Un intrusivo básico Ordovícico en la Formación La Tinta, provincia de Buenos Aires, Rep. Argentina

RAPELA, C.W.; DALLA SALDA, L.H.; CINGOLANI, C.

Revista de la Asociación Geológica Argentina

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 1974 vol. 29 p. 319 - 331

0004-4822

intrusive body (normal subalkaline mafic rock) are here given. This rock occurs as a sill intruded in the so called Formación La Tinta. Thermal and metasomatic effects are seen in the contact between the intrusive and country rocks. The metamorphic products were classified as hornfels like rocks with evidence of metasomatism. According to radiometric data obtained (450, 495 and 498 m. y.), the basic magmatism is referred to an Ordovician age. Through paleontological information (Borrello, 1966), together with the above mentioned ages, it is thought that La Tinta Formation (Sierra de Los Barrientos area) could be referred to a Cambrian-Lower Ordovician age.