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Earthquake clustering inferred from Pliocene Gilbert-type fan deltas in the Loreto basin, Baja California Sur, Mexico

1997; Geological Society of America; Volume: 25; Issue: 8 Linguagem: Inglês

10.1130/0091-7613(1997)025 2.3.co;2

1943-2682

Rebecca J. Dorsey, Paul J. Umhoefer, Peter D. Falk,

Geology and Paleoclimatology Research

Research Article| August 01, 1997 Earthquake clustering inferred from Pliocene Gilbert-type fan deltas in the Loreto basin, Baja California Sur, Mexico Rebecca J. Dorsey; Rebecca J. Dorsey 1Department of Geology, Box 4099, Northern Arizona University, Flagstaff, Arizona 86011 Search for other works by this author on: GSW Google Scholar Paul J. Umhoefer; Paul J. Umhoefer 1Department of Geology, Box 4099, Northern Arizona University, Flagstaff, Arizona 86011 Search for other works by this author on: GSW Google Scholar Peter D. Falk Peter D. Falk 1Department of Geology, Box 4099, Northern Arizona University, Flagstaff, Arizona 86011 Search for other works by this author on: GSW Google Scholar Author and Article Information Rebecca J. Dorsey 1Department of Geology, Box 4099, Northern Arizona University, Flagstaff, Arizona 86011 Paul J. Umhoefer 1Department of Geology, Box 4099, Northern Arizona University, Flagstaff, Arizona 86011 Peter D. Falk 1Department of Geology, Box 4099, Northern Arizona University, Flagstaff, Arizona 86011 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1997) 25 (8): 679–682. https://doi.org/10.1130/0091-7613(1997)025 2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Rebecca J. Dorsey, Paul J. Umhoefer, Peter D. Falk; Earthquake clustering inferred from Pliocene Gilbert-type fan deltas in the Loreto basin, Baja California Sur, Mexico. Geology 1997;; 25 (8): 679–682. doi: https://doi.org/10.1130/0091-7613(1997)025 2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract A stacked sequence of Pliocene Gilbert-type fan deltas in the Loreto basin was shed from the footwall of the dextral-normal Loreto fault and deposited at the margin of a marine basin during rapid fault-controlled subsidence. Fan-delta parasequences coarsen upward from marine siltstone and sandstone at the base, through sandy bottomsets and gravelly foresets, to gravelly nonmarine topsets. Each topset unit is capped by a thin shell bed that records marine flooding of the delta plain. Several mechanisms may have produced repetitive vertical stacking of Gilbert deltas: (1) autocyclic delta-lobe switching; (2) eustatic sea-level fluctuations; (3) climatically controlled fluctuations in sediment input; and (4) episodic subsidence produced by temporal clustering of earthquakes. We favor hypothesis 4 for several reasons, but hypotheses 2 and 3 cannot be rejected at this time. Earthquake clustering can readily produce episodic subsidence at spatial and temporal scales consistent with stratigraphic trends observed in the Loreto basin. This model is supported by comparison with paleoseismological studies that document clustering on active faults over a wide range of time scales. Earthquake clustering is a new concept in basin analysis that may be helpful for understanding repetitive stratigraphy in tectonically active basins. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.