The closed basin of Ascourida is found in Kato Olympos (Thessaly) at an elevation of 1000 meters. Its formation is primarily due to tectonic activity and occurred in two stages. Before or at the beginning of the Neogene we have fault tectonism which formed NE-SW trending faults. Along the tectonically weakened zone an elongated valley evolved which constituted part of the drainage basin of the region.
Following the Neogene, a more recent tectonic activity formed NW-SE trending faults followed by uplifting movements in Olympos. During this stage, due to the differential uplifting rates of the blocks, the upper part of the valley of the initial stream was cut off and the closed basin of Askourida was formed. It is possible that the basin of Askourida was cut off from the drainage basin of Karavida stream as is seen by the geometry of its catchment basin, which exhibits an area smaller than expected, by its position in relation to the basin and its orientation. Two terraces were observed at a height of 11 and 20m above the plain surface, which indicate the lake level in different periods. The evolution and morphology of Askourida took place during the Quaternary. The weathering and accumulation of sediments in the lake bottom started after the severance of the basin from the parent stream. The weathering started from the tectonically weakened places, like the faults and the overthrust scarps, and advanced vigorously due to the favourable climatic conditions that prevailed during the Quaternary. The development of alluvial cones along the thrust scarp of the Kryovrissi-Kalipefki unit on the Olympos unit is proof of active tectonism.
Η κλειστή λεκάνη της Ασκουρίδας βρίσκεται στη ΒΑ πλευρά του κάτω Ολύμπου, σε υψόμετρο 1000m. Η Ασκουρίδα μέχρι το έτος 1907 ήταν αβαθής λίμνη, οπότε άρχισαν τα αποστραγγιστικά έργα με την κατασκευή μιας σήραγγας στο νότιο τμήμα της λεκάνης, με την οποία αποστραγγίζονται τα νερά. Η εργασία αυτή αναφέρεται στη γεωλογία, την τεκτονική και τη μορφολογία της λεκάνης της Ασκουρίδας, στην παλαιογεωγραφική εξέλιξη και τις μορφογενετικές διαδικασίες που οδήγησαν στη δημιουργία της κλειστής αυτής λεκάνης.
