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The role of land-marine teleconnections in the tropical proximal Permian-Triassic Marine Zone, Levant Basin, Israel: Insights from stable isotope pairing

Korngreen, D., Zilberman, T.
Global and planetary change 2017 v.154 pp. 44-60
basins, carbon, climate, hinterland, organic matter, oxygen, stable isotopes, Israel
Three Late Permian – early Middle Triassic successions (Avdat 1, Pleshet 1 and David 1 boreholes, Levant Basin, Israel), located in relatively proximal and distal order from land within a broad tropical mixed carbonate/siliciclastic open marine zone, were studied using carbonate and organic matter contents (organic and inorganic carbon) in order to demonstrate the degree of effect of the land-marine teleconnection on the isotopic signatures at the depositional environment. The δ¹³Ccarb profiles exhibit sequential negative/positive fluctuations, which are correlatable with the reported worldwide sequential negative-shift events, enabled further stratigraphic division of the successions to stages and sub-stages. The successions changed their relative siliciclastic content relative to the degree of influence of each terrestrial influx source (eastern or southern), an outcome of humid up to extreme aridization hinterland exchanges, actually recording the expansion or contraction of the paleo-ITCZ. The δ¹⁸O profiles exhibited a range of values (−5‰ to −7.5‰ on average) typical to the western NeoTethys and similar to the reported worldwide climate trends with three major warming periods: (I) Late Permian to the PTB; (II) Late Dienerian - most of the Smithian; (III) early-mid Anisian, and two relatively cool periods: Griesbachian-Dienerian and Late Smithian – Spathian, but each of the three periods exhibiting short respites with the opposite trend. The δ¹³Ccarb, δ¹⁸Ocarb and the δ¹³Corg profiles of the proximal position consistently differ in magnitude from the distal ones, assuming a high contribution and involvement of meteoric water rich in terrestrial OM derived from the nearby supercontinent and affecting also the original water δ¹⁸Oseawater value (calculated to about −3‰),which seemingly should be applied on the entire western Tethys seaway. During times of associations with maximum ITCZ contraction, the δ¹³Corg values of −31‰ to −33‰ in the distal succession exhibit the end member values of the regional marine OM, while values of −22.5‰ to −25‰ of the proximal succession are considered representing the regional terrestrial signature. Our data show good correlation between warming trends, the proximal/distal location of succession and the disparity of δ¹³Ccarb+org values that may explain the differences in reported worldwide values.