Location: Stanford University
Anyone wishing to attend the lecture only is welcome at no cost.
This will be the 339th meeting since 1954.
Three different intrusive igneous units are represented in the study area: (1) Middle Jurassic, I-type, metaluminous plutonic rocks of the Barcroft comagmatic suite-mineralogically and chemically intergradational, chiefly mafic granodiorite, gabbro/diorite, metadiorite, and rare alaskite-aplite; (2) Late Cretaceous, apparently S-type, faintly peraluminous granitic plutons sensu stricto of the McAfee Creek suite-differing among themselves only in grain size; and (3), Tertiary, unmetamorphosed, fine-grained diabase dikes. Members of the Barcroft granodioritic pluton are K-poor, exhibit a broad range of mineralogic compositions, and appear to represent the products of fractional crystallization. The younger, K-rich granite sensu stricto suite is quite homogeneous, as is the yet younger, more mafic diabasic dike series.
These three contrasting intrusive igneous series + adjacent superjacent units on the north and south testify to the inferred plate-tectonic history of the region: (a) evolution of a long-lived passive margin from latest Proterozoic through early Mesozoic time (interrupted by contractional events of the Antler and Sonoma orogenies); (b) mid-Mesozoic subduction, partial fusion of the downgoing lithospheric slab and/or the overlying mantle wedge, and ascent of voluminous, relatively refractory magma attending Andean-style volcanic-plutonic arc production; (c) Late Cretaceous crustal thickening, heating, and partial melting of recycled, deeply buried, fusible sialic materials; and (d), Tertiary Basin and Range asthenospheric upwelling, lithospheric transtension, and the tapping of minor amounts of upper mantle interstitial melts. Tilting and strike-slip faulting accompanied Plio-Pleistocene uplift and glaciation of the White Mountain block. Continuing elevation of the Sierra Nevada and White-Inyo ranges may reflect enlargement of the subcrustal high-temperature realm (shallowing of the lithosphere-asthenosphere boundary), resulting from westward encroachment of North American lithosphere over the East Pacific Rise heat source. The region constitutes a typical example of the Phanerozoic evolution of the Californian continental margin. At least, I think so!
Ernst was chairman of the Board on Earth Sciences of the National Research Council (1984-87), served on the NRC Board on Earth Sciences and Resources (1988-1993), and is a trustee of the Carnegie Institution of Washington, D.C. (1990-present). Member, National Academy of Sciences (chairman, section of Geology, 1979-82; secretary, Class I, Physical Sciences, 1997-2000, chair, 2000-present), American Philosophical Society. Fellow: American Academy of Arts and Sciences; American Geophysical Union; American Association for the Advancement of Science (chair section on geology and geography, 2001), Geological Society of America (president, 1985-86); Mineralogical Society of America (president, 1980-81). Author of six books and research memoirs, editor of 14 other research volumes, and author of more than 180 scientific papers (and numerous abstracts, book reviews, etc.) dealing with: (1) the physical chemistry of rocks and minerals; (2) the Phanerozoic interactions of lithospheric plates and mobile mountain belts, especially in central Asia, the Circumpacific and the western Alps; (3) early Precambrian petrotectonic evolution; (4) ultrahigh-pressure subduction-zone metamorphism and tectonics; and (5) Earth System science/remote sensing.
Fulbright Research Scholar, University of Tokyo, 1963; Crosby Visiting Professor, M. I. T., 1968; MSA Award recipient, 1969; NSF Senior Postdoctoral Fellow and Adjunct Professor, University of Basel, 1970-71; Guggenheim Memorial Fellow and Visiting Extraordentlich Professor, Swiss Federal Institute, Zürich, 1975-76; William Evans Visiting Professor, Otago University, Dunedin, New Zealand, 1982-83, Visiting Professor, Universitade Federale de Pernambuco, Recife, Brazil, 1988; Japan Society for the Promotion of Science Fellow, and Visiting Professor, Kyoto University, 1995. He received the Geological Society of Japan Medal for 1998.
Gary Ernst demo-ing acreation (photo by Mary Jane Coombs)
If you want to pay in advance:
Stanford faculty and students: Please make dinner reservations by Friday, October 12. Contact Dr. Juhn Liou via his mailbox (and leave check), Geological and Environmental Sciences Office, Geocorner - Bldg. 320 (Rm. 118). Make checks out to"PGS."
All others, including faculty and students from other Bay Area universities and colleges and USGS: Please make dinner reservations by Friday, October 12. Contact Janice Sellers, at Seismological Society of America, 201 Plaza Professional Building, El Cerrito, CA 94530, phone (510) 559-1780. Send check made out to"PGS"to Janice.
Dinner is $26.00. Includes wine (5:30 to 6:15 PM.), dinner (6:15-7:30 PM.), tax, and tip. Note: PGS does not make revenue on this price.
For students from all universities and colleges, the dinner, including the social half-hour, is $5.00 and is partially subsidized thanks to the Associates of School of Earth Sciences, Stanford University (Note, no-show reservations owe the full price).
Dues for Academic Year 2001-2002 ($10.00) should be sent to Janice Sellers, Seismological Society of America, 201 Plaza Professional Building, El Cerrito, CA 94530. Janice's phone: (510) 559-1780.
Officers: Gary Ernst, President; Mike Diggles, Vice President; Vicki Langenheim, Secretary; Janice Sellers, Treasurer
Date created: 09/14/2001
Last modified: 04/10/2003
Created by: Mike Diggles, Vice President, PGS.