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
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@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!
@truthseqr I will take a look to see if I can figure it out. Thanks!
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.
I'd be happy to help out with SLO county.
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
This open area is a tiny serpentine outcrop:
https://www.inaturalist.org/observations/28411007
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
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
@jhorthos I've got what you're looking for
Thanks so much @reodell, looking forward to incorporating them.
@yerbasanta sorry I didn't respond... I think those maps are similar to or identical to the starting maps I have used.
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
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