eocene

This study focuses on Eocene pteropods from the Kopet-Dagh sedimentary basin. Two genera and five species, including Heliconoides bartonensis (Curry 1965), Heliconoides mercinensis (Watelet and Lefèvre 1885), Heliconoides daguini (Cahuzac and Janssen 2010), Limacina cf. aegis and Limacina dzheroiensis (Janssen, King and Steurbaut, 2011), have been reported from the type section of the Khangiran Formation near Yaghol village in Dargaz, Khorasan Razavi province. The pteropod assemblage corresponds to the Early-Middle Eocene boundary. The presence of these assemblages indicates that the Khangiran Formation sedimentary succession was deposited in warm waters, above the aragonite saturation horizon, and within the outer neritic to continental slope paleobathymetric range. This study focuses on Eocene pteropods from the Kopet-Dagh sedimentary basin. Two genera and five species, including Heliconoides bartonensis (Curry 1965), Heliconoides mercinensis (Watelet and Lefèvre 1885), Heliconoides daguini (Cahuzac and Janssen 2010), Limacina cf. aegis and Limacina dzheroiensis (Janssen, King and Steurbaut, 2011), have been reported from the type section of the Khangiran Formation near Yaghol village in Dargaz, Khorasan Razavi province. The pteropod assemblage corresponds to the Early-Middle Eocene boundary. The presence of these assemblages indicates that the Khangiran Formation sedimentary succession was deposited in warm waters, above the aragonite saturation horizon, and within the outer neritic to continental slope paleobathymetric range.

The Eocene deposits in the stuady area composed of a thick succession of pyroclastic, volcanic, and sedimentary rocks (Hajian, 1970). This study is mainly focused on the E5 lithozone in Takht-e Chakab area which is composed of tuff, sedimentary rocks and rhyolite. Based on Hajian (1970), the Eocene deposits are subdivided into 6 informal lithozones (E1 to E6).  i.e., the E1 unit are attributed to Ypresian–Lutetian and the E6 unit is attributed to Priabonian.

In order to determine effective diageneic proceses in the studied succession, one stratigraphic section is selected which is located in Takht-e Chakab anticline, 35 km noth of Delijan city. 78 thin sections were prepared and analysed.

The component allochems identified in the carbonate E5-5 lithozone including skeletal grains especially benthic foraminifera (Nummulitidae and Discocyclinidae), planktonic foraminifera, bivalve, gastropod, serpulids, bryozoa, red algae and corals. Hybrid samples consist of in-situ carbonte particles, clastic components, ash and volcanic particles. Petrographic studies of the studied deposits indicate that these sediments severly affected by diagenetic processes, which led to constructive and destructive porosity. One of the diagentic processes that affected Eocene carbonte deposits in burial environments is compaction. The mechanical compaction led to grain packing, deformation and sometimes crushed of the bioclasts. The grains contacts suturing and stylolite features are evidence of chemical compaction. Silicification is the main diagenetic processes in the studied section. Based on petrographic study some types of diagenetic silicification including chalcedony, micro and megaquartz that occurred in the form of secondary and replacement. Both selective and non-selective silicification is also recorded in some samples. Selectively silica replacement in the shell fragments, and pores filling siliceous cements were mainly filled interparticle porosities. The silica replacement of chalcedony type in bioclasts ocured as spherulitic replacement and controlled ones.The chalcedony fibers have radial pattern in the spherulitic replacement type and independent from microstructures of the test and its orientation. In contrast to spherulitic replacement, in the controlled type of replacement the position and configuration of chalcedony fibrous follow the microscopic structures of the test and showing preferntial orientation. The microcrystaline quartz with equant crystals is less than 20 µm (Maliva and Siever, 1988). In some of bioclasts microquartz is replaced in the form of silica. This process occurred in some bioclasts such as Assilina and Nummulites. Megaquartz occured as intraparticle and interparticle cements. While the interparticle cement involved higher frequently. The petrography of the studied succession reveals that the selective silicification is mostly take place in Assilina, Nummulites and, also ostera fragments. The effects of this process are not the same in different Nummulites species, as it is very common in larger shells rather than smaller ones. Silicification is more common in hyaline foraminifera, while it is absents in porcelaneous ones. Typically, this process is also different in hyaline foraminifera test (very developed in Assilina and Nummulites, it is, rare in Discocyclina, Actinocyclina and Asetrocyclina). The silica source for silicification is usually provided via the biogenic and volcanic activities (Robertson, 1977). Some authors considerd the dissolution of biogenic Opal and or volcanic glasses in as the sources of silica in connate waters, while others considered clay minerals alteration (Nobel and Van Stempvoort, 1989). Based on rare occurences of fossils with siliceous tests such as radiolarian and sponge spicules in the studied sections, the organic silica for this widespread silicification is not rational, so the volcanic materials are a valid source for silicification in these deposits (Okhravi and Mobasheri, 1997).

