1. Metals and minerals
Since antiquity, the islands of the Aegean have been of particular interest regarding their natural wealth, due to their great variety of useful minerals that are hidden in their subsoil. The ancient obsidian quarries in the Nychia area of the island of Milos are very well know. There, the ancient quarryworkers quarried the pieces of obsidian and manufactured tools, as it is testified by the piles of quarrying products that are still preserved .
Also known from antiquity are the marbles of Paros, Thassos, Naxos, Chios and Tinos. The Paros’ marble was known among the ancient Greeks as Parian lithos (stone) or lychnitis (lamp), because the exploitation took place in underground galleries using the light from the oil lamps . This is a white marble, homogenious, with characteristic radiation and great penetrability by the solar light. Paros marble was the construction stone of some of the masterpieces of ancient Greece (eg the Victory of Paeonios, Hermes of Praxitelis, Venus of Milos etc.).
Also known from antiquity, the marble of Naxos that can be found mainly in the western part of the island was quarried since antiquity and was competing in quality that of neighbouring Paros. It was widely used in building and decoration of the sanctuaries at Delos and Delphi, while the famous terrace of the Lions in Delos was also contstucted from Naxos marble. The white marbles of Thassos belong to the metamorphic rocks of the Pangee unit belonging to the mass of Rodopi which covers the biggest part of the island. The systematic exploitation of marbles started in the beginnings of the 7th century BC from settlers coming from Paros. Today, the dolomitic marbles that are mainly found in the northern part of Thassos, are most coveted.
In Sifnos ores are known since the prehistoric times, while the island was of great importance at the antiquity, as it was one of the most important mining centres of silver-containing deposits of lead, zinc and copper.
Today, despite the fact that the methods of exploitation have been improved and the use of metals and other minerals in new areas is continuously increasing, often the techno-economical terms of deposit exploitation (terms that are related to the constitution, the texture, the reserves, as well as the transportation of the mineral), limit the possibilities of exploitation in the area of the Aegean.
The exploitable deposits are mainly the industrial minerals and quarry products, like gypsum, kaolin, perlite, betonit and others, which are quarried in several islands. The deposits of barit (Milos, Mykonos) and iron (Serifos) are also significant.
A short report on the most important deposits in the area of the Aegean follows, providing information on the islands where the particular layers have been found.
In Paros, in the region of Thapsana,a remarkable deposit of manganese created due to the hydrothermal activity is found. Furthermore in Milos, in the area of Vani, an ore deposit of manganese appears, which is connected with the recent volcanic activity on the island.
Bauxite, the only mineral from which aluminium is received, appears in small deposits in Amorgos, Skopelos, southern Chios and Samos.
Big deposits of gypsum are found mainly in Crete (Sitia, Chania, Ierapetra etc) and Kasos, but also in Rhodes and Karpathos.
In Skyros copper, with medium content in copper (approximately 6%) appears .
In various regions of the Aegean sedimentary layers of organic origin have been found, which are not particularly known to non specialists: coal in Chios, important layers of lignite in Crete, lignite of smaller importance in Kos, Rhodes, Lesvos and Alonnissos.
Deposits that emanate from chemical alteration, as well as quarry products have been found on islands where intense volcanic activity took place. In this category falls the perlite in Milos and Kos. Similar deposits also exist in Gyali of Nisyros, in Lesvos and Antiparos. Betonit has been found in Milos and Kimolos, while of smaller importance are the deposits that were found in Lesvos and Chios. These deposits have been created by the alteration of volcanic rocks.
The biggest deposits of kaolin have been found in Milos and smaller deposits in the islands of Lesvos and Kimolos. Pumice as well as puzzolana consisting of pumice and volcanic tuffs can be found in Thera. Sulphur soils with important exploitation, as well as layers of alounit (styptiriatis) are found in Milos. The creation of sulphur is a result of intense hydrothermal activity which is active also today in the island. Proof of this activity are the surface measurements that give temperatures that approach 100 C.
