Paradise for geologists

Welcome to incredible Iran: Paradise for geologists!

Give us your hands until to familiar with beauties of Iran. Geological history of Iran is full of events, created widespread volcanic, magmatic and metamorphic outcrops. Thick stratigraphic sequences are naked across the country.

Our country hosts so many major faults, long anticlines and perched synclines, the beauty phenomena for structural geologists. Iran also is the country of Quaternary deposits and landforms extend from mountains top (glaciers) to the hill slope (alluvium) and from there to the lowlands in central Iran where the fascinated deserts, salt lakes, sand dunes and Yardangs have created a very attractive landscape for geologist and geomorphologists.

West of Iran is domain of karstic features, such as beautiful caves and large sinkholes which are formed during the last glacial stage.

Landslides are frequent in everywhere, including the Seimareh landslide with kilometers in length and width, well known as the largest landslide in the world.

The Zagros Mountain is located in the south and southwest of Iran. The famous structural – sedimentary zone contains the largest oil and gas reservoirs.

Our international guests can see the continuous stratigraphic sequence with several kilometers thick from Jurassic up to Pliocene, bare and easily to investigations.

The south of Iran also is the best place for visit unique salt domes, mud volcanoes and recent reefal limestone.

Iran also has an exceptional geographic and climatic conditions. The difference temperature between north and south sometimes reaches to 30 centigrade.

In the North, the shore line of the Khazar Sea, as the largest lake in the world, and its surrounding area with mountainous forest, are the attractive place for millions of tourists in all seasons. In this region, the natural beauties are in your path.

Toward central and southern parts of Iran can enjoy the magnificent and beautiful deserts, Kavirs as well as salt lake and playas have extended far away.

Damavand, Sabalan and Sahand as the most famous volcanoes of Iran and their young volcano-clastic rocks welcome to all volcanologists throughout the world.

There are so many Geo-parks and Geo-sites that increase your familiar with other natural beauties of Iran.

All attractions with low cost traveling, unbeatable security and hospitable people will excite you for travelling to Iran again and again.

“ZaminGasht” is a window to meet you the natural beauty and geological phenomena of Iran. We have numbers of Iranian experts in all branches of geoscience who can identifying natural beauty of Iran to all international geoscientists and geo-tourists.

Star Valley

The Star Valley, which is called “Estareh Kafteh” in local dialect, is one of the most important erosional phenomena in Iran. this valley is located in south east of Qeshm Island in Persian Gulf. In this valley there is variety of geomorphological phenomena which shaped several interconnected branches of small valleys.

Besides the mechanical erosion of water which is the main factor of shaping this area, there are many other factors such as different types of rocks with different resistance, the intercalation of gypsum and the different regional tectonic activities.

The walls of the valley are formed by two types of layer: the thick and soft layer in bottom and the thin and hard layer on top. As the top layer has calcareous cement, is more resistance than the loose lower one; so it acts as the protector. Therefor where ever the top layer was destroyed or has some joints, erosion effects quickly and it causes the small valley’s forming.

Referring to the mentioned causes; the layers of this valley are so brittle, so even the weight of just one person can be dangerous and causes collapsing. Although the upper layer may seems to be strong, but the lower layers may has been destroyed due to erosion.

The Mishan formation is the main formation of the Star Valley. In Qeshm Island this formation includes the alternation of marl and silty marl in olive green to grey color with some lenses of intra formation conglomerate which intercalates with sandstones.

The age of formation in star valley back to Middle or late Miocene (5 to 10 million years ago), but the phenomena relates to several thousand years ago.

In sedimentary sequences of Mishan formation, there is variety of structures such as thin – middle – thick and massive layering, fossiliferous limestone and sandstone in the channel shapes, graded bedding, plane lamination, lens form lamination and other structures can be found.

From the structural geology point of view, the layers in the Star Valley have low dip or they are horizontal. Due to tectonic activites in Mishan formation, the systematic joints have been created in this area. The gravity force and weathering and erosional phenomena are the main reason of joints opening.

In local ancient’s belief, this valley has been formed by impact a meteorite and rising up of stones and soils and freezing there. On the other hand, they believed this valley was the resort goblins and the voice of howling the wind was because of their movements.

Keywords: Erosion , Geo site , Geology , Geotourism , Iran , Limestone , Marl , Mishan formation , Persian gulf , Qeshm Island , Sandstone , Star Valley

Namakdan Salt Cave

Namakdan cave is among the most important geosites in the Qeshm Island Geopark (Hormozgan province, Iran). The salt dome (diapir) of Namakdan is a unique structure in the Island including several outstanding structural, mineralogical, erosional and sedimentary sceneries. In this Geosite the world record Namakdan Cave exists, the world longest salt cave, 6500 meters.

The Namakdan Salt Complex (Combrian) actually includes several smaller geosites. There are Salt flats, Playa, Salt springs, Amazing salt outcrops, Sink holes and many other structure and forms. This geosite has been registered in the National List of Natural Heritages (2010).

The main entrances of cave are N1, N2 and N3. N1 is open for general visits; visit to N2 needs arrangements with geopark management and should be done by geopark guide assistance. N3 is very delicate and also dangerous; it is possible to visit just for speleology professionals, geology specialist’s holded particular, written permission from the Qeshm Island Geopark management.

There is a spectacular polygonal form on the southern wall of salt dome in front of the sea. This structure created by salt surface fractures and step erosion in the beddings surface at the same time.

Geology of Salt Dome and Salt Cave

Namakdan Salt dome has an outcrop of 7 kilometer in diameter. This feature has covered the western plunge of Salakh Anticline. Namakdan Salt Dome has been formed from Hormoz Series deposits (preCambrian-Cambrian).

Because of its plasticity nature, it was always inclined to rise up to escape the pressure by upper rocks. Field evidences and seismic logs shows that Hormoz Series had a very slow movement and uplifting; so caused to thinness of the sedimentary formations and making slop in the basement.

Namakdan Salt Cave is located inside Namakdan Salt Dome resulting Karst process and salt dissolution and forming underground channels and galleries. Inside the cave there are different types of sedimentary forms and speleothems. Erosion forms are more than sedimentary forms because of the water high capacity of saturation.

Keywords: diapir , Geopark , Hormoz Series , Hormozgan province , Iran Geology , Iran Geotourism , Namakdan Cave , Namakdan dome , Qeshm Island , world longest salt cave , zamingasht

جزیره قشم

Qeshm Island

Qeshm is the largest island in the Persian Gulf, with rocky coastlines that protects a mountainous and often beautiful interior. Qeshm Island is located a few kilometers off the southern coast of Iran (Persian Gulf), opposite the port cities of Bandar Abbas and Bandar Khamir. Qeshm has about 60 villages which are dotted mostly by coasts .Qeshm was always a high rated area because of its strategic location. The people there has a mixture of cultures which is good to mention you will be able to see the history through the left cultures. Historical records concerning the Qeshm island date far back into the pre-Islamic era. Names as Qeshm, Kish and Tunb mark the lengthy stay of Ilamids in the area, several centuries BC.

The island has an abundance of wildlife, including birds, reptiles, dolphins and turtles. Local communities are heavily involved in projects to protect the environment, and there is some disquiet about the effect that the country’s first heavy oil refinery, currently being constructed on the island’s southern coast, might have on the hitherto pristine natural landscape. Construction of the refinery is scheduled for completion in 2013.

Qeshm is also a supposed site of the Garden of Eden according to Cassells Bible.

Fishing is a leading occupation practiced by the inhabitants of the island. On what little cultivated land there is, dates andmelons are grown. Salt is mined on the southeastern coast. Qeshm is famous for its wide range of ecotourist attractions such as the Hara marine forests. According to environmentalists, about 1.5% of the world birds and 25% of Iran’s native birds annually migrate to the forests, which are the first national geo park in Iran. The language in Qeshm is localized Persian with a mixture of Arabic, Indian, Portuguese and English which are added through different chapters of time.

