Position & lithologic characteristics "Bushehr province"
From geographical view point & relation to structural zone, Bushehr province is apart of south western margin of Zagros mount that are located in mountainous frontier of these heights & beside of Persian Gulf.
Most part of Bushehr province is high & mountainous morphology so in coastal parts have physiographic features of the province is plain hence the province has two different features & morphologic rocky unit is like other areas in zagros & it has a trend of NW-SE that contains a sequence of non symmetric anticlines & compacted syncline is southwards.
Coastal plain of the province has erosional erosion that they have covered mountainous areas to sea shores.
Kazerun fault, is as one of linear & old structures of Iran in north of Borazjan, it reaches to Bushehr Province & more or less it is in a trend of N-S of Bushehr province & it is divided into two eastern & western parts.
North western part of the province, from Borazjan to Gonaveh, is a part of trough of Khuzestan that oldest rocky exposure of that is a part of clastic strata of Fars group that facies has contemporary sequences to orogeny & their sedimentary structures is representative of deposition in a sedimentary regressive basin southwards.
Among lithostratigraphic units in Fars group, Aghajari Fm., especially Lahbari member has most extent whose their age change is from middle Miocene to Pliocene. Deposits of bakhtiari conglomerate has out crop generally as a Plio - Pleistocene lithostratigraphic strata in mountainous part of anticlines & or in core of synclines.
In south eastern part of Bushehr province (east of kazerun fault) as a part of "Fars platform", consequence of lithostratigraphic units is more complete.
Oldest lithologic unit of this part is evaporate – clastic set of Hormoz series that it has of late preambrian- Cambrian age that they have out crop as several salt domes (Jask, Khor moj & Chah pir domes) in core of anticlines & or through Kazerun Fault.
Hormoz halite set is a part of tectonostratigraphic unit from lore pre Cambrian middle Triassic plat form that only its hormoz part has been reached to ground surface because of plastic behaviors of salt & dominant tectonic pressures as "dome". Other accompanying of this sequence (Paleozoic-middle Triassic) do not have outerop but their presence is certain under younger rocks (Mesozoic- Cenozoic).
Mesozoic rocks are more carbonate strata of "Khami Group" that have out crop in core of anticlines. Cenozoic set, in south eastern part of Bushehr province are relatively complete. Here Cenozoic Eocene is started with Pabdeh marine marls & or Jahrum – Asmari carbonates & with set of Fars group (Gachsaran, mishan & aghajari formations) are covered.
From the set of Fars group, Lahbari member of aghajari Fm. cover vast areas. Bakhtiari conglomerate Fm. has much extent that it is seen in low height part of anticline sides & or in core of syncline.
In south east of Bushehr province, as a part of Fars arc, structural pattern are as parallel & long anticlines & synclines with a NW-SE trend. Anticlines are generally asymmetrical & their south western side is steep slope. Mentioned structure is a part of folds in mountainous frontier of Zagros that they have been located beside of Arabian platform. Limit between these two is abrupt that it passes from northern margin of Persian gulf (the areas hear to the shore).
Permanence of tectonical stresses is resulted from shortening in the test & also movement of salt domes results in that Bushehr is one of seismic provinces of the country. However, fortunately power of earthquakes & its damages was not too much.