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Research in Time and Space

Research in Time and Space
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Actively Funded Research
$1,744,231.00
(sorted by start date)

  • Collaborative Research: Hawaiian Plume Heterogeneity Revealed by Kilauea's Ongoing Eruption, Prehistoric Lavas and Olivine-Hosted Melt Inclusions - Aaron Pietruszka
  • Using 226Ra-230Th-238U Disequilibria to Test the Hypothesis of Peridotite-Pyroxenite Melt Mixing at Hawaiian Shield Volcanoes - Aaron Pietruszka
  • A Petascale Cyberfacility for Physics-based Seismic Hazard Analysis - Luis Dalguer-Gudiel
  • Enabling Earthquake System Science Through Petascale Calculations (PetaShake) - Kim Bak Olsen and Steven Day
  • A Petascale Cyberfacility for Physics-based Seismic Hazard Analysis - Steven Day and Kim Bak Olsen
  • Research Experiences for Undergraduates - George Jiracek
  • 3-D and 2-D Modeling of Strong Ground Motion from an M 7.0 Earthquake on the Salt Lake City Segment of the Wasatch Fault, Utah: Collaborative Research with San Diego State University and the University of Utah - Kim Bak Olsen
  • Conditions of Occurrence of the Tien-Shan Earthquakes According to the Data of Earthquake Mechanisms - Rob Mellors
  • Education and Outreach Web Site Development for the CSSC - Rob Mellors and Eric Frost
  • Collaborative Research: Chemical, Isotopic and Volatile Constraints on the Evolution of the Lau Basin - Barry Hanan
  • SAGE (Summer of Applied Geophysical Experience) Supplement - George Jiracek
  • Elastoplastic Dynamics of Non-planar Faults - Steven Day
  • High-resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region - Rob Mellors
  • ITR/IM/AP: Websim 3 D- A Web-based System for Generation, Storage and Dissemination - Kim Bak Olsen
  • RUI Collaborative Research: Integrated Isotopic Provenance Analysis: Constraining the Dynamic Linkage between Orogenic Exhumation and Basin Evolution - Dave Kimbrough
  • Collaborative Research: Investigation of Holocene Seasonality and Inter-annual Variability Along the California Current System - Stephen Schellenberg
  • Production of High-purity 229th for Analyses of U - and Th-series Isotopes in Geological Materials - Aaron Pietruszka
  • Forward and Inverse Modeling of Rupture Dynamics in Three Dimensions - Kim Bak Olsen
  • Acquisition of a Multi-collector Inductively Coupled Plasma Mass Spectrometer - Barry Hanan, William Tong (Dept. of Chemistry)
     
Student Research
  • Hydrological investigations of the Santo Domingo Basin, New Mexico using electromagnetic soundings - Joshua Woodworth
  • Testing the application and precision of optically stimulated luminescence on dating lacustrine shorelines in the Imperial Valley, southern California - Caitlin Lippincott
  • Geochemistry and U/Pb geochronology of the eastern-most Peninsular Ranges batholith of southern California and northern Baja California; implications for magmatism and tectonics at the onset of the Laramide orogeny - Robert Moniz
  • Correlation of static and peak dynamic coulomb failure stress with mainshocks, aftershocks, seismicity rate change, and triggered slip in the salton trough - Jeff Eddo
  • A Geomagnetic Survey in Santee, California - Henry Schaeffer
  • Biotic response of deep-ocean ostracodes across the Paleocene-Eocene boundar - Elizabeth Landau
  • A Morphometric Approach to Competition in Ordovician Brachiopods - Carrie Tyler
  • Geochemical, petrological, and grain size analysis of the Santa Margarita River sand bar deposits - Brandon Koons
  • Hydrogeology of Lee Valley, Jamul, CA - Jeremy Jensen
  • Cenozoic changes in the South Atlantic Carbonate Compensation Depth: Constraints from Ocean Drilling Site 1262 (Walvis Ridge) - Diego Almanza and Tina Baynes
  • Provenance of quartzite clasts from the Upper Cretaceous Cabrillo Formation, San Diego County, California - John Abeid
  • Geochemistry and Petrogenesis of the Jacumba Volcanics, California - Maureen Moses
  • Utilizing Remote Sensing to Estimate Seismic Hazards within the Panama Region - Andy Arifandy
  • Mineralogical and textural changes accommodating the production of saprolite from a dioritic corestone in a Mediterranean climate, Peninsular Ranges, southern California - Chris Martinez
  • The Death and Rebirth of Kilauea’s Magma Chamber 2.8 - 1.1 kyr Before Present Inferred from the Major- and Trace-Element Chemistry of the Uwekahuna Ash - Kyle Welchans
  • Testing the use of GPR to detect clandestine graves in a San Diego soil - Luke Zimmerman
  • Evaluating the robustness of Mytilus californianus skeletal chemistry as an paleoenvironmental archive: Effects of microenvironment and ontogeny - Heather Ford
 
