Petrified Forests

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At present, there are many petrified forests that are exponents of that millenary process throughout Patagonia: the best known either for their size or for their proximity to tourist cities are the José de Ormachea Petrified Forest in Sarmiento, Chubut province, the Natural Monument Jaramillo Petrified Forest in the north of Santa Cruz province and La Leona Petrified Forest just 100km from El Calafate also in Santa Cruz province.

The first of them is located 30 kilometers from the town of Sarmiento (province of Chubut). The José de Ormachea Petrified Forest is a provincial reserve, which receives thousands of visits annually.

For its part, the Jaramillo Petrified Forest Natural Monument is located 240 kilometers from the town of Puerto Deseado in the north of the province of Santa Cruz.

Finally, the Petrified Forest La Leona is located only 100km from El Calafate, very comfortable for most tourists who travel to the city of El Calafate to see the Perito Moreno Glacier.

All these petrified forests contain fossil remains of trees, which measure between 10 and 15 meters, as well as branches, leaves, fruits and seeds. The petrified forests of Patagonia are considered the most important in South America, since they have the largest bush fossils on the Continent

How the petrified forests of Patagonia were created

Petrified forests emerged in Patagonia 150 million years ago, as a result of a strange natural phenomenon.

150 million years ago, a natural phenomenon occurred in Patagonia, which determined the appearance of the petrified forests. Multiple volcanic eruptions, which took place over the centuries, covered the wood of ancient giant trees with a blanket of lava and ash, turning them into rock over time.

The Petrified Forests in Chubut (Dr. Wilf scientific approach)

“Patagonia is home to an extraordinary concentration of lurid petrified forests”

Dr. Wilf and a team from the USA Together with the MEF (Museo Paleontológico Egidio Feruglio) in Argentina they have studied the petrified forests and fossil-rich lands of Patagonia for 16 years.

In the landscape of the province of Chubut, in southern Argentina, there are strange stone monuments to life that thrived until 65 million years ago . The province is home to strange “petrified forest” – where life has been turned to stone.

In places like these, fossil-filled rocks are exposed on the surface, revealing the history of life on planet Earth.

Petrification is when the organic matter of an animal or plant is replaced by minerals and eventually “turns to stone” thanks to the absence of oxygen. The process preserves natural shapes in minute anatomical detail in 3D.

“In the Petrified Forest area in Chubut there is almost no modern vegetation, it is very dry and the winds are extremely strong. I am a big build type, and sometimes the wind knocks me down.”

In Chubut there are unique dinosaurs, fossilized mammals, as well as plants, flowers and fruits from “almost all geological times.”

The Petrified Forests in Chubut (Dr. Wilf scientific approach)

“Here were very tall conifers and flowering trees” that lived along the rivers near the South Atlantic coast about 65 million years ago “not long after the last dinosaurs were extinct” – all of this is scattered throughout the world. landscape, says Dr. Wilf.

But these trees did not grow here. They were carried by water when the banks of the rivers they lived in eroded during storms, ending in sandy estuaries where they were buried by layers of sediment.

Over time, dissolved silica replaced the organic materials in trees. And the rise in temperature and pressure turned the trees into rock.

Therefore, the Ormachea Petrified Forest National Park is not a “petrified forest” in the true sense, because its trees are not where they would have originally grown but were carried by rivers here.

This extraordinary site is one of the most important in paleobotany: it offers a rare glimpse of time immediately after the dinosaurs were exterminated in the late Cretaceous period, having dominated the Earth for 165 million years.

But each petrified forest tells a different story

La Leona Petrified Forest, the petrified forest of El Calafate

Just 110 kilometers from El Calafate, the petrified forest known as La Leona invites you to immerse yourself in the past and find prehistoric remains on the Patagonian surface a short distance from the tourist city of El Calafate.

You can do the excursion in 1 full day from El Calafate.

You should get up early in El Calafate and go to La Leona ranch. After traveling 33 kilometers east on Provincial Route 5, you will have to turn north on National Route 40 and travel another 67 kilometers.

Once at the La Leona hotel, you will have the feeling that you have traveled back in time. There is this immutable hotel. It looks the same since 1916, when it housed a Theodor Baash bar and shop.

Ask for information at the Hotel to go to Mount Los Hornos where the Petrified Forest is located.

Already in the forest you will see that the landscape, similar to the lunar surface, is the result of the erosion of the wind and the water that have modified this soil over the years. The trees that suffered this geological phenomenon, together with other fossil remains, make up this impressive petrified site.

La Leona Petrified Forest, the petrified forest of El Calafate

As we have already discussed in the late Middle Jurassic period, intense volcanic activity occurred at the same time as the Andes mountain range was being formed. It then buried the hot and humid Patagonia and its forests under a thick layer of ash to begin to make it what it is today.

Unlike other petrified forests, these La Leona trees were dragged by both rivers and glaciers, to the place where they are today. Protected by the slopes of the hills and immersed in an extremely arid climate, innumerable pieces have been preserved in the ground. Many of them are large, some of them up to a meter in diameter.

The La Leona Petrified Forest, only 110 kilometers away from El Calafate, is an invitation to travel back in time and enter the time when enchanting Patagonia looked very different.

Petrified Forest Jaramillo

In this petrified forest you will find some specimens that can measure up to 35 meters long, which makes them the largest petrified logs on earth.
The Jaramillo Petrified Forest is located in the north of Santa Cruz, 256 kilometers from Puerto Deseado.

The place is literally a forest. Although their stone trunks scattered on the steppe seem from another context, their roots are in the same place where they spent their lives.
In the same place where the petrified forest is, there was a giant coniferous forest 150 million years ago in Patagonia.

The site is impressive and is considered one of the most important fossil sites in the country.

Petrified Forest Jaramillo

Why? … Because there are the longest petrified trees in the world: some specimens reach a length of 35 meters (not including the buried parts, under the branches and the crown) and are up to 3 meters in diameter. Until they were petrified they were 1,000 years old.

To preserve this impressive site, in 1954 the Jaramillo Forest was named a National Natural Monument.

Original structure cut where you can see the growth rings and their ranges of colors.

Original structure cut where you can see the growth rings and their ranges of colors.

In this vast area of 10,000 hectares there are not only trees. Despite being an almost desert-like place (no more than 200 mm of rain a year) and very windy, numerous species of fauna inhabit the place: you will be able to see guanacos, red foxes, pumas, maras, lizards, skunks, piches, ostriches, rhea, eagles and martinetas among other species that walk next to the petrified trees.

From Puerto Deseado you can take National Route 3 heading north and then connect with Provincial Route 49 until you reach Petrificado Jaramillo Park.

Sarmiento Petrified Forest, José Ormachea Forest

It is 150 km from Comodoro Rivadavia by paved road. From Comodoro you take provincial route No. 26, until you reach the town of Sarmiento. From there, along a gravel road, signposted, you will reach the José Ormachea Petrified Forest.

Sarmiento Petrified Forest, José Ormachea Forest

The area covered by the forest is quite extensive and there are huge logs, leaves and even seeds scattered throughout the land. According to experts, the wooded area of this place is very important and it is almost certain that there are still specimens of trees that reached more than 100 meters in height.

Pieces of petrified wood

Pieces of petrified wood

The surrounding deep depressions in the ground still keep vestiges of other realities: mollusk shells, dinosaur fossils and strange rock formations, known as Red Stones, are some of them.

Petrified forest at Estancia Bahía Bustamante

One of my favorite places, the Bahía Bustamante ranch on the sea about 180 KM from the city of Comodoro Rivadavia has a spectacular environment of fauna and birds as well as a small petrified forest about 30 minutes from the Estancia.

Petrified forest at Estancia Bahía Bustamante

In order to visit the park, you have to stay at the ranch that has different types of accommodation and rates for tourism.

Other little-known petrified forests in Patagonia

In addition to the petrified forests already mentioned above, there are innumerable fossil outposts in Patagonia scattered throughout Patagonia.
Some have already been discovered and are in private fields, others are yet to be discovered.

Aside from Argentina, famous petrified forest sites include the Greek island of Lesbos. And in the US, the petrified forest of Arizona and Wyoming are home to some of the best examples of petrification.

What is the best way to tour the petrified forests in Patagonia

It is not so easy to access the petrified forests as they are in remote and lonely places. Most of the time in the middle of the steppe and far from the urban centers of Patagonia.

The best way to get to these places is with a rental vehicle.

In Patagonline we have prepared a travel itinerary called Route 40 that allows you to visit at least 2 petrified forests also visiting other places of interest such as the Cueva de la Manos, the Fauna of the Atlantic Coast in Patagonia and Finishing in El Calafate next to the Perito Glacier Brown.


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About the author

I am Matias, born in Patagonia, and a lover of my land.

For more than 20 years I help foreign travellers to organise their trip to Patagonia.

I also manage this exotic accommodation on the Atlantic coast.