Montaña de Timbaiba is a horseshoe-shaped volcanic cone, formed during the fissure eruption in the Middle Pleistocene. This building was constructed over a wind sand dune from the Pleistocene. There are two dune systems separated by a paleosol and by two pyroclastic deposits during the Timbaiba eruption. On the oldest dune there are fossils, such as bone remains of extinct bird fossils, like the pardela extinta Puffinus holeae, himenopteros and coleopteros nests, and different land gastropod shells such as Hemycicla sarcostoma, Theba geminata or the Rumina decollata. The most recent sand covers the hillside of the Timbaiba cone forming spectacular rampant dunes on the inside of the crater. We can see sedimentary structures typical of this kind of deposit, such as crossed stratifications. These sand deposits intertwine with torrential detrital deposits from the erosion of the hillsides of the crater.
This geosite’s main interest is paleontological, although also vulcanological, stratigraphic, sedimentological and geomorphological. This is a place of reference to research the paleo-climate of the Quaternary.[…] There is large geological diversity, especially on the inside of the crater, despite its small size.