الفهرس 
Investigating the Shape Evolution of Neogene rift-Related Volcanics Via Facies Analysis and Surface Texture characteristics; An Example from Bahariya Depression, Western Desert, Egypt
Published paper1Only 14 pages are availabe for public view
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Abstract
The Bahariya volcanoes, in the Northwestern Desert of Egypt, are a well preserved and complex example of Neogene volcanoes that are formed under subaerial conditions.They are an early remain of the initial stage of volcanism associated with the Red Sea Rift initiation in the early Tertiary time. This magmatism terminated in the formation of isolated masses with highly variable morphologies, deposits, and eruptive styles.The lithofacies analysis and the evolution of the Bahariya volcanoes details are still poorly understood. So, the study of these volcanoes through lithofacies analysis and construction of eruption evolution offers an opportunity for understanding the style of volcanoes eruption and related deposits, magma genesis, and eruptive mechanism; and can assist to compare these volcanoes edifices with other rift-related volcanoes.The Bahariya volcanoes are recorded in five locations, namely; Gabal El Hefhufe, El Mandisha, El Agoez, El Maysera, and Gabal El Marssous within the Bahariya depression.The complex architecture of the studied volcanoes revealed by detailed mapping has determined the extent of the various volcanic rocks and aided in correlating them to specific eruptive sources to allow for a better assessment of the nature of the eruptions. Also, sedimentological, textural, glass shard morphologies, grain size, and vesicularity have been used to characterize the different lithofacies and eruptive mechanisms of these volcanoes. Other methods including geochemistry and petrography are used as discriminant tools for different facies.Ten lithofacies have been identified along the study areas; five coherent and five volcaniclastics (two peperitic pyroclastics and three proximal pyroclastics).The five major facies associations include pahoehoe lava flows, proximal pyroclastics, rubbly pahoehoe lava flows, peperitic pyroclastics, and coherent subvolcanic intrusions.The first two facies associations form a mafic scoria cone that occupies the Gabal El Marssous (Batch 2), whereas the latter two facies associations are observed at the hills of Hefhufe, El Mandisha, El Agoez, and El Maysera (Batch 1).The subvolcanic intrusions (dikes & sills) disrupt the two batches