Perlite – is most aggregation volume of perlite in Iran is located in Mianeh Region. In this trend, we can name Sari –Ghamish Area, shirin Boulagh , Ajami , Ashlagh chay and Abak .
High potential for this region indicates geological characteristics of Azerbaijan and in other hand there is a geological descriptive explanation in this area.
Perlite Geology of Mianeh Area
Lithologic coverage of the area is perlite in Tertiary volcanic Rocks and Quaternary sedimentary Deposits. Beginning of Tertiary Period is accompanied with very abruptly activities in most points of Iran, central Iran and Alborz. So, extrusive rocks are depended on these volcanoes with various compositions. These rocks are mainly from andesite lava mixed to volcanoclastic rocks during Eocene, trachyte, basalt, rhyolite, rhyodacite and acidic tuffs in Oligocene and Miocene .Young sedimentary deposits depends on Miocene and Pliocene which have been caused from marl and detrital sediments takes conglomerate.
Eocene period is with many volcanic eruption and it is caused from three parts of middle, lower and upper parts. Although separation of these areas in perlite susceptible areas is difficult but it is easy in around areas .Lower Eocene is began with conglomerate and it is in accordance to fining grains which is stretched to silt and they are accompanied with volcanic and lava deposits . In middle Eocene, some nummulite –bearing limestone is accompanied too and again volcanic activities are accelerated in lower Eocene and lava are extensive.
This total appearance is accompanied with lava aggregation contemporary to marine deposits as volcanic activities are main units of lithology.
Volcanic activities are present in Oligocene and to early Miocene .These activities are with big ratio in Azerbaijan that we can name that as porphyry series. In comparison to volcanic volume which are not important and most of volcanoes are acidic composition and Iran perlites have a more age.
Plio – Pleistocene
On Oligo-Miocene volcanic lava displacement of volcanic aggregations is seen with Plio- Pleistocene age but if we go further into this topic, extent of these activities is not as much as two periods.
Quaternary Deposits are extensive to south Area in low steppe and in river path which are:
- Alluvial Deposits: includes gravel and sand sediments which are not compacted and they are used as farming lands.
- Fluvial Alluviums: It includes some rock deposits which are deposited by floods which are seen in major rivers in the region.