Cour. Forch.-Inst. Senckenerg, 113: 159-175. Frankfurt am Main, 30.6.1989 ate Pleistocene, Holocene, and Recent ostracods from the Gulf of Argos, Greece EBERHARD ZANGGER & HEINZ MALZ 2 Text-igures, 4 Plates t ue objective of this study is to outline the ate Quaternay histoy of a submarine desitional environment and the evolution of its strad auna. Samples rom the each and the ottom of the Gulf of rgs prided Recent ostracd opulations, which are ued here as ecologial indiators and compared with fsil aemblages taken rom core amples of buried marine Holcene and Pleistcene desits. ue ate Quatenay desitional environment of the · Gulf of Args i s characteried y ediment accumulation and eustatic ea-level changes which have prduced a suc sion of transgresive and regre�ive equenes. Each transgre�ive equene egins with an aemblage of the organisms whici irst opulated the newly oned euyhaline environment, in which the near-shore auna as a whole an e characteried as a little diversiied Xstoebes/Loconcha aemblage. Rising ea-levels during the Holcene and Plei stcene interglacials are indiated y more divesi ied aemblages ccurring at deeer biotoes. In such desits the Xestoebers and concha secies are aciated increasingly, and altemately, with the of Bsserites, Pontyhere, Ponts, Letythre, Hlemannithere, A, ytde, Cthe, Cy thefoide, ytherett, Cstthe, See- . r, Urthees, Ptegthes, Tenethre, Cytheres, Cudites, Cost, Bnton, Acnthy thes and Henyhowe. In regresive equences, the pure marine opulations change upwards into mono tonous Cyides aemblages indiating a change from marine to brackish conditions and recording the with drawal of the coastline. Some amples near the preent surae are rich in reshwater taxa such as Con, Cs and lyys. nduo ue Gulf of Args i s a shallw castal bay at the northem end of a major graen system on the eastem Peloonnee eninsula in Greece (text-ig. 1). lt is surrounded y steeply rising sloes of the Arkadian mountains in the west and the gently rolling outhem Argolid hills in the east. Physiography and bathymety of the gulf have changed signiiantly during the Qua temay and the astline was never ixed in its pre ent lation (FINE, 198). Quatemay cillations of ea-level of 10-120 m aued shoreline shits ver a distane of aout 10 km (V N NDEL et L, in prep.). Sedimentation during thee ea-level luctua tions prdued everal transgre�ive/regresive equen ces in the desitional record. Marine ediments were desited on the originally terrestrial bae during interglacial transsions. Regre�ions resulted in the suersition of each and backshore desits on top of marine ediments, thus preeing the marine acies in the susurae. Up to our of thee trans grsive/regresive ycles an e reognized in drill holes, 30 m deep, which were made near the preent astline (text-ig. 2). ue ycles orrsond to the latst our interglacial high ea-lvels, with buried Holcene marine ediments at the top. In this paer we dicu� the edimentoloy and microalaeontoloy of the our marine equenes and omare them with the prent situation in the Gulf of Args. ue availability of Pleistcene, Holcene and mden amples ermits an anatysis of the ate Qua temay evolution of the marine environment baed on its strad opulation. ue strad aemblages in general and the bathymetrial distribution of secies in articular eve as a tol to intepret the al aeenvironment. During the last deade such alaeo-