Collaborative Projects
  • Universitas Gadja Mada, Indonesia - Tectonostratigraphic information from real-time field mapping.
  • University of California San Diego - Multi-method Paleoseismology: Characterizing the Activity of the West Tahoe Fault On and Offshore.
  • University of Utah - Construction and Verification of a Wasatch Front Community Velocity Model and 3-D and 2-D Modeling of Strong Ground Motion from an M 7.0 Earthquake on the Salt Lake City Segment of the Wasatch Fault, Utah.
  • William Associates - Multi-method Paleoseismology: Characterizing the Activity of the West Tahoe Fault On and Offshore.
Research Highlight (December)
Subduction Erosion Model
Evidence for rapid recycling of subduction erosion forearc material into Cordilleran TTG batholiths:
Insight from the Peninsular Ranges of southern and Baja California
 

The La Posta TTG Flareup
The defining characteristic of the Peninsular Ranges of southern and Baja California is a petrologically distinctive, high Sr/Y plutonic suite of 95 & 3 Ma tonalite, trondhjemite, and granodiorite that is referred to as the La Posta TTG suite. These rocks are chemically similar to high-Al tonalite-trondhjemite-granodiorite gneiss terrains of Archean crust produced by high pressure melting of mafic source regions. La Posta belt magmatism records an eastward relocation of the Cretaceous arc accompanied by abrupt chemical change to TTG compositions. This shift was preceded by tectonic shortening and thickening of the crust along the locus of pluton emplacement. Intrusions occur as a series of large internallyzoned intrusive centers with outcrop areas that range up to at least 1400 km2. Field and thermobarometric data indicate emplacement at -3-6 kbar depths followed by rapid uplift and denudation at rates of -1-2 mmlyr. Zircon U-Pb ages (n=43) from throughout the -1300 km length of the batholith indicates the bulk of the La Posta rocks were emplaced in a narrow time frame from -98-92 Ma. Mainphase biotite k hornblende tonalite from individual zoned intrusive centers were emplaced over -3-4 m.y. time intervals followed by small volume peraluminous core zone intrusions. A series of distinctly earlier (c. 105-11 0 Ma) and smaller "precursor" intrusions parallel the western edge of the main locus of intrusion. The La Posta TTG belt is more deeply exhumed in the north (up to 25 km) relatively to south (-10 km) providing an oblique cross-section through arc crust. Zircon oxygen isotopic compositions indicate that high 6180 predominate in the deeper northern part of the La Posta TTG belt (7.6-12.2) while lower values characterize the shallower southern part (6.3-7.2). This pattern indicates the possibility of significant and previously unrecognized depth gradients in a180 in the PRB consistent with large input of supracrustal contaminants into deeper parts of the batholith relative to shallower parts. The implication is that vertical gradients in 6180 within the eastern zone La Posta belt may be as great as the wellestablished west to east surface gradients across the northern part of the batholith. Because the volume La Posta-type crust in the Peninsular Ranges may easily exceed a million cubic kilometers, simple mass balance considerations require supracrustal recycling on a massive scale. The fact that high a180 La Posta-type zircon are from rocks with Sri values mostly ~0.706co nstrains the nature of the supracrustal contaminant. Assimilation of high Sri Julian Schist-type metasedimentary wallrock to account for La Posta zircon oxygen isotope compositions is unrealistic on several counts. We speculate that large-scale sediment underplating of isotopically primitive accretionary prism material may have played an important role leading up to La Posta-type melt generation. This view is supported by a sediment deficit in adjacent forearc basin & accretionary prism belts of the California borderland.

Catalina Schist and La Posta

Was deeply accreted Catalina Schist an important component of the La Posta source region?
Studies at oceanic convergent margins show unambiguously that large volumes of continental material are recycled into the mantle by sediment subduction and forearc subduction erosion. The fate of this subducted continental material is poorly known; mass balance consideration suggest that at least 95 percent of this material is recycled to deep mantle circulation. The Late Cretaceous La Posta-type TTG suite of the eastern Peninsular Ranges batholith however displays evidence that accretionary prism sediments were subducted and magmatically recycled into the Late Cretaceous the on a very short ( 4 0 Ma) timescale. The La Posta suite represents a tremendous flare-up of deep (garnet-involved) partial melting preceded by an episode of crustal shortening and presumed crustal thickening from ca. 98-92 Ma. Evidence from the Catalina Schist subduction complex terrane directly outboard of the PRB demonstrates that these rocks were being underthrust and metamorphosed synchronously with La Posta magma generation. Elevated 6180 values from La Posta plutons indicate substantial contributions of isotopically unevolved (initial Sr < 0.706) intermediate to mafic composition supracrustal materials into the melt souce regions consistent with contributions from the Catalina Schist accretionary complex. Further, inherited zircon in the La Posta rocks are dominated by a 120-100 Ma component that closely matches the age of the western PRB as well as the dominant detrital zircon component in Catalina Schist. These results are consistent with "conveyor belt-type" recycling of western PRB material into the forearc and then downward via underthrusting into the magma source region of La Posta melts.

