Japan Geoscience Union Meeting 2019

Presentation information

[J] Poster

B (Biogeosciences ) » B-CG Complex & General

[B-CG07] Decoding the history of Earth: From Hadean to the present

Wed. May 29, 2019 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall8, Makuhari Messe)

convener:Tsuyoshi Komiya(Department of Earth Science & Astronomy Graduate School of Arts and Sciences The University of Tokyo), Yasuhiro Kato(Department of Systems Innovation, Graduate School of Engineering, University of Tokyo), Katsuhiko Suzuki(Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology)

[BCG07-P11] Tectonic-sedimentation reconstruction of Neoproterozoic metavolcanic sequences; the El-Dabbah area, Central Eastern Desert, Egypt

*Shoichi Kiyokawa1, TAISHI SUZUKI1, Maher Dawoud3, El-Hasan Mohamed3, Kenji Horie2, Mami Takehara2 (1.Department of Earth and Planetary Sciences Faculty of sciences, Kyuushu University, 2.National Institute of Polar Research, 3.Department of Geology, Faculty of Science, Menoufiya University,)

Keywords:Neoproterozoic, Island arc, strike-slip basin, banded iron formation

In the Eastern Desert of Egypt, Neoproterozoic island arc sequence with Banded Iron Formations (BIFs) are reported within volcano-sedimentary sequence whose geological structure and stratigraphy are not well understood. In this study, the geological structure was established to reconstruct the stratigraphy in El Dabbah in the Central Eastern Desert.

It preserves a sequence of relatively undeformed lower greenschist-facies rocks, overlain by subaerial sedimentary strata deposited in strike-slip basins (the Atsham Formation and the Hammamat Group). Reconstructed a stratigraphic–tectonic history of this metavolcanic sequence is understand the Neoproterozoic iron formation stratigraphy and characteristics, which related snowball earth event or not. New geochronological data are used to date the crystallization of granite at ca.638.1±2.9 Ma and a rhyodacite at 659.6±3.0 Ma. Four generations of structural deformation have been identified in this area: accretional phase (D1: 700–680 Ma); strike-slip deformation with transtension, normal faulting, and strong left-lateral shear after the Atsham Formation deposition (D2: 650–640 Ma); and subaerial sedimentation of the Hammamat Group coincident with the activity of a strike-slip fault and formation of a pull-apart basin (D3: 638–600 Ma) and followed by extensional deformation. Hear we show stratigraphic and structural interpretation in low grade metamorphosed sequence at the El-Dabbah area, in Central Eastern Desert in Arabian-Nubian Shield.