The first landmass, from which Crete would eventually evolve, formed between 27 and 20 million years ago (mya) during the Late Oligocene (28 to 23 mya) and the Early Miocene periods (23 to16 mya). An extended land, called Aegaiis occupied the whole Aegean region connecting mainland Greece with Asia Minor. Some 11 mya during the Late Miocene (11.6 to 5.3 mya), intense fragmentation of the south Aegean, and subsidence of large areas resulted in the formation of the Cretan islands. Crete remained a cluster of small islands until the end of the Miocene 5.3 mya.
At the beginning of the Pliocene 5.3 mya intense fragmentation continued and significant vertical movements took place, resulting in the uplift by more than 700 mtrs. of several regions including the Dikti Mountains.
During the Pleistocene 2.6 million to 12,000 years ago, Crete took on it’s present shape as a result of major changes to the landscape. These changes are still taking place.  
The Katharo plain also known as the Katharo basin or the Katharo plateau is situated to the north of the Dikti mountain range. It is 16.5 km. west of Kritsa and is 6 kms. long, 1.5 kms. wide at an average altitude of 1150 mtrs. above sea level. To the south of Katharo are the peaks of Spathi (2148 mtrs.) and Lazarus (2085m) and to the north the peaks of Tsivi (1665 mtrs.) and to the east Platia Koryfi (1485 mtrs.).

Katharo is described as a classic karstic feature, the result of chemical weathering of carbonate rocks. It is a sediment filled basin that formed about 2.5 million to 12,000 years ago, during the Pleistocene period, consisting of clays, clayey sands, and angular gravels. These sediments lie over a subsoil of strongly weathered sedimentary rocks that usually consist of siltstone, carbonate rocks, conglomerates and sandstone. Deposits that are associated with lakes (Lacustrine deposits) indicate that the basin was a lake during portions of the Pleistocene.
The plain is still being reworked by the continuing actions of the weather, tectonic activity and various streams that merge into two river systems, which  eventually drain into the Havga gorge, then down onto the Lassithi plateau some 200 mtrs below.

Charalampos G. Fassoulas. (2001) Field guide to the geology of Crete.

David S. Reese (1996) Pleistocene and Holocene Fauna of Crete and its First Settlers.