Sciencemadness Discussion Board

Uranium in Southern California?

careysub - 12-9-2014 at 06:37

I downloaded the EPA Uranium Mining Database, which lists 15,000 mines and claims in the U.S. (and is apparently a nearly complete list of same), and ran some calculations to see if any were near where I live in Southern California. I was surprised to find more than 100 within 70 miles of my house.

There is a well known mineral collecting site in the nearby mountains called Pacoima Canyon that yields specimen-quality thorite/uranothorite in pegmatite veins (and which is not in the DB):

http://www.minsocam.org/ammin/AM39/AM39_831.pdf

http://www.highdesertinsider.com/html/pacoima.htm

I am wondering whether some/many of these 100+ claims are outcrops that yield uranium minerals in collectible quantity.

elementcollector1 - 12-9-2014 at 20:11

Would you mind linking the rest of us to the database? I'd certainly like to get in on this gig, even if I am trapped in Ohio.

careysub - 13-9-2014 at 06:50

Uranium minerals are a very interesting sub-category of mineral collecting. The number of known uranium minerals is surprising (at least to me). Of the 3800 known mineral species, at least 249 of them contain uranium, 6.6%.

A quick check against other heavy elements (excluding the siderophiles that are rare in the crust), and elements of similar crustal abundance (within a factor of 2), or both, shows that this is indeed an anomalously high number.

I end up with a list of 21 elements - the only elements on the list with more species are lead and arsenic, and lead gets a free ride of sorts since uranium decays into lead, and thus some uranium minerals contain lead as well. The median number of minerals for elements on this list is 45, the average 111.

Thorium is more than 3 times as abundant, but has only 71 minerals.

The multiplicity of these minerals is partly due to the multiple oxidation states of uranium, particularly the +6 uranyl ion, and thus the ability to form a wide variety of secondary mineral compounds under the action of water.

Many of these secondary minerals are highly colored, and given the fluorescence of the uranyl ion are intensely fluorescent as well. These propertied led to the first use of uranium: in those artificial mineral compositions called "glass".

Thorium frequently occurs with uranium, especially in the primary minerals, as uraninite and thorianite (uranium and thorium dioxides) are miscible in all proportions.

careysub - 13-9-2014 at 06:53

Quote: Originally posted by elementcollector1  
Would you mind linking the rest of us to the database? I'd certainly like to get in on this gig, even if I am trapped in Ohio.


You have to download it, and it can be loaded into a spreadsheet (LibreOffice opened it without a problem). The link is on this page:
http://www.epa.gov/radiation/tenorm/pubs.html

The actual link:
http://www.epa.gov/radiation/docs/tenorm/uld-ii.dbf

elementcollector1 - 14-9-2014 at 18:37

Yeah, I don't have LibreOffice, and Excel is just not helping.

BobD1001 - 14-9-2014 at 20:07

Excellent resource! I live in southeastern PA and was looking into collecting some Uranium minerals as well. Turns out a little mountain town somewhat near me, Jim Thorpe, holds the states largest Uranium deposit. I was just up there camping with some buddies and brought my geiger counter along, but really didn't have much time to prospect. However in the 10 minutes I played around, the ground itself there seemed somewhat "hotter" than any numbers I've seen back home. Average counts were about 45cpm compared to the 20ish I see near home.

[Edited on 15-9-2014 by BobD1001]

careysub - 14-9-2014 at 20:20

Quote: Originally posted by elementcollector1  
Yeah, I don't have LibreOffice, and Excel is just not helping.


Download it. It is free and runs on all OS's.


crazyboy - 14-2-2015 at 23:32

Thanks for the resource, I extracted the latitudes and longitudes from the dbf into a text file as comma separated coordinates. I orignally intedded to write a program that would be more thourough but this got the job done. You can copy paste the coordinates into this website http://www.darrinward.com/lat-long/ to display all the points.

I found a mine about 25 miles from my work, I may check it out.

Attachment: mines.txt (301kB)
This file has been downloaded 1469 times