TL and ESR dating of Middle Pleistocene lava flows on Lanzarote island, Canary Islands (Spain)

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• 作者：Hans von Suchodoletz^a ; ^b ; ^{hans.von.suchodoletz@uni-leipzig.de} ; Henrik Blanchard^c ; ^{henrik.blanchard@uni-bonn.de} ; Alexandra Hilgers^d ; ^{a.hilgers@uni-koeln.de} ; Ulrich Radtke^d ; ^e ; ^{u.radtke@uni-koeln.de} ; Markus Fuchs^f ; ^{markus.fuchs@geogr.uni-giessen.de} ; Michael Dietze^b ; ^{micha.dietze@mailbox.tu-dresden.de} ; Ludwig Zö ; ller^g ; ^{ludwig.zoeller@uni-bayreuth.de}
• 关键词：Canary Islands ; Red thermoluminescence dating ; ESR dating ; Middle Pleistocene ; Volcanic activity
• 刊名：Quaternary Geochronology
• 出版年：2012
• 期刊代码：9_18711014
• 类别：ear
• 出版时间：June, 2012
• 卷：9
• 期：Complete
• 页码：54-64
• 文件大小：1317 K

摘要

In the north of the island of Lanzarote (Canary Islands, Spain), two palaeosols from different sites were baked by overlying lava flows. Using red thermoluminescence (RTL) dating, late Middle Pleistocene ages were obtained, both varying around 170聽ka thus indicating the simultaneity of the volcanic events. Blue thermoluminescence dating using different measuring techniques of the same sample material from one site (the M谩la dune) yields somewhat lower ages, varying around 125聽ka. However, this result is not in contradiction with the RTL age since anomalous fading was detected, expected to cause a significant underestimation of blue thermoluminescence results. Electron spin resonance dating from land snails overlying the lava flow yielded ages between 204 and 123聽ka. Although this dispersion is rather large for material originating from the same stratigraphic horizon, it has to be taken into account that the amount of sample material and thus signal intensity was very low. Furthermore, small measured sample quantities are very vulnerable to dosimetric inhomogenities in the surrounding material, being a further source of uncertainty. Thus, these ESR ages bracketing the RTL age are a further support for a late Middle Pleistocene age of the lava flow.

The Middle Pleistocene RTL ages of about 170聽ka fill a conspicuous gap in the volcanic chronostratigraphy of Lanzarote, demonstrating that post-erosional volcanism on Lanzarote was obviously more continuous during the Middle and Late Quaternary than known before. Thus, these results demonstrate the potential of RTL and ESR dating to improve the timing of the Quaternary volcanism of the Canary Islands.