INVESTIGATORS
David Kimbrough and Marty Grove



Archives
 
Recent Publications
  • Seismogenic, electrically conductive, and fluid zones at continental plate boundaries in New Zealand, Himalaya, and California, USA: Jiracek, G. R., Gonzalez, V. M., Caldwell, T. G., Wannamaker, P. E., and Kilb, D., 2007, : in D. Okaya, T. Stern, and F. Davey, eds., A continental plate boundary: Tectonics at South Island, New Zealand, Geophys. Mono. Ser. 175, AGU., Washington, DC, 347-369.New Window
  • Yellowstone plume–continental lithosphere interaction beneath the Snake River Plain: Hanan, B.B., Shervais J.W., and Vetter, S.K., 2007, Geology, v.34, Issue 1, pp. 51–54. DOI: 10.1130/G23935A.1 New Window
  • Influence of spatiotemporal scale on the interpretation of paleocommunity structure: Lateral variation in the Imperial Formation of California: Redman C M, Leighton L R, Schellenberg S A, Gale C N, Nielsen J L, Dressler D L, Klinger M K, 2007, PALAIOS, vol. 22, no. 6, p. 630-641. New Window
  • Natural Disasters, 6th edition Abbott, Patrick. McGraw-Hill : New York, NY, United States, 2008New Window
  • Physical and chemical evidence of the 1850 Ma Sudbury impact event in the Baraga Group, Michigan: Pufahl P K, Hiatt E E, Stanley C R, Morrow J R, Nelson G J, Edwards C T, 2007, Geology; September 2007; v. 35; no. 9; p. 827-830; DOI: 10.1130/G23751A.1 New Window
  • Rapid passage of a small-scale mantle heterogeneity through the melting regions of Kilauea and Mauna Loa Volcanoes: Marske J P, Pietruszka A J, Weis D, Garcia M O, Rhodes M, 2007, Earth and Planetary Science Letters, Volume 259, Issues 1-2, 15 July 2007, Pages 34-50New Window
  • Shock-metamorphic petrography and micro-Raman spectroscopy of quartz in upper impactite interval, ICDP drill core LB-07A, Bosumtwi impact crater, Ghana: Morrow, J.R., 2007, Meteoritics & Planetary Science, v. 42, p. 591-609.New Window
  • Staggered-grid split-node method for spontaneous rupture simulation , Dalguer, Luis A. and Day, Steven M. In: Journal of Geophysical Research, February 04, 2007, Vol. 112, Issue B2
  • Paleolimnology; Marine Ostracods, Schellenberg, S. A. Encyclopedia of Quaternary science; Volume 3. Elias, Scott A., 2007, pp. 2046-2062
  • Recent and long-term behavior of the Brawley fault zone, Imperial Valley, California; an escalation in slip rate?, Meltzner, Aron J, Rockwell, Thomas K., Owen, Lewis A In: Bulletin of the Seismological Society of America, December 2006, Vol. 96, Issue 6, pp.2304-2328New Window
  • Comparison of fault representation methods in finite difference simulations of dynamic rupture , Dalguer, Luis A. In: Bulletin of the Seismological Society of America, October 2006, Vol. 96, Issue 5, pp.1764-1778
  • Impacts and mass extinctions revisited , Morrow, Jared R. In: Palaios, August 2006, Vol. 21, Issue 4, pp.313-315
  • Strong shaking in Los Angeles expected from southern San Andreas earthquake , Olsen, K. B. In: Geophysical Research Letters, April 16, 2006, Vol. 33, Issue 7
  • The long record of San Jacinto Fault paleoearthquakes at Hog Lake; implications for regional patterns of strain release in the southern San Andreas Fault system , Rockwell, T. In: Seismological Research Letters, April 2006, Vol. 77, Issue 2, pp.270
  • TeraShake; strong shaking in Los Angeles expected from southern San Andreas earthquake , Olsen, K. In: Seismological Research Letters, April 2006, Vol. 77, Issue 2, pp.281-282
  • Dynamic failure stress for the great 1906 San Francisco earthquake as a predictor for later events , Olsen, K. In: Seismological Research Letters, April 2006, Vol. 77, Issue 2, pp.300
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