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April 20 @ 4:00 pm - 5:00 pm CDT

Current Research in Earth Science Seminar

Who: Nick Swanson-Hysell, Assistant Professor, Department of Earth and Planetary Science, UC-Berkeley

What: “Rapid rates of Proterozoic paleogeographic change”

Abstract:
Progressions of paleomagnetic poles are known as apparent polar wander paths (APWPs) and enable the development of ancient paleogeographic reconstructions. In Precambrian time, reliable paleomagnetic poles on a given craton are often widely spread in time restricting the possibility of generating well-resolved APWPs. The development of the North American Midcontinent Rift between ca. 1110 and 1080 Ma has provided an opportunity to develop extensive paleomagnetic data sets spanning this time period resulting in an APWP for Laurentia that goes from a high latitude apex known as the Logan Loop into a swath known as the Keweenawan Track. A long-standing challenge of these data was the appearance of asymmetry between relatively steep reversed polarity data from older rift rocks and relatively shallow normal polarity data from younger rift rocks that was used as support for an interpretation that there were large non-dipolar components to the geomagnetic field at the time. Data sets we have developed support the interpretation that this directional change was progressive and therefore a result of very rapid motion of Laurentia rather than stepwise change across non-dipolar reversals. Constraining these data with new high-precision U-Pb dates and applying novel inversion techniques constrains this motion to have been ~26 cm/year—significantly faster than the fastest plate rates in more recent time.

When:  4:00 pm, Thursday, April 20, 2017

Where: Room 100, KWGL

Details

Date:
April 20
Time:
4:00 pm - 5:00 pm
Event Category:

Venue

100 Keith-Wiess Geological Laboratories
Rice University, 6100 Main Street, MS 126
Houston, TX 77005 United States
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Phone:
713-348-4880
Website:
earthscience.rice.edu

For outside visitors, the best way to get to our department is to come in on Rice Blvd and turn into entrance 20 (intersection of Rice and Kent St.). At the stop sign, you will see a visitor parking lot.  From there, walk east to the department.  The google map below shows exactly where our building is.