Excursions from Comodoro Rivadavia

Petrified Forest José Ormachea

From Comodoro Rivadavia, 150 km. of asphalted route away, through the provincial route Nº 26, until reaching the locality of Sarmiento. Thence, through a gravel road which leads to the south, signposted and looked after by a ranger, you’ll reach the Petrified Forest José Ormachea.
The area covered by the forest is quite extensive and there are huge logs, leaves and even seeds spreaded over the land. According to the experts, the wooded area in this place is very important and it is almost certain that there are specimens over 100 metres high.

The deep surrounding depressions in the ground still hold vestiges of other realities: mollusc shells, dinosaurs fossils and strange rocky formations, known as Red Stones, are some of them.

It is necessary to have a favourable environment in order for this fossilized wood to get accumulated. The environment in Patagonia is one of the bests: when the folding of the Andes Mountain range occurred, the humid winds of the pacific stopped and for long periods of time the abundant volcanic activity provided the  raw material: the silica.

The prettification is a very slow process in which the organic material becomes stone. For this to happen, the organisms (vegetable or animal) must get covered by dirt, ashes, sand or mud which forms a protective layer. This layer must be permeable for all liquids in general. If the liquid enters through the layer, which contains as well the silica or salt, a change will begin, molecule by molecule, in which the organic tissue will  become stone.

In this location of Patagonia, the ancient forests of the tertiary period underwent this process thus being covered by the ashes as a consequence of the great volcanic activity.  Afterwards, the winds running through a land progressively dryer eroded the terrain until leaving this magnificent fossils out in the open, witnesses of a time in which Patagonia was one of the greenest places on the planet.
 
(See excursions from Sarmiento in Central Patagonia)