JOURNAL OF EARTH AND RESOURCES
Year:2010 | Volume:3 | Issue:1 (6)|Papers Count:10

Submarine volcanic rocks with cretaceous age are situated in central Alborze Mountain and located in Kojor area at 25 Km, south of Noshahre town. These rock are mainly composed of pyroclastics (Aglomarate, Epiclastic & Autoclastic breccias,…..) and lava flows (Olivine Basalt, Basalt,BasalticAndesite, Andesitic Basalt,….). Petrogaphical and geochemical investigation on these rocks are shown sequentially exchange evidence such as: Fractional crystallization process, sieve texture, Resorption of some phenocrysts shown non-equilibrium conditions between melt and crystals during magma cooling in magma chamber. Geochemical characteristics indicated that these rocks located in the alkaline domain. The highly enrichment of LREE and HREE in comparison with Chonderite and primitive mantel and to be present in WPB (with in plate basalt) domain shown they may have formed in an extentional tectonic regime.

In this study after field observations and XRF analysis of rock samples, statistical and experimental methods have been used to determine the geochemical anomalies of uranium and assessment of correlation between these elements with other elements in anomaly No. 6 of Khoshumi area which is located in structural-sedimentary zone of Central Iran. Therefore, we first normalized the distribution of elements and then calculated the values of MEAN and SATANDARD DEVIATION and after determining the amount of background and threshold of anomalies, the anomaly map of each element have been provided. hence, based upon achieved results the background amount of uranium in this area was 5ppm and its maximum amount calculated 20 ppm which represented uranium anomaly. Moreover, in studied area 3 uranium anomalies have been identified that the most important one is located in the location N0S0 and in anatectic granite and migmatite host rocks and their adjacent propylitic alteration zone. Further, cluster dendrogram analysis, spearman's correlation coefficient and geochemical anomaly maps of the elements have been utilized to determine relationship and correlation between elements and to distinguish the pathfinder elements of uranium. Consequently, uranium has negative correlation with Th, Zr, Sr, Rb, Pb, Ce, Ba and positive correlation with Y, V, Ni, Nb, Zn, Mo, Cu, Cr, Co and two major oxides Fe2o3 and Tio2.

Karaftou as one of important caves of Iran is located in Kurdistan Province. This cave, located within high cliffs at 74 km east of Saghez City. It is important and unique due to various viewpoints of geology, archaeology, and specially geotourism. Karaftou Cave formed naturally and artificially (cliff architecture records) and today possesses four stages. The Cave placed within limy mountains above a deep valley. There are many signs of burrows, crypts and caverns beside its main entrance. With general and partial modifications, this Cave usually was a secure place for human living over time. The massive limy layers, which embraced Karaftou Cave, formed through Oligo-Miocene series and they belong to Qom Formation. The Cave with about 750 meters length has a unique structure, as its entrance is about 25 meters higher than surround hill side which created a difficult path to enter through past times. According to archaeological studies, probably the Cave has been used by man for dwelling from fifth to fourth millenniums B.C. also after Seleucid time, namely during Parthian, Sassanid and Islamic periods. This beautiful and mysterious cave registered between Iranian national heritages by Number 330.

Basaltic rocks of Southern Amlash are a part of an ophiolitic sequence. Based on field studies these basaltic rocks often are outcropped to pillow lavas form and rarely of lava flow and lava breccias form. Petrographic studies show that these rocks are in the two different groups that are: alkali basalts (containing of titaniumaugite clinopyroxene, plagioclase, olivine, iron and titanium oxides and apatite) and subalkali basalts (including clinopyroxene (diopside to augite), and plagioclase as the main minerals that are rarely have been associated with olivine and sulfide minerals. Most of rocks show oceanic metamorphic and thus initial minerals (plagioclase, clinopyroxene and olivine) have been altered. Geochemical studies indicate that producer magma of these rocks have tholeitic nature from the subalkaline type. Rare earth elements pattern of in these rocks indicates LREE-rich in them. Whereas clear depleted of Zr, Nb, Ti and P elements are visible in these rocks. This is characteristics are specified properties of the suprasubduction environment. In compared distribution pattern of alkaline basalts similarly are rich in LREE and MREE and are clear depleted in HREE elements and shows the OIB nature of them. Accordingly, based on the petrography and geochemical studies, two distinct groups are found in the region.

