Qeshm Island UNESCO Global Geopark

Qeshm Island UNESCO Global Geopark is an island of the Islamic Republic of Iran, which has the shape of a dolphin. It is the largest island of the Persian Gulf region and stands parallel to the south coasts of the Hormuz Strait. The highest point on the island, Kish Kuh Mount, is 397 m high.


Geomap of Qeshm Island UNESCO Global Geopark

Qeshm Island UNESCO Global Geopark is part of the huge mountain range of Zagros, which has been deformed and folded as the result of the last phase of the Alpine orogeny in the Plio-Pleistocene. The geological formations of this mountain belt belong to the Late Precambrian to Cambrian (more than 480 million years old) and include salt diapirs attributed to the Precambrian period called Hormoz Series. According to the majority of geologists, the tectonics of this region has been active from the Late Tertiary. The tectonic zone is represented by the south part of the deformed forehead or the convergent belt (Mesopotamia and Persian Gulf region), as well as by the margins of the compression and collision plates of the Iranian-Arabic continent.

The Qeshm Area of the Persian Gulf Region forms part of the south and eastern extreme foreland of the Zagros geological and structural Province, expressed in the NW-SE trending Zagros Mountain ranges. The more southerly part of the Zagros Fold Belt faces, but is separated from the Oman Region, while the Mokran geological and structural Province lies to the east, beyond the Minab-Oman fracture zone. The highest mountain peak on Qeshm Island is related to the Kish Kuh Anticline structures that have increased the height in part as an effect of diapirism tectonics, related to the Namakdan Salt Plug. Qeshm Island UNESCO Global Geopark has also the world longest salt cave, 6600 m in length. In addition to the salt formation and complex, other sedimentary formations are exposed in the different anticline structures on the island. The succession consists of conformable Neogene (Mio-Pliocene) units, with a total thickness of about 1200 to 1850 meters from the eastern to western ends of this island, respectively. In general, mountainous or high ranges nearly coincide with the folds having anticline structure, or in part as salt dome diapers, and the relative lowlands are mainly within or based on intermediate forms or synclines. Several major geosites are also located around the anticlines.

The island has abundant wildlife, including birds, reptiles, dolphins and turtles. In Qeshm Island, zoogeographical areas of Palearctic and Oriental, and phytogeographical areas of Afro-tropical, Oriental and Eurasian, are meeting each other, which generated a huge variety in fauna and flora.

2. General geology of Qeshm

According to the tectonic and sedimentology evidences, we can include Qeshm as part of the south of Zagros. The external similarities as well as the existing harmony between Qeshm Island’s big anticlines and Zagros' anticlines are some proofs confirming this idea.

The effect of  Namakdan mount's salt dome on the west part of the island is totally obvious and has caused morphologic and tectonic changes in this part of the island.

The north of  Persian Gulf  includes a part of the southeast of zagros structural zone which has been deformed and folded as the result of the last phase of Alpine orogeny in Plio-Pleistocene. The geological formation of this belt may belong to the late Precambrian to Cambrian and include diapirs attributed to the Precambrian called Hormoz Series, which has been active till now with a trend toward the upper formations at the earth level. According to the majority of geologists, this region from the tectonic point of view – has been active since the late Tertiary as the tectonic zone in the south part of the deformed forehead or the convergent belt along with the margins of the compression and collision plates of Iranian- Arabic continent. The region located in the southeast stretch of Persian Gulf along with Hormoz and Qeshm Island can be identified by the structural, sedimentological and geological features such as the mainland which is distant from from it- with 2.5km width in the narrowest parts.

Sea terraces of Tertiary sediments in Qeshm Island are partially accompanied by Quaternary deposits; therefore they have resulted from the compressive tectonic forces related to Alpine orogeny.

Quaternary Sea terraces very well often are horizontally stretched, while having a little slope toward the sea. The older terraces particularly those located on the anticline have a steeper slope and some mild foldings. The terraces are made of corals, zoomorphic shells and deposited marine settlements in the old coastal regions whose thickness varies from a few meters to 10m.

