## 3 Geology of the Study Area  
The Samaria Gorge area is geologically structured by Neogene-Quaternary geological formations, as well as by Alpine bedrock. The geological and topographical complexity of the study area has been highlighted by various researchers, who contributed to the theoretical background establishment. In these proposals, the following geological formations/terms are referred to:  
The \"Plattenkalk\" term, which was initially introduced by [PERSON] [35], describes a thin- to medium-bedded crystalline limestone sequence, including chert intercalations or/and nodules, located in Eastern Crete. Numerous geological studies, performed in the Peloponnese and Crete regions, consider that this sequence is predominantly exhumated as a tectonic window throughout these regions. On the contrary, [PERSON] [36] applied a different terminology, introducing the \"Madara-Kalke\" term in order to describe  
Figure 3: Contact (yellow line) between the Gigilos and Plattenkalk formations.  
a thick complex of white to dark recrystallized limestones (=machtiger Komplex), bedded in the lower part and unsorted in the upper part. The Triassic age was questioned as it underlies the Permian \"Phyllites-Quartzites\" unit.  
Regarding the Western Crete region, the \"underlying system of the Plattenkalk\" term was introduced by [PERSON] and [PERSON] [3] to describe a system of approximately 300 m in thickness that consists of phyllites, dolomites, microbreccia limestones, cherts and clays, while numerous Upper Triassic occurrences (with Ostrea, Myborria and probably Halobia) are documented within the dark, thin-bedded limestones.  
In the geological map of Crete (1:200,000 scale) constructed by [PERSON] et al. [37], the aforementioned beds are defined as the \"Gigilos formation\", which underlies the Plattenkalk\" formation. On the contrary, [PERSON] [38] proposed the existence of a tectonic unconformity between the Gigilos beds and the Plattenkalk formation; the gradual stratigraphic transition is the potential between the two formations, and the estimated age of the Gigilos formation is Liasian-Doggerian. Furthermore, apart from the common elastic sediment alternations (clays, calc-phyllites, sandstones, microbreccia limestones), an additional formation was identified, which resembles flysch and consists of clays with a thin gypsum layer, thin-bedded sandstones and thin-bedded, clastic limestones.  
Therefore, according to various researchers [31; 38; 39; 40; 41], the generally accepted geological model highlights an anticlinic megastructure occurrence, which considers Mt Gigilos as the core [6; 7]. It should be emphasized that the Trypali unit dolomitic limestones are documented southwest of the Samaria Gorge, while the corresponding underlying system of the Plattenkalk Group is not. The Trypali dolomitic limestones tectonically overlie the Plattenkalk formation, while the in-between contact is accompanied by a tectonic breccia, locally exceeding 2 m thick.  
In particular, the Trypali unit and Plattenkalk Group constituting the bedrock of the wider area of Samaria Gorge show different lithological characteristics; intensively brecciated, strongly karstified, predominantly carbonate formations dominate in the Trypali unit, characterized by their cellular texture, resembling rauhwackes. The Plattenkalk Formation consists of thin-bedded marbles, including chert intercalations and/or nodules, while the underlying Gigilos Formation rocks consist of alternations of metaclastic and metacarbonate rocks with cherts.