پیدایش کانسار آهن جلال آباد زرند

The Jalal Abad iron ore deposit is one of the seven most important iron ore deposilS in the central Iran. with a probable are reserve of 200.4 million tons of iron ore in which the average grades are estimated as 44.28% Fe, 0.83% Sand 0.07%P. In the Jalal Abad deposit two types of orebodies are identified: the orebodies which are concordant with respect to the sedimentarY most rocks (Jalal Abad I). and the orebodies which are discordant with respect to their carbonate host. rocks (Jalal Abad II). In this deposit the primary ore minerals are magnetile and hematite. Hematite is also formed from the oxidation of magnetite. It is proposed that the deposit was rormed in two stages as describled below. 1) The principal orebodies were 'formed contemporaneous with the sedimentation. from the exbalites and precipitates associated with volcanic activity within an intracontinental sources. This pan of the deposit is named Jalal Abad l. 2) After formation of the Jalal Abad orebodies. due to emplacement or the igneous rocks within the ore zone, the meteoric and/or connate water contained in the Jalal Abad J: then iron was redeposited from the upwelling iron bearing solution as replace,m ent orebo<1ies within the carbonate rocks. 1n this manner JalaJ Abad II orebodies were formed.