بررسی تاثیر گسلها بر الگوی تجمع رخ‌ دادهای مس در منطقه سرچشمه با استفاده از روشهای سنجش از دور و gis

کانسار مس سرچشمه و سایر اندیس های مس پیرامون آن در کمربند دهج ساردوئیه ( استان کرمان) قرار گرفته اند. گسلها گاه با ایجاد شرایط مناسب سینماتیکی و مکانی می توانند الگوی تشکیل رخ‌داد های مس را کنترل کنند. در راستای بررسی صحت این فرضیه، با استفاده از روشهای سنجش از دور، خطواره ها، استخراج و سپس با مشاهدات صحرایی، گسلهای اصلی و فرعی مشخص شدند. بررسیهای ساختاری در قالب تهیه نمودار گل سرخی و محاسبه محور فشارش انجام شد. با استفاده از قابلیتهای gis، اقدام به تهیه نقشه هم‌شکستگی و فاصله داری رخ‌دادهای مس از گسلها شد و لایه موقعیت رخ‌دادهای مس بر روی سایر لایه های خروجی منطبق شد. نتایج بررسی نقشه های خروجی نشان می دهد گسلهای اصلی دخالت مستقیمی در کنترل محل رخ‌دادهای پورفیری و رگه ای نداشته و رده های دوم این پهنه های گسلش، موقعیت رخ‌دادها را کنترل کرده اند. همچنین مشخص شد که محل رخ‌دادهای مس آغشتگی ارتباط نزدیکتری با گسلها داشته و بیشتر رخ‌دادها نزدیک به گسل رفسنجان قرار دارند.

Fault Control on Copper Depositsin the Sar Cheshmeh Area Indicated by Remote Sensing & Geographic Information Systems (GIS)

Introduction#13;The Sar Cheshmeh copper deposit and indications of other deposits are located in the DehajSarduieh belt in the Kerman region (Khadem and Nedimovic, 1973). This belt is one of the most important provinces of Cu mineralization in Iran, with approximately 300 Cu deposits and prospects, includingtwenty of the porphyry copper type (Ghorbani, 2013). This belt, 300 km in length and 30–45 km width, is situated in the southern part of the UramiaDokhtar volcanic belt in central Iran (Shafiei, 2010). Zarasvandi (2004) has proposed that faulting has played a role in the location of copper deposition in this area. #13;#13;Methods of Investigation#13;In order to check Zarasvandi’s hypothesis, the spatial relationship between faults and Cu deposits was investigated using remote sensing and GIS techniques together with field investigations in the Sar Cheshmeh area. The the following steps were used in this research: #13;1. Review of available data#13;2. Surface geology field studies#13;3. Preparation of digital overlay of Copper occurrences #13;4. Analysis of the relationshipof faulting to Copper occurrences#13;Using remote sensing techniques, a geometrically corrected satellite image was filtered with high pass and Sharpen Edge filters to detect possible lineaments (Lillesand and Keifer, 2008; Sabins, 1996). Directional filters (45º, 90º, 135º and 180º) were then applied to the processed image to enhance the linear structures. Subsequently,the major lineaments were documented in the field as major and minor faults (Safari et al., 2011). Four main faults, designated as the Rafsanjan, Mani, GaudeAhmar and Sar Cheshmeh faultswere determined to be major. These faults were digitized and overlaid on other data layers in GIS environment. The strikes, dips, striae and directions of movementof the faultswere measured at 20 locations in the field. Structural analyses were done with Rose diagrams, calculation of Paxes and preparation of a structural map. #13;Copper occurrences on the mineral distribution map of Lotfi, et al. (1993) were used in this study and the locations of somecopper occurrences were determined in the field using GPS. The locations and main characteristics of the copper occurrences were entered into a GIS map. Finally, anisofracture map, was prepared using the GIS environment based onfault lengths within a 1000 ×1000 mgrid and on the buffer map of ore occurrences relative to faults. The copper occurrence locations were overlaid on these prepared maps and the relationship between faults and ore occurrences locations was analyzed.#13;#13;Results#13;This research indicates that:#13;1.The faults in the Sar Cheshmeh area trend predominantly 090°110°, 130°150°, 050°070° and 170°190°.#13;2.The data show that three major NW trendingfaults, the Mani, GaudeAhmar and Rafsanjan faults show rightlateral strikeslip movement and the two major EW trending Sar Cheshmeh and Darreh Zar faults have leftlateral strikeslip displacements.#13;3. The control of the calculated Paxes shows that at least two older movements have happened along these faults.#13;#13;Discussion#13;The results show that the main faults did not directly control the locations of the mineralized porphyries and veins, but that rather the locations are due tothe secondorder faults. Also, the saturated occurrence locations have the closer relationship with main faults and most indexes are located near the Rafsanjan fault and its secondorder faults.#13;#13;References#13;Ghorbani, M., 2013. The Economic Geology of Iran: Mineral Deposits and Natural Resources. Springer Science, Business Media Dordrecht, Heidelberg, 581 pp.#13;Khadem, N. and Nedimovic, R., 1973. Exploration for ore deposits in Kerman Region. Geological Survey of Iran, Report Yu/53, 247 pp (in Persian).#13;Lillesand, T.M. and Kiefer, R.W., 2008. Remote sensing and image interpretation. John Wiley and Sons, New York, 756 pp.#13;Lotfi, M., Sadeghi, M.M. and Omrani, S.J., 1993. Mineral distribution map of Iran, scale: 1/1000000. Geologic Survey of Iran.#13;Sabins, F.F., 1996. Remote sensing principle and interpretation. Macmillan Education Australia, New York, 494 pp.#13;Safari, H., Pirasteh, S. and Shattri, B.M., 2011. Role of Kazerun Fault for Localizing Oil Seepage in the Zagros Mountains, Iran: an Application of GiT. International Journal of Remote sensing, 32(1): 116.#13;Shafiei, B., 2010. Lead isotope signatures of the igneous rocks and porphyry copper deposits from the Kerman Cenozoic magmatic arc (SE Iran), and their magmaticmetallogenetic implication. Ore Geology Reviews, 38: 2736.#13;Zarasvandi, A.R., 2004. Geology and genesis of the DarrehZerreshk and AliAbad copper deposits, Southwest of Yazd, based on fluid inclusion and isotope studies. Ph.D. Thesis, Shiraz University, Shiraz, Iran, 280 pp.