The Study on Provenance and Meandering River Delta System of Shan 2 Member in Southeastern Ordos Basin

Key words: 
• meandering river delta /
• provenance /
• depositional model /
• Shan 2 Member /
• southeastern Ordos Basin

Abstract: Shan 2 Member in southeastern Ordos Basin is an important gas bearing stratum. The provenance system is analyzed based on heavy mineral distribution, sandstone composition, rock fragments type and cathodoluminescence characteristics. The sediments of Shan 2 Member mainly comes from the north and south source areas. The sorting of the sediments is moderately to well sorted and rounded. Trough cross bedding, parallel bedding and wave ripples mainly developed in Shan 2 Member, the sedimentary facies of Shan 2 Member is a meandering river delta front based on sedimentary texture and sedimentary structures. The sediments of Shan 2 Member is dominated by saltation and featured by 3 sections and 4 sections while the mouth bar is characterized by well sorted sediments and 2 sections and 3 sections grain size distribution patterns. The sandstone thickness in the south, north and central areas like Zhidan and Ganquan is large. The fluvial sandstone body is characterized by an asymmetric type and stacking pattern. The hydrodynamic condition is moderate to strong. Based on provenance system reconstruction, sedimentary features analysis and identification of thin sections, the sedimentary model of Shan 2 Member which is double sourced meandering river delta is established, which provides a theoretical support for gas exploration and exploitation.