Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada, and Inyo County, California
5
Citation
20
Reference
10
Related Paper
Citation Trend
Abstract:
Ground water moving through permeable Paleozoic carbonate rocks represents the most likely pathway for migration of radioactive contaminants from nuclear weapons testing at the Nevada Test Site, Nye County, Nevada. The strontium isotopic composition (87Sr/86Sr) of ground water offers a useful means of testing hydrochemical models of regional flow involving advection and reaction. However, reaction models require knowledge of 87Sr/86Sr data for carbonate rock in the Nevada Test Site vicinity, which is scarce. To fill this data gap, samples of core or cuttings were selected from 22 boreholes at depth intervals from which water samples had been obtained previously around the Nevada Test Site at Yucca Flat, Frenchman Flat, Rainier Mesa, and Mercury Valley. Dilute acid leachates of these samples were analyzed for a suite of major- and trace-element concentrations (MgO, CaO, SiO2, Al2O3, MnO, Rb, Sr, Th, and U) as well as for 87Sr/86Sr. Also presented are unpublished analyses of 114 Paleozoic carbonate samples from outcrops, road cuts, or underground sites in the Funeral Mountains, Bare Mountain, Striped Hills, Specter Range, Spring Mountains, and ranges east of the Nevada Test Site measured in the early 1990's. These data originally were collected to evaluate the potential for economic mineral deposition at the potential high-level radioactive waste repository site at Yucca Mountain and adjacent areas (Peterman and others, 1994). Samples were analyzed for a suite of trace elements (Rb, Sr, Zr, Ba, La, and Ce) in bulk-rock powders, and 87Sr/86Sr in partial digestions of carbonate rock using dilute acid or total digestions of silicate-rich rocks. Pre-Tertiary core samples from two boreholes in the central or western part of the Nevada Test Site also were analyzed. Data are presented in tables and summarized in graphs; however, no attempt is made to interpret results with respect to ground-water flow paths in this report. Present-day 87Sr/86Sr values are compared to values for Paleozoic seawater present at the time of deposition. Many of the samples have 87Sr/86Sr compositions that remain relatively unmodified from expected seawater values. However, rocks underlying the northern Nevada Test Site as well as rocks exposed at Bare Mountain commonly have elevated 87Sr/86Sr values derived from post-depositional addition of radiogenic Sr most likely from fluids circulating through rubidium-rich Paleozoic strata or Precambrian basement rocks.Keywords:
Outcrop
Lithology
Cite
Outcrop
Cite
Citations (0)
PreviousNext No AccessSEG Technical Program Expanded Abstracts 2005Combining seismic stratigraphy, multi attribute analysis and rock physical modeling to identify carbonate facies and karst along an upper palaeozoic carbonate platform, Barents SeaAuthors: Arnout ColpaertJürgen MienertJack DvorkinLeif Bjørnar HenriksenArnout ColpaertSearch for more papers by this author, Jürgen MienertSearch for more papers by this author, Jack DvorkinSearch for more papers by this author, and Leif Bjørnar HenriksenSearch for more papers by this authorhttps://doi.org/10.1190/1.2144427 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract Lithofacies prediction from combined inverted seismic interpretation and physical rock properties analysis in wells is important for prediction of play models in the Upper Palaeozoic carbonates from the Barents Sea.Permalink: https://doi.org/10.1190/1.2144427FiguresReferencesRelatedDetails SEG Technical Program Expanded Abstracts 2005ISSN (print):1052-3812 ISSN (online):1949-4645Copyright: 2005 Pages: 2668 publication data© 2005 Copyright © 2005 Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished: 07 Dec 2005 CITATION INFORMATION Arnout Colpaert, Jürgen Mienert, Jack Dvorkin, and Leif Bjørnar Henriksen, (2005), "Combining seismic stratigraphy, multi attribute analysis and rock physical modeling to identify carbonate facies and karst along an upper palaeozoic carbonate platform, Barents Sea," SEG Technical Program Expanded Abstracts : 724-726. https://doi.org/10.1190/1.2144427 Plain-Language Summary PDF DownloadLoading ...
Carbonate platform
Cite
Citations (0)
Abstract This paper presents detailed mineralogical analyses of the non-carbonate material obtained from four cored boreholes in the Chalk of Berkshire and Oxfordshire, England. Consideration is given to the relationship between the non-carbonate material and the interstitial water chemistry. Sample preparation was by means of acid digestion followed by vacuum sedimentation. Analyses were carried out using X-ray diffraction techniques. Results are presented in a semi-quantitative form based upon integrated peak intensities and are compared to those of previous studies on the Chalk of southern England. It is concluded that the zones of occurrence of the major clay minerals as demonstrated in this study are in general agreement with those established by other authors. The non-carbonate content of the Chalk increases from the concealed beds at the Fair Cross site towards the outcrop Chalk of Lambourn and Harwell. The variation in mineralogy and purity is ascribed to changing conditions of deposition and to diagenesis related to groundwater circulation.
