stripes
In the area north of San Miguel de Tucuman is a province of dykes, sills and chimneys predominantly of alkali olivine basalts but containing abundant zeolite and some nepheline. Leucite tephrites are found at a number of localities (Stappenbeck, 1921, geological map) and biotite-analcime monchiquites, trachytephrites, essexites and limburgites have also been described. For a brief review see Quartino and Llambias (1964, p. 7).
QUARTINO, B. J. & LLAMBIAS, E. 1964. Synopsis on rocks with alkaline affinities in the Argentine Republic. International Geological Congress, Report of the 22nd Session, India, 16 1-12.
STAPPENBECK, R. 1921. Estudios geologicos e lidrogeologicos en la Zona Subandina de las Provincias de Salta y Tucuman. Anales del Ministerio de Agricultura de la Nacion, Seccion Geologia, Mineralogia y Mineria, XIV (5)‚ 1-136.