The carbonate deposits belong to lithozone 5 (E5) consist of limestone, tuffa limestone and marl. Hybrid limestones are also observed in some horizons. Silicification as the main diagenetic process determined as replacing silica and pore-filling siliceous cement that influenced the studied strata. Skeletal factors play vital roles in type and amounts of silicification. Based on petrographic analysis, perforate hyaline foraminifera have undergo more silicification process in compare with other present bioclasts.

In central part of the Mesozoic Ashin ophiolite (Northwest of Anarak, Isfahan province, Iran), the Upper Eocene monzonitic stock cross cuts the Ashin ophiolite and Middle Eocene volcanic rocks. Amphibolite xenoliths are enclosed in the stock and associated Eocene volcanic rocks. Xenoliths are more abundant in the margin of the monzonitic stock. Rock-forming minerals of the stock are plagioclase with andesine to labradorite composition (An=34-60%), Alkali-feldspar with orthoclase composition (Or= 70.8 to 96.1%), diopsidic clinopyroxene with (Mg# =0.71-0.90), and phlogopite mica with (Fe#=0.3). Opaque minerals are magnetite and titanomagnetite (TiO2=1.6-4.4 wt.%). Main textures of samples from this intrusive body are granular, intergranular and poikilitic. Samples from the margin of this stock represent porphyritic texture. 
Geochemistry of minerals and whole rock samples of this stock indicate that they belong to the calc-alkaline magmatic series and are similar to the samples from the continental magmatic arcs.
These magmatic rocks possibly were formed by subduction of the CEIM (Central-East Iranian Microcontinent) confining oceanic crusts (Ashin and Nain oceanic crusts) during Mesozoic and Early Cenozoic eras.