Important deposits of emery are found on Naxos, as well as in the neighbouring islands. The formation is rich in corundum and emanates from the metamorphosis of older bodies of karstic bauxite. The emery has usually erratic lens-shaped form and can be found in the marbles of the metamorphic rock system of the island. The metamorphosis of bauxite and the corresponding formation of emery took place in the two metamorphic, greenschist phase, episodes of the island, during Eocene and upper Oligocene. There are three types of emery in Naxos, distinguished by their chemical composition- the marketable type is constituted mainly by corundum and iron and titanic oxides (rutile, hematite, magnetite, ilmenite), and is rich in Al2O3 and poor in SiO2.
Small deposits of chromite have been found in Rhodes, while sulphurous deposits of nickel, copper and iron can be found in Skyros.
Molybdenite has been located in the village of Stypsi on Lesvos, while deposits of leukolite (magnesite), developed in veins, exist in the area of Achladeri Lesvos, in the ultrabasic rocks of the ophiolithic cover of the island. As the abandoned galleries and the magnesite piles testify, in the past magnesite was exploitated in this region, to be used as raw material for the production of synthetic magnesium products and metal magnesium, while its uses expanded in the construction and the iron industry as well. The veins of magnesite are in cleavage zones of ultrabasic rocks originating from decomposition of serpentinite during the metamorphosis.
Appearances of unexploited mixed sulphurous deposits of galena, zinc blade, pyrite can be found in many islands of southern Aegean, as well as in Thassos and Samothrace. In Thassos the mineral is in veins and replacement pockets and is composed of smisthonite, hemimorphite, zinc blade, Wurtzite, galena, cerussite, baryte and anglesite. The quality of the mineral varies. The content in zinc locally is very high, up to 40%, while in lead up to 26%.
Ores with Manganese exist in Lesvos, Samos, Ikaria, Paros and Antiparos.
Noteworthy iron ores exist in Thassos, Serifos and western Crete, while deposits of smaller importance are found in many islands in the Cyclades.
The most impressive appearance of skarn in Greece is in Serifos. This important outcrop was formed during the infiltration of a magmatic body (granodiorite) in a series of metamorphic sediments (mica schists, marbles and gneiss), causing intense contact metamorphism. The main minerals of the Serifos skarn are garnets, diopside, magnitite, wollastonite and scapolite. The magnitite was the metal mineral of the Serifos skarns with economic interest. The existence of a quartz form, the so-called green quartz (prassios) is unique in Greece.
Antimonite has been located in Chios - in the village of Keramos where it was exploited in the past. It is an ore found in veins consisting of antimonite and quartz. Large deposits of barite can be found in Milos, Kos, Kimolos, Mykonos and in Dragonisi. Exploitation takes place in Milos and Mykonos. Asbestos is found in Samos and Anafi.
In the volcanic rocks of northern Lesvos, a system of quartz veins, which hosts an epithermal ore deposit containing gold and silver, has been developed. In these areas, as some abandoned galleries testify, some basic metals were exploited during the Byzantine times. These were mainly lead, zinc, copper and silver, which are connected with the above mentioned ore deposits. Ιn western Thassos there are deposits of lead and zinc and in the north-eastern and eastern part of the island there are deposits of gold.
The submarine area of the Aegean remains relatively unexplored and with unknown, apart from oil, wealth-producing possibilities in minerals and other material of economic use. Since 1938, when the research for oil in the Aegean begun, all attempts in finding oil were unsuccessful, apart from the one in the area of Prinos, southern of Kavala.
2. Biogeography of the Aegean
2. 1. Flora
Regarding the biogeography of the Aegean, it is pointed out that most of the surface of the islands as well as the coastline of mainland Greece is covered by Mediterranean ecosystems, maquis and short spiny boshes called “frygana”, with the typical plants of the Mediterranean that adapt in the long periods of drought, the low temperatures in the winter, the short period of rainfalls, the intense sunlight, the small depth of soil but also the human activity.
The maquis vegetation is a dense and almost impenetrable cluster consisting of tall bushes and small trees, where the species Quercus coccifera L., Phillyrea latifolia and Phillyrea media L., Pistacia terebinthus L. and Pistacia lentiscus dominate. Wherever the ground is poorer or intense pasturage takes place frygana (named by Theophrastus) grow. Many of these types are aromatic and each one has a particular scent, as the thyme, the sage, the oregano, the wild lavender et al.
