Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Geochemical Exploration and Heavy Mineral Study of Stream Sediments in Barandagh Quadrangle, NE of Zandjan, Iran

Document Type : Original Research Paper

Authors
Hosein Hadizadeh
Ali Asghar Calagari
Ali Abedini
Department of Geology, Faculty of Natural Sciences, Tabriz University, Iran
Abstract
       Barandagh quadrangle (1:50000), a part of Tarom-Hashtjin polymetallic district, is located in NE of Zanjan and SE of Ardabil. The results of preliminary regional geochemical explorations have led to the discovery of anomalous areas for a variety of elements. The anomalies were verified by studies on heavy minerals in stream sediments and mineralized and altered samples taken from the surface outcrops. The identified heavy minerals are hematite, goethite, pyrite, barite, ilmenite, native copper, native zinc, native lead, malachite, molybdenite, micaceous hematite, limonite, cerussite, galena, smithsonite, marcasite, chrysocolla, rutile, zircon, pyroxene, amphibole, and apatite. The identified heavy metallic minerals are principally affiliated with zones of widespread alterations and dispersed veinlet-type mineralization. Chemical analysis of some litho-geochemical samples from the anomalous areas shows noticeable assays for elements such as Ba, Zn, Cu, Sr, Mo, and Be. The majority of anomalous areas are intimately associated with alteration zones in the region. Based on field evidence and mineralogical studies, the alterations are categorized into two discrete types, (1) acid-sulfate alterations (e.g., silisified, alunitized, advanced argillic, phyllic, and propylitic) which are related to shear zones and (2) alterations developed in neutral pH conditions (e.g., argillic, calc-silicate-bearing, and zeolitized) cropped out along the margin of Ghezel-Ozan river. Combination of the overall obtained data from chemical analyses, study of the heavy minerals, petrography of mineralized and altered samples, and field relations led to identification of ten anomalous spots that some, in south and along the margin of the Ghezel-Ozan River, have more potential for ore deposits. The comparison of final anomaly map with the map of fault density depicts that there exists a good correlation between them that may indicate that the fault and shear zones have played a crucial role in creation of these anomalies. Finally the overall results obtained from geochemical investigations in Barandagh show that the identified anomalies belong chiefly to elements such as Sn, Sb, As, Ag, W, Au, Bi, and Pb that can be used as tracer for exploration of epithermal gold and silver and of polymetal (Au, Ag, Cu, Pb, Zn) deposits.
Keywords
Geochemical anomalies
Heavy minerals
The Ghezel-Ozan River
Barandagh quadrangle

Subjects

Barnes, H. L., 1979- Geochemistry of hydothermal ore deposits, 2nd edition. John  Wiley & Sons, 798p.
Beus, A. A., Grigorian, S. V., 1977- Geochemical exploration method for mineral deposits. Translated by R.T. Schneider Ed. by A. A Levinson, Illiais Applied Publishing, 924p.
Brown, P. R. L., 1978- Hydrothermal alteration in active geothermal field. Review of Earth and Planetary Sciences 6, 229-250.
Clark, G. C., Davis, R. G., Hamzehpour,  B., Jones, C. R., 1975-Explanatory text of the Bander-e-Anzali quadrangle map (1:250000). Geology a survey of Iran. Rep. No.D3, 198p.
Clark, D. S., Govett, J. S., 1990- Southwest pacific epithermal gold: a rock-geochemistry prespective. In: J.W. Hedenquist, N. C. White, and G. Siddeley (ed). Epithermal gold mineralization of the circum-pacific. Association of Exploration   
       Geochemists, special publication, No.16a, 225-240.
Davis, R. G.,  Hamzehpour, B., Clark, G. C., 1972- Geology of  masuleh sheet (1:100000). NW  Iran. Rep. No.24, Geological Survey of Iran, Tehran, 110p.
Ginzburg,I.I.,1960-  Principles of geochemical prospecting, 1st English edition.  Pergamon Press, New York and London, 311p.
Govett, G.J., 1983- Handbook of Exploration Geochemistry (Statistical Data Analysis in Geochemical Prospecting), Amesterdam, Elsevier, 461p.
Hirayama, K., Samimi, M., Zaahedi M., Hushmandzadeh, A., 1965- Geology of Tarem district western part (Zandjan area – Northwest of Iran). Geological Survey of Iran. Rep. No.80.
Hemley,  J.J., Hostetler, P.B., Gud A.J., Mountjoy, W.T., 1969- Some stability relations of alunite. Economic Geology 64, 599-612.
Hemley, J.J. Joines, W. R., 1964 - Chemical aspect of hydrothermal alteration with emphasis on hydrogene metasomatism. Economic Geology 59, 538-569.
Levinson, A. A., 1980- Introduction of exploration geochemistry. Applied publishing Ltd., Wilmette, Illinois,  924p.
Peters, W. C., 1987- Exploration and Mining Geology. John Wiley & Sons Ltd, 704p.
Reyes, A.G., 1990- Petrology of philippine geothermal systems and the application of alteration mineralogy to their assessment. Journal of Volcanology and Geothermal Research 43, 279- 309.
Richardson, C. K.,  Holland, H. D., 1979- Flourite deposition in hydrothermal systems. Geochimica  et Cosmochimica Acta 43, 1327-1335.
Rose, A.W., Hawkes, H. E., Webb, J. S., 1979- Geochemistry in  mineral exploration. Academic Press, New York. 657p.
Rye, R.O., Bethk P.M.,  Wasserman M.D., 1992- The stable isotope geochemistry of acid-sulfate alteration. Economic Geology 87, 225-262. 
Sanford, F., Pierson T.,  Crovelli R.A., 1993- An objective replacement method for censord geochemical data, Mathematical Geology 27, 59-79.
Stofferegen, R., 1987- Genesis of acid-sulfate alteration of Au-Cu-Ag mineralization at Summitiville, Colorado. Economic Geology 82, 1575-1591.
Swan, A. R. H.,  Sandilands M., 1995- Introduction to geological data analysis, Blackwell Science,  Cambridge, 446p.
Wellmer, F. W., 1998- Statistical evolution in exploration for mineral deposits. Springer Verlag, New  York, 379p.
 
Scientific Quarterly Journal of Geosciences
Volume 16, Issue 62
Winter 2007, vol. 16, no. 62
Winter 2007
Pages 102-115