Hydrothermal fluids and petroleum in surface sediments of Guaymas Basin, Gulf of California; a case study

Author(s): Gieskes, Joris M.; Simoneit, Bernd R. T.; Brown, Thomas; Shaw, Timothy; Wang, Yong-Chen; Magenheim, Andrew
Author Affiliation(s): Primary:
Scripps Institution of Oceanography, Ocean Research Division, San Diego, CA, United States
Other:
Oregon State University, United States
Volume Title: Sea-floor hydrothermal mineralization
Volume Author(s): Barrett, Timothy J., editor; Jambor, John L.
Source: The Canadian Mineralogist, Vol.26(Part 3), p.589-602; Sea-floor hydrothermal mineralization conference, Montreal, QC, Canada, Feb. 5-6, 1987, edited by Timothy J. Barrett and John L. Jambor. Publisher: Mineralogical Association of Canada, Ottawa, ON, Canada. ISSN: 0008-4476 CODEN: CAMIA6
Note: In English with French summary. 32 refs.; illus., incl. 3 plates, 3 tables, sketch map
Summary: Surface sediments and their interstitial waters from hydrothermally active zones of the Guaymas Basin have been analysed for Li, Na, Mg, Al, Si, P, Cl, K, Ca, Mn, Fe, H2S, SO4 and NH4. The organic chemistry of the sediments also has been determined. Analysis of the inorganic constituents of vent fluids collected in 1988 indicate that there has been little change in their chemical composition since 1981. Five short surface (push) cores obtained by ALVIN in areas characterized by upward advecting hydrothermal fluids, both in areas of strong flow as well as of seepage through large bacterial mats of Beggiatoa, were studied. Interstitial-water compositions suggest that mixtures of hydrothermal fluids and sea-water rise to the surface, often carrying a supply of sulphide of shallow origin; this in turn may serve as an energy source for the growth of sulphide- oxidizing bacteria. Studies of the composition of hydrothermally generated petroleum show that it is a condensate (C1-C20 hydrocarbons and polynuclear aromatic hydrocarbons), and much of this material has migrated with the upward-advecting fluids from short depths below the sediment-water interface. The petroleum in the sediments is found mainly in fractures in silica- cemented clasts and is biodegraded. In the vent/mound, the petroleum is an unaltered condensate, indicating active migration that exceeds biodegradation.
Year of Publication: 1988
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; 29 Economic Geology, Energy Sources; Algal mats; Algal structures; Aromatic hydrocarbons; Assemblages; Bacteria; Biogenic structures; Carbon; Case studies; Chemical composition; Chemical ratios; DSDP Site 477; DSDP Site 478; DSDP Site 481; Deep Sea Drilling Project; Diffusivity; East Pacific; Fluid phase; Gas chromatograms; Geochemistry; Guaymas Basin; Gulf of California; Hydrocarbons; Hydrothermal alteration; Hydrothermal vents; IPOD; Leg 64; Marine sediments; Metasomatism; Mineral assemblages; Natural gas; North Pacific; Northeast Pacific; Organic carbon; Organic compounds; Pacific Ocean; Paragenesis; Petroleum; Petroleum exploration; Polycyclic aromatic hydrocarbons; Pore water; Sedimentary structures; Sediments; Sulfides
Coordinates: N270000 N270300 W1112300 W1112600
N270151 N270151 W1112401 W1112401
N270548 N270548 W1113027 W1113027
N271511 N271511 W1103028 W1103028
Record ID: 2007039240
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom