Cipollari, Paola

Cosentino, Domenico

Darbaş, Güldermin

Faranda, Costanza

Gennari, Rocco

Gliozzi, Elsa

Grossi, Francesco

Gürbüz, Kemal

Nazik, Atike

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25costAnzA fArAnDA1, elsA Gliozzi1, frAncesco Grossi1, pAolA cipollAri1, DoMenico cosentino1, Güldermin darbaş2, rocco GennAri3, KeMAl GürBüz 4, AtiKe nAziK4 1Dipartimento di Scienze Geologiche, Università Roma Tre, L.go S. Leonardo Murialdo, 1, I-00146 Roma, Italy; 2Jeoloji	 Mühendisliği	Bolümü,	 Kahramanmaraş	 Sütçü	 İmam	 Üniversitesi,	 Avşar	 Kampüsü,	46100	-	Kahramanmaraş	Turkey;	3Dipartimento di Scienze della Terra, Università di Parma, Parco Area delle Scienze 157A - 43100 Parma, Italy; 4Jeoloji	Mühendisliği	Bolümü,	Çukurova	Üniversitesi,	Mimarlık	Fakültesi	Maden	Mühendisliği	Bölümü	01330	Balcalı Adana, TurkeyFor the Palaeo-Mediterranean Basin, the Messinian stage was a cru-cial event characterised by palaeoenvironmental changes linked to im-portant	palaeoceanographic	modifications.	In	this	paper	we	present	the	palaeoenvironmental reconstruction of the Adana Basin, south Anatolia (one of the easternmost Neogene sedimentary basin developed in the Palaeo-Mediterranean) during Messinian, through the paleontological Messinian paleoenvironmental changes in the easternmost Mediterranean: a case study in the Adana Basin (southern Turkey)26analyses of the sediments referable to the Kuzgun and the Handere for-mations. In particular mollusc, ostracod, planktonic and benthonic fora-minifer, and calcareous nannofossil assemblages have been analysed from three stratigraphic sections at about 6 km NW of the city of Adana, in the vicinity of the Kabasakal village. From the uppermost part of the Kuzgun Formation, two sedimentary successions were analysed: a) the 13 m thick section named Adana-1, that	consists	mainly	of	fine-grained	silty	deposits	with	the	intercalation	of	two main massive sandy layers; b) the very close Semiramis section (21 m thick),	already	studied	by	Darbaş	&	Nazik	(2010).	Also	at	the	Semiramis	section,	the	Kuzgun	Formation	is	characterized	by	fine-grained	silty	depo-sits with the intercalation of sandy layers. From the Adana-1 section, 22 samples (ADA-1 1-22) were collected, while 10 samples were analysed from	 Semiramis	 section	 by	 Darbaş	 &	 Nazik	 (2010).	 Biostratigraphical	analyses carried out integrating biostratigraphic results from calcareous nannofossils, planktonic foraminifers and ostracods yielded a possible age interval of 7.226- 6.83 Ma for the Semiramis section and 7.226- 6.43 Ma for the Adana-1 section, both included in the early Messinian. From the lowermost part of the Handere Formation, the 50 m-thick section	of	Adana	was	studied,	which	consists	mainly	of	fine	grained	de-posits (marls) and several thick layers of resedimented evaporites, mainly gypsum rudites, made up of fragments of selenite, different gypsum clast size,	 and	 huge	 blocks	 of	 banded	 selenite,	 suggesting	 debris-flow	 pro-cesses. From the Adana section, 42 samples (ADA 1-42) were collected for microplaeontological analyses. Stratigraphic and biostratigraphic analyses carried out on ostracods have suggested for the Adana section ages comprised between 5.60 and 5.55 Ma, during the step 2 of the Mes-sinian Salinity Crisis (CIESM, 2008) corresponding to the deposition of the Resedimented Lower Evaporites and the lago-mare biofacies.The palaeoenvironmental analyses on the three studied section showed that the Kuzgun Fm deposited in true marine conditions. The slightly most ancient Semiramis section documents a littoral open mari-ne environment, characterised by the presence of abundant planktonic foraminifers among which warm water species of Globigerinoides and Orbulina are dominant, and by infralittoral ostracods accompanied by infra-circalittoral species such as Occlusacythereis occlusa, Bairdoppi-lata subdeltoidea, Costa tricostata, Bosquetina carinella, and Ruggieria tetraptera.	The	presence	of	spicules	of	siliceous	sponges	confirms	an	open external neritic environment. The slightly younger Adana-1 section records	a	very	shallow	coastal	marine	environment	testified	by	the	scar-27city	of	nannofloras	and	planktonic	foraminifers	and	the	low	diversity	of	benthic foraminifers and ostracods. The presence of A. beccarii, (do-minant among benthic foraminifers), Neomonoceratina laskarevi and Phlyctenophora farkasi (dominant among ostracods), typical of shallow water environments such as marshes, lagoons and estuary, together with accompanying Cribroelphidium decipiens testify an enclosed ma-rine environment characterised by local sporadic freshwater inputs that lowered the salinity. There is no clear evidence for oxygen depletion, al-though Ammonia beccarii can tolerate abundant input of organic mat-ter.	Anyway,	well-defined,	even	if	limited,	open-sea	influx	is	documented	in the lower portion of the section by the presence of abundant and well	preserved	nannofloras,	more	diversified	ostracod	and	 foraminifer	assemblages (among which Quinqueloculina gr. is rather well represen-ted) and by the presence of euhaline gastropods.The Handere Fm, deposited unconformably over the Kuzgun Fm af-ter a iatus of at least 830 kyr., documents a very unstable shallow brackish environment, characterised by high mesohaline salinity in the lower portion (“Cyprideis-Ammonia assemblage, Grossi et al. 2008) and mesohaline salinity in the upper portion (“Cyprideis-Loxoconcha assemblage”, Grossi et al. 2008).From the present study it is possible to conclude that the palaeoen-vironmental changes occurred during the Messinian in the Adana Basin can be compared with the palaeoceanographic changes that affected the whole Palaeo-Mediterranean during the Messinian.28ReferencesCIESM (Commission Internationale pour l’Exploration de la Mer Mediter-ranee, Monaco), 2008. The Messinian Salinity Crisis from Mega-Depos-its to Microbiology: A Consensus Report. CIESM Workshop Monograph, 33, 1-168.Darbas, G., Nazik, A., 2010. Micropaleontology and paleoecology of the Neogene sediments in the Adana Basin (South of Turkey). Journal of Asian Earth Sciences, 39, 136–147.Grossi, F., Cosentino, D., Gliozzi, E., 2008. Palaeoenvironmental recon-struction of the late Messinian lago-mare successions in central and eastern Mediterranean using ostracod assemblages. Bollettino della Società Paleontologica Italiana, 47 (2), 131-146.

Messinian paleoenvironmental changes in the easternmost Mediterranean: a case study in the Adana Basin (southern Turkey)

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Messinian paleoenvironmental changes in the easternmost Mediterranean: a case study in the Adana Basin (southern Turkey)

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