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  Economic Geology
The history of economic geology of Iran
Author : Mansour ghorbani
Publisher date : July 2002
Chapter title : Chapter 4 -States, belts, and mining and Metallogenic areas in Iran
Data title : 4-5 Takab Metallogeny Zone

Obvious geological features, including tectonic, magmatic, metamorphic, stratigraphic and mineralogical cognitive construction in Late Precambrian time period - the former Cambrian and Tertiary, Neogene, especially, has led Takab quad, as a region important Metallogeny be raised in less space than the examples we know of.

4-5-1 - General geological region

stratigraphic column

Takab area, a variety of types of sedimentary rocks, igneous, metamorphic age, they have exposed the Late Precambrian to the Quaternary will change. These rocks, frequency and spatial distribution - at the same time not Takab rectangle. Stratigraphy of the rocks can be said when the two turns of Late Precambrian - Cambrian former and four ears oligomiocene Takab, both in terms of variety of stones and cognitive development, on the other stones is increasing.
Generally attributed to the Cambrian rocks in the square so Takab works Naien Alavi and others (1982), can be classified into three categories:

A) Gneiss metamorphic rocks including amphibolite, marble, Micaschist, Mygmatyt green schist and amphibolite facies to low-metamorphic rocks beneath the Kahar Formation are placed so far as the oldest rocks in the area of
​​Iran and Azerbaijan are sometimes considered as Iran in the basement are considered.

B) metamorphic rocks with low birth and origin of clastic and tuff formations Kahsar as the most exposed in the East and the West have Takab rectangle.
C) during the granitic rocks.

According to studies, have said that the older rocks of the Kahar Formation have been considered more, because they are metamorphic grade was not based on fossil evidence and geological dating evidence-based studies and paleontological studies Hamdi (1374) and author of studies and field observations, it is recognized that these rocks fall into the Kahar Formation and equivalent parts are high Kahar. Granitic mass on the period according to the type of studies must be said that some of these masses of granite type during the Late Precambrian age are but some of them just look like granite and period of much younger age are.
Considering what was said, Kahar Formation rocks Nagorno Dash series with stones and granite stones during the type attributed to the formation Bayandor, all belonging to the Precambrian are. In addition to the mentioned rocks in the middle part of the region Takab, stone and there is Late Precambrian and Cambrian former belong together, sometimes separating them is impossible. Why they titled rocks above Precambrian - Lower Cambrian is referred.
Soltanieh Formation

Significant expansion in Takab rectangular and often on the slope of the Kahar Formation is located. Soltanieh formation in the middle part of the quadrangle Takab should be followed, but shows different facies.

In fact, in the middle part of rocks more rectangular Takab 1:250000 map as the marble stones have been brought, are Soltanieh. Some fossils found in the marble that have lower Cambrian age.

Barut Fm.

Formation of gunpowder in Takab rectangular, not much exposed and only stronghold in the northeast Shahin has exposed stone formation.

 Complex set of stone age Takab Late Precambrian - Cambrian previous
This collection, mostly middle part Takab 1:250000 quadrangle is based on studies Naien Alavi and others (1982), defined in four complexes, which are respectively:
- Complex mountain with rocks Micaschist fodder, Gneiss, and quartzschist migmatite. It Takab in northwest and east around the village of Fort Shahin Khan Z Gholi and Khaza’i is located.
- Complex in the western city of months-months that includes marbles back to the mountains and Gneiss of Aq.

- Complex Kheirabad around the village, including gneisses, schists and marbles grapes.
- Complex Layout Layout around the village, including rocks Gneiss, and Micaschist Migmatite.
Victim, (1378) Three B-complex as the last large complex Precambrian - Cambrian Takab and complex as the four great central square Takab complex is considered. In Figure 4-6, this stone is marked with a PCM signal, as previously noted by the authors of this stone et 1:250000 geological maps and more previous researchers, the Precambrian Kahar Formation and older than given. Studies (victim, 1378) data indicate that these rocks of equivalent age and upper formations Soltanieh Kahar and gunpowder.

