Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Deep Spring Valley

stripes

Occurrence number: 
174-00-050
Country: 
United States
Region: 
California
Location: 
Longitude: -118.07, Latitude: 37.25
Carbonatite: 
No

At Deep Spring Valley approximately 40 km east of Bishop four vertical, cylindrical plugs of olivine melaleucitite and olivine-leucite trachybasalt cut Mesozoic granitic rocks. Distinct rim and core zones are present at each plug, the best exposed of which is some 80 m in diameter, the rim zone being 6-16 m thick. The rock of the rim contains 18% olivine and 18% leucite microphenocrysts in a groundmass of 30% augite, 12% sanidine, 11% biotite and 11% magnetite. The core zone is slightly coarser, locally vesicular and has a vertical, concentric foliation. It comprises 12% olivine, 6% leucite, 31% augite, 25% plagioclase (An65), 16% sanidine, 8% magnetite and 3% biotite. The rim zones contain numerous granitic xenoliths which show little or no reaction.

References: 

NASH, D.B. and NELSON, C.A. 1965. Leucite-bearing volcanic plugs, Deep Spring Valley, California. Special Paper, Geological Society of America, 82: 267

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith