EFFECTS OF MUTIPLE METEOR IMPACTS ON PETROLEUM SYSTEMS TARIM, ORDOS AND SICHUAN BASINS CHINA

The tectonic effects of large-scale hypervelocity impacts may explain the hydrocarbon occurrence in the Tarim, Sichuan and Ordos basins China, which all produce significant oil and gas. Three meteor impacts may have affected the structural geology: 1) Multiple Middle Paleozoic Carboniferous (300 Ma) Ordos and Sichuan impact events resulting in an impact-tectonic far-field strains (ITFF) between a1600-2900m shock-wave reflection-refraction boundary zone and 2) A Mid-Eocene (43.5 Ma) impact with structural deformations associated , identified by Buthman (2023) and associated ITFF strains. The impact outer rim imprint areas are based upon geophysical signatures, bilateral symmetries, circular, radial geometries, plate tectonic motions based on GPS ground fixed data, and gravity magnetic potential fields.

For the Carboniferous age impacts, structural responses simulated by glass ball projectile impact experiments of Herman (2023) at 85 degrees’ impact angle demonstrate downrange and lateral deformation structural patterns as occurring in the Ordos Basin and extending out to the Tarim basin. A possible far- field ejecta strewn field (305 Ma) may be attributed the Ordos or Sichuan events which occur as microspheres from marine Carboniferous deposits in the Cirsuralian Foredeep Russia.

Tarim and Sichuan basin’s satellite gravity define the circular arc elements. Seismic data for both postulated impact support impact geometries..

The Tarim Basin reservoirs are between 5800 m to 8000 m in depth in ultra-deep wells of Cambrian-Devonian age rocks formed by mesodiagenesis. Strike–slip related fracture systems are critical in providing high permeability in low matrix porosity reservoirs. The highest performing reservoirs are within 1000 m from major faults.

In the Sichuan multiple significant fractured sandstone, ultra-deep carbonate ( mesodiagentic altered dolomites) and shale reservoir gas fields (12) have been discovered and a 10,225 m well is currently drilling.

In all basins 6 tectonic orogenys creating fracture networks or reactivated by significant impact events. Thermal maturation modelling suggests generation began significantly earlier than the impact event providing moveable hydrocarbons for migration.