Assessing the potential of luminescence dating for fault slip rate studies on the Garlock fault, Mojave Desert, California, USA

作者：Roder Belinda; Lawson Mike; Rhodes Edward J^*; Dolan James; McAuliffe Lee; McGill Sally

来源：Quaternary Geochronology, 2012, 10: 285-290.

DOI：10.1016/j.quageo.2012.03.013

• OSL
• IRSL
• Isothermal TL
• Fault slip rates
• Paleoseismic trench

Although there has been significant advancement of OSL (optically stimulated luminescence) dating of quartz and feldspar over the past decade, the luminescence characteristics of quartz grains in many tectonically active areas are not suitable for accurate age determinations using this technique. This study investigates the reasons for this unsuitability and tests a new measurement protocol (ITL), which appears more promising. At two sites along the central Garlock fault in the Mojave Desert, California, USA, samples collected for OSL dating for this study have proven problematic. At the El Paso Peaks (EPP) trench site, a sequence of OSL samples was collected from sandy units with a well-established radiocarbon chronology, providing the opportunity to assess different approaches and optimize our luminescence dating procedures. At Christmas Canyon West (CCW), where future Garlock fault slip rate studies will be conducted using luminescence dating, samples were collected to assess the luminescence characteristics of both quartz and feldspar in this environment. At both sites, signals from quartz and K-feldspar grains are consistently dim. At EPP, quartz results provide age underestimates, while K-feldspar IRSL yields erratic values; the causes of this problematic behavior are unclear. Preliminary minimum isothermal thermoluminescence (ITL) signals of K-feldspar measured during preheating appear to be consistent with the radiocarbon age estimates, demonstrating potential for accurate age determination in this kind of environment using this protocol.

• 出版日期2012-7