Temporal dissection of the Huckleberry Ridge Tuff using the ⁴⁰Ar/³⁹Ar dating technique

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• 作者：Ben S. Ellis^a ; ^{ben.ellis@wsu.edu} ; Darren F. Mark^b ; Chad J. Pritchard^c ; John A. Wolff^a
• 关键词：Yellowstone ; Super-eruption ; Reunion ; Geomagnetic ; 40Ar/39Ar
• 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：34-41
• 文件大小：921 K

摘要

New high-precision single crystal sanidine ⁴⁰Ar/³⁹Ar ages for the Huckleberry Ridge Tuff (HRT), Yellowstone volcanic field, show that the three HRT members (A, B, and C) represent at least two different eruptions. The new ⁴⁰Ar/³⁹Ar ages (all ages calculated relative to the optimisation model of ) are: 2.135聽卤聽0.006聽Ma, 2.131聽卤聽0.008聽Ma, and 2.113聽卤聽0.004聽Ma (2蟽, full uncertainty propagation), for members A, B and C, respectively. Members A and B are within uncertainty of one another and both are more precise than, but in agreement with, previously published ages. Member C was erupted later than members A and B. HRT members A and B were deposited during the Reunion Normal Polarity Subchron (C2r.1n). Member C was deposited during Subchron C2r.1r. Previously published radiogenic and stable isotope data show that member C was sourced from an isotopically discrete magma with a higher fraction of crustal material than members A and B. The volume of the first HRT eruption is reduced by c. 12%from previous estimates and explosive eruptions from the Yellowstone volcanic field occurred more frequently, producing more homogeneous magma than was previously believed. High-precision ⁴⁰Ar/³⁹Ar dating is key for resolving the eruptive history of Yellowstone, temporal dissection of voluminous ignimbrites, and rigorous investigation of what constitutes a 鈥榮uper-eruption鈥?