Study area semnan province and south-south east damghan located details of mining area and is metallogenic toroud. Mining area toroud in the northern part of central iran zone outcrops Precambrian rocks to sediment all testament view is. Rocks area oldest attributed to Precambrian been including set of gneiss, Amphibolites, and schist. There is copper mineralization range chah galeh within rocks traky andesite as a vein with copper trend east-west during streak 1200 meter and mining vein of grade two parts, high grade and low grade classification. Thickness average section high grade 40 cm and section low grade 100 cm. average grade copper at high grade section about 3.1 percent and low grade section 0.2 percent has been determined. Rate save copper ore high grade section 26 thousand ton and low grade section 65 thousand ton is estimated. Based on studies, origin chah galeh deposit hydro thermal solutions low temperature is, from volcanic rocks andesitic type and traky andesite origin have been.

Several important characteristics such as suitable parent rocks, hydrodynamics system for carrying uranium complexes and pervious sedimentary layers play key role for transportation and deposition of soluble uranium. In this paper, we present the results of investigations of parent rocks and host rock of sedimentary uranium in Razgah region to examine intrusive of nepheline syenite in Razgah together with surrounding sedimentary units with regard of sedimentary uranium mineralization. Razgah nepheline syenite located in the northwest of Sarab county in East Azerbaijan province in the north of Iran which covers an area of about 20 square kilometers. A sandstone unit spreads in the southeast of the area which was explorated as probable host rock of sedimentary uranium deposit. Radiometry survey of intrusive body and likely host sedimentary unit was done with scintilometer after examination of previous studies and field observations which showed radiation increment due to radioactive elements in both parts especially altered parts of the nepheline syenite body. Then rock samples were taken from highly radiation points in the nepheline syenite intrusive body and the likely host rock which results implying high content of uranium in the parent rock (Razgah nepheline syenite body) and concentration of this element in the host rock. Due to radiation increment to 2400 CPS in altered parts of the nepheline syenite body which involve uranium content of over 30 ppm and uranium content of 40 to 154 ppm in sedimentary host rock, it can be said that uranium content of Razgah nepheline syenite intrusive was transported during hydro dynamical and destruction process to the host sandstone unite that resulted in uranium enrichment. Investigation of the host sandstone unit extension and uranium grade in its various parts requires more detailed exploration survey.

A survey in nourthern region of Iran and apart of new highway between Gazvin-Rasht under struction achieved which because of passing Alborz Mountain; it is not safe locationally, so that it can caust the landslide and rockfall in length of highway. Some of them are old and inactive while others are active. 13 of these happened between Rudbar and Rostamabad regions of highway. Out of them, 6 accidents old and the vest are yang. The focus of our studies was located over the new landslides inside the region of Galevarz village. The vastity of this landslide is 180 meters long, 170 meters wide and about 15 meters depth. The landslide happened over the alluvial sediments, weak contacts; irrigation of upper part of the oliv gardens and rainwater channels in alluvial deposits can be important factors of this landslide according to studies conducted one choice for. According to studies conducted one choice for, 8 meters vertical walls by 1 meter horizontal flats can be controlled Galevarz landslide and some drainage system is made above landslide to control it. In the future, instability in highway will occur drainage and also, in upper part can be effective in control of the landslide.

Taking apart and modeling of various mineralized zones and evaluation of their reservoirs and resources in porphyry deposits is so important. In this research the main aim is modeling of mineralized zones in the southern part of Dali deposit. According obtained results from exploration drilling in southern part of this deposit until now, three zones, that they are consist of oxide, transition and hypogene zones, are recognized. For modeling of the southern part of Dali deposit, first of all data of 6 boreholes of this part was regularized in a database. Then three dimension modeling zones in this deposit was made by RockWorks14 software and combining data with surface geological data. Subsequently, amount of copper and gold resources in every three zones was separately evaluated by inverse square distance method. Results indicate that the most concentration of Au-Cu bearing ore is situated in hypogene zone. Moreover, transition zone in some parts is consists of Cu and Au enrichment and it is possible that part of transition zone is introduced as supergene enrichment zone.