Tucumán Province, Argentinai

Regional Level Types
Tucumán Province	Province
Argentina	Country

Geological features and history:
The province of Tucumán in their 22,524 km2 of extension approximately, has the most varied morphological characteristics: mountains high, partly sterile, but generally covered with vegetation, with numerous streams, extensive plains, small desert areas, everything crossed by a dense drainage network that ply practically its territory to go to lead the general collector than the river "Salí".
Petrografically its mountain ranges are formed by deposits of various types and geological age.
The core of its mountains consists of older deposits of Precambric age, composed of so-called metamorphic rocks, i.e. rocks which have undergone transformation processes by the action of physical and chemical agents. These ancient metamorphic rocks, forming the so-called "crystalline basement" and are especially slate, shale filitics, micacits quartz, etc... in part migmatized and with intrusions of igneous rocks.
On this complex of ancient rocks were deposited more modern sediments, possibly of Mesozoic age. These Mesozoic deposits would be formed by the destruction resulting conglomerates and consolidation of reddish sandstones, ancient rocks, partly calcareous Marly, i.e. a series of deposits still not completely well chronologically identified.
Then in the tertiary sediments of fluvial origin, generally reddish sandstones, conglomerates, also volcanic gaps, tufaceos deposits, are deposited after having largely been eroded deposits previously cited, these along with the more modern; composed of sediments of one smaller grain size, mud, sand, you loess and gravel deposits fanglomerados thick gravel, and medium-sized sands, especially in terraces, usually form the surface of the flat areas of the province.

Geological history:
In the Precambric or in the early stages of the Earth's history were depositing sediments silty, clay, charcoal and fine sands, as a result of a process of sedimentation at the bottom of the sea, which at that time covered much of the surface of Tucumán.
To remove the sea or raise these lands, materials that were gradually consolidated and later were affected by this already announced metamorphism, which transformed these sediments in metamorphic rocks that we see today. As result of this metamorphism and movements affecting the Earth's crust cracks and planes of separation where subsequently ascended the granitic magma (material in a State of fusion from the interior of the Earth) form which cooled and crystallized form bodies granite like "San Ignacio", "Potrerillos", "Balcosna", etc...
After these events, the region suffered orogenic processes, i.e. suffered an uprising and the weathering agents acted on this formations staying too long in this state of mind, until the invasion of a sea possibly of Mesozoic age which deposited marine sediments to his retirement, continuing until mid-tertiary sedimentation processes or end of this erathat brings a new event, volcanic activity, as a result, the accumulation of materials and formation of deposits of ash, tuffs, gaps and eruptive rocks observable in many parts.
Later suffers the basement a promotion and an erosion motivating the deposition of sediment conglomeradics.
Then appear the first glacial demonstrations at summits as a result of the drop in temperature, this already in the Quaternary era.
You spend glaciation, improves the climate, the temperature climbs, produced the effects of glacial erosion, glacial deposits, then dragging those deposits of foothills, later reaching the stage of rainfall and minor rivers drag force.