Rare earth, major, and trace elements in chert from the Franciscan complex and Monterey group, California: Assessing REE sources to fine-grained marine sediments

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(91)90030-9· OSTI ID:5862620

Murray, R W; Jones, D L ^[1]; Buchholtz Ten Brink, M R; Gerlach, D C; Russ, III, G P ^[2]

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1. Univ. of California, Berkeley (United States)
2. Lawrence Livermore National Lab., CA (United States)

Rare earth element (REE), major, and trace element analyses of 77 samples from the Mesozoic Franciscan Complex and Miocene Monterey Group of California (USA) indicate that magnitudes of the Ce anomaly (Ce/Ce{asterisk}) and total REE abundances ({Sigma}REE) in these rocks are controlled dominantly by (a) amount of included metalliferous material, (b) the amount of direct terrigenous input, and (c) the overall burial rate. The relative importance of these individual processes varies across an ocean basin in such a way that REE relative fractionations and {Sigma}REE correspond with its depositional environment. The authors conclusions are supported by an extensive review of published REE data from various river, coastal, open-ocean, and ridge-influenced waters, as well as terrigenous, pelagic, and metalliferous sediment. The chert sequences record deposition in spreading ridge, open-ocean basin, and continental margin environments. The relative importance of metalliferous and terrigenous influences and the role of scavenging from seawater may be estimated from a sample's inferred depositional distance (km) from the spreading ridge, the major element chemistry, and the stratigraphic context. REEs in chert appear less affected by post-depositional processes than either major or trace elements, indicating that REEs are better tools for paleoceanographic or tectonic reconstructions that are based on chert chemistry. This work complements recent efforts to elucidate the factors determining large-scale REE distributions in marine sediments and has direct bearing on previous attempts to use the Ce anomaly in older rocks and sediments as a recorder of secular variations and anoxic events in the overlying water column.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5862620
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Journal Name: Geochimica et Cosmochimica Acta; (United States) Vol. 55:7; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CALIFORNIA
CENOZOIC ERA
CHEMICAL COMPOSITION
CHEMISTRY
CHERT
DEPOSITION
DEVELOPED COUNTRIES
ELEMENTS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
MESOZOIC ERA
METALS
MIOCENE EPOCH
NORTH AMERICA
RARE EARTHS
ROCKS
SEDIMENTARY ROCKS
SEDIMENTS
TERTIARY PERIOD
USA