Petrographic aspects of the intrusive complex of Arroyo Marincho and granodiorite of Arroyo Grande.Part I

The epimetamorphis of Arroyo Grande formation (lower Precambrian) are integrated by several granitoid bodies. The Marincho complex represented by;a) main unit integrated by hornoblenditic diorite to mozongranite b) an incomformable belt of porfinoblastic honobledite c) one unit characterized by a two mica granite heterogranular to porphiroic.The petrographic diagrams shows evolutive lines, suggestings differentd origins for the main granodiorite, granodiorite the Arroyo Grande, south granite and the hornoblendites.