Paleogeographic Reconstruction of the Upper Miocene Sequences of the Wadi Yunis Member of the Al Khums Formation, Sirt Basin, Central Libya Khaled S. Amrouni 1,2 , Ahmed S. El-Hawat 2 , Michael C. Pope 1 , Aimen Amer 2 , Adel A. Obeidi 2 , Hassan S. El-Bargathi 2 , Ahmed M. A. Al-Alwani 2 , Mohamed SH. Abdalla El-Jahmi 2 , Khalid A. M. Mustafa 2 , and Essa A. Elbileikia 2 1 Department of Geology and Geophysics, Texas A&M University, MS 3148, College Station, Texas 77843 2 Earth Sciences Department, Garyounis University, Benghazi, Cyrenaica 55555, Libyan Arab Jamahiriya GCAGS Explore & Discover Article #00002 * http://www.gcags.org/exploreanddiscover/2016/00002_amrouni_et_al.pdf Posted September 13, 2016. * Article based on a full paper published in the GCAGS Transactions (see footnote reference below), which is available as part of the entire 2016 GCAGS Transactions volume via the GCAGS Bookstore at the Bureau of Economic Geology (www.beg.utexas.edu) or as an individual document via AAPG Datapages, Inc. (www.datapages.com), and delivered as a poster presentation at the 66th Annual GCAGS Convention and 63rd Annual GCSSEPM Meeting in Corpus Christi, Texas, September 18–20, 2016. ABSTRACT The main objective of this work is to reconstruct the paleogeographic distribution of the depositional facies of the Upper Miocene carbonate sequences of Wadi Yunis Mem- ber, Al Khums Formation, Sirt Basin. The sequence stratigraphic correlation of 38 field measured high-resolution sedimentological sections indicates that the Upper Miocene Wadi Yunis Member consists of two successive shallowing-up sequences. Each sequence consists of six vertically stacked depositional facies (oolitic grainstone facies, oo-skeletal grainstone-packstone facies, algal pelle-skeletal facies, bioclastic wackestone facies, algal stromatolite facies, and coarsely crystalline selenite gypsum facies). These carbonate depositional facies formed in restricted shelf lagoonal-tidal inlet and beach-bar shoal- subtidal channel complex environments along a NW–SE trending, 150 km long, wave- dominated carbonate ramp. Mapping analysis of these two depositional sequences resulted in the reconstruction of the paleogeographic distribution of the Wadi Yunis Member depositional facies. Dur- ing the transgressive systems tract (TST) of the lower shallowing upward sequence, the oolitic grainstone facies belt was deposited above the marly bioclastic wackestone facies. Then a younger channeled oolitic grainstone belt was created above a structural high seaward of the older oolitic grainstone belt, and between these two oolitic belts lagoonal bioclastic wackestone facies were deposited. During the highstand systems tract (HST), channel inlets partially closed and the bioclastic wackestone facies with dwarfed fossils, stromatolites, algal pelletal facie and some gypsum restricted lagoonal facies were depos- ited. During the lowstand systems tract (LST), the lagoons were completely restricted and selenitic gypsum facies deposited in an eye-ball shaped geometry and the lower shal- lowing-up sequence completed. Originally published as: Amrouni, K. S., A. S. El-Hawat, M. C. Pope, A. Amer, A. A. Obeidi, H. S. El-Bargathi, A. M. A. Al- Alwani, M. SH. A. El-Jahmi, K. A. M. Mustafa, and E. A. Elbileikia, 2016, Paleogeographic reconstruction of the Upper Miocene sequences of the Wadi Yunis Member of the Al Khums Formation, Sirt Basin, central Libya: Gulf Coast Associa- tion of Geological Societies Transactions, v. 66, p. 3–14. 1