OBSIDIAN BUTTE

This source has been covered in fine detail by Richard Hughes. I refer you to his paper. We have a good source standard data library for this source at Berkeley, and routinely analyze archaeological collections from San Diego, Imperial, and Riverside Counties:

Hughes, Richard E. (1986). Trace element composition of Obsidian Butte, Imperial County, California. Southern California Academy of Science Bulletin 85:35-45.

Raw elemental concentrations for Obsidian Butte source standards. All measurements in parts per million (ppm).

`SAMPLE`	`Ti`	`Mn`	`Fe`	`Rb`	`Sr`	`Y`	`Zr`	`Nb`	`Ba`
`OB1`	`725.89`	`359.58`	`15916.91`	`140.11`	`19.40`	`123.62`	`304.86`	`30.64`	`491.90`
`OB2`	`1811.62`	`482.94`	`22987.09`	`132.31`	`53.72`	`102.76`	`458.93`	`18.70`	`586.22`
`OB-3`	`1480.97`	`379.67`	`19659.40`	`120.93`	`48.81`	`94.82`	`427.46`	`18.39`	`624.12`
`OB-4`	`1135.40`	`447.34`	`19953.92`	`152.94`	`31.24`	`122.44`	`355.47`	`33.16`	`528.54`
`OB-5`	`1592.07`	`445.27`	`21570.17`	`143.51`	`48.08`	`110.31`	`420.98`	`25.83`	`624.07`
`OB-6`	`992.23`	`484.79`	`18983.53`	`152.35`	`26.07`	`135.03`	`342.78`	`28.82`	`490.20`
`OB-7`	`1791.71`	`459.91`	`21773.29`	`132.24`	`53.94`	`99.50`	`434.85`	`22.68`	`641.50`
`OB-8`	`1180.10`	`414.26`	`17794.00`	`136.06`	`31.78`	`113.17`	`351.84`	`24.09`	`561.00`
`OB-9`	`1752.35`	`446.90`	`22111.66`	`137.63`	`53.91`	`101.15`	`446.03`	`20.69`	`646.63`
`OB-10`	`1741.01`	`419.28`	`22161.28`	`131.00`	`54.82`	`97.25`	`441.86`	`22.37`	`604.41`