About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
Pacific Section of AAPG
Abstract
Prehistoric Large Earthquakes Produced by Slip on the San Andreas Fault at Pallett Creek, California
Abstract
Late Holocene marsh deposits composing a terrace about 55 km northeast of Los Angeles, California, contain geologic evidence of many large seismic events produced by slip on the San Andreas fault since the sixth century A.D. I excavated several trenches into the deposits in order to study this evidence. The principal indicators of past events are (1) sandblows and other effects of liquefaction, (2) the termination of secondary faults at distinct levels within the stratigraphic section, and (3) sedimentary deposits and relationships along the main fault. The effects upon the marsh deposits of the eight prehistoric events are comparable to those of the great (MS=8.25+) 1857 event, which is the youngest of the nine events that disturbed the strata and is associated with about 4.5 m of right-lateral slip nearby. Radiocarbon dates indicate that the events occurred in the nineteenth, eighteenth, fifteenth, thirteenth, late twelfth, tenth, ninth, seventh, and sixth centuries A.D. Recurrence intervals average 160 years but vary from century to about 3 centuries. The dates may indicate a fairly systematic pattern of occurrence of large earthquakes.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |