Alkaline Rocks and Carbonatites of the World

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



Occurrence number: 
Santa Cruz
Longitude: -55.71012, Latitude: -16.27129

The Candelaria region of western Santa Cruz, Bolivia, hosts a number of minor alkaline intrusives, primarily dykes thought to be related to the Mercedes Rift. They are poorly described structurally, but known to intrude into Neoproterozoic(?) ignimbrites, and quartz sandstones belonging to the Cerro Redondo Formation. Rocks from two localities in the region, Cerro Los Angeles and Cerro Puntudo, have been described. They are metaluminous to peralkaline microsyenites and trachytes, with notable minerals including nepheline in the former, and apatite and zircon within the hypohyaline to pilotaxitic groundmass of the latter. Geochemical data, including whole-rock major and trace element and Sr-Nd isotopic, can be found in Comin-Chiaramonti and Gomes (2005).

79 ± 8 Ma Sr-Nd whole rock (Comin-Chiaramonti et al, 2005)

COMIN-CHIARAMONTI, P., GOMES, C.B., VELÁZQU, V.F., CENSI, P., ANTONINI, P., COMIN-CHIARAMONTI, F. & PUNTURO, R. 2005. Alkaline complexes from southeastern Bolivia. In: Comin-Chiaramonti, P. & Gomes, C.B. (eds) Mesozoic to Cenozoic alkaline magmatism in the Brazilian Platform. Editora Universidade de São Paulo, São Paulo, 159-211.

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