DOI: 10.1016/j.quascirev.2018.03.024
Scopus记录号: 2-s2.0-85044442680
论文题名: Geochemistry and mineralogy of late Quaternary loess in the upper Mississippi River valley, USA: Provenance and correlation with Laurentide Ice Sheet history
作者: Muhs D.R. ; Bettis E.A. ; III ; Skipp G.L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 187 起始页码: 235
结束页码: 269
语种: 英语
英文关键词: Geochemistry
; Glaciation
; Last glacial period
; Laurentide Ice Sheet
; Loess
; Mississippi River
; North America
; Pleistocene
; Sediment mineralogy
Scopus关键词: Curricula
; Feldspar
; Geochemistry
; Glacial geology
; Glaciers
; Ice
; Landforms
; Mica
; Rivers
; Salinity measurement
; Silicate minerals
; Glaciation
; Last glacial period
; Laurentide ice sheets
; Loess
; Mississippi river
; North America
; Pleistocene
; Sediments
; clay mineral
; feldspar
; glaciation
; Laurentide Ice Sheet
; loess
; mineralogy
; Pleistocene
; sediment chemistry
; Mississippi River
; North America
; United States
英文摘要: The midcontinent of North America contains some of the thickest and most extensive last-glacial loess deposits in the world, known as Peoria Loess. Peoria Loess of the upper Mississippi River valley region is thought to have had temporally varying glaciogenic sources resulting from inputs of sediment to the Mississippi River from different lobes of the Laurentide Ice Sheet. Here, we explore a new method of determining loess provenance using K/Rb and K/Ba values (in K-feldspars and micas) in loess from a number of different regions in North America. Results indicate that K/Rb and K/Ba values can distinguish loess originating from diverse geologic terrains in North America. Further, different loess bodies that are known to have had the same source sediments (using other criteria) have similar K/Rb and K/Ba values. We also studied three thick loess sections in the upper Mississippi River valley region. At each site, the primary composition of the loess changed over the course of the last glacial period, and K/Rb and K/Ba values parallel changes in carbonate mineral content and clay mineralogy. We thus confirm conclusions of earlier investigators that loess composition changed as a result of the shifting dominance of different lobes of the Laurentide Ice Sheet and the changing course of the Mississippi River. We conclude that K/Rb and K/Ba values are effective, robust, and rapid indicators of loess provenance that can be applied to many regions of the world. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112224
Appears in Collections: 气候减缓与适应
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作者单位: U.S. Geological Survey, MS 980, Box 25046, Federal Center, Denver, CO 80225, United States; Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242, United States
Recommended Citation:
Muhs D.R.,Bettis E.A.,III,et al. Geochemistry and mineralogy of late Quaternary loess in the upper Mississippi River valley, USA: Provenance and correlation with Laurentide Ice Sheet history[J]. Quaternary Science Reviews,2018-01-01,187