Iran is a part of the Alpine-Himalayan orogenic system, including the Paleozoic to Cenozoic ophiolites, magmatic and metamorphic rocks (Takin, 1972; Berberian and King, 1981; Berberian et al., 1982; Dercourt et al., 1986; Alavi, 1994; Mohajjel et al., 2003; Shahabpour, 2007). The main pulse of the Paleogene and Neogene magmatic (volcanic and intrusive) activities of Iran can be attributed to the two Cenozoic subduction events, including the western Neo-Tethyan oceanic crust subduction beneath the Sanandaj-Sirjan block in the west and the eastern Neo-Tethyan oceanic crust subduction beneath the Central Iran (e.g., Shirdashtzadeh et al., 2022). The former subduction possibly caused to the formation of the Urumieh-Dokhtar Magmatic Arc, but the later subdution results is not well studied yet. 
In the this research, the target region is located in the west of the Yazd block (Central Iran), where the Eocene volcanic and plutonic rocks represent subduction-related characteristics (Jamshidzaei et al., 2021). The investigated subduction-related monzonitic stock that cross cuts the central part of the Ashin ophiolite in the Kuh-e-Kalut-e-Ghandehari region, in the northwest of Anarak (Isfahan Province, Iran). The main lithologies in the Kuh-e-Kalut-e-Ghandehari are Mesozoic lithologies of Ashin Ophiolite, Paleocene limestone, Eocene volcanic rocks, monzonitic stock, Lower Red Formation, and Akhoreh Formation. Ashin ophiolite was formed in the mesozoic (Shirdashtzadeh et al., 2022) and emplaced in the Late Paleocene (~60 Ma; Pirnia et al., 2020; Shirdashtzadeh et al., 2022), before than Eocene volcanism and plutonism. The studied monzonitic stock of the Kuh-e-Kalut-e-Ghandehari intrudes the Mesozoic Ashin ophiolite and Middle Eocene volcanic rocks.
The calc-alkaline affinity of the volcanic and plutonic rocks of the area, tectonic activity of the Great Kavir fault caused to the crushing and mylonitization of the surrounding rock units, as well as the alteration evidences in the field studies point to suitable conditions for the ore deposit exploration in the area (e.g., copper). In this research, the petrology, mineralogy, and whole rock geochemistry of the Upper Eocene monzonitic stock are considered. This research will expand our understanding of the geochemical nature of subduction-related Cenozoic magmatism in Central Iran.

After detailed field studies and sampling, the selected fresh samples were used for microscopic thin section and polished-thin section studies by the polarizing binocular microscope (Olympus BH-2). The microprobe analyses were performed at the School of Natural Systems, College of Science and Engineering, Kanazawa University (Kanazawa, Japan) using a wavelength dispersive electron probe microanalyzer (EPMA) (JEOL JXA-8800R). The mineral analysis was achieved under an accelerating voltage of 20 kV, a probe current of 20 nA, and a focused beam diameter of 3μm. 14 whole rock samples analyses were performed by Brucker S4 PIONEER XRF in the central laboratory of the University of Isfahan and 3 samples were analyzed in the Isfahan Nuclear Technology Center by neutron activation analysis (NAA).

Based on the field relation ships, this gray to light gray pluton intrudes into the Middle Eocene volcanic rocks and belongs to the Upper Eocene. The Middle Eocene volcanic rocks and Upper Eocene monzonitic stock crosscut the Ashin Ophiolite. This Eocene stock and volcanic rocks contain amphibolite xenoliths with the same mineralogy and petrography. Xenoliths are more abundant in the margin of the monzonitic stock. Gradual decreasing of modal plagioclase content indicates that the xenoliths range from amphibolite (plagioclase + amphibole) to hornblendite (only amphibole) in composition.
Rock-forming minerals of the stock are plagioclase with andesine to labradorite composition (An = 34-60 %), alkali-feldspar with orthoclase composition (Or = 70.8 to 96.1%), diopside clinopyroxene with Mg# = 0.71-0.90, and phlogopite mica with Fe# = 0.3. Opaque minerals are magnetite and titanomagnetite with TiO2 = 1.6-4.4 wt%. The main textures of samples from this intrusive body are granular, intergranular and poikilitic. Samples from the margin of this stock represent porphyritic texture. The SiO2 value in the whole rock compositions ranges from 47.9 to 61.65 wt.% (basic to intermediate). The average content of alkalis is 9.75 wt.%). The Kuh-e-Kalut-e-Ghandehari rocks show sodic affinity by higher Na2O than K2O, based on the Na2O/K2O versus SiO2 and K2O/Na2O versus SiO2 diagrams (Jaques et al., 1985). The Eocene intrusive and volcanic rocks of this area are similar in terms of mineralogy and texture. Petrography and whole rocks chemical analyses indicate that the studied stock is geochemically composed of gabbro, monzodiorite to monzonite in composition with metaluminous affinity. Monzonite is the predominant rock.

