economical gelogy report and telemetry in sheet of forumad in asclae of 1:100,000(Davarzan – Miami zone)

Description

Abstract The sheet with a scale of 1:100,000 of forumad lies in north east of Semnan province and between longitude of 56 ° 30 ´ and 57 ° 00 ´E and latitude of 36 ° 30 ´ and 37 ° 00 ´ N. exploration was carried put in sheet with ascale of 1:10,000 of Forumad in frame of metalogenic – structural of Miami – Davarzan which is one of twenty exploration zones. In geology viewpoint magor part of this region involves trail of ophilitic zone in north of Sabzevar that its general trend is E-W. the south of the sheet is belonged to this ophiolitic zone that regional mineralization is carried out in this zone. Ophiolites in north of Sabzevar belongs to Mesozoic ophiolites in margin of microcontinent in north of Central Iran and has been created in small rifts of Cretaceous age. This strata is composed of a set of sedimentary, ultramafic and mafic deposits which begun from early cretaceous and terminated in late cretaceous  - Paleocene. Generally this is believed that present set involves relatively complete date from condition of pre, contemporary and post continental rift which results in opening of a basin with oceanic crust, for short time interval and then it has been sealed due to tectonical convergent movements. Thrust fault of Dasturan (Miami) forms northern boundary of ophiolitic units of plate as there is no exposure of ophiolitic rocks in north of this fault. This fault is most important fault of this region and in some cases mineral elements likes magnesium mineralization and formation of magnesium and formation of listonite can be in close relation to Miami Fault. Regarding the geological structures of the plate, most of mineralization occur in ophiolitic zone and it is related to chromites mineral. Chromites appears in lenses shape and bound often by dunite directly (dunite membrane). Moreover major parts of ultramafic rocks are altered and turn to serpentinite. Serpentinite have many mines and indices of chromites with them. In contrast to exploration, magnesium mineralization does not have much extent in the plate and the except to one case of indices, with low carat of magnesium, other case has not been reported.   One case of limited mineralization of iron is in shape of streak and in frame of magnetite mineral is formed in center of the plate, in dolomitic rocks equivalent to Soltanieh Fm. That its carat is good but amount of saving is low.