Consideration about the use of "petrotects" in the evaluation of industrial rocks. Some examples in the northwestern territory, Argentina

AVILA, JULIO CESAR

New Delhi

Simposio; Twenty first International Symposium on Mine Planning & Equipmente selection; 2012

MPESIndia

The term “petrotect” have been defined by Avila and Fogliata in 1995 as “any geológical feature believed to have played a role in forming a certain type of rock with such characteristics that can be used for a determined purpose”. This paper deals about two examples in Tucumán province situated in the northwest of Argentina. In the first case, metamorphic rocks (phyllites, metagraywackes and quartzites) assigned to Precambrian-Eocambrian ages conform east slope of Cumbres Calchaquíes. Grey phyllites with S1 cleavage axial planes parallel to SO planes crops out The pelitic layers have about 5 meters thickness without intercalations of psammitic beds or joints planes. No others weakness or discontinuities are present in the rocks, so, those rocks can be used as flagstones. Litologic and structural are the principal petrotecs defined. The second case refer to San Ignacio Los Pinos granitic outcrops studied to be used as ornamental rocks. The rocks have gray and rosy color predominantly, of fine to medium grain. The mineral components have scarce alteration and few planes of weakness. Two ornamental varieties of commercial value have been defined. In this case mineralogical and structural are the principal petrotecs defined.