Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4725416 | Quaternary Geochronology | 2007 | 6 Pages |
Abstract
Optical dating of liquefied sand structures formed during major earthquakes in Upper Assam, northeast of India, has been carried out to constrain the timing of prehistoric earthquakes in this seismically active region. The bleaching of source material and of the same material during the creation of a liquefaction feature was tested using quartz extracted from 21 samples associated with two different liquefaction structures in Upper Assam. Due to the poor sensitivity of quartz from this region, a sensitisation procedure was used in our SAR protocol to reduce the scatter in optical ages. Various internal consistency tests of the measurement protocol and the excellent reproducibility of the OSL ages indicate that the dose estimates from the quartz are accurate and the optical ages reliable. The preliminary OSL ages indicate that the liquefaction features were formed between 1430 AD and 1630 AD. This study demonstrates that using OSL, 'direct dating' of prehistoric earthquakes may be possible, if sand blows from liquefied dykes are preserved.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geochemistry and Petrology
Authors
Puthusserry J. Thomas, Dontireddy V. Reddy, Devender Kumar, Pasupuleti Nagabhushanam, Balbir S. Sukhija, Radhendra N. Sahoo,