Iranian Journal of Geology
Year:2013 | Volume:7 | Issue:25|Papers Count:12

The Moro Mountains are located in the 27 km of the north-west of hanging wall of Tabriz Fault. Tabriz Fault with the strike-slip movements caused the feather fractures in both side that these fracture linkage to each other and finally make the North Moro Fault. Both Tabriz Fault and North Moro Fault are having strike-slip movement. North Moro Fault have arcship trend, and in the west ending point terminate in the Tabriz Fault. Their geometric locations of these faults related to each other caused engender a transpression duplex in their limitation of distance. Stress regime transpression caused positive topographic feature in between two faults that engender of Moro Mountain. This uplift occurs along longitude faults that having strike parallel with two big faults and have the same mechanism. With considering of the existing both shear and pure stress and style of deformations, probably style of transpression of Moro Mountains is inclined transpression model.

Fissure-ridge type travertines are exposed in extensive area in Azarshahr and eastern part of the Urmia Lake in Azarbaydjan, NW Iran. Some of the ridges are still active in the area indicating active displacement along the faults in this region. Field observations indicated that abundant ridges up to 2 km long and 150 m height are generated in tow vein and layered types along the extension fractures in the area. Quaternary active Sahand volcanic complex close to the travertine ridges had reasonable influence on solution of the Jurassic and Cretaceous carbonates and stained travertine layers. Climate changes, strongly affects the amount of water supply in travertine ridges. This is well identified by inter-bedded paleo-soil bands sub-horizontal to the travertine layers and change of dip in travertine layers.Normal faults and steep extension fractures cut the travertine layers and indicate latter active extension in the area. Trends of fissures in the ridges have structural relation with the NW-SE oriented active faults in the area. Vertical veins in central fissures of the travertine ridges contain horizontally oriented aragonite and calcite fibers. These fibers are measured in the ridges to get the locally developed extension orientation in the travertine ridges.Structural evidence indicates that travertine ridges are generated in pull-apart basin of the active NW-SE oriented dextral strike-slip faults.

It is crucial to study the widespread growth of saline soils in Iran and having significant impacts on crop yields. In order to approach the awareness of spatial variability of this environmental phenomenon, we need several samples depending on the expansion of these soils. However, it requires a lot of time and high cost. Therefore, we probably are able to provide proper information on the area with the help of different science and technology considering financial difficulties and time limitations. According to this crisis, in part of Arsanjan plain of Fars Province (8062 h), vicinity of Tashk and Bakhtegan lake, soil salinity maps obtained from Kriging method and then evaluated. Analysis of geostatistics with salinity data was expressive that spatial dependency is moderate. MBE value of estimation of the salinity and sodicity data indicated overestimating in both two Kriging methods, after cross validation, RMSE for ordinary kriging in depth of 0-5 and 0-50 cm was 27.65 and 17.56 for salinity and 12.83 and 12.34 for sodicity data. Estimation of salinity using of digital numbers of LISS III sensor (as secondary data) in cokriging method, had not positive effect on the estimation. The evaluation of the obtained maps indicated salinity values were very high close to lake and decreased one with distance, in center of the plain and increased in agricultural lands because of mismanagement of water resources. In the north of the area there are crops such as barley, alfalfa and wheat which planted with irrigation agriculture.therefore it seems, using unfavorable water, makes the soil saline and rich in sodium.

The Kiki Batholith in the north Semnan Mountains of north-central Iran consists of granite, granodiorite, diorite, and gabbrodiorite sharply intruding Precambrian units. All rocks are met aluminous to slightly peraluminous, defining a calcalkalic trend. Rare earth element patterns indicate that all studied rock types are comagmatic. Mineralogic, petrographic, and major- and trace-element data demonstrate that all rocks are I-type granitoids and crustal material along with derived mantle material may have contributed to their formation. Spider diagrams show troughs for Ti, P, and Nb, indicating magma genesis in a subductionzone setting. Other geochemical evidences such as high SiO2, low Mg# and transitional elements, and also Nb/La, Nb/Ce and (La/Sm) n average ratios indicate that the lower crust with derived mantle material had played an important role in generation of the Kiki granites.

The Chabahar coastal area is located in the Makran sedimentary-structural zone. The basement of the Makran zone consists of an oceanic crust and flysch units which completely overlie by thick sequences of mudstone, sandstone and conglomerate in the Chabahar area.Fifty samples were taken from sections of Tiss, Ramin, Lipar, Gorankash and Gareeandar and were studied by calcimetry, XRF, ICP and XRD. The result of calcimetry analyses shows lime contents of marl samples vary from 9 to 21 percent, and it is better to introduce them as mudstone. Na2O, P2O5 and Fe2O3 contents of the study rocks are lower than the upper continental crust CWI=88.8 shows arid to semi-arid. Based on geochemical data, mudstones and sandstones of Chabahar coastal area were derived from a quartzose sedimentary source. Geochemical characteristics of the study rocks and using of discrimination diagrams for tectonic setting, based on major and trace elements, suggest that they formed in an active continental margin, This conclusion is logical because the Makran zone is an active subductional continental margin.

The study area is located in north of Tehran province. This area is a part of central Alborz zone. Intrusive (basic) and extrusive bodies of late Eocene, have caused several alteration zones. Au- Cu and Pb-Zn mineralization evidences have been found in Darband and Pass-Qaleh areas. The average grade of Pb and Zn in this area is 5% and 3% and the average of Au-Ag is 600 – 10 ppm respectively. Also the amount of 25 and 65 gram per tons has been reported for Au – Ag in this area. Main lithology of this area are volcano-sedimentary rocks of the Eocene. Considering the fact that there is an appropriate stratigraphic situation between lower shale and lithic tuffs for mineralization and due to structural conditions of the area, the conditions of massive sulfide ore forming (Kuroko type) are provided. The major and most important field evidences of this opinion are: The presence of propylitic, serisitic, argillic alterations and their placement; the mineralization type (pyrite, chalcopyrite, galena, sphalerite, jasperoides and Mn-bearing minerals and barite and its sequences and zoning; the existence of thin layers of pyrite in silicified tuffs; Gold mineralization in sulfides minerals; the existence of late hydrothermal phases with increasing of gold ratio and the presence of hydrothermal breccia and silicified veinlet which cut the massive sulfides. In addition, geochemical halos which have extended about 150 meters lead to a polymetalic massive sulfide mineralization that is similar to Kuroko type mineralization.

The Ilam Formation in the north east of Shiraz was studied based on calcareous nannofossils and planktonic foraminifera. This formation consists of sedimentary dark limestone.In this study, for thefirst time 18 genera and 26 species of nannofossils were identified.According to the stratigraphic development of calcareous nannoplankton, interval time is suggested from late Coniacian-early Santonian to Early early Campanian corresponding to Micula decussata zone, Reinhardtites anthophorus zone, Lucianorhabdus cayeuxii zone and Calculites obscurus zone. Calcareous nannofossils in this study were investigated along with planktonic foraminifera. Based on the information obtained from planktonic foraminifera, the age of the section is late Coniacian-early Santonian to early Campanian corresponding to Dicarinella concavata zone, Dicarinella asymetrica zone and Globotruncanita elevata zone. The presence of index species of calcareous nannofossils indicates that the Ilam Formation deposited in the low latitudes and Warm Ocean.