Geochemical exploration in 1:100000 sheet of Nokabad
1:100000 map of Nokabad is in boundary between Iran and Pakistan from Sistan-va-Balouchestan section and Khash County that located in 60?30' to 61? eastern longitudes and 28?30' to 29? northern latitudes in 65 Km south of Zahedan.
This area from geological view is located in the Southeast zone of Iran and Nehbandan-Khash subzone. Most of its rocks have more or less flysch facies and distribution of its Eocene volcanic rocks is relatively low. The sheet is one of the ophiolite-bearing sheets of Iran. The basement of the area is ophiolitic type that probably formed during intracratonic rifting of late Mesozoic. Then a succession of flysch type rocks of late Jurassic to lower Cretaceous and Eocene covered the basement.
Granodiorite, tonalite, granite and trondhjemite masses that intruded in metamorphosed rocks of Eocene are located at southwest corner of the map. These masses that strike NW-SE, are acidic to intermediate in composition with medium to coarse granular texture.
Main units in this area include colored mélange, flysch, Eocene volcanic rocks, Taftan Quaternary volcanic rocks and Quaternary alluviums and terraces. Two last units have no faulting and deformation. But the two first units show intensive faulting and folding, where most of structures and structural elements of the area appeared in these two units. Cretaceous mélanges just form a small part of central area of the sheet; however, Eocene facies covered a large part of sheet and volcanic rocks located in southwest of it. Many left-lateral and right-lateral strike slip faults with different trends seen in this sheet that generally are in Eocene rocks. Generally, these faults include two separate groups with NW-SE and NNE trends.
Among structural elements of Sistan-va-Balouchestan region that include faults, folds, lineaments and ring structures, magmatic domes and ring structures have more importance in mineralization. So far, from metallogeny view in Lout block, copper, lead, zinc, antimony, mercury and gold mineralization has reported as vein type. Geological and mineralization evidences indicate that in north and northwest part of the Lout zone (that is near Tabas block), copper, lead and zinc mineralization followed with dominance of lead and zinc over copper mineralization, when in south and southeast area copper mineralization followed by gold.