Growth Faults, a Distinct Carbonate-Siliciclastic Interface and Recent Coastal Evolution, NW Nile Delta, Egypt
نویسنده
چکیده
A sharp, well-defined interface between a late Pleistocene carbonate sandstone ridge (kurkar) and Holocene unconsolidated coastal siliciclastic sediment has formed largely as a consequence of recent structural activity along the NW Nile delta coast at Abu Qir, Egypt. Joint patterns in the coastal kurkar exposed on land, and its irregular and dislocated configuration beneath Abu Qir Bay, suggest that the ridge east of Alexandria was stretched, down-bowed and offset in a NE direction. The ridge has subsided by growth faults to shallow depths in the bay, resulting in westward coastal regression toward the Abu Qir peninsula by headscarp retreat. Deformation of the coastal margin and development of the distinct lithological interface occurred primarily from late Pleistocene to early Holocene time, although continued sub.sidence and disruption of the late Quaternary section has occurred locally in the bay as recently as the first millennium C.E. Both emerged land and coastal-to-shallow bay phenomena are a probable response to readjustment at depth of the thick (>5000 m) Mesozoic to Quaternary sediment section lying beneath the recent NW Nile delta. This shift deep within the underlying sediment pile has lowered the bay floor and likely accounts for some shallow to intermediate depth earthquakes along, and proximal to, the Alexandria to Abu Qir coastal margin.
منابع مشابه
Submergence and burial of ancient coastal sites on the subsiding Nile delta margin, Egypt Submersion des sites littoraux le long de la marge deltaïque subsidente du Nil, Egypte
A/uiciit siles orii;iiuil!y posilioiwd íIIOIIí; the Nile delta's coastal iitargin arc used us ¡íIIUííCS to measure effects of «eustutic» sea-level rise (~l mm/year) and latid loweriii)> (= subsidence) of the sediment substrate beneath settlements during die late Holocene. The combined effect of titese two factors, referred to as relative sea-level chanfle, resulted in submergence and/or burial ...
متن کاملTectonic evolution of the Khoy ophiolitic complex, NW Iran
The Khoy Ophiolitic Complex (KOC) as a part of Tethyan, Izmir-Ankara- Erzincan and Bitlis-Zagros sutures of South East (SE) Turkey is broadly exposed around Khoy region (NW Iran). This complex comprises dismembered fragments of mantle lithosphere, obducted oceanic lithosphere and parts of volcanic arc remnants. The Khoy Ophiolitic Complex can be structurally divided into two major eastern and w...
متن کاملInfluence of growth faults on coastal fluvial systems: Examples from the late Miocene to Recent Mississippi River Delta
متن کامل
Stratigraphic and structural evolution of the Blue Nile Basin, Northwestern Ethiopian Plateau
The Blue Nile Basin, situated in the Northwestern Ethiopian Plateau, contains 1400 m thick Mesozoic sedimentary section underlain by Neoproterozoic basement rocks and overlain by Early–Late Oligocene and Quaternary volcanic rocks. This study outlines the stratigraphic and structural evolution of the Blue Nile Basin based on field and remote sensing studies along the Gorge of the Nile. The Blue ...
متن کاملBivalve taphonomy in tropical mixed siliciclastic-carbonate settings. I. Environmental variation in shell condition
—Contrary to the geological stereotype of pure-carbonate reef platforms, approximately 50% of shallow shelf area in the Tropics is accumulating siliciclastic and mixed siliciclastic-carbonate sediments. Taphonomic characterization of these settings is thus essential for assessing variation among major facies types within the Tropics, as well as for eventual comparison with higherlatitude settin...
متن کامل