Research Article
Structural Characteristics and Exploration Significance of the Lower Paleozoic Detachment Thrust Belt in the Eastern Ordos Basin
Issue:
Volume 15, Issue 1, February 2026
Pages:
1-9
Received:
1 September 2025
Accepted:
16 September 2025
Published:
23 January 2026
DOI:
10.11648/j.earth.20261501.11
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Abstract: Utilizing 2D and 3D seismic data, a large-scale detachment thrust structure within the Lower Paleozoic Ordovician Majiagou Formation (O1m) has been identified west of Lishi in the eastern Ordos Basin. This study investigates the structural characteristics, spatial distribution, evolutionary stages, and exploration potential of this structure. The results indicate: (1) The Lower Paleozoic Lishi West Detachment Thrust Belt (DTB) in the eastern Ordos Basin margin is 5–10km wide, extends nearly north-south parallel to the Lishi Fault Zone, and has considerable strike length. (2) The main faults of the Lishi West DTB initiated in the Precambrian and subsequently underwent four major evolutionary stages: stable sedimentation in the Ordovician epicontinental sea; formation of the detachment thrust belt from the Late Ordovician to Late Carboniferous; stable sedimentation from the Late Carboniferous to Middle Jurassic; and compressional uplift from the Middle Jurassic to Cretaceous. (3) The Lishi West DTB originated during the Caledonian period as a deep-seated structural weak zone. During the Yanshanian period, the eastern basin margin experienced westward compression, leading to regional tilting and uplift. Stress release along this pre-existing weak zone caused significant variations in formation dip angles and fault characteristics across the belt. This DTB is interpreted as the boundary separating the Jinxi Warp-Fold Belt and the Yishan Slope. (4) The detachment thrust belt in the eastern margin plays a critical role in hydrocarbon accumulation and subsequent migration/readjustment. The area west of the belt is favorable for exploring various coal-measure hydrocarbon resources, including deep coalbed methane (CBM) and in-source to near-source tight gas. A series of positive structural traps with large aerial extent have developed within the O1m Formation along the Lishi West DTB, demonstrating high exploration potential.
Abstract: Utilizing 2D and 3D seismic data, a large-scale detachment thrust structure within the Lower Paleozoic Ordovician Majiagou Formation (O1m) has been identified west of Lishi in the eastern Ordos Basin. This study investigates the structural characteristics, spatial distribution, evolutionary stages, and exploration potential of this structure. The r...
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,
Li Yongzhou
