Determining the cooling age using luminescence-thermochronology

Abstract

Luminescence technique has been shown to have great potential in low-temperature (< 100 °C) themochronology. This study investigates the kinetic process of luminescence in a cooling system. We present a new formula that can be used for determining the cooling age based on luminescence-thermochronology. The cooling rate can be obtained directly from a plot of luminescence age versus the present temperature. We show that the application and capacity of luminescence-thermochronology are significantly controlled by the saturation of luminescence and environmental dose rate. AbstractLuminescence technique has been shown to have great potential in low-temperature (<100 °C) themochronology. This study investigates the kinetic process of luminescence in a cooling system. We present a new formula that can be used for determining the cooling age based on luminescence-thermochronology.The cooling rate can be obtained directly from a plot of luminescence age versus the present temperature. We show that the application and capacity of luminescence-thermochronology are significantly controlled by the saturation of luminescence and environmental dose rate.Keywords: luminescence, thermochronology, cooling age, closure temperature IntroductionThermochronology refers to determining or constraining the thermal history of a specific rock, mineral, or geologic unit using various dating techniques. Different techniques in thermochronology have been developed using various dating techniques, such as fission track dating of zircon and apatite, K-Ar and Ar-Ar dating of K-feldspars, (U-Th)/He dating of zircon and apatite and 4 He/ 3 He dating, etc. A full review of thermochronology has been provided by Reiners et al (2005). In terms of low-temperature thermochronology, radiation damage dating techniques, such as electron spin resonance (ESR) dating (Grün et al., 1999) and thermoluminescence (TL), are applied (Johnson 1966). Recently, in the study of the relief evolution and exhumation rates within the last glacial cycle in the Southern Alps of New Zealand, a new low-temperature 2 thermochronology has been introduced using the technique of optically stimulated luminescence (OSL) dating of quartz (Herman et al., 2010) .Luminescence refers to the light emitted by irradiated crystal materials in response to external stimulus, such as heat (TL), visible light (OSL) and infrared (IRSL). During the geological processes, the minerals contained in geological materials (e.g. rocks and sediments) are exposed to ionization radiation (alpha and beta particles and gamma rays) emitted by the decay of radioactive isotopes within the minerals themselves and the surrounding matrix. The high-energy ionizing radiation can create free electrons and holes which may be subsequently trapped at the structural defects and chemical impurities inside the crystal lattice. When the minerals are stimulated by heat or light, the trapped electrons are ejected and recombined with holes. The evicted electrons diffuse around the crystal lattice and some of them ma...

Rapid denudation of Higher Himalaya during late Pliestocence, evidence from OSL thermochronology

“…However, the limitations are early saturation of quartz luminescence and possible athermal fading of feldspar signal. These limit the upper age range which additionally depends on the environmental radiation dose rate (Li and Li, 2012).…”

“…Using activation energy (E a ) as 1.59 eV and frequency factor (s -1 ) of 8×10 12 and the Dodson (1973) Herman et al (2010) estimated the closure temperature of the fast component of quartz OSL signal as 30-35°C for a cooling rate of 10°C/Ma. Li and Li (2012) provided a new relation to determine the cooling age, and provided ways to obtain the cooling rate directly from a plot of luminescence age versus ambient temperature. Applicability of thermoluminescene (TL) and feldspar infra-red stimulated luminescence (IRSL) also show promise and are being developed (Jain and Ankjaergaard, 2011;Li and Li, 2012).…”

Low temperature thermochronology using thermoluminescence signals from K-feldspar

“…Firstly, it has multiple thermochronometers which correspond to a group of closure temperatures (Li and Li, 2012;Tang and Li, 2015;Qin et al, 2015). The continuous cooling process can be estimated based on a group of apparent ages, which initiate at different times and temperatures.…”

“…The continuous cooling process can be estimated based on a group of apparent ages, which initiate at different times and temperatures. Secondly, the luminescence thermochronometry has very low closure temperatures between 35-80°C (Li and Li, 2012). It can document cooling histories within the uppermost portion of the crust, such as river incision and glacier denudation.…”

“…Prokein and Wagner, 1994;Herman et al, 2010;Li and Li, 2012;Qin et al, 2015). It was only recently that this method was applied to exhumation process in rapid uplifting areas, such as the Southern Alps in New Zealand, the Eastern Himalaya and Nujiang River (Herman et al, 2010;Sarkar et al, 2013;Tang and Li, 2015).…”