Based on similarities between Qeshm Islands’ anticlines and Zagros anticlines, it is assumed that Qeshm Island could be part of southern Zagros. Another determining factor would be the Salt Dome which has been pulling up on the western part of the island causing morphologic and tectonic changes. Finally, erosion which is mainly caused by wind, sea waves, and seasonal rainstorms, could be considered as a determining factor in forming the present geomorphology of Qeshm Island. Based on abundant natural resources and unique landscapes, especially exceptional geological formations, the Qeshm Global Geopark was established in the Western part of Qeshm Island. Qeshm Geopark as the only Geopark in the Middle-East has been registered by the Global Network of Geoparks

(GGN) in Paris, on 21st March 2006. As of October 2010, 77 Geoparks in 25 Member States had joined GGN, assisted by UNESCO. Obviously, Qeshm Geopark is of high importance due to its strategic location in the Persian Gulf, representing a region between East Asian and European Geoparks. In terms of geological diversity as well as variety of its sites, the Qeshm Geopark enjoys from an ecological and cultural diversity.

Some of important Geosites in this Island as follows:

Stars Valley:

Located near Berkeh Khalaf Village, not far from the Town of Qeshm, the Star Valley is at present the most visited among all Geosites. The Star Valley is a unique example among all Geosites to study erosion. The local name for this area is “Estalah-kaftah” which means “the Fallen Star”. The reason for naming this area as such is that the locals believe that once upon a time a star (commit) (meteor) has hit the earth at this site and as a result of this collision, the stones and soil have been thrown in the air and been frozen, forming these geological structures. There are also local beliefs regarding the presence of Ghosts and “Jinns” in this Valley during the dark which may be due to the unusual geological forms and wind blowing into the Valley at night. The geological morphology of this site is the result of erosion by rainstorms, wind and gravity on various layers. In areas where the geological structures are more resistant to erosion, they have remained intact, however in areas with softer geological structures, erosion has altogether degraded and vanished those parts. In the walls of this Valley, one can observe two different types of layers: A thick and soft layer of light color (beige or light grey) underneath a thinner layer of harder nature, in white or dark grey. The bottom layer due to its soft structure usually gets eroded while the layer above because of having some kind of natural cement (limestone), is more resistant to erosion, protecting the whole structure. In areas where the upper layer is eroded, smaller canyon-like structures have been formed. In some areas within this Valley, geological structure in form of “Pillars” columns may be observed,some of which are needle-shaped. One of the factors which have caused these structures is rainstorm water that is in general seasonal, washing away in circles the soft parts of the geological structure, leaving the harder parts intact as pillars columns or needle shapes. The remnant of hard structures sometimes are “Hat-like” cap rock which almost protects the pillar column from further erosion, while the rest of the structure has been already eroded and disappeared. Various layers in this Valley are thus very vulnerable and fragile, some of them may not even tolerate the weight of a human being. Thus stepping on geological structures could be very dangerous as they might fall apart. Despite a harmonious strong appearance, some areas are critically soft and vulnerable as the bottom layers have already been emptied by erosion. Please note that although by stepping on these structures they do not fall apart right away, the upper layers may get thinner and more fragile by trembling and as a result of narrow cracks these geological structures may get degraded more easily in the future. Thus, avoiding to walk on top of the structures overlooking the Valley may help in protecting this geological heritage for future generations to observe.

Roof of Qeshm:

The Roof of Qeshm is one of the main attractions among all Geosites. It is a semi-high plateau that is located in the central parts of the island, continuing into the western parts of the island and overlooking the northern coastline. It is called the Roof of Qeshm because it is the largest and highest plateau in the island and offers a unique opportunity for visitors to observe the beautiful landscapes from above. The Roof of Qeshm overlooks the Tandis Valley from the north, where its beautiful geomorphology may be observed. The top layers at the Roof of Qeshm are formed from hard structures (mainly limestone) covered by numerous fossils (mainly bivalves), while in its peripheral sections, presence of silt and marl as well as sand, has resulted in heavy erosion. A good way to access this Geosite is to travel through Tabl-Salakh road which through a gravel road and ١۵ minute hike could lead to the Roof of Qeshm. When arrived at the main plateau, the remnants of an ancient village (Kalat-Koshtaran) may be observed where relics of walls, “Aghols” and “Anbars” still remain. In addition, pieces of pottery that probably date back to the Islamic period may be found among the ruins. It is worth noting that limestone was used in forming these manmade structures which has probably been extracted from the upper layers of the plateau. The presence of a traditional water reservoir (Ab-anbar) with a roof shows that in recent years the villagers (from Table and Salakh) may have been using the area more as a picnic ground during the hot season. The Roof of Qeshm offers a unique opportunity to observe beautiful landscapes of the northern coastline, the Harra Mangrove forest, and the azure blue waters of the Persian Gulf as well as the mainland, encouraging the visitor to take a moment to think and breathe in fresh air, and enjoy the clear skies, also suitable for astronomy.