Is essential to note that these rocks, Qt age equivalent of Kahar and upper formations are Soltanieh and gunpowder, in terms of facies, lithology and metamorphic grade, with the formations mentioned in the Alborz and Azerbaijan in many cases the difference gross, but especially the central region of high similarity are Anarak. The rocks in the region and issues Metallogeny issues tectonic - magmatic Iran in Late Precambrian - Cambrian earlier, has a special place. In these rocks can be divided into two groups is the following:
A) The origin ultramafic rocks, mafic and volcanic - clastic (tuff game), today such as various schists, serpantinite, amphibole, epidote schist, chlorite schist, epidote amphibole schist, epidote actinolite schist, amphibolite, tremolite amphibolite actinolite , garnet amphibolite, ortho-Gneiss exist. It should be mentioned any of this group rocks, wherever found views are important Metallogeny be.

B) the origin of sedimentary rocks, most of the type and carbonate plates, which form carbonate sequences - Plate, Gray appear. Top two more rocks in amphibolite facies metamorphic schist are green. Rocks of group A, most parts under the stone is placed in group B, although a gradual transition can be considered for them. So that in some places, in the first group of high rocks, carbonate rocks of the tape can be seen.
Zarigun and Lalun formations

In rectangular Takab, the most exposed rocks in the north have Shahin Dej. Mentioned rocks, especially rocks formations Lalun  great transformation in the middle part series quad, wherever that is observed, similar regions are the Alborz and Azerbaijan.
Late Paleozoic

Top of the Paleozoic rocks, only Permian rocks in the square are Takab Outcrop. This time with two rocks clastic facies (Doroud Formation sandstones) and carbonate (Ruteh Formation) is seen. Of course a bunch of igneous rocks are accompanying them. One of the characteristics of the ore horizon time zone Shahin hairy old castle - is Triassic.
Mesozoic rocks, such as upper Paleozoic rocks, the most exposed, ie the west quadrangle Takab stronghold in the north and south are hawks. East-months course in the Mesozoic rocks are exposed on the Permian rocks are located. Basically in the middle rectangle Takab, Mesozoic rocks are rarely seen.

Takab Tertiary Zone

 Tertiary time, phenomena stratigraphic, facies conditions and performance of the tectonic divided into three categories we:

A) Paleocene - Eocene: facies characteristics Formation Paleocene - Eocene Eocene quite similar central Alborz range is south.

B) oligomiocene: the Precambrian rocks - Cambrian, rock formations and Oligocene - Miocene greatest expansion in the region are related to the square Takab. Takab rectangle in the middle part, rocks and sediments Oligocene - Miocene rocks and sediments on the Precambrian - Cambrian Despite finding and typically is placed on them. Obvious features of rocks in the square and make oligomiocene Takab increasing lava and tuff and tuff rocks are sedimentary rocks on the offspring.

C) rock formations and Plio - Quaternary in rectangular Takab: extend the time in rectangular stones Takab ratio is significant. Most sedimentary rocks of this time, the slope on the other older rocks is placed.

Takab Regional structural conditions

Quad Takab of structural conditions as other geological phenomena Takab, interesting and significant study. The case that parts of the quadrangle, geologic and structural features of central Iran shows, while the regions, geological and structural features similar to the Alborz and Sanandaj - has Sirjan. The rectangular structures, significant extraterrestrial, Grabon, discontinuity, and thrust orogenic phases, especially the young Alpine orogenic phases can be seen.
Takab rectangular structure of Naien by Alavi and others (1982) to five sections A, C, Bb, Ba, and D based on a 4-3 split is formed. The classified report based Takab map is discussed. Opinion writer, and Ba between zones and between zones C and Bb A, geological and structural differences observed are not specific. Therefore, based on common characteristics of cognitive stratigraphy, Magmatym, transformation and deposition of cognitive, structural and general tectonic performance quad Takab into two zones based on a 4-3 B-forms have divided.
A1 subzones most geological features of the Alborz region and is similar. The marginal parts are to North East and North West Takab rectangular covers.