Outcrop
Carbonate minerals
Sedimentation
Cite
Citations (23)
内蒙古林西县双井地区出露一套含暗色包体的花岗质岩体，位于双井片岩和房框子单元花岗质片麻岩接触带，该岩体对厘定古亚洲洋演化阶段、西伯利亚板块和阿穆尔板块最终碰撞缝合时限具有重要意义。本文对该岩体进行了详细的岩相学、岩石地球化学以及锆石U-Pb年代学研究，讨论了该岩体成因、岩浆源区以及研究区造山带地壳演化等问题。岩体中暗色包体和周边花岗岩大部分锆石记录了~285Ma和~270Ma两期年龄，少量锆石记录了~320Ma的较老年龄，表明该区域在晚石炭世就存在岩浆活动，并在~285Ma、~270Ma更为显著，且岩浆活动具有幕式发生的特点，通过锆石的Ti温度计算得岩浆形成温度为~670℃。暗色包体相较周边花岗岩部分更富Al2O3（>13.96%）、CaO（>1.61%）、Na2O（>4.61%）以及Fe2O3（>3.67%）、MgO（>0.62%）、TiO2（>0.28%）、P2O5（>0.08%）等，但贫K2O（< 2.10%），但二者发育有一致的变形现象，具有相同的侵位时代（误差范围内一致）、相似的微量元素配分模式、相近的Sr-Nd-Hf同位素组成，指示二者可能为同源岩浆不同演化阶段的产物。此外，暗色包体样品中，Zr/Hf比值介于31.74~37.08之间（接近原始地幔的Zr/Hf比值36.25），黑云母有壳源和壳幔混合源两种成因类型，ISr值介于0.7039~0.7055之间，εNd（t）值介于-7.30~-5.87之间，锆石的εHf（t）介于-3.58~6.72之间等地球化学特征，均指示暗色包体的母岩浆在形成过程中有幔源物质的加入，以上特征显示岩体为壳幔混合源岩浆经历不同演化阶段后的产物。岩体中锆石Eu/Eu*与地壳厚度的拟合结果显示研究区在ca. 290~270Ma地壳经历了一次显著的减薄过程（ca. 50~35km），为区域存在地幔物质上涌提供了动力学证据。结合前人资料，本次研究的含暗色包体的花岗质岩体属于大石寨期，其母岩浆的形成、侵位时代，以及壳幔混合源等地球化学特征精细地约束了该区大石寨期岩浆活动的发育时间及过程，为研究西拉木伦缝合带晚古生代构造演化提供了新证据，同时也清晰地指示出古亚洲洋在晚古生代末期并不处于大洋俯冲阶段，而是造山后的伸展裂解阶段。
Cite
Citations (4)
From a review of recent Russian geologic literature, outlines (1) a graphic method for determining the general lithologic character of carbonate rocks on the basis of the content of CO 2 and insoluble residues, and (2) a classification of the different types of chemically precipitated calcium carbonate.
Lithology
Cite
Citations (1)
Research Article| April 01, 1962 Paleozoic Sequences and Thrust Slices of the Seetoya Mountains, Independence Range, Elko County, Nevada J. WILLIAM KERR J. WILLIAM KERR Geological Survey of Canada, Ottawa, Ont Search for other works by this author on: GSW Google Scholar Author and Article Information J. WILLIAM KERR Geological Survey of Canada, Ottawa, Ont Publisher: Geological Society of America Received: 26 Apr 1960 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1962, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1962) 73 (4): 439–460. https://doi.org/10.1130/0016-7606(1962)73[439:PSATSO]2.0.CO;2 Article history Received: 26 Apr 1960 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation J. WILLIAM KERR; Paleozoic Sequences and Thrust Slices of the Seetoya Mountains, Independence Range, Elko County, Nevada. GSA Bulletin 1962;; 73 (4): 439–460. doi: https://doi.org/10.1130/0016-7606(1962)73[439:PSATSO]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Three stratigraphic sequences of lower Paleozoic rocks in the Seetoya Mountains east of Tuscarora, Nevada, are of partly equivalent age. The highest sequence is Lower Silurian and younger, composed of bedded cherts, quartzite, volcanic rocks, and graptolitic shales, deposited in a western eugeosynclinal belt, and thrust southward or southeastward for some scores of miles. Each of two lower sequences includes the same five Ordovician and Silurian formations which differ markedly in thickness and slightly in lithology. They are predominantly carbonate rocks with some quartz sandstones, deposited in an eastern miogeosynclinal belt. The upper of these latter sequences has been thrust about 6 miles southward or southeastward.The eastern sequences were folded, faulted, and eroded, probably in pre-Carboniferous or Permian time. Siltstones, laid unconformably on the southern of the two eastern sequences, may have been derived from rising lands in the eugeosynclinal belt. Thrusting of uncertain age carried a thick plate of allochthonous rock of the western belt southerly or southeasterly. Presence of younger rocks beneath the thrust in the south suggests that there was a regional southward slope at this time. A second thrust, which developed within the eastern belt, carried parautochthonous rocks and may be a subsidiary thrust initiated by movement of the overriding rocks of the western belt. This thrust shows a close similarity to the peel thrusts of the Western Alps. Block faulting during Tertiary is largely responsible for the present-day north-south trend of the range. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Geological survey
Icon
Cite
Citations (9)