7 Sep, 2018, 15:50 - 16:10

Mario Alfaro Cortés, Consultant Geologist, Qualified Person, Mario Alfaro Asesorías Geológicas Ltda.

Curriculum Vitae
Consultant geologist of international companies. Fiftythree years of experience in the minerals industry, both mine and exploration, always in porphyry copper-gold and epithermal related gold ore deposits, with successfully managing exploration survey responsible for the discovery of copper and gold world class deposits. Qualified Person. Development and implementation of exploration strategies for project generation, property acquisition, property evaluations and joint ventures. Conducted project definition through grass-root exploration, joint ventures and /or acquisitions. Development of conceptual geological models for grass root exploration program for porphyry copper deposits in Chile, Argentina, México (Sonora-Costa Pacífico-Baja California- Chiapas), Perú ( Cordillera Blanca oeste-este, Cordillera Negra and southern porphyry copper belt ), Serbia ( Bor-Majdanspek Metallogenic Province In the Carphatos Adeba Belt), Colombia, Costa Rica, Panamá, China (Fujian Province ). Epithermal HS deposit explorations in Perú, Chile-Argentina high Cordillera, Cuba, República Dominicana, Ecuador, Bolivia, Panamá, Colombia, Honduras, Costa Rica, Nicaragua, Guatemala, Venezuela, Serbia, China. Lecturer and workshop given about porphyry and epithermal ore deposits in Chile, México, Mexican Geological Survey (SGM),Grupo México ( La Caridad, El Arco ),UNAM, Instituto Politécnico de México, Colegio de Ingenieros (CIMMGM), Asociación de Ingenieros de Minas, Metalurgistas y Geólogos ( AIMMGM), Universidad de Guanajuato, San Luis Potosí, Zacatecas, México, Perú, Bolivia, Ecuador, Guatemala, South Africa, Argentina and in international mining companies were I have been work as consultant geologist.

Summary

A dome is a roughly circular intrusion-extrusive resulting from the slow extrusion of viscous lava from a volcano. The geochemistry of lava domes can vary from andesite to rhyolite- dacite (QEP) although most preserved domes tend to have high silica content. The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Lava domes grow by endogenous dome or as an exogene dome growth. It is the high viscosity of the lava that prevents it from flowing far from the vent from which it extrudes, creating a dome-like shape of viscous lava that then cools slowly in situ. Flow dome complexes are common in a variety of volcanic environments and structures. In strato volcanoes, dacitic domes may occupy the summit caldera. Adventive sites on the margins In resurgent calderas, occupying the core or marginal ring fractures Also domes or groups of domes may be isolated from other volcanic features or not clearly controlled by pre-existing volcanic structures. Dome emplacement is an integral part of the development of a larger volcanic structure.In strato-volcanoes dome emplacement follow construction of the main edifice but often triggers phreatic or phreatomagmatic eruptions that partly destroy the edifice and form a major pyroclastic deposits In calderas dome form by resurgence of devolatised magma following major ignimbrite eruption and subsequent caldera collapse. Fluids play an important rol in the development of domes. Magmatic volatile accumulate in the top of the magma chamber in the later stages of crystallisation at the subvolcanic level. The development of mineralised hydrothermal system can take at the place at any stage in the evolution of dome complex and their relationship with porphyry and epithermal system will be discuss in this presentation.