Horco Molle, San Javier, Yerba Buena Department, Tucumán Province, Argentinai

Regional Level Types
Horco Molle	- not defined -
San Javier	Municipality
Yerba Buena Department	Department
Tucumán Province	Province
Argentina	Country

Geology:
Horco Molle is located at an altitude of 695 m. asl. in the foothills of the Sierra de San Javier. The climate is humid, rainy summers and dry winters. The average annual minimum temperature is around 13 degrees and the average maximum is 27°C. The rains, terrain type are in the order of 1000 - 1300 mm and watercourses draining normally towards the East-Southeast. The region is an area of hills (Imbaud Lomas) and a plain sloping towards the city of Yerba Buena / Tucumán. These hills, of tectonic origin, originated by a rise caused by a fracture which is located on its western flank. These are formed by sediments of sandy and loamy, fluvial origin and conglomerates from the mid-Quaternary. These sediments have been deeply incised by erosion of the tributaries of the Horco Molle stream. It should be noted that the boulders that constitute the cluster are originated in the mountains of San Javier and are composed of metamorphic rocks of low grade (slate and quartzite).

Mineralization:
Quartz crystals and Limonite pseudomorphs after cubic Pyrite, included quartzose Phyllite and iron ochres covering cavities in phyllites.

Quartz: crystals are presented as small prisms, hexagonal, colourless, white or coloured dark by iron and manganese oxides. Some have iridescent blue and green. They are often striated and twinned and distorted.

The oxides of iron and manganese are filling clefts and cavities of the quartzose phyllites and Quartz.

Hematite, pseudomorphs after Pyrite: perfect and well-defined edges, reddish dark brown and adamantine lustre to submetallic cubic crystals were found loose and included in schists.

Other Regions, Features and Areas containing this locality

References