Slope sediments of a Paleocene ramp-to-basin transition in NE Egypt

Abstract

Sedimentary structures, microfacies and stratigraphy of a late Paleocene ramp-to-basin transition have been studied in the Galala Mountains in the northern part of the Eastern Desert of Egypt. Three phases of ramp progradation were observed. During non-progradation hemipelagic sediments were intercalated. These progradational phases are indicated by mass-transport deposits of glides slumps and debris flows which came from different directions except from the south. At least two of these mass-transport deposits may reflect deposition during sea-level lowstands, whereas the hemipelagic intercalations indicate transgressive phases. Microfacies analysis provided evidence of a change in the origin of the debris flow deposits. They show a transition from a basinal-to-outer-ramp setting to a middle-to-inner-ramp setting and a change in organism distribution. While coralline red algae prevailed on the inner ramp in the Selandian to Thanetian, nummulitids dominated in the late Thanetian.

From platform to basin: the evolution of a Paleocene carbonate margin (Eastern Desert, Egypt)

“…This genetic approach considers the variability of depositional profiles, from rimmed carbonate platforms to homoclinal ramps, as a function of the type of sediment, especially in terms of bioclast contribution to the sediment, the location of sediment production, and the hydraulic energy. Drzewiecki and Simó (2002) and Scheibner et al (2000) concentrated on the depositional processes and triggering mechanisms of debris flows whilst Kenter and Schlager (1989), and Kenter (1990) focused on the relationship between sediment composition and angle of repose. Others, e.g., Kenter and Campbell (1991), have described the facies distribution along a rimmed platform margin for the early Jurassic (High Atlas, Morocco).…”

“…It shows a continuous 360-m-wide outcrop of mass-flow deposits (Scheibner et al 2000), in which the internal lateral transitions of the different types of mass-flow deposits were studied (approximately perpendicular to the former transport direction). Scheibner et al (2000) postulated several progradational phases for the late Paleocene, starting at 59 Ma, due to existence of different generations of mass-flow deposits. Microfacies analysis of the debris flows provided evidence for a change in their origin from a more distal setting to a more proximal setting.…”

Middle-Upper Miocene paleogeography of southern Turkey: insights from stratigraphy and calcareous nannofossil biochronology of the Olukpınar and Başyayla sections (Mut-Ermenek Basin)

“…Debris flows related to sea-level falls have been identified from different basins, from the Cambrian up to the Miocene (Drzewiecki & Simó 2002 and references therein). Scheibner et al (2000Scheibner et al ( , 2003, working on slope sediments of a Paleocene ramp-to-basin transition in NE Egypt, reported depositional facies quite similar to the facies recognized at the Olukpınar section, with hemipelagic marls and debris flow deposits that were related to transgressive/highstand and lowstand phases, respectively. According to our age model for the Olukpınar section, derived from an updated biostratigraphical scheme for nannofossils (Fornaciari et al 1996), and the global/regional cyclicity of sea-level changes, the debris flows recognized at the Olukpınar section may be related to different phases of sea level fall.…”

“…Although mass gravity flows and related deposits could be triggered by different processes (e.g., margin oversteepening during sea-level highstands, seismic activity, or erosion during sea level lowstands), the most common process for triggering mass gravity flow on the slope is a relative sea-level fall with erosion of the basin margins (Handford & Loucks 1993;Scheibner et al 2000Scheibner et al , 2003Drzewiecki & Simó 2002 and references therein; Warrlich et al 2002;Bosence & Wilson 2003). Debris flows related to sea-level falls have been identified from different basins, from the Cambrian up to the Miocene (Drzewiecki & Simó 2002 and references therein).…”

Late Paleocene–early Eocene Tethyan carbonate platform evolution — A response to long- and short-term paleoclimatic change

“…The Maastrichtian-lower Eocene deposits of a carbonate platform margin-to-basin transect in the Galala Mountains (approximately 200 km SE of Cairo on the western side of the Gulf of Suez) exhibit excellently exposed outcrops across the upper Paleocene to lower Eocene. Over 20 sections have been studied during the last years with respect to lithostratigraphy and paleogeography (Scheibner et al, 2001a), biostratigraphy (Marzouk and Scheibner, 2003;Scheibner and Speijer, in press), ostracode biogeography (Morsi and Scheibner, in press) and platform evolution Scheibner et al, 2000Scheibner et al, , 2001bScheibner et al, , 2003a.…”