As for the composition, they contain coral deposits, lumachelle sandstone, limestone and sandstone which often discordantly cover the formation of the thicker yet weaker bedrock with a duricrust surface ( usually with layers of red sandstone and silty marl of Miocene, Pliocene, Mishan and Aghajari Formations cover it). The internal extension of the marine terraces at its most can observed in about 10km of the present coastline in Qeshm Island.

Erosion

Erosion is the most effective factor in creating and forming the geological  phenomena in Qeshm. After erosion, we would refer to the effect of Namakdan Salt dome, which is also the main cause of emergence of the ores colorful outcrops and various layers. One can also see the sedimentary and stratigraphic phenomena in Qeshm, which in turn are to be discussed.

Erosion in Qeshm is primarily the result of the work of wind, sea waves, seasonal rainstorms, temperature change, humidity, mineral crystallization and secondarily factors such as tectonics and gravity. Erosion mainly happens in the Neogene' s sediments, which are softer, and the most erosion can be seen in the silt, marl and sandstone layers. In many regions due to the rapid erosion of the lower layers, which are weaker than upper ones, the space beneath the hard layers gets emptied and the layers due to effect of gravity collapse. Good examples of this feature can be seen in the coastal terraces near Souza and Doostkooh. In the regions far from the coast, wind erosion as well as seasonal rainstorms can also strongly affect the softer sediments and create a totally heterogeneous morphology of which the best example is Darreh-Setareha ( The Valley of Stars ) in the vicinity of Berkeh Khalaf village.

Erosional Forms and statues

Almost all throughout the island, one can find a wide array of beautiful phenomena, which are the work of the erosion’s artistic hand. Abundance of weak and not resisting beds and their alternation with more resisting ones, results in the formation of erosional forms. In other words, intense erosion in some parts and the survival of more resisting parts is the main cause of such formations. Of course, these phenomena can be observed in the homogeneous layers as well and the cause behind this is the direction in which erosion factors ( such as wind, sunshine, slope and flow of water ) work; this finally results in the different levels of erosion to occur in different parts of the layer. Among the numerous form of erosion we can name the erosional columns such as Chimney Rocks, and mushroom-shaped, arched, global, kidney-shaped forms, small and big cones and pyramids, as well as the shapes similar to human profiles and different animals.

The plains and areas in the neighborhood of the sulfurous mineral spring in Kargah region include a collection of erosional forms. In this region, there are extensive hilly lands and fells, which are suggestive of the Bad Land type.

3. Local communities

Qeshm Island UNESCO Global Geopark has three cities and 57 villages. There are about 120,000 people residing on Qeshm Island. The major business opportunities of the people are trading and fishing. Local communities are now also engaged in geotourism activities and profit from the benefits of this sustainable and environment-friendly business, which provides a real motivation for the local community to conserve the geosites.

The culture of Qeshm is based on its intact nature and geological heritage. The oldest human settlement in the Qeshm Island UNESCO Global Geopark is about 40,000 year old. According to archaeological analysis, the island inhabitants were famous traders in ancient Persia, especially during the Sassanid era, with the Far East, the west coast of the Indian subcontinent, the southern shores of the Persian Gulf and especially the east coast of Africa. This trade continued during the Islamic periods. According to anthropological observations, some cultural traces, clothing or music, observed on the island, have their roots in African and Indian cultures. Qeshm is also a supposed site of the Garden of Eden according to Cassell’s Bible.

©Qeshm Island UNESCO Global Geopark, Islamic Republic of Iran / Asghar Besharati

In some of its geosites, Qeshm Island UNESCO Global Geopark has established an educational programme for the local community aimed at conserving these natural zones. An example is the educational visiting center built in the tourist-jetty of Soheili village, lying on the southern coast near the Hara Biosphere Reserve. The Qeshm Island UNESCO Global Geopark also produced a specific educational programme based on the framework of schools’ science textbooks. It persuades students to learn about the Earth, stimulates their sense of responsibility about the Earth’s resources and encourages them to do teamwork. The educational-promotional programme encourages students to care about the environment. There is a special programme dedicated to kids aged 7 to 11 that aims to leave a durable and happy impression about taking care of the Earth.
 

Source: http://www.unesco.org/new/en/natural-sciences/environment/earth-sciences/unesco-global-geoparks/list-of-unesco-global-geoparks/iran/qeshm-island/
             http://qeshmgeopark.ir/en