Serpentine Maps

I have put a lot of work into improving maps of exposed ultramafic (serpentine) rocks in California, Oregon, and Washington. Anyone who knows a local area is invited to help (you can just advise me - I will handle all the map generation).

One example is shown at https://docs.google.com/presentation/d/1vPJH04YXaf67UrBTdP6CD0AABA4Yw0mxWLhg96RFiI4/edit?usp=sharing

Posted on February 15, 2023 06:42 PM by jhorthos jhorthos

Comments

@jhorthos, it is my understanding that there are areas within Sierra Azul Open Space Preserve (near Los Gatos, CA) that are serpentine.
Thanks for all the work you're doing on this project!

Posted by truthseqr over 1 year ago

@truthseqr I will take a look to see if I can figure it out. Thanks!

Posted by jhorthos over 1 year ago

Yeah I have made some additions in that area and two regions are on the USGS maps. If you want me to send specifics let me know.

Posted by jhorthos over 1 year ago

I'd be happy to help out with SLO county.

Posted by paulexcoff over 1 year ago

Hi Paul - that would be great! If you send me your regular email I can send images (or better yet KML files which are easy to load into Google Earth). - James

Posted by jhorthos over 1 year ago

This open area is a tiny serpentine outcrop:
https://www.inaturalist.org/observations/28411007

Posted by jenniferlchandler over 1 year ago

Cool - that spot lies just outside a USGS boundary so I just added a little bulge to cover it. That is exactly the kind of outcrop I can't do from sat maps. - James

Posted by jhorthos over 1 year ago

This might be useful for Serpentine leads if you haven't already incorporated it:
https://www.calflora.org/entry/help/layer-help.html#serp
https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=CAum3

Also this site (map at bottom):
https://www.mindat.org/min-11135.html

Posted by yerbasanta about 1 year ago

@jhorthos I've got what you're looking for

Posted by reodell 6 months ago

Thanks so much @reodell, looking forward to incorporating them.

Posted by jhorthos 6 months ago

@yerbasanta sorry I didn't respond... I think those maps are similar to or identical to the starting maps I have used.

Posted by jhorthos 6 months ago

I have been working on detailed shapefiles of the ultramafic areas of CA and OR, on and off, for the past 3 years. Started with digitizing ultramafic polygons from georeferenced geologic maps (National Geologic Map Database) and then adjusted the polygon boundaries to match the actual ultramafic geologic boundaries, based on high resolution satellite imagery and field observations. Then I looked very carefully through the satellite imagery and drew polygons for ultramafic masses and ultramafic landslides that the geologists missed. I have completed the Sierras, South Coast Ranges, and North Coast Ranges in detail. I have the digitized, unaltered polygons of ultramafic areas for Klamath Mtns (NW. CA, SW. OR) and Blue Mtns (E. OR). I would be glad to share GIS shapefiles (or KMZ) with anyone who wants them. That's why I am doing it. There are not any good, detailed shapefiles of the ultramafic distribution in CA and it is needed by ecologists.
https://ngmdb.usgs.gov/ngmdb/ngmdb_home.html

Posted by reodell 6 months ago

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