Alkaline Rocks and Carbonatites of the World

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

Volta Redonda

stripes

Occurrence number: 
025-00-086
Country: 
Brazil
Region: 
Rio de Janeiro
Location: 
Longitude: -44.08, Latitude: -22.55
Carbonatite: 
No

A lava flow with a maximum thickness of 20 m outcrops over a semicircular area less than 1 km in diameter, 4.5 km southeast of Volta Redonda. It is associated with sediments of the Resenda Formation. The rock, provisionally classified as an ankaramite, consists of phenocrysts of titanaugite and olivine in a matrix of pyroxene, plagioclase, opaques, nepheline and analcime.

Age: 
K-Ar on whole rocks gave 43.8±6.2 and 41.7±5.7 Ma (Riccomini et al. 1983).
References: 

C. B. Gomes, personal communication, 1985. RICCOMINI, C., MELO, M.S. de, CARNEIRO, C.D.R., ALMEIDA, F.F.M. de, MIOTO, J.A. and HASUI, Y. 1983. Sobre a occorencia de um derrame de ankaramito na bacia de Volta Redonda (RJ) e sua importancia na datacao das bacias tafrogenicas continentais do sudeste Brasileiro. Boletim de Resumos, Sociedade Brasileira de Geologia Nucleo de Sao Paulo, 4 Simposio Regional de Geologia: 23-4

Map: 
Fig. 1_204 Distribution of alkaline rocks around Rio de Janeiro.
Location: 
All locations > South America > Brazil > Rio de Janeiro
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith