Writers : Ghaderi,Ghasem;Supervisor: M,Sabzei
Refference : M.Sc.Thesis-Research Institute for Earth Sciences, Tehran
Publishing Year : 1380

Abstract :

The studied area is located in 78 Km of Sabsevaran (Giroft) that named as "Dalfard Area". Geological coordinates are as follows: Latitude 57°, 36'- 57°, 39' and Longitude 28°, 56'- 28°, 58'. Oldest rocks in this area are Greenschist
and Marble that exposed Regional metamorphism in Early Paleozoic. Permian debries consist of Conglomerate, Sandstone and Siltstone have covered this rocks. In upper Jurassic, in the first, basic magma phase and the second acidic magma phase have intruded protolith rocks consist of Greenschist and Marble and have formed Hornfels and Skarn during the contact metamorphism. Two process of skarnization realative two phase of magmatic intrution were happened. so, two sets paragenesis were formed:
1- Anhydrous paragenesis that produced in the first contact metamorphic-metasomatic phase due to the intrusion of basic magma and characterized by presence of anhydrous minerals like Diopside.
2- Hydrous paragenesis that produced in the second of contact metamorphic-metasomatic phase due to the intrusion of acidic magma and charactrized by presence of hydrous minerals such as Vesuvianite and Prehnite Grossularite and Wollastonite can be formed by 1120, Si02 bearing fluid during acidic phase Epidote formed by 1120, C02 bearing fluid due to Retrograde metamorphism. Each phase of skarn formation is attributed to magmatic phase, consequently, these skarns can be named as "polygenetic skarns Acording to mineral paragenesis, studied skarns are "Calcic Skarns ".
Metamorphic and metasomatic reactions of first phase are mainly "Decarbonization Reactions". So, these reactions proceed in presence of low Xco2. In the same way, In the second phase, fluid should bear considerable
amount of 1120, Sio2 that have provided from granitic magma.
There isn't transitional zone between intrude bodies and skarn. Distance from
granitic magma to skarns is so far, therefore form of skarns can't expressed by "diffusion "corc1usiveIy prevailing mechanism of skarnization, is "contact Infiltration". prosses.
Conditions of skarn formation conform with high temprure, low presure and low Xco2.
First phase has occurred in the condition of Pyroxen Hornfelse while second phase has occurred in Horubland Hornfelse. Retrograde metamorphism express condition of A1bite-Epidote Hornfelse. From an economic point of view field investigation have reveald that 3.5*106 ton wollastonite can be extracted from wollastonite skarns.

Subject List : Skarn