flora (Yena et al 2005). Major et al (2006) showed that intense meltwater pulses at the end of the Würm glacial between 18 and 16 ka BP raised the level of the Black Lake, probably to its outflow, so that lower parts of the shelf were drowned. But during the following warm post glacial periods of the Bølling-Allerød (15-13 ka BP) and the Preboreal (11.6-9.4 ka BP) the complete shelf was again well above the sea level (Major et al 2006).…”

“…Major et al (2006) showed that intense meltwater pulses at the end of the Würm glacial between 18 and 16 ka BP raised the level of the Black Lake, probably to its outflow, so that lower parts of the shelf were drowned. But during the following warm post glacial periods of the Bølling-Allerød (15-13 ka BP) and the Preboreal (11.6-9.4 ka BP) the complete shelf was again well above the sea level (Major et al 2006). Consequently it seems likely that finally this entire area was inhabited by the western spinosus-like population of C. tauricus.…”

Abrupt drainage cycles of the Fennoscandian Ice Sheet

“…1A) was recently suggested by the discovery of peculiar sedimentary structures known as the Red Layers (RLs). RLs are a series of four individualized intervals of reddishbrown clays and are thought to represent the sedimentary imprints of the meltwater inputs (12)(13)(14)(15) that occurred during Heinrich Stadial 1 (HS1) (16). To date, however, the genesis and origin of the RLs remain enigmatic, even if three main hypotheses have been proposed to account for their occurrence in BS sediment sequences.…”

Estimation of successive coseismic vertical offsets using coeval sedimentary events – application to the southwestern limit of the Sea of Marmara's Central Basin (North Anatolian Fault)

“…1), the Sea of Marmara has become the focus of paleoenvironmental investigations (Çagatay et al, 2009;McHugh et al, 2006). In particular, late Quaternary climatic cycles, and especially associated sea level changes, left a strong sedimentary imprint in shallow parts as well as in deep basins (Çagatay et al, 2000;Major et al, 2006;Vidal et al, 2010, etc.). Different hypotheses (including catastrophic flooding) have been proposed for the last "reconnection" of the three realms through the Bosphorus and Dardanelles (Çanakkale Straits) sills (Ryan et al, 1997(Ryan et al, , 1999Aksu et al, 1999, Eriş et al, 2007.…”

“…Due to its importance for the study of the last climatic cycle, the hydrologic evolution of the Sea of Marmara has been intensively surveyed by different authors through sedimentation. Biological, chemical, mineralogical, and isotopic proxies, have been analyzed to detect the respective influence of the Black Sea and the Aegean Sea since the Last Glacial Maximum (MIS 2) depending on their surface level (Çagatay et al, 2000;Major et al, 2006;Reichel and Halbach, 2007;Eriş et al, 2007;Vidal et al, 2010). The impact of these variations has also been investigated in shallow parts (Çagatay et al, 2003).…”