Late Quaternary slip rates for the southern Elsinore fault in the Coyote Mountains, southern California from analysis of alluvial fan landforms and clast provenance, soils, and U-series ages of pedogenic carbonate

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985891%3A_____%2F19%3A00517425" target="_blank" >RIV/67985891:_____/19:00517425 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/abs/pii/S0169555X18300813?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/abs/pii/S0169555X18300813?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geomorph.2018.02.024" target="_blank" >10.1016/j.geomorph.2018.02.024</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Late Quaternary slip rates for the southern Elsinore fault in the Coyote Mountains, southern California from analysis of alluvial fan landforms and clast provenance, soils, and U-series ages of pedogenic carbonate

Popis výsledku v původním jazyce

Offset alluvial fans along the Elsinore fault in the south-central Coyote Mountains were studied to resolve an average late Quaternary slip rate for this major western strand of the San Andreas fault system in southern California. Alluvial fans and their offsets were mapped using high-resolution DEMs combined with field observations of fan-surface morphology and the character of the soils developed in each fan remnant. Clast assemblage data was used to determine the source of each alluvial fan upstream of the fault, and U-series dating of pedogenic carbonate was used to estimate minimum ages of the alluvial fan surfaces. Forty U-Th dates on pedogenic carbonate confirm the utility of the technique for dating late Pleistocene alluvium in arid regions and suggest that age variation among late Pleistocene fans grouped on the basis of soils and geomorphic criteria may be significant. Based on these data, the southernmost segment of the Elsinore fault has sustained a slip rate of 2.4 +/- 0.4 mm/y for the past 60-70 ka and probably for the past 150 ka. Because displacement in the most recent surface rupture increases northwest of our slip rate sites, this rate is likely a minimum for the southern Elsinore fault, with the actual rate more likely close to 3 mm/y in the central part of the range. These new data confirm that slip gradients along individual fault segments must be considered when estimating pre-Holocene slip rates for seismic hazard estimates. These new results show that the southern Elsinore fault accounts for about 6% of the total relative motion between North America and the Pacific lithospheric plates in southernmost California. Assessment of previous estimates of slip in the most recent event suggests earthquakes of about Mw 6.8 and, when combined with the slip rate data, a recurrence of such events about every thousand years.

Název v anglickém jazyce

Late Quaternary slip rates for the southern Elsinore fault in the Coyote Mountains, southern California from analysis of alluvial fan landforms and clast provenance, soils, and U-series ages of pedogenic carbonate

Popis výsledku anglicky

Offset alluvial fans along the Elsinore fault in the south-central Coyote Mountains were studied to resolve an average late Quaternary slip rate for this major western strand of the San Andreas fault system in southern California. Alluvial fans and their offsets were mapped using high-resolution DEMs combined with field observations of fan-surface morphology and the character of the soils developed in each fan remnant. Clast assemblage data was used to determine the source of each alluvial fan upstream of the fault, and U-series dating of pedogenic carbonate was used to estimate minimum ages of the alluvial fan surfaces. Forty U-Th dates on pedogenic carbonate confirm the utility of the technique for dating late Pleistocene alluvium in arid regions and suggest that age variation among late Pleistocene fans grouped on the basis of soils and geomorphic criteria may be significant. Based on these data, the southernmost segment of the Elsinore fault has sustained a slip rate of 2.4 +/- 0.4 mm/y for the past 60-70 ka and probably for the past 150 ka. Because displacement in the most recent surface rupture increases northwest of our slip rate sites, this rate is likely a minimum for the southern Elsinore fault, with the actual rate more likely close to 3 mm/y in the central part of the range. These new data confirm that slip gradients along individual fault segments must be considered when estimating pre-Holocene slip rates for seismic hazard estimates. These new results show that the southern Elsinore fault accounts for about 6% of the total relative motion between North America and the Pacific lithospheric plates in southernmost California. Assessment of previous estimates of slip in the most recent event suggests earthquakes of about Mw 6.8 and, when combined with the slip rate data, a recurrence of such events about every thousand years.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/LH12078" target="_blank" >LH12078: Hodnocení tektonických pohybů na aktivních zlomech</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geomorphology

ISSN

0169-555X

e-ISSN

—

Svazek periodika

326

Číslo periodika v rámci svazku

SI

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

22

Strana od-do

68-89

Kód UT WoS článku

000457811100006

EID výsledku v databázi Scopus

2-s2.0-85043457341