干旱区生态环境知识资源中心(Arid): Alluvial karstification and paleodoline development in Eocene limestones, a case study from west Sohag City, Egypt: implications for causes and impacts

Arid

DOI	10.1007/s12517-019-4409-x
	Alluvial karstification and paleodoline development in Eocene limestones, a case study from west Sohag City, Egypt: implications for causes and impacts
	Mahran, Tawfiq Mohamed; Hassan, Abdallah Mohamed
通讯作者	Hassan, Abdallah Mohamed
来源期刊	ARABIAN JOURNAL OF GEOSCIENCES
ISSN	1866-7511
EISSN	1866-7538
出版年	2019
卷号	12 期号:7
英文摘要	The Late Oligocene pre-Eonile paleoriver flows northwesterly over the Eocene Limestone Plateau in the east central Western Desert, west of the Nile Valley (Sohag), building an alluvial plain and leading to the karstification of the limestone bedrock, as paleoerosional surfaces and paleodolines. Knowledge of this alluvial karstification is completed with the detailed studies of the sedimentary evolution of the fluvial system and its contemporary deposition. Analysis of the sedimentological and geomorphological features allows discussing the natural environmental conditions that favored karst in the past and its main genetic mechanisms. The architectural elements of the fluvial deposits indicate that they were deposited in a gravel-dominated braided fluvial system, characterized by high availability of water and sediment supplies. The current study proves that genesis of paleodolines was mainly related to this high water supply. Some of them were progressively filled by syn-sedimentary deformed unconsolidated deposits. Such deformation is due to dissolution of the underlying sagging synclinal limestone, conditioning the location of sinking waters where preferential dissolution and later suffosion took place. A model for the evolution of the paleodoline fills is proposed and interpreted in three different stages: (1) gravitational processes developed and disorganized gravels were remobilized and dragged toward the created paleodolines; (2) flooding of the paleodolines acted as lakes where Gilbert-type deltas and gravel slope deposits accumulated, exhibiting several unconformities interpreted as a result of continued subsidence of the paleodoline related to dissolution; and (3) nondeformed fluvial facies sealed the whole deposits, marking the end of the karstification process. Combinations of different types of factors that could cause karstic subsidence and associated hazards include soluble rock lithology, paleoclimate, and deformational structure.
英文关键词	Karstification Nile Valley Paleodolines Geomorphology Geohazards Pre-Eonile
类型	Article
语种	英语
国家	Egypt
收录类别	SCI-E
WOS记录号	WOS:000462143600001
WOS关键词	SINKHOLE HAZARDS ; KARST SUBSIDENCE ; EVAPORITE KARST ; EASTERN SAHARA ; OUTWASH FANS ; NILE VALLEY ; EBRO BASIN ; LAND-USE ; DESERT ; EVOLUTION
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/214320
作者单位	Sohag Univ, Fac Sci, Geol Dept, POB 82524, Sohag, Egypt
推荐引用方式 GB/T 7714	Mahran, Tawfiq Mohamed,Hassan, Abdallah Mohamed. Alluvial karstification and paleodoline development in Eocene limestones, a case study from west Sohag City, Egypt: implications for causes and impacts[J],2019,12(7).
APA	Mahran, Tawfiq Mohamed,&Hassan, Abdallah Mohamed.(2019).Alluvial karstification and paleodoline development in Eocene limestones, a case study from west Sohag City, Egypt: implications for causes and impacts.ARABIAN JOURNAL OF GEOSCIENCES,12(7).
MLA	Mahran, Tawfiq Mohamed,et al."Alluvial karstification and paleodoline development in Eocene limestones, a case study from west Sohag City, Egypt: implications for causes and impacts".ARABIAN JOURNAL OF GEOSCIENCES 12.7(2019).