The Serra Fault is positioned approximately 1.5–3 kilometers (0.93–1.86 mi) northeast of the San Andreas Fault; moreover the Serra Fault extends for more than 20 km (12 mi) from the town of Hillsborough to a point near Daly City.
According to Kennedy: "Three angular unconformities within the Merced and overlying Colma Formations have formed on the steeply dipping fold forelimb".[1] Mid to later Holocenefluvial channel deposits inset into the Merced Formation along the forelimb of the fold seem to be deformed, illustrating that the folding is active.
The Serra Fault is a low angle imbricate fault that has thrust older Franciscan Assemblage rocks and soils of the Merced Formation over the younger Colma Formation. The Serra Fault was originally zoned as potentially active by the State of California [2] under the mandated special studies for surface fault rupture. 1980s studies concluded that evidence for active Holocene age faulting (displacement within past 11,000 years) along the Serra Fault is lacking.[3] The Serra Fault is, therefore, not zoned for Special Studies by the State of California and is classified as Quaternary in age: that is, fault displacement within the past two million years.
Regional geology
Age constraints for coastal exposures of the Pleistocene Colma and uppermost Merced Formations have prior to 2005 been primarily correlative, generating uncertainty about the depositional history of these units as well as the timing of fault activity responsible for lifting them to elevations up to seventy meters along the northwestern coast of the San Francisco Peninsula. Yi notes that: "Recent studies have suggested that Merced and Colma deposits, as well as younger Holocene inset channel deposits, show fault-propagation fold growth and tilting" related to activity on the Serra Fault itself.[4]
Kennedy, Drew G., LATE PLEISTOCENE TO HOLOCENE FOLD GROWTH ABOVE THE SERRA FAULT, NORTHERN SAN FRANCISCO PENINSULA, CALIFORNIA, Sanders & Associates Geostructural Engineering, Geological Society of America (2005)
California Division of Mines and Geology, Special Studies Zone:Serra Fault, (1974) Sacramento, California
Earth Metrics, (1989) Marc. Papineau, Ballard. George, Jill Buxton et al., Environmental Impact Report for the Metro Center, Colma, California, Rpt Number 10062, city of Colma Planning Department and published by the California State Clearinghouse, December, 1989
Chimi Yi, Karen Grove, John Caskey, Drew Kennedy, and Glenn Berger, Depositional and Deformational History of the Colma and Uppermost Merced Formations, Southwest San Francisco, (2005), Geological Society of America
External links
Richard Cardwell, Merced Formation Field Trip
January 06, 2023
serra, fault, northernmost, fault, zone, northwest, striking, range, front, thrust, faults, adjacent, northeast, francisco, peninsula, segment, andreas, fault, eastern, mateo, county, california, positioned, approximately, kilometers, northeast, andreas, fault. The Serra Fault is the northernmost fault in a zone of northwest striking range front thrust faults adjacent to and northeast of the San Francisco Peninsula segment of the San Andreas Fault in eastern San Mateo County California 1 The Serra Fault is positioned approximately 1 5 3 kilometers 0 93 1 86 mi northeast of the San Andreas Fault moreover the Serra Fault extends for more than 20 km 12 mi from the town of Hillsborough to a point near Daly City Contents 1 Serra geology 2 Regional geology 3 See also 4 Reference notes 5 External linksSerra geology EditAccording to Kennedy Three angular unconformities within the Merced and overlying Colma Formations have formed on the steeply dipping fold forelimb 1 Mid to later Holocene fluvial channel deposits inset into the Merced Formation along the forelimb of the fold seem to be deformed illustrating that the folding is active The Serra Fault is a low angle imbricate fault that has thrust older Franciscan Assemblage rocks and soils of the Merced Formation over the younger Colma Formation The Serra Fault was originally zoned as potentially active by the State of California 2 under the mandated special studies for surface fault rupture 1980s studies concluded that evidence for active Holocene age faulting displacement within past 11 000 years along the Serra Fault is lacking 3 The Serra Fault is therefore not zoned for Special Studies by the State of California and is classified as Quaternary in age that is fault displacement within the past two million years Regional geology EditAge constraints for coastal exposures of the Pleistocene Colma and uppermost Merced Formations have prior to 2005 been primarily correlative generating uncertainty about the depositional history of these units as well as the timing of fault activity responsible for lifting them to elevations up to seventy meters along the northwestern coast of the San Francisco Peninsula Yi notes that Recent studies have suggested that Merced and Colma deposits as well as younger Holocene inset channel deposits show fault propagation fold growth and tilting related to activity on the Serra Fault itself 4 See also EditCrystal Springs ReservoirReference notes Edit a b Kennedy 2005 California 1974 Earth Metrics 1989 Yi 2005 Kennedy Drew G LATE PLEISTOCENE TO HOLOCENE FOLD GROWTH ABOVE THE SERRA FAULT NORTHERN SAN FRANCISCO PENINSULA CALIFORNIA Sanders amp Associates Geostructural Engineering Geological Society of America 2005 California Division of Mines and Geology Special Studies Zone Serra Fault 1974 Sacramento California Earth Metrics 1989 Marc Papineau Ballard George Jill Buxton et al Environmental Impact Report for the Metro Center Colma California Rpt Number 10062 city of Colma Planning Department and published by the California State Clearinghouse December 1989 Chimi Yi Karen Grove John Caskey Drew Kennedy and Glenn Berger Depositional and Deformational History of the Colma and Uppermost Merced Formations Southwest San Francisco 2005 Geological Society of AmericaExternal links EditRichard Cardwell Merced Formation Field Trip Retrieved from https en wikipedia org w index php title Serra Fault amp oldid 1117253895, wikipedia, wiki, book, books, library,