Tandis ha Valley:

This Valley is located south of the Harra Forest. It is known for its beautiful geological structures that represent a highland that has been heavily eroded. In fact, the Tandis Valley is remnant of a high plateau that has been once connected to the Roof of Qeshm. As the island has risen and the seawater has retrieved gradually, the surface area of the island has increased. The Tandis Valley is part of those areas which have been once underneath the water, and when pulled up, it has been heavily eroded by sea waves among other factors. This type of erosion gets reduced gradually while moving more towards the Roof of Qeshm, which has remained intact. In the Tandis Valley, similarly to other geosites, whenever the upper and harder structures (mainly limestone) that usually protect the softer layers beneath, have been degraded, erosion has been a determining factor in forming the geomorphology. However, if these harder structures remain, softer ones are also protected. This is the main reason high plateaus are observed among lower and heavily eroded lands in Qeshm Island.
At this geosite, interesting forms may be observed as if nature has been powerfully carving them through ages.

In some areas of the Valley numerous fossils may be found including fossils of bivalves, in some areas as colonies. Another interesting geological phenomena in the Tandis Valley is sedimentation forming muddy mud cracks, which has created beautiful and interesting landscapes. During and after the rainfall, it is important to pay attention to muddy areas where sometimes the mud is very sticky and dangerous to walk on at this geosite.

Chahkuh gorge:

Chahkuh gorge is on the north-western part of the island not far from Table Village. This Geosite is an exceptional example of erosion through rainstorm water. Heavy rainstorms (that are also rare) quickly flush water through geological structures. Erosion however has been a secondary factor in forming this beautiful valley In fact, it has primarily been affected by the Salt Dome and related anticline. An anticline is a fold that is convex up and formed
due to tectonic compression. While under pressure, these arch-like structures may break in areas that are weaker, forming grooves on the walls. Chahkuh has been initially formed by these geological phenomena, and secondarily been washed away by erosion. Vertical to the main valley axis, there is a second valley, which has also been formed through tectonic pressures. In general, anticlines and areas around them could be counted as «unstable”
as they are more or less exposed to tectonic pressures and compression causing numerous joints and faults in formations.
The presence of concave and round structures or linear and oval structures on the walls of the valley is the result of erosion by water. One of the main characteristics of geological formation of this geosite is its impermeability to water, which keeps the water in holes and grooves, causing further erosion. The locals have taken advantage of this structure by digging wells inside the main axis of the valley to act as water reservoirs. Considering the low level of rainfall on the island, and the scarcity of freshwater, this was a very innovative way to gather water from rainstorms and use it during dry seasons. Chahkuh is aesthetically very attractive, and it is very important to warn the visitors against writing any graffiti on its walls.

Namakdan complex:

