[Geoldept] Interesting USGS Seminar - Live Stream

Thu Mar 14 08:39:36 PDT 2019

Hi,
This may be of interest to many of you.

---------- Forwarded message ---------
From: Cerovski-Darriau, Corina <ccerovski-darriau at usgs.gov>
Date: Thu, Mar 14, 2019 at 8:01 AM
Subject: TODAY: GMEG Seminar--Mar 14 (11am)--Ziva Shulaker (Stanford)
To: All Menlo <GS-CAmnl_All at usgs.gov>, GS-G-Menlo-All <gs-g-menlo-all at usgs.gov>, GS-G-WR EHZ Menlo ALL <gs-g-wr_ehz_menlo_all at usgs.gov>, GS-G-WR VHZ All <gs-g-wr_vhz_all at usgs.gov>, GS-PSWA GMEG ALL <gs-pswa_gmeg_all at usgs.gov>, GS-N-WGSC All <GS-N-WGSC_All at usgs.gov>, GS-PSWA GMEG MENLO SEMINAR SERIES <GS-PSWA_GMEG_MENLO_SEMINAR_SERIES at usgs.gov>, Steven Ingebritsen <seingebr at usgs.gov>, Shaul Hurwitz <shaulh at usgs.gov>, Mark Huebner <mhuebner at usgs.gov>, Jessica Ball <jlball at usgs.gov>, Jennifer Lewicki <jlewicki at usgs.gov>, <gs-n-wgsc_northwest_fed_emp at usgs.gov>, <gs-n-wgsc_northwest_non_fed_emp at usgs.gov>, Jorge Vazquez <jvazquez at usgs.gov>, Marsha Lidzbarski <mlidzbarski at usgs.gov>, Seth Burgess <sburgess at usgs.gov>, <prcmarc at gmail.com>, <pcmsc_all at usgs.gov>, <kvenvolden at earthlink.net>

Please join us March 14th @ 11am in the Rambo Auditorium (Bldg 3, USGS, Menlo Park) or via livestream for...

Title:
Development and application of coupled K-feldspar Pb isotopic and 40Ar/39Ar methods to reconstruct Late Cretaceous/Cenozoic deformation of the California margin

Summary:
Laramide flat-slab subduction has long been recognized as a major player in the thermal evolution of southern California. However, the Late Cretaceous-Eocene cooling history of the southern Sierra Nevada and Mojave Desert (SSN/MD) cannot be uniquely resolved using current geo- and thermochronology methods.

This talk presents a new provenance technique using same-grain K-feldspar Pb isotopes and 40Ar/39Ar thermochronology to rapidly create detrital and source region databases that show crustal response to the changing plate boundary. We employ a sampling strategy that exploits both presently exposed basement and corresponding depocenters which record the unroofing history of the region. 40Ar/39Ar thermochronology provides constraints on timing of subduction refrigeration and Pb isotope compositions reflect drainage evolution in response to upper crustal deformation related to Laramide subduction.

Specifically, 40Ar/39Ar thermochronology suggests that the western Sierra Nevada rapidly cooled ca. 90 Ma, but it took 10 m.y. to remove material beneath the arc. The western Mojave was then refrigerated ca. 80 Ma. Detrital K-feldspar Pb isotopes from lower Eocene to lower Miocene California forearc strata that derive from the SSN/MD region show an evolving source region that switched from a localized source in the early Eocene, then expanded eastwards to encompass the entire Mojave region in the late Eocene, before finally sourcing a limited, westernmost Mojave source. The paleodrainage evolution reflects the upper crustal response to the plate boundary switching from normal to shallow subduction and returning to normal subduction. In the future, this methodology could be applied to other plate boundary settings where detrital datasets can constrain crustal thermal history.

Speaker Info:
Ziva Shulaker is a PhD student at Stanford, and you can read more about her here<https://profiles.stanford.edu/danielle-shulaker>. If you would like to meet with the speaker, contact the USGS host below.

USGS Host:
Kathryn Watts
kwatts at usgs.gov<mailto:kwatts at usgs.gov>

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Livestream: http://media.wr.usgs.gov/live/<https://www.google.com/url?q=http%3A%2F%2Fmedia.wr.usgs.gov%2Flive%2F&sa=D&ust=1552192480503000&usg=AFQjCNG4fTnPbylvG82YUDsaDWkcrJrLFA>

Upcoming GMEG seminars: https://calendar.google.com/calendar/embed?src=doi.gov_b87rlq2rodqsdhhq067erpmgfo@group.calendar.google.com

Speaker suggestions?: https://docs.google.com/spreadsheets/d/1AOV8AwBxNK2fO1gV1KdxLU48HBVBSf-R-PVnOROaLhI/edit?usp=sharing

--
Corina Cerovski-Darriau
Research Geologist
U.S. Geological Survey
345 Middlefield Road, MS973
Menlo Park, CA 94025

Phone: (650) 329-4143
Email: ccerovski-darriau at usgs.gov<mailto:ccerovski-darriau at usgs.gov>
Profile: www.usgs.gov/staff-profiles/corina-cerovski-darriau<http://www.usgs.gov/staff-profiles/corina-cerovski-darriau>

--
Eric E. Grossman, PhD
Research Geologist, U.S. Geological Survey
Pacific Coastal and Marine Science Center
Tribal Liaison, USGS Natural Hazards Mission Area
Dept. of Geology, Western Washington University
516 High St, MS 9080, Bellingham, WA 98225
360-650-4697 (office)  831-234-4674 (cell)
email: egrossman at usgs.gov<mailto:egrossman at usgs.gov>
http://walrus.wr.usgs.gov/climate-change/lowNRG.html
https://walrus.wr.usgs.gov/coastal_processes/cosmos/puget/index.html
http://coralreefs.wr.usgs.gov/
http://puget.usgs.gov/

Eric E. Grossman, PhD , Research Geologist
U.S. Geological Survey, Pacific Coastal and Marine Science Center

Research Associate, Dept. of Geology Western Washington University

516 High St., MS 9080, Bellingham, WA, 98225<tel:831-234-4674>

360-650-4697<tel:831-234-4674> (office)   831-234-4674 (cell)

email: egrossman at usgs.gov<mailto:egrossman at usgs.gov>
email: Eric.Grossman at wwu.edu<mailto:egrossman at usgs.gov>
<http://puget.usgs.gov/>http://walrus.wr.usgs.gov/climate-change/lowNRG.html
http://puget.usgs.gov/
http://coralreefs.wr.usgs.gov/
http://www.usgs.gov/coastsalish
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