Cementation in Los Angeles basin: compositional and isotopic constraints
Conference
·
· AAPG Bull.; (United States)
OSTI ID:6916534
Evidence of carbonate and laumontite cementation has been documented in wells from several oil fields within the Los Angeles basin. Petrographic examination reveals that carbonate cementation can be both early and late diagenetic phases. Early calcite commonly replaces the matrix but preserves the detrital grains, whereas later carbonate cement may replace matrix and fill porosity resulting from earlier dissolution. Laumontite cement is commonly observed replacing the matrix and detrital components (primarily plagioclase). Compositional variations (particularly trace elements) occur within carbonate cements and are useful in determining the relative timing of multiple cementation events, whereas the composition of laumontite cement seldom varies from its stoichiometric formula. Oxygen isotope analyses of the cements permit limits to be placed on the temperatures of crystallization, which also places further constraints on the timing of cementation. Strontium isotopes are also being used as a tracer to determine the potential sources of calcium necessary to crystallize both calcite and laumontite. Comparison of strontium isotope ratios (/sup 87/Sr//sup 86/Sr) from calcite and laumontite cements reveal whether the source of calcium is the same for both cements or different. The determination of possible calcium sources together with the timing of cementation enable calculations to be made concerning the timing and amount of mass transfer that has occurred.
- Research Organization:
- Univ. of California, Santa Barbara (USA)
- OSTI ID:
- 6916534
- Report Number(s):
- CONF-8804144-
- Conference Information:
- Journal Name: AAPG Bull.; (United States) Journal Volume: 72:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Laumontization and its relationship to carbonate cementation and dissolution within Santa Fe Springs oil field, Los Angeles basin, California
Fluid flow and mass transfer in central San Joaquin basin, California: strontium isotope study of carbonate cements
Tracking calcium in the San Joaquin basin, California: A strontium isotopic study of carbonate cements at North Coles Levee
Conference
·
Fri May 01 00:00:00 EDT 1987
· AAPG Bull.; (United States)
·
OSTI ID:6443577
Fluid flow and mass transfer in central San Joaquin basin, California: strontium isotope study of carbonate cements
Conference
·
Mon Feb 29 23:00:00 EST 1988
· AAPG Bull.; (United States)
·
OSTI ID:6596748
Tracking calcium in the San Joaquin basin, California: A strontium isotopic study of carbonate cements at North Coles Levee
Journal Article
·
Tue Aug 01 00:00:00 EDT 1989
· Geochimica et Cosmochimica Acta; (USA)
·
OSTI ID:7164445