查看文章

Henaon, H.< I~ 1..//I/.. I. Coal &IO/., lY4f1. 30,(l-2). 25-35. The geological and high-resolution seismic reflection studies of Pennsylvanian coal deposits provide new information on the Cottage Grove Fault System (CGFS). a major east-west oriented wrench fault system in southern Illinois. The age of the faulting had previously been estimated to be late Pennsylvanian to early Permian, baaed upon K-Ar dating of igneous intrusive rock< associated with subsidiary faults. Although these dates are accurate for intrusions and faulting at certain locations, the duration of the Cottage Grove master fault zone or subsidiary faulting is still unclear. High-regolution seismic reflection profilcs were collected approximately 6.4 km north of the master fault zone in the vicinity of mapped suhaldiary faulting to study coal deposits. Other information was interpreted from the seismic records. thus indicating that subsidiary faulting of the CGFS occurred as early as middle Pennsylvanian time.