The Miocene–Pliocene boundary and the Messinian Salinity Crisis in the easternmost Mediterranean: Insights from the Hatay Graben (Southern Turkey)

Abstract

The Hatay Graben is one of three easternmost basins in the Mediterranean that preserve sediments that span the Miocene-Pliocene boundary, including gypsums from the Messinian Salinity Crisis (MSC). Here we integrate existing data and present new sedimentological and micropalaeontological data to investigate the palaeoenvironments of late Miocene to early Pliocene deposits and place this important area into a regional stratigraphic framework. Six sections are described along a ~ W -E transect illustrating the key features of this time period. Late Miocene (Pre-MSC) sediments are characterised by open marine marls with a benthic foraminiferal fauna suggestive of water depths of 100 -200 m or less. Primary lower gypsum deposits are determined to be absent from the graben as sedimentological and strontium isotopes are characteristic of the resedimented lower gypsums. The intervening Messinian erosion surface is preserved near the basin margins as an unconformity but appears to be a correlative conformity in the basin depocentre. No Upper Gypsums or 'Lago-Mare' facies have been identified but available data do tentatively suggest a return to marine conditions in the basin prior to the Zanclean boundary. Sediments stratigraphically overlying the Messinian gypsums and marls are coarse-grained sandstones from coastal and Gilbert-type delta depositional environments. The Hatay Graben is not only strikingly similar to Messinian basins on nearby Cyprus but also to the overall model for the MSC, demonstrating the remarkable consistency of palaeoenvironments found in marginal basins across the region at this time. This research also raises questions as to the timing of the Mediterranean reflooding and the significance of the widespread mega-breccias of the resedimented gypsum deposits.

New insights on Messinian evaporites based on field and seismic interpretations in the Neogene Antalya Basin, SW Turkey

“…Similarly, Glover and Robertson (1998a) indicated that reefal limestones (Gebiz limestone) were Tortonian in age, whereas gypsum layers were Messinian in age in the Aksu subbasin. However, we believe that the gypsum blocks lying on the MES (Glover and Robertson, 1998a;Netzeband et al, 2006;Cornée et al, 2006;Stefano et al, 2010;Tekin et al, 2010;Roveri et al, 2014aRoveri et al, , 2014bBoulton et al, 2016) are time-equivalent to lower-middle parts of the Gebiz limestone. These gypsum blocks would have been the consequence of tectonic activity, as indicated by a number of thrust faults (mainly fault-bend folds) leading to emer- gence and erosion of a subsurface gypsum formation and then reworked into different lithological units of the subbasins ( Figure 12).…”

“…Stratigraphic model of Late Miocene to Early Pliocene MSC events and deposition characteristic of MSC in the studied area. PLG: Primary lower gypsum; RLG: resedimented lower gypsum; UG: upper gypsum (modified fromRoveri et al, 2014aRoveri et al, , 2014bBoulton et al, 2016). local and small carbonate platforms with patch reefs and rhodolite-bearing algal flats. The Pliocene started with a new depositional regime characterized by prograding delta and siliciclastic shore.Gebiz limestone is not deposited in the Manavgat subbasin.…”

Early Pliocene molluscs from the easternmost Mediterranean region (SE Turkey): biostratigraphic, ecostratigraphic, and palaeobiogeographic implications

“…Samandağ Formation (HS subbasin) Six stratigraphical sections were measured and sampled (Figures 2 and 10). The earliest Pliocene Samandağ Formation consists of fossiliferous yellow sandstones and grey mudstones (Boulton et al, 2016). The unit overlays Messinian evaporites of the Vakıflı Formation that contain grey mudstone/marl interbeds in the Mızraklı-Kireçtepe section.…”

“…The Altınözü Unit from the AB subbasin is an informal lithostratigraphical that we introduce for the purpose of this study; it includes shallow water siliciclastics and pelagic intervals, but also dyke and sills. In previous works, the fine detritic deposits of the unit were assigned to the Late Miocene (Tortonian) Nurzeytin Formation based on nannoplankton (Tekin et al, 2010, Boulton et al, 2016). Here we report for the first time an early Pliocene mollusc fauna from these intervals.…”

“…The HG consists of several subbasins that have a Late Miocene-Pliocene infill. The basinal configuration, stratigraphy, and depositional environments of these subbasins were mainly affected by changing tectonic regimes from a late-stage continental collision phase in the Late Miocene (Messinian) to a westward tectonic escape during Early Pliocene (Zanclean) times (Boulton et al, 2006(Boulton et al, , 2016Robertson, 2007, 2008). The area consists of two tectonically originated NE-SW directed small subbasins, the Hatay-Samandağ (HS) and Altınözü-Babatorun (AB), and the neighbouring İskenderun-Arsuz (İA) basin.…”