CI zone of all the geological features are central. This zone, the middle part Takab rectangular forms and has the highest spread, and in fact the main area of ​​this section is Metallogeny Takab.
SS Subzones all features of Sanandaj - Sirjan and can be said is part of Sanandaj - is Sirjan. The southwestern part Subzones Takab the rectangle are included.

 Among the three cases mentioned, the following zones and CI SS, the difference together, but show similarities with two other A1 Subzones difference is higher.

Faults located in the rectangle can be divided into two groups: those faults that trend northwest - southeast are likely to have been created in the Precambrian and parallel to the stairs and they can be outside the area the study followed. Other categories faults northeast - south-west that grow on vertical faults are first class. It seems that these faults have emerged in the Mesozoic.

 Takab Tertiary metamorphism is in the region, close relationship with these flowers, especially in the area treat them.

Orogenic phases

Most orogenic phases and earth movements in the central Iranian are in rectangular Takab, especially in the CI zone are seen. The most important phases in the region Takab as follows:
Orogenic movements and phases of Late Precambrian - Cambrian
The author believes in a phase of Late Precambrian tensile Takab occurred in the region that it works is up to Iran to be central. The result of this phase, tensile, creating crevasse Late Precambrian - Cambrian in central Iran is. The crevasse, CI zone of the four ears Takab is taken.
For the tensile phase, a compression phase which precedes the closing crevasse is mentioned. CI is the natural time zone crevasse has much more bandwidth. Faults north west - south east of the stairs are the primary, in this phase are formed. The compression phase has led to the CI region, and AH appear extraterrestrial cause high altitude, in the next times marine conditions parts to be handled there.

Far squeeze mentioned, an regional metamorphism has also followed.

This phase can be terminated prior to the deposition attributed Lalun  sandstone of the world, the equivalent of Pan phase knew that Iran, in the interval 630 to 530 million years ago has been active.

Alpine phase (Cimmerian and Laramide) in the Mesozoic

Alpine phase in the square below Takab and SS zones A1 and has had considerable impact.

 This phase generally makes the following process is:

A - Create and fault with NE trend - Southern Astronomy, geology in this process is to be followed.
B - Gaps stratigraphy and sedimentary discontinuity in some of the Mesozoic and Tertiary period.
C - schist facies metamorphic facies to green slate, most of the Subzones SS.
Phases of the Tertiary Alpine

Although previous Cimmerian and late phases in the square of SS Subzones Takab more and A1 can be followed in the CI zone be much, but the Tertiary Alpine phases, in all square Takab detectable and can be pronounced in the zone and CI possible to be fluid.

Alpine phases in the Paleocene

Likely to continue this movement, Laramide orogenic phase that the overall performance, establish territories in continental Subzones of S-S and A1 has been.
Pyrenees phase (Eocene - Oligocene previous)

The symptoms in all four phases can listen Takab be followed. It seems that in this time period, tensile mode is for the whole region that precedes the tensile occurs in central Iran, are consistent.

Savian phase (late Oligocene – early Miocene)

This phase of subsidence was accompanied with stretching and deep sea and gradually grows, so that the lower red continental sediments, rather than to calcareous and marly sediments will. Depths of the sea stretching phenomenon, is associated with extensive volcanism, which continues until the end of Burdigalian. Large part of the rocks this time tuff rocks, lava and volcanic Tufite and limestone forms.

Therefore, Takab area, equivalently great part of the Qom Formation, volcanic tuff and lava is. Tufite tuff and with high and extend almost all CI zone are visible, but only in a range of lava faults trend northwest - southeast, and especially the junction of two fault categories can be seen.


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