Mutti, Maria (2000): Microbial origin of microcrystalline carbonate sediment and cements filling fractures in basalts recovered at Site 1001, Caribbean Sea

Leg/Site/Hole:
ODP 165
ODP 165 1001
Identifier:
2000-062892
georefid

10.2973/odp.proc.sr.165.015.2000
doi

Creator:
Mutti, Maria
University of Southern California, Earth Sciences Department, Los Angeles, CA, United States
author

Identification:
Microbial origin of microcrystalline carbonate sediment and cements filling fractures in basalts recovered at Site 1001, Caribbean Sea
2000
In: Leckie, R. Mark, Sigurdsson, Haraldur, Acton, Gary D., Abrams, Lewis J., Bralower, Timothy J., Carey, Steven N., Chaisson, William P., Cotillon, Pierre, Cunningham, Andrew D., D'Hondt, Steven L., Droxler, Andre W., Galbrun, Bruno, Gonzalez, Juan, Haug, Gerald H., Kameo, Koji, King, John W., Lind, Ida L., Louvel, Veronique, Lyons, Timothy W., Murray, Richard W., Mutti, Maria, Myers, Greg, Pearce, Richard B., Pearson, D. Graham, Peterson, Larry C., Roehl, Ursula, Garman, Phyllis (editor), Proceedings of the Ocean Drilling Program, scientific results, Caribbean Ocean history and the Cretaceous/Tertiary boundary event; covering Leg 165 of the cruises of the drilling vessel JOIDES Resolution, Miami, Florida, to San Juan Puerto Rico, sites 998-1002, 19 December 1995-17 February 1996
Texas A & M University, Ocean Drilling Program, College Station, TX, United States
165
227-232
This paper presents the results of a petrographic and scanning electron microscope study of carbonate sediments and cements found within basalts cored at Ocean Drilling Program Site 1001. The basaltic sequence is pervasively cut by fractures that show vugs filled by carbonate cements. This study focuses on the nature of micritic sediment and cements and documents the occurrence of two types of micrites. The first (m1) has been observed at only one location (interval 165-1001A-54R-5, 13-18 cm). It consists of recrystallized pelagic carbonate, which was infiltered from the seafloor and deposited within the newly formed cavities within the basalt. The second micrite (m2) is more widespread and is present as an asymmetrical, mostly geopetal lining of fractures and cavities. Optical microscopy reveals laminae characterized by undulated upper surfaces that contain micritic lumps forming pseudopeloids. Typically, these structures are considered to result from the dismantling of microbial filamentous mats. The data generated in this study present evidence for a new mechanism for the origin of micrite that is commonly found within basalt sequences. Results from previous studies indicate this cement is formed in situ, but the new data indicate precipitation is controlled by processes related to microbial activity. At this stage of study, additional data are needed to determine whether this precipitation process takes place in marine or marine-modified pore waters.
Coverage:Geographic coordinates:
North:15.4524
West:-74.5436East: -74.5436
South:15.4524

Sedimentary petrology; Atlantic Ocean; basalts; biogenic processes; biomineralization; carbonate rocks; carbonates; Caribbean Sea; cement; genesis; igneous rocks; Leg 165; limestone; micrite; Nicaragua Rise; North Atlantic; Ocean Drilling Program; ODP Site 1001; precipitation; sedimentary rocks; SEM data; volcanic rocks;

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