M. Mirjalili; F. Ghaemi; B. Rahimi; M. Moshrefifar; M. Gholamzadeh
Abstract
The study area is located in the east of Yazd and is part of Yazd block (western block of central Iran). There are two major fault systems, Anar and Kharanagh with lengths of 100 and 62 km and numerous minor faults represents an important tectonic phenomenon in the region. The aim of this study is to ...
Read More
The study area is located in the east of Yazd and is part of Yazd block (western block of central Iran). There are two major fault systems, Anar and Kharanagh with lengths of 100 and 62 km and numerous minor faults represents an important tectonic phenomenon in the region. The aim of this study is to investigate neotectonics in this area by using geomorphic indicators. To achieve this goal, have been used of seven geomorphic indicators: Hypsometric integral (HI), Drainage basin asymmetry factor (AF), Stream length- gradient index (SL), Mountain Front sinuosity (Smf) and the ratio of valley floor width to depth Valley (Vf), River sinuosity index (S), Basin shape factor (Bs). Based on Active tectonics indices (Iat), the study area is divided in Four terms of tectonic activity rates, category 1 (very high tectonic activity, 7.4% of the region), category 2 (up 74%), category 3 (average 11%) and category 4 (less 7.4%). Morphotectonical and morphological evidences indicate that the rate of tectonic activity in this region is moderate to high. According these evidences, the northern part of Kharanagh fault and southwestern part of Anar fault are more active than other parts.
F Jalili; F Hadavi; B Rahimi; A.R Khazaei
Abstract
In this research, biostratigraphy of a stratigraphic section in the east Afzalabad section in Lut Block (part of flyschoid basin in East Iran) were investigated based on calcareous nannofossils. Nineteen genera and 52 species of calcareous nannofossils were identified based on which the studied ...
Read More
In this research, biostratigraphy of a stratigraphic section in the east Afzalabad section in Lut Block (part of flyschoid basin in East Iran) were investigated based on calcareous nannofossils. Nineteen genera and 52 species of calcareous nannofossils were identified based on which the studied sequence confirm with NN8- NN10 biozones of Martini (1971) indicating a middle Miocene to late Miocene age.
R Ahmadi Rohany; M.H Karimpour; B Rahimi; A Malakzadeh Shafaroudi
Abstract
The studied area is located in east of BajestanTownship, KhorasanRazaviProvince and this region is a part of the Lut Block. Granite is the most important rock in this area with covering approximately 70km2. Processing of satellite data in this area was done by using of SPOT, ASTER and Landsat ETM+ data. ...
Read More
The studied area is located in east of BajestanTownship, KhorasanRazaviProvince and this region is a part of the Lut Block. Granite is the most important rock in this area with covering approximately 70km2. Processing of satellite data in this area was done by using of SPOT, ASTER and Landsat ETM+ data. SPOT images processing and using PCA methods (standard and selective) on the ETM+ data show this intrusive body doesn't have an equal chemical composition. The central part of the intrusive body has distinctive from margin and it seems that the central part have more mafic mineral. For enhancing linear structure, high pass, directional, threshold and sobel filters were applied separately and compositional on the SPOT data. By using these filters linear structures became completely obvious and were vectorized digitally. The most of them show northwestern-southeastern trend. ASTER data processing by spectral angle mapper (SAM), band ratio and band composition methods enhanced epidote, sericite, hematite, argilic and silicified alterations. Processing and Interpretation of airborne geophysical data (potassium, thorium, uranium and total magnetic intensity), which collected by airplane show the amounts of these triple elements (K,U,Th) are high and in vice versa Total Magnetic Intensity data (TMI) is low in this granite. Separating geological boundaries and enhancing major faults are other results from processing of geophysics data. Merging all of the data consist of: satellite and geophysics data processing and field research indicate alteration zones have relation to linear structures in this area. This research specifies the most probability of mineralization presence in this area so that Fe and Cu mineralization conform to epidotic-chloritic and argilic alterations. Introducing favorable area can help us to concentrate exploration activities and next researches in this area and prevent wasting money and time.
M.A Salehi; S.R Mousavi-Harami; A Mahboubi; B Rahimi
Abstract
The Lower Jurassic Ab-Haji Formation consists of siliciclastic sediments, which are widely exposed in the Tabas Block. This formation varies in thickness from tens of meters to more than 500 m in northern Tabas Block. The Ab-Haji Formation with avearge thickness of 75 meters presents in the Tabas Coal ...
Read More
The Lower Jurassic Ab-Haji Formation consists of siliciclastic sediments, which are widely exposed in the Tabas Block. This formation varies in thickness from tens of meters to more than 500 m in northern Tabas Block. The Ab-Haji Formation with avearge thickness of 75 meters presents in the Tabas Coal Mine area and consists mainly of sandstone, siltstone, claystone with a few thin interbeds of coal seams. Two outcrops and three exploration boreholes were studied in order to identify lithofacies and to interpret the depositional environment. The lithofacies analysis in outcrops imply two siliciclastic coarse grained (Gcm, Gt), four medium grained (St, Sp, Sr, Sh), two fine grained (Fl, Fm) and one coal lithofacies. Identified lithofacies can be grouped into four architectural elements including channel, point bar, crevasse splay and coastal plain swamps. The electorofacies and log motif analysis led to recognition and differentiation of architectural elements in exploration boreholes. The lithofacies and architectural elements show that the siliciclastic sediments of the Ab-Haji Formation were deposited in the meandering river system within a coastal plain with widespread swamps. The sedimentological analysis led to reconstruction of paleogeography in eastern part of the Tabas Block, which shows deposition of nonmarine to coastal plain environment in this part of the block.
