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Pecten – gypsum lime stones Jp

Pecten – gypsum lime stones

In long zones of central Iran , from north of Kerman to north of Kalmard ,upper Jurassic strata are strata from thin layer light lime stones ,marl and gypsum with considerable amounts of bivalves especially pecten. Hockride and et al ,1962, named this particular facies from upper Jurassic of Kalmard , Abdoughi , Bahabad , Ravar and north of Kerman areas , "gypsum pecten bearing lime stone facies" this formation does not have type section .In these deposits , it has measured a stratigraphic section which can be representative of their characteristics

In Kalmard area of other exposures ,Pecten –bearing lime stone has homogenous frequency of layered lime stone with green color or cream and with a corrosive plains with negligible up and down, which id covered by usually plates of crushed lime stone. From Kalmard to Kerman gypsum horizon are added into this unit so that in Ravar area most value of formation is evaporites deposits. Microfacies of these, limestone are representative of types of mudstone and micrites without clastic and Eolith element what they are deposited apparently in very quiet and limited environment this facies is stable in all of exposure and stability of facies is representative of stability of conditions and in depended sedimentary basins which are limited to Esfandiar lime stone rifts from east and to Posht- e – Badam old pre ecosystem from west.

In most of exposures pectin bearing lime stone are accommodately on Baghamshah Fm. In spite of apparent transitionally of boundary , existence of corossive planes in lost plane of Baghamshah layer and presence of brown-red clastic strata in base mental peaten-bearing lime stones can imply to a erosional cycle and sedimentary gap. From west of Tabas (Kalmard)to north of Bahabad , upper boundary of pectin lime stone, with a indea  litho strari graphic unit is named " Nar limestone "However, there is Nar Fm. in north of Kerman and Pecten bearing lime stone are covered by Orbitholine and Roudist –bearing lime stone in Cretaceous as unconfirmed. Due to not containing index fossil pre-dating of pectin bearing lime stone is very different .Bivalves and micro fossils indicate general age of late Jurassic , pectin bearing lime stones are known of Malm . Neocomian  age in Kerman area (Hock ridden ,1962).

Geographical extent of pectin bearing lime stone is limited to independent basin of Kerman – Kalmard. Salty and gypsum come from Jurassic of above north of Ravar (stocklin,1961) have accon paining of pectin bearing lime stone and it seems that east word, pectin bearing lime stones reach to evaporative facieses. In spite of difference in facies from Chronologic and stratigraphic position aspect comparison of these rocks with Ghale Dokhtar, Esfanyar, Mozduran (Kopet Degh) , Lar (Alborz) and a part of Surmeh Fm. (Zagros) formations is logical.