| Description |
1 online resource (iii, 15 pages) : illustrations, map. |
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text txt rdacontent |
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computer c rdamedia |
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online resource cr rdacarrier |
| Series |
Evolution of sedimentary basins/onshore oil and gas investigations--Santa Maria Province ; ch. C |
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U.S. Geological Survey bulletin ; 1995-C |
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Evolution of sedimentary basins/onshore oil and gas investigations--Santa Maria Province ; ch. C.
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U.S. Geological Survey bulletin ; 1995-C.
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| Bibliography |
Includes bibliographical references (pages 13-15). |
| Summary |
Phosphatic concretions occur within diatomite in the upper part of the Miocene Monterey Formation near Lompoc, Calif. Absence of disruption of fine laminar bedding in the associated sediment by the concretions shows that they formed after complete compaction of the enclosing sediment.The concretions exhibit a strongly concentric color, chemical, and mineralogic zonation. Many of them are composed of a nucleus in which vivianite is the dominant mineral. Amorphous ferric phosphate, mitridatite, and francolite are the dominant phosphatic phases in successive layers toward the surface of the concretions. Cd and As contents increase tenfold from the nucleus outward, reaching a maximum of 2,000 ppm, whereas Ni content, with a maximum of 720 ppm, and Co content show the opposite trend. This mineralogy and elemental composition favor accretion under conditions of continuously increasing Eh and pH, during uplift into the fresh-ground-water zone of the terrestrial environment. Shale-normalized rare-earth-element patterns, however, suggest a marine source for the elements biogenic debris consisting of opal-A, organic matter, and carbonates of the enclosing sediment. |
| Note |
Description based on print version record. |
| Access |
Use copy Restrictions unspecified star MiAaHDL |
| Reproduction |
Electronic reproduction. [S.l.] : HathiTrust Digital Library, 2011. MiAaHDL |
| System Details |
Master and use copy. Digital master created according to Benchmark for Faithful Digital Reproductions of Monographs and Serials, Version 1. Digital Library Federation, December 2002. http://purl.oclc.org/DLF/benchrepro0212 MiAaHDL |
| Processing Action |
digitized 2011 HathiTrust Digital Library committed to preserve pda MiAaHDL |
| Subject |
Phosphate minerals -- California -- Santa Maria Basin.
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Geology, Stratigraphic -- Miocene.
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Geology -- California -- Santa Maria Basin.
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Monterey Formation (Calif.)
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Geology. (OCoLC)fst00940627
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Geology, Stratigraphic. (OCoLC)fst00940727
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Miocene Geologic Epoch. (OCoLC)fst01353827
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Phosphate minerals. (OCoLC)fst01061340
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California -- Monterey Formation.
(OCoLC)fst01249216
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California -- Santa Maria Basin.
(OCoLC)fst01257500
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| Chronological Term |
From 10 to 25 million years ago
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| Genre/Form |
Electronic government information.
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Electronic books.
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| Added Author |
Isaacs, Caroline M., author.
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Medrano, M. D., author.
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Geological Survey (U.S.), issuing body.
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| Other Form: |
Print version: Piper, David Z. Cooccurrence of Fe-, Fe-Ca-, and Ca-phosphate minerals in concretions within the Monterey Formation (DLC) 92028029 (OCoLC)26309279 |
| Gpo Item No. |
0620 (online) |
| Sudoc No. |
I 19.3:1995-C |
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