Lancaster EPrints

ESR dating of quartz phenocrysts in some rhyolitic extrusive rocks using A1 and Ti impurity centres.

Wild, Mark and Tabner, Brian J. and Macdonald, Ray (1999) ESR dating of quartz phenocrysts in some rhyolitic extrusive rocks using A1 and Ti impurity centres. Quaternary Science Reviews, 18 (13). pp. 1507-1514. ISSN 0277-3791

Full text not available from this repository.


ESR has been employed to determine the eruption date of rhyolitic rocks from three different tectonic settings. Samples from the Olkaria complex, Kenya rift valley, yielded ages of 31±3 and 38±5 ka (148a) and 23±4 and 34±8 ka (570) from the Al and Ti centres, respectively. These compare with an inferred formation age of 65±12 ka (148a), obtained from U-series isochrons, and an eruption age of 5.7–9.7 ka (570), based on 14C and lake stands. Glass (melt) inclusions in sample 570 may have distorted the ESR age. The Youngest Toba Tuff (YTT), Sumatra, gave an average ESR eruption age of 81±17 ka which compares well with K/Ar and 40Ar/39Ar ages in the range 73–75 ka. However, there is evidence of thermal annealing in the Oldest (OTT) and Middle (MTT) Toba Tuffs by the more recent YTT eruption, with mean ages of ca. 349 ka and 326 ka, respectively, significantly below the K/Ar age of 840±30 ka (OTT) and the 40Ar/39Ar age of 501±5 ka (MTT). A sample from the Battleship Rock Tuff, Jemez Volcanic Field, New Mexico, gave a mean ESR age of ca. 247 ka which contrasts markedly with a previously determined ESR age of 59±6 ka, but compares more favourably with previous K/Ar ages of 278±52, 130±70 and 180±70 ka. Subsequent geothermal activity and high ambient temperatures in this area may be responsible for these apparent discrepancies.

Item Type: Journal Article
Journal or Publication Title: Quaternary Science Reviews
Subjects: ?? ge ??
Departments: Faculty of Science and Technology > Lancaster Environment Centre
ID Code: 21769
Deposited By: ep_ss_importer
Deposited On: 05 Feb 2009 13:42
Refereed?: Yes
Published?: Published
Last Modified: 10 Apr 2018 11:34
Identification Number:

Actions (login required)

View Item