Important part of the Aegean islands is covered by rural ecosystems, natural land or swampy ecosystems. In these ecosystems the man intervenes, by cultivating olive groves, vineyards, vegetables, potatoes et al. In smaller percentage pinewoods grow, as well as various species of cypresses and cedars depending on the region. In the regions where the conifers are dense, frygana or maquis grow. The wetlands, torrents, rivers, lakes, marshes with thrifts, canes, tules are less frequent. Between the plants insects, clams (worms, shells et al), crustaceans (crabs, prawns), fishes, reptiles, suckling and a large number of birds live. The birds that visit the wetlands, because of the abundance of food can stay permanently. Many of these birds are rare or protected. Along most of the torrents develops vegetation with characteristic hydric plants that dominate in this environment, as the Vitex agnus - castus, Nerium oleader, and Rudus fruticosus, Platanus orientalis, Populus sp., ivy Hedera helix, Myrtus communis et al.
The coasts are also important ecosystems. When they are sandy and particular conditions of salinity, temperature and humidity prevail, bushes can be found or Salicornia europaea, Suaeda maritima, Salsola soda, Spergularia marina, Aster tripolium, Polypogon monspeliensis, Limonium sp., Hordeum marinum, Atriplex hastata, Eryngium maritimum, Cynodon dactylon et al. and often many other rare and endemic species often adapt to these conditions. When the coasts are rocky, the rocks often rise a lot of metres above the sea level. The lack of ground, the increased salinity and the isolation, create particular conditions for plants and animals. Many rocky islands belong in this category as well. In these regions, plants that sprout in the cavities of rocks where some soil is retained grow. In addition, a lot of species of raptor birds like falcons, eagles et al. and seabirds which need isolated and steep places for nesting and high points that helps them in finding food live in the steep rocks.
2. 2. Fauna
The fauna of the Aegean consists of land mammals such as:
- carnivorous like fox, marten, weasel, badger et al.
- artiodactyls like deers, wild goats, ibeces, wild boars
-insect eaters like hedgehogs, talpa
- lagomorpha like rabbits and hares
- rodents like squirrels, mice, rats, moles et. al.
A big number of raptor birds, seed eaters, coastal birds et al live in the above mentioned ecosystems, while the islands of the Aegean constitute resting areas for the migratory birds. The amphibians and the reptiles constitute important part of the fauna in the region and include toads, frogs, salamanders, tritons, snakes, lizards et al.
The marine waters of the Aegean have in general a poor variety of living organisms, but despite this, species of the Mediterranean Sea, the Black Sea, the Red Sea and the Indian ocean are found. 447 species of fish have been recorded and thousands species of other organisms like sea stars, sea urchins, clams, mussels, oysters. 15 species of marine mammals like seals, dolphins, whales have also been recorded.
The geographic position, the climate and the big variety of biotopes of the Aegean compose the physiognomy of the fauna, which is characterized by a big biodiversity. The fauna of the Aegean is rich and is a mixture of European, Asian and African species, with various endemic species.
From the 115 species of mammals of the Greek fauna some of the rarest live in the region of the Aegean. The Dama dama, known also as “roditiko” deer, numbers few animals, which live in the forests of Rhodes. The ibex of Crete, known as kri kri, lives in the Samaria gorge and in certain small islands where it has been transported. In Crete the very rare Cretan wildcat appears as well. In addition, the ibex of Antimilos lives only in the steep island of Antimilos. Other rare species of land mammals that live in the area of the Aegean are the Asiatic squirrel that lives only in Lesvos, the Cretan dasomyoxos, the badger of Crete, the badger of Rhodes, the Cretan wild rabbit.
The marine mammals that are present in the Aegean are the Mediterranean seal (monachus monachus), with population that does not exceed the 350 individuals, the zonodelphino (beltdolphin), the grey dolphin that is rare in the area of the Aegean, while very rare are certain species of whales.
As for the birds of the Aegean, many species met also in other regions of Europe nest in the area, like kruper’s nuthatch and cinereous bunting. Very few individuals of the harrier eagle are also present.
Concerning the reptiles, in the area of the Aegean, the viper of Milos, the blanus strauchi of Dodecanese islands and the salamander of Karpathos are protected.