Greece records the highest level of seismic activity in Europe, and is an area where the geology is young and dynamic. Earthquakes are a frequent occurrence, and have shaped the course of Greek civilisation and culture. Titanic, subterranean forces have moulded some fascinating and unique geological features, sculpting rugged mountain ranges and precipitous, tumbling valleys.
THE FORMATION OF GREECE AND THE PELOPONNESE
200 million years ago, the area that would become Greece lay under the Tethys Ocean, trapped between the ancient super-continents of Pangaea and Laurasia. During the Triassic and Cretaceous periods, calciferous marine organisms died and sank to the sea-floor, gradually forming thick sedimentary deposits of dolomite and limestone.
As these two super-continents rotated towards each other, the entire Tethys Ocean was subjected to slow and irresistible pressure. The huge stresses caused by this gradual squeezing deformed the earth's crust, and led to a steady uplifting and buckling of the sedimentary rocks. Intense heat and pressure metamorphosed the parent limestone and sandstone, into marble and quartzite, respectively.
This huge area of uplifting stretches from the Alps through to the mountains of Iran, all of which are, geologically speaking, very young ranges. The boundary regions of these tectonic plates are complex and changeable; Greece occupies the Hellenic plate, which is slowly stretching, in a north-east / south-west direction. This micro-plate is spreading out over the descending African plate to the south-east, and the Turkish plate to the east.
The underlying geology is extremely complex, and the spreading Hellenic plate has created a series of horsts and grabens. These form the backbone of the area, giving rise to the jagged mountains and steep sided valleys. Constant kneading, and squeezing, of the bedrock has caused high levels of tectonic and volcanic activity in the area, influencing the underlying fabric of Greek culture and history.
For example, the volcanic explosion of c1644 BC, at Thera (Santorini), destroyed the cultured Minoan civilization on Crete. Ancient Sparta was levelled, in 464, and the aftermath of this destruction led to the first Peloponnesian war against Athens. More recently, Kalamata suffered serious damage in 1986, necessitating a complete rebuild of the city.
THE FORMATION AND GEOLOGY OF THE TAYGETOS MOUNTAINS
The complex uplifting of the whole Eastern Mediterranean formed the inspiring mountains of the Peloponnese, and the area is crossed by a complex web of inter-connected fault-lines. Gradual deformation of the Hellenic plate has created many localised faults within the peninsula, which constantly slip and shear. The Taygetos and Parnonas Mountains are large horsts, with deep grabens on either side. Thus, the mighty Taygetos range is sandwiched by two faults, causing the large tremors that frequent the area.
ROCK FORMATIONS IN TAYGETOS
Due to its turbulent geological history, the Taygetos Mountains possess some interesting rock formations, consisting mainly of limestone and dolomite, formed when the area was under the Tethys ocean. Veins of quartz are embedded within this matrix, and many quartz based crystals are found in the area, including citrine and amethyst.
The Parnonas mountains, on the other side of the Evrotas Valley, contain Lapis Lacedaemonium, a rare type of serpentine porphyry found only around the village of Krokees. This semi-precious stone was one of the major exports of Ancient Sparta, and was extensively quarried by the Romans, who used it to adorn their villas and public buildings.
THE DIROS CAVERNS
The Diros caverns, near Areopolis, are one of the longest cave systems in Greece, and are popular with casual tourists and speleologists alike. This hidden gem is ranked as the third most important cave system in the world,. The cave system itself was known in ancient times, and was referred to as an entrance to the underworld.
The sheer extent and scale of the caves was first discovered by I. Petrocheilos and his wife, Anna, in 1949. 1971 saw the start of a systematic cave diving and mapping process, and this research is still ongoing. The explored length of the network is 6.2 km, but there is a huge amount still to be uncovered. Scientists believe that the whole Peloponnese peninsula is honeycombed with a huge, and interconnected, network of caves.
The Diros caves are extremely beautiful, containing many interesting rock-formations and a series of awe-inspiring caverns. The Glyfada River runs through the calcium carbonate rocks, carving out a multitude of channels, and sculpting cathedral-like caverns. Steady infiltration by rainwater, when the river level was lower, created many beautiful and interesting stalagmite and stalactite formations.
It is impossible to visit the Taygetos region without noticing the pyramidal Mount Taygetos. The mountain actually consists of five peaks, known locally as the Pentedaktylos (Five Fingers), and the highest, Prophet Ilias, rises to 2410 metres. The mountain is an imposing sight, and looms ominously over the city of Sparta.
Taygetos was the site where Ancient Sparta executed criminals, cruelly throwing transgressors to their death. Sometimes the peak glistens in the sun, at other times a blanket of clouds caresses the summit. Throughout the winter, it is covered in a layer of pure, white snow, the pyramid standing out starkly against the crisp blue sky.