Evidence for deep-water deposition of abyssal Mediterranean evaporites during the Messinian salinity crisis

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doi: 10.1016/j.epsl.2015.06.060
Author(s): Christeleit, Elizabeth C.; Brandon, Mark T.; Zhuang, Guangsheng
Author Affiliation(s): Primary:
Yale University, Department of Geology and Geophysics, New Haven, CT, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.427, p.226-235. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 58 refs.; illus., incl. 2 tables, geol. sketch map
Summary: Scientific drilling of the abyssal evaporites beneath the deepest parts of the Mediterranean basin gave rise to the idea that the Mediterranean sea completely evaporated at the end of the Messinian. Herein, we show, using new organic geochemical data, that those evaporites were deposited beneath a deep-water saline basin, not in a subaerial saltpan, as originally proposed. Abundant fossil organic lipids were extracted from evaporites in Mediterranean Deep Sea Drilling Project cores. The archaeal lipid distribution and new analyses, using the ACE salinity proxy and TEX86 temperature proxy, indicate that surface waters at the time of evaporite deposition had normal marine salinity, ranging from ∼26 to 34 practical salinity units, and temperatures of 25-28 °C. These conditions require a deep-water setting, with a mixed layer with normal marine salinity and an underlying brine layer at gypsum and halite saturation. After correction for isostatic rebound, our results indicate maximum drawdown of ∼2000 m and ∼2900 m relative to modern sea level in the western and eastern Mediterranean basins, respectively. Our results are consistent with previously proposed scenarios for sea level drawdown based on both subaerial and submarine incision and backfilling of the Rhone and Nile rivers, which require Messinian sea level drops of ∼1300 m and ∼200 m, respectively. This study provides new evidence for an old debate and also demonstrates the importance of further scientific drilling and sampling of deeper part of the abyssal Messinian units. Abstract Copyright (2015) Elsevier, B.V.
Year of Publication: 2015
Research Program: DSDP Deep Sea Drilling Project
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Abyssal plains; Balearic Basin; Biomarkers; Brines; Cenozoic; Chemically precipitated rocks; DSDP Site 124; DSDP Site 134; DSDP Site 374; Deep Sea Drilling Project; Deep-water environment; Depositional environment; Depth; Drawdown; East Mediterranean; Evaporites; Ionian Sea; Leg 13; Leg 42A; Lipids; Mediterranean Sea; Messinian; Messinian Salinity Crisis; Miocene; Neogene; Ocean floors; Organic compounds; Paleosalinity; Paleotemperature; Sea-level changes; Sedimentary rocks; Tertiary; Upper Miocene; West Mediterranean
Coordinates: N355052 N355052 E0181147 E0181147
N391142 N391142 E0071815 E0071815
N385224 N385224 E0045942 E0045942
Record ID: 2015091447
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands