Fuentelsaz stratotype

Fuentelsaz stratotype

Nestled in the Molina-Alto Tajo Geoparkthe Fuentelsaz stratotype is considered the world's oldest record of the transition between the Lower and Middle Jurassic, around 175 million years ago. To reconstruct the Earth's history, geologists look for places where continuous and uniform sedimentation has been recorded over certain periods of time.

These sites, known as stratotypes, are used as patterns or models for comparison with other sites where the record is not as complete or preserved in as much detail. When a stratotype shows an overall process it is assessed by the International Union of Geological Sciences (IUGS), which selects the most representative worldwide, and in Spain we only have five, one of them at Fuentelsaz, since 2000.

The outcrop of the Fuentelsaz Stratotype is located about 500 metres north of the town itself, on the hill called Cabeza Quemada. From the village itself you can see If you want to visit it, at the exit towards the GU-435 road, you can walk to the outcrop by crossing some crops. The section consists of two outcrops located in two ravines, just a hundred metres apart.

At Fuentelsaz have created a small information centre which can help to better understand the visit, although the opening of a new interpretation centre is planned.

The exceptional character of the Toarcian-Aalenian transition materials in the Fuentelsaz Section, together with its extraordinary palaeontological record, have led the IUGS to choose this section as the boundary stratotype and point for the base of the Aalenian, or in other words for the base of the Middle Jurassic. The Fuentelsaz section is also of marked palaeontological interest as there are records of numerous groups of animal and plant fossils. There are also non-biotic data, such as palaeomagnetic, geochemical, mineralogical and isotopic data.