The Salt Dome is located on the south western part of Qeshm of island, and hosts the longest salt cave of the world (Namakdan Cave) that is 6km in length.Salt domes are formed when a huge amount of salt moves towards the earth’s surface due to its light structure compared to its surrounding structures. Salt domes emerge in areas which have weak surface structures and openings, and appear as Salt domeon the earth surface.
The Salt domes have many interesting aspects such as salt falls, salt springs and salt caves, with various geological formationsthat have been prone to erosion and dissolution processes.Rainwater gradually penetrates the Salt Dome through its crevices, allowing the water dissolve the salt and enter the dome. Similarto other calcareous caves of the world, the formation of the Salt Cave has been following a Karst-like mechanism, by which waterpenetrating through a joint may gradually dissolve the surrounding areas, forming open and large cave-like structures.As the dissolution process is not the same for all areas, size and shape of these caves and openings differ, giving rise to largeand open spaces in some areas, while in other areas very narrow corridors are formed where one only can get through the caveby crawling.
Some of the most amazing structures that may be found inside the Salt Cave are Stalactites and Stalagmites, as well as saltcrystals (such as needle-shaped, round, or multi-facet) formed by sedimentation of salt. In addition, in some areas where waterhas penetrated to the ground, some beautiful ponds have been formed with salt crystals at the bottom.One of the main attractions around the Salt Dome and the Salt Cave, are geological structures that are composed of various layersof colorful minerals and stones. These are indeed gifts from the depths of the earth which have been brought to the surface throughthe rise of the Salt dome. The age difference between these minerals andother geological structures on the island is over millions of years, anddifferent color in minerals represent different chemical elements. Forexample, the red color represents the Iron, and the yellow color reflectsthe presence of Sulfur.
Another interesting phenomena around the Salt Dome, is the presenceof very shiny and silvery particles, reflecting the presence of Oligist (atype of Iron oxide )that may be observed on the sandy beaches, creatinga beautiful landscape. These are the remains of large Oligists that havebroken down and eroded, and widely distributed. Oligists and other Ironoxides may be found in abundance around Salt domes.While visiting the Salt Dome and the Salt Cave, one has to be extremelycautious not to fall, as there are many holes that have been formed bydissolution process and are sometime hidden and covered by a thin layerof salt, which is hard to distinguish at first sight.
It is important to note that this geosite is very vulnerable to visitation,as the Salt Dome and the Salt Cave and their related structures havetaken thousands of years to form. Each piece of salt crystal that has beenformed inside the Salt Dome and Salt Cave, if damaged, needs anotherhundreds of years to be formed. Therefore, extreme caution by visitors ishighly required and advised to protect and conserve this unique geositefor the next generations.

Naaz Island:

Naz Island in Qeshm is set to emerge as one of the important tourist destinations in Iran. The island is located almost one km to the east of Qeshm and expands over three hectares but lacks sandy coasts. It is surrounded by cliffs rising close to 10 meters. The island is totally flat and when there is a low tide, a narrow patch of land connects Naz to Qeshm Island. Presently there are no dwellers on the island and local fishermen have built arbors there as temporary resting places.

Hara Mangrove forests:

Mangrove forests are unique wetland ecosystems that are established directly in theintertidal zone. Mangrove forests of southern Iran mainly consist of Avicennia marina, aspecies that was named after the great Iranian scientist, Avicennia (or Abu-Ali Sina). The Harra forestconstitutes the most western limits of the mangrove forests of south-east Asia. Harra Protected Areais located in the Khuran Straits, between Qeshm Island and mainland (Khamir Port), consisting ofmangrove forests that have grown more or less densely in the wet and muddy areas of this intertidalwetland. Daily tidal change is the main determining factor in forming the Harra ecosystem. Althoughthe Harra forest is quite homogenous in its composition, with low diversity of plant species, it ishome to a very diverse fauna. This Protected Area is also on the list of Internationally ImportantWetlands (Ramsar Convention).

The Unique Ecosystem of Harra

The Harra forest is a mangrove forest that is only found in coastal areas in tropical regions. Athigh tide, the tree coverage may only be seen above the water level (salt water), while the rest ofthe tree parts are underneath the water. Only at low tide, one can see the trunk and aerial roots ofmangroves. Mangrove forests can easily grow in salt water. Mangroves may have been floweringplants that were pushed to their limits due to lack of capacity in competing with other terrestrialplants. They have then adapted to the difficult conditions of the intertidal zone, which has formedthis unique ecosystem.

High and low-tide in Mangroves

High and low-tide have been critical in shaping the mangrove forests and its related biodiversity.Mangrove forests host a variety of water birds,which, at low tide feed on the muddy intertidalzone. In fact, each bird species is well adaptedto feed on very specific organisms that live atcertain depths in salt water or the mud.

Fighting salinity

In general mangroves can’t use sea water,because the salt that enters the plant throughthe sea water, after evaporation of water fromthe surface of the leaf , will form a salt solutionin the leafs. To address this issue, the rootsof mangroves act as a goal-oriented filter, andallow distilled water to pass through them,preventing the salt to enter. Only minimallevels of salt that are necessary for normal cellfunctions may enter the plant and get stockedin the leaf cells. Leafs with too much salt fall,and in this way, the salt is eliminated. Anothermechanism to eliminate the salt is the glandsthat are located underneath the leafs.

Reference: Qeshm Island Geopark