کلهرود KALAHROD

Role of Tectonics in Forming of the Kalahrod Cave

role of Tectonics in Forming of the Kalahrood Cave , North Isfahan , Iran

Caves are perhaps the most spectacular of the combined effects of weathering and erosion by groundwater. As groundwater  percolate through carbonate rocks , it dissolves and enlarges fractures and openings to form a complex interconnecting system of crevices ,  caves , caverns and underground streams . Caves and caverns form as a result of the dissolution of carbonate rocks by weakly acidic groundwater . Groundwater percolating through the zone of aeration slowly dissolves the carbonate rock and enlarges its fractures and bedding planes.  During dissolving and deposition of calcite , many various dripstone deposits , stalactite and stalagmite    structures form  

There are many caves in Iran that have formed with the above procedure . Opposite of the procedure , the Kalahrood Cave , in the north of Isfahan has another scenario for its forming . The cave located in southwestern boundary of high mountains of the Urumieh-Dokhtar Magmatic Belt of Central Iran . It has formed in Lower Cretaceous grey limestones . There are many NW-SE- trending faults in the study area . The faults have thrust and dextral strike-slip motions . The Kalahrood cave formed in footwall of the Kalahrood thrust . Structural studies and filed observations in the Kalahrood area and in the cave indicated that the Kalahrood cave has formed during thrusting and dropping the cave roof in footwall and littering the floor with fallen debris . We have considered three episodes for forming the Kalahrood cave : 1 – Thrusting and motion of hangingwall . There are many  traces of faulting on the walls and roofs of the cave . 2- Dropping of crushed rocks and separated blocks of the roof in footwall and creating the cave space . Maximum distance between floor and roof has measured about 15 m . 3 – Affect of groundwater on the rock units and increase of disbandment and enlarging the fractures . Some small stalagmite and stalactite structures have formed in internal part of the cave .

 

 

A . Nadimi   and    A . Sohrabi

http://arashshrb.blogfa.com

 

Geophysical Research Abstracts,
Vol. 11, EGU2009-3936-1, 2009
EGU General Assembly 2009
© Author(s) 2009
Role of Tectonics in Forming of the Kalahrood Cave, North Isfahan, Iran
A. Nadimi and A. Sohrabi
Payame Noor University, Geology Department, Kohandej, Isfahan, Islamic Republic Of Iran (geotecton@yahoo.com)
Caves are perhaps the most spectacular examples of the combined effects of weathering and erosion by groundwater.
As groundwater percolate through carbonate rocks, it dissolves and enlarges fractures and openings to form
a complex interconnecting system of crevices, caves, caverns and underground streams. Caves and caverns form
as a result of the dissolution of carbonate rocks by weakly acidic groundwater. Groundwater percolating through
the zone of aeration slowly dissolves the carbonate rock and enlarges its fractures and bedding planes. During
dissolving and deposition of calcite, many various dripstone deposits, stalactite and stalagmite structures form.
There are many caves in Iran that have formed with the above procedure. Opposite of the procedure, the Kalahrood
Cave, in the north of Isfahan has another scenario for its forming. The cave located in southwestern boundary of
high mountains of the Urumieh-Dokhtar Magmatic Belt of Central Iran. It has formed in Lower Cretaceous grey
limestones. There are many NW-SE-trending faults in the study area. The faults have thrust and dextral strike-slip
motions. The Kalahrood cave formed in footwall of the Kalahrood thrust. Structural studies and filed observations
in the Kalahrood area and in the cave indicated that the Kalahrood cave has formed during thrusting and dropping
the cave roof in footwall and littering the floor with fallen debris. We have considered three episodes for forming
the Kalahrood cave: 1- Thrusting and motion of hangingwall. There are many traces of faulting on the walls and
roofs of the cave. 2- Dropping of crushed rocks and separated blocks of the roof in footwall and creating the cave
space. Maximum distance between floor and roof has measured about 15 m. 3- Affect of groundwater on the rock
units and increase of disbandment and enlarging the fractures. Some small stalagmite and stalactite structures have
formed in internal part of the cave.

 

http://meetingorganizer.copernicus.org/EGU2009/EGU2009-3936-1.pdf

نویسنده : کلهرودی : ٥:٢٩ ‎ب.ظ ; ۱۳۸٧/۱۱/٢٦
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