Age dating fault gouge friends then dating
On the other hand, the ESR age obtained from the MTL is younger than the KAr age (about 11 Ma), which is presumably overestimated due to the existence of the source minerals in the KAr dating sample.Since it is geologically known that the MTL at the outcrop had moved until the Late Pleistocene-Holocene, the fault movement of the MTL at this outcrop probably began at 6.76–9.28 Ma B. after the intrusion of the felsitic dyke (12–16 Ma) which is the source rock of the fault gouge into the fault boundary.The ESR dating method has been applied to the fault gouge of the Nojima Fault, the outcrop of which arose due to the southern Hyogo Prefecture Earthquake on January 17th, 1995, and to the fault gouge of the Median Tectonic Line (MTL) which is a major active fault in Japan, without considering the resetting of ESR signals.The ESR ages obtained for clay minerals in the fault gouges are considered to indicate the age of the beginning of the fault movements at the outcrop.
Our analysis yields overlapping, early Paleocene ages for neoformed (1Md) gouge illite (63?? 2 Ma), which are compatible with results elsewhere. In conjunction with other evidences from the lacustrine records in the region, phases of regionally extended tectonic activities at about 40 ka and 60 ka are inferred.strata in Himalaya are being continuously stressed due to an ongoing northward movement of the Indian plate.If not indurated and the freshest clay gouge can be collected at the outcrop, the ESR age of the most recent movement may be obtained from the clay gouge.The field investigations in the epicentral area of the 1994 Wadakkancheri (Desamangalam), Kerala, earthquake (M 4.3) indicate subtle, but clearly recognizable expressions of geologically recent fault zone, consisting of fracture sets showing brittle displacement and a gouge zone.