Abstract
The Canada David detachment, a west-dipping low-angle normal fault, juxtaposes Pliocene and Pleistocene(?) sedimentary units over sheared bedrock in the Sierra El Mayor, Baja California. Along the west-central range front, the detachment is overlapped by Quaternary alluvial fans that are, in turn, cut by fault scarps up to 7 m high. Map relationships suggest that scarp-forming faults may sole into the detachment at very shallow depth (<200-300 m). Palinspastic restoration of a topographic profile across 15 north-striking scarps suggests that the ratio of net heave to net throw along scarp-forming faults is ~2, consistent with them soling into a low-angle (~30°) fault. These 15 scarps may have all formed in one earthquake, with rupture propagation from depth to the near-surface aided by clay gouge along the detachment. The detachment is abandoned in the footwall east of the scarps.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 247-250 |
| Number of pages | 4 |
| Journal | Geology |
| Volume | 27 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1999 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Geology
Cite this
Range-front fault scarps of the Sierra El Mayor, Baja California : Formed above an active low-angle normal fault? / Axen, Gary J.; Fletcher, John M.; Cowgill, Eric; Murphy, Michael; Kapp, Paul A; MacMillan, Ian; Ramos-Velázquez, Ernesto; Aranda-Gómez, Jorge.
In: Geology, Vol. 27, No. 3, 03.1999, p. 247-250.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Range-front fault scarps of the Sierra El Mayor, Baja California
T2 - Formed above an active low-angle normal fault?
AU - Axen, Gary J.
AU - Fletcher, John M.
AU - Cowgill, Eric
AU - Murphy, Michael
AU - Kapp, Paul A
AU - MacMillan, Ian
AU - Ramos-Velázquez, Ernesto
AU - Aranda-Gómez, Jorge
PY - 1999/3
Y1 - 1999/3
N2 - The Canada David detachment, a west-dipping low-angle normal fault, juxtaposes Pliocene and Pleistocene(?) sedimentary units over sheared bedrock in the Sierra El Mayor, Baja California. Along the west-central range front, the detachment is overlapped by Quaternary alluvial fans that are, in turn, cut by fault scarps up to 7 m high. Map relationships suggest that scarp-forming faults may sole into the detachment at very shallow depth (<200-300 m). Palinspastic restoration of a topographic profile across 15 north-striking scarps suggests that the ratio of net heave to net throw along scarp-forming faults is ~2, consistent with them soling into a low-angle (~30°) fault. These 15 scarps may have all formed in one earthquake, with rupture propagation from depth to the near-surface aided by clay gouge along the detachment. The detachment is abandoned in the footwall east of the scarps.
AB - The Canada David detachment, a west-dipping low-angle normal fault, juxtaposes Pliocene and Pleistocene(?) sedimentary units over sheared bedrock in the Sierra El Mayor, Baja California. Along the west-central range front, the detachment is overlapped by Quaternary alluvial fans that are, in turn, cut by fault scarps up to 7 m high. Map relationships suggest that scarp-forming faults may sole into the detachment at very shallow depth (<200-300 m). Palinspastic restoration of a topographic profile across 15 north-striking scarps suggests that the ratio of net heave to net throw along scarp-forming faults is ~2, consistent with them soling into a low-angle (~30°) fault. These 15 scarps may have all formed in one earthquake, with rupture propagation from depth to the near-surface aided by clay gouge along the detachment. The detachment is abandoned in the footwall east of the scarps.
UR - http://www.scopus.com/inward/record.url?scp=84879886819&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84879886819&partnerID=8YFLogxK
U2 - 10.1130/0091-7613(1999)027<0247:RFFSOT>2.3.CO;2
DO - 10.1130/0091-7613(1999)027<0247:RFFSOT>2.3.CO;2
M3 - Article
AN - SCOPUS:84879886819
VL - 27
SP - 247
EP - 250
JO - Geology
JF - Geology
SN - 0091-7613
IS - 3
ER -