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Perlite and Pumice
Title book : Perlite and Pumice
Author : Mansour Qorbani
Publisher date : February 2000
Chapter title : Chapter 4 – pumice and mineral gangs in Iran
Data title : 1-4-Damavand volcano

As it is said pumice and mineral pumices depends on young pyroclastic rocks Young pyroclastic rocks have outcrop in Iran but recognized deposits of pumice and mineral gangs are negligible in Iran.

All of recognized or non – recognized deposits are pumice and Iran mineral gangs are located around domes and volcanic craters from Neogene – Quaternary and or Quaternary Hence, in this writing , for explaining of recognized deposits of pumice and mineral gangs and also for identification of deposited places, Quaternary – Neogene Quaternary

So extent, lithological evolution and chemical composition will be counted by their eruption type and some of mineral gangs are depended on that.


Neogene and Quaternary volcanoes in Iran

Most important volcanic regions are classified from Neogene – Quaternary and Quaternary:

1- Damavand Region, Damavand volcano in central Alborz.

2- Sahand Region (South Tabriz, North Maraghe, East Urumieh Lake), Sahand volcano

3- Sabalan Region, Sabalan Volcano

4- Sistan and Baluchistan Region (North Jazmurian),Taftan , Bazman Axis , Shahsavaran  mount..

5- Ghorveh – Bijar volcanic Regions

6- Takab – Ghave Aghaj volcanic regions

7- Volcanic Regions to south east kerman, craters around Ghale Hasani, Ghale Heidar, Tutak and kuh Mozahem volcano

8- Saveh volcanic Regions, Khalifa Kondi volcano

9- Maku Region, Ararat Volcano

It should be said more than pumice and mineral gang which is mentioned in most of cases depended on mentioned volcanic regions some regions are found in Iran which have been reported by acidic vitric tuffs, ignimbrite   and other acidic pyroclastic rocks ( Tertiary )

Which has considerable amount with amorphous especially amorphous silica and it has been reported late rocks con be replaced by pumice and mineral gangs in these conditions (for example, structural stuff)


1-4-Damavand volcano

1-4-1 –Geographical position and condition)

Damavand volcanic cone lies between 52 60 24 E and 35 57 0 No Cities near to Damavand volcano are: Rheineh (in Southern Side), Plour, Damavand and Firouzkuh(in its eastern side).

Lana and volcanocalstic materials extent reach up to 400 tons which covers an area about 52 18 E to 51 59 E and 36 4 30 N to 35 48 38 Height of Damavand volcano is 56.0 m.

There are two paths for ascending the crest and a south eastern path that it is easily rather than and other one is another side for Northern side that its ascendance is very difficult .several refuge are initiated for ascending mountain climbing’s in these paths that it is upper than 5.000 m and winters are very cold in Damavand Region with glaciations and its summer is temperate .In most months, Damavand volcano crest is covered by snow.

Most suitable month for ascending is to crest for Mordad Month. It is a part of Damavand which is observed in Mordad Month and it belongs to sulfur, exited from caldera cone


2-1-4- Structural position

Damavand volcano cone is situated in central Alborz. It western and eastern Alborz are extended these two trends are separated from each other in Damavand Location

Alborz Range are in body of Kaman, Ali Abad of Gorgan to Astara around Caspian Sea. According to StÖcklin, two important orogenic, Asynthic (in Precambrian) and Alpine (in Mesozoic and Cenozoic) with Alborz structure.

Late oregenic movements has occurred in Pliocene – Pliestocene these movements results in faults , gentle thrust and Alborz heights Damavand  Volcano depends  on volcanism which is occurred during Quaternary in Alborz .

All of tectonical structures are as a member of faults, thrusts, central Alborz folds which is disappeared in Damavand Region during reaching lava area.


3-1-4- Cone morphology and extent of lava

Damavand volcano is in a body of symmetrical cone that lava has much extent in south western part of that.

To north Nonal Depression, lava makes identification of Sardovich Mount. Sardovich lava is older than Nonal Depression lava around Haji Dola (Alen Bach, 1966)

Sardovich mount lava is not completely linear but they have superficial extent (Alen Bach, 1966)

Some lava is found in North mountain of Hareh Mount. that they are likely older than Damavand  and likely before Quaternary (Irannejady, 1370)

Conical morphology  indicated that  result of activities is not limited to central caldera but lateral caldera  have role in cone structure Number of lateral caldera at the top of cone are located to south west and also North East Damavand but major activity of Damavand  has begun from central part .


4-1-4- Petrography

In litho logy composition of Damavand volcano based on this amount mineralogical composition, three groups of them are separated (map 1=4)

A- Basic Rocks

B-Medium Rocks

c- Acidic Rocks


A- Basic Rocks:

These rocks are situated in Plour area (south west Damavand crest) in eastern side of Nineh and Verkuh Bridge (in much distance rather than Tineh to south Eastern side).

Basic Rocks are alder rather than other rocks in Damavand, so that we can have composition of Damavand lava from basic composition because they are seen on basic rocks in Plour Region with little amount of medium lava (trachyte – andesite) (Iran Nejadi, 1370). These realities has been reported from basic lava in Verkuh Bridge by Alen Bach (1966) because basic lava is seen only in gentle side of the Damavand (sometimes it is located in further distance from volcano (Verkuh Bridge) and it is where cone dip is not seen with steep slope and basic lava have much extent in its nature .Young lava are lowered by young lava but younger lava can not cover them.


Petrography of basic Rocks

A-         Basic rocks in Plour Region : These rocks are more basic in Damavand and regarding mineralogist  can have flow manner to them as Alkali olivine basalt and it has a porphyry texture with microlite texture.

Matrix of rocks is sometimes with current manner.

Sometimes some pores are seen in these rocks which are filled by calcite

B- Basic Rocks in Tineh Region: These rocks are in type of trachy-basalt at the top and also under these lavas, trachy-andesite rocks are seen (Irannejadi, 1370) Mineralogical composition in a sample of rocks is as follow.

1) Phenocrysts are augite minerals which are mainly automorph and its most length is 1.5mm

Apatite

Analysm is reported only in these rocks (Iran Nejadi, 1370).

2) Matrix includes only plagioclase, clinopyroxene finally alkaline feldspar in little amount and in manner of xenomorph in a space among other matrix crystals.


B- Medium Rocky

There rocks include lava and volcanoclastic rocks and they have mainly Damavand Cone that they have some trachy-andesite and trackyte mineralogic composition.

Lithology and geochemical changes are transitional for trachyte and andesite and some intermediate types are abundant in these two types

 

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