Friday, March 28, 2008

Caving in on the Owyhee...A public service announcment

This conveniently dated photo of Lisa logging strat pits in the dark is telling for several reasons. Firstly, it notes the date of the first Owyhee adventure...back when we were focused on the boring floods of the Holocene; secondly, it represents the last year that I used a conventional camera. Very recently, I noted that I was completely ignoring my geologic slide collection. So, instead of picking some choice slides and scanning them myself, I sent 996 slides to a company in Arizona that scanned them all at 2000 dpi, burned them as tifs and jpgs to DVDs, archived them, and mailed them back in less than 3 weeks for only $550. It would have taken me weeks of my own time to do the same. Check it out:

Accept the fact that you also need to cave in and send your slides to a similar place so that you can actually view them, organize them, remember them, etc. Your slides are just getting older and older. One day they will mean very little to you. Digitize them now. You will be very happy with the results.
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Thursday, March 27, 2008

Owyhee Research at GSA in Vegas

Cordilleran Section (104th Annual) and Rocky Mountain Section (60th Annual) Joint Meeting (19–21 March 2008)
Paper No. 1-9
Presentation Time: 11:00 AM-11:20 AM


SHORT, Emily J., JASTRAB, Jamie M., and HART, William K., Geology, Miami University, 114 Shideler Hall, Oxford, OH 45056,

The Owyhee Plateau tectonomagmatic province is located in the Oregon-Idaho-Nevada border region and preserves evidence of complex magmatic processes and mantle reservoir interactions over the past 17 Ma. Quaternary basaltic volcanism is concentrated along the northern and northwestern margins of the Plateau in a number of discrete to overlapping volcanic fields characterized by monogenetic cones and small shields. The focus of this investigation is three young basalt volcano fields, the Saddle Butte field (SdB), Jackie's Butte field (JB), and Scott's Butte field (ScB), that lie near the suggested physical northwestern edge of the Owyhee Plateau. In contrast to the multiple monogenetic shield vents of the SdB and the JB, the ScB is dominated by a single vent complex (Scott's Butte) that preserves evidence of early hydrovolcanic activity followed by emergent central and satellite vent Strombolian and Hawaiian activity. New stratigraphic observations and preexisting K-Ar data, when viewed in the context of more extensive chronologic data for the nearby Jordan Valley volcanic field (JVVF), indicate that the volcanism considered in this investigation is less than approximately 1.2 Ma, with portions of the Saddle Butte field likely less than 100 ka in age. Furthermore, stratigraphic relationships along the Owyhee River canyon document the presence of flows likely emanating from 1.9 Ma and older JVVF vents stratigraphically beneath eruptive products of the SdB. Between volcanic field and between vent major and trace element variability is observed including little fractionated, LIL and HFS element depleted olivine tholeiites (HAOT) in the SdB and JB, basalts with characteristics in common with certain Snake River olivine tholeiites (SROT) and young JVVF alkaline basalts in the JB, and basalts transitional to these varieties in the ScB. Within vent geochemical heterogeneities also are observed, only some of which may be produced via shallow fractional crystallization and/or small differences in degree of melting. The observed geochemical complexities require the presence of heterogeneous lithospheric mantle and lower crustal reservoirs beneath this region and post magma generation differentiation processes that involve mixing of heterogeneous melts and/or melts and solids derived from these reservoirs.

Cordilleran Section (104th Annual) and Rocky Mountain Section (60th Annual) Joint Meeting (19–21 March 2008)
General Information for this Meeting

Session No. 1
Igneous/Metamorphic Petrology, and Volcanology
University of Nevada-Las Vegas: Student Union 208C
8:00 AM-12:00 PM, Wednesday, 19 March 2008

Geological Society of America Abstracts with Programs, Vol. 40, No. 1, p. 34

© Copyright 2008 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.

Tuesday, March 4, 2008

Yeehoogle Earth

While procrastinating on some very important things today, I taught myself how to make an attractive and viable Google Earth layer that highlights geology. I started doing it to accompany a map and related text in southern Nevada, and then remembered that I claimed that I would produce this type of thing (with help!) for the Owyhee project.

I did this with a lot of help from Google who have recently created a spreadsheet template (using Google Docs) that makes this a pretty painless process. I thought it would be hard until I watched a 5-minute tutorial.

I can't post a file on Blogger, so I will be sending each of you a kmz file for the Owyhee project and a slighly more realized one from the lower Colorado River. If you keep one or both of them in Google Earth (i.e. not in the Temporary Places folder) they will automatically update. If you are truly adventurous, I will share the spreadsheet with you so that you can add things (that means you, Liz...).