Seismic Stratigraphy of the Nahr Menasha (Lago Mare) in the Levantine Basin: Implications for Fluvial Drainage Development During the Latest Miocene (Messinian), Eastern Mediterranean

Abstract

The offshore Levantine basin in the eastern Mediterranean is a structurally-complex evaporite basin with considerable remaining subsalt potential. The southern portion of this basin has been explored, and is currently producing and moving toward several large gas developments; however, the northern portion is currently undeveloped with sparse well control. Four 3D seismic surveys, as well as dense 2D seismic lines, provide an exceptional view of distributive fluvial systems and subsequent incised-valley fills contained within the Messinian Nahr Menasha unit of the Lago Mare. This succession provides a high-resolution record of drainage development prior to widespread marine flooding of the Mediterranean Sea during early Pliocene (Zanclean) time. The Nahr Menasha contains a record of south-flowing paleodrainages that were likely sourced from the northeastern margin of the basin. During the <0.3 Myr transition from widespread Messinian desiccation to Zanclean flooding across the Mio-Pliocene boundary, fluvial fans prograded southward before becoming bypassed and erosionally degraded by incision of river valleys that created an inverted topography, which was then preserved by rapid inundation of the Zanclean megaflood. The high-quality 3D data provide an opportunity to examine geomorphic and stratigraphic records of topographic inversion that have largely been unaltered by subsequent erosional and depositional processes. The unique history of this region permits tests of sequence-stratigraphic interpretations regarding the spatial and temporal character of stratigraphic and geomorphic surfaces formed by fluvial conduits that route sediment into the basin. Interpretations of this succession indicate a temporal lag between widespread desiccation and flooding, suggesting a stronger climatic influence on late Messinian hydrology of the eastern Mediterranean basin than has been previously assumed.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016