Various tectonomagmatic discrimination diagrams are used to determine the tectonomagmatic setting of the Kuh-e-Kalut-e-Ghandehari stock. Mineral chemistry and whole rock geochemistry of the Kuh-e-Kalut-e-Ghandehari monzonitic stock indicate a calc-alkaline magmatic series similar to the subduction-related magmas in the normal continental magmatic arcs formed during the mantle metasomatism. According to the the temporal and geological situation, as well as the geochemical characteristics of the Kuh-e-Kalut-e-Ghandehari stock, it is considered as a part of an arc magmatism, related to the subduction of Neo-Tethyan oceanic crust beneath the CEIM (Central–East Iranian Microcontinent) during the Late Mesozoic and Early Cenozoic eras.

We are grateful to the University of Isfahan and the Department of Geology of Kanazawa University (Japan) for their supports. We are also grateful to anonymous reviewers for their useful comments and suggestions that improved the quality of this paper.

The Kimia copper area is located in the Eocene volcano-sedimentary complex northwest of Bardskan in Razavi Khorasan Province. The geology of the area includes volcanic rocks with andesite-basalt composition, conglomerate with andesite fragments, nummulitic limestone and tuffaceous sandstone. Mineralization is found in andesite and conglomerate units as well as at the border between these units in the form of vein-veinlets, disseminated, replacement and open space filling. Primary minerals are chalcocite, pyrite, and secondary minerals are malachite, caveolite, and iron oxide. The faults in this region are formed in two directions, northeast-southwest and northwest-southeast, with a slope of 45 degrees. The main veins in this zone are calcite-quartz-pyrite, calcite-chalcocite and calcite-barite-pyrite. Alterations related to veins are siliceous and carbonate and are related to igneous, propylitic, carbonate and chloritic units. The amount of copper element ranges between 6950 and 47935 ppm and other elements have low values. Based on fluid inclusion study, the minimum formation temperature ranges between 228 and 368 °C and the salinity is between 10.4 and 16.9 percent. Based on the evidence of the host rock, structure, textures and existing alterations, copper mineralization in Kimia area is Manto type.

The study area is located in the north of the Yusef -Kandi village, north of Lahrud, Ardabil Province (northwestern Iran). This area comprises portions of the Alborz-Azarbaijan structural zone, which together with the Little Caucasus and the highlands of southeastern Turkey have evolved due to the convergence of the Arabian and Eurasian plates during the Alpine-Himalayan orogeny. The study area includes outcrops of Eocene volcanic and volcano-sedimentary sequences which were deposited in marine to continental environments. The volcanic portion of these sequences consists of volcanoclastic rocks as well as lava flows. A few acidic volcanic rocks and ignimbrite are locally exposed in this area. The petrographic studies show that the Yusef-Khan-Kandi volcanic rocks include picrobasalt, basalt, tephrite, basanite, trachybasalt, basaltic trachyandesite, phenotephrite, tephrophenolite, trachyandesite and trachyte compositions. Phyric texture is common within the volcanic lavas. The majority of the samples show transitional to potassic trends, with only a few samples exhibiting sodic trends. The transitional trend observed in a significant number of the studied samples probably has resulted from the mingling of the sodic and potassic magmas. The Harker binary variation diagrams indicate trends that are consistent with fractional crystallization. The chondrite-normalized REE patterns and primitive mantle-normalized spider diagrams show high LREE/HREE ratios which could be explained by partial melting of an enriched mantle (including asthenospheric) or a metasomatized mantle in collisional to continental arc environments. Most of the studied volcanic rocks plot in the active continental arc or within plate domains. It seems that following the convergence between the Arabian and Eurasian plates in the Late Cretaceous, the northward subducting Neotethyan slab in the Eocene, triggered partial melting of the metasomatized subcontinental lithospheric mantle. Therefore, we suggest that the Yusef-Khan-Kandi Eocene volcanic rocks were erupted in a post-collision extensional environment.

The Gooreh Mountain is located about 55 km northwest of Anarak (northeast of Isfahan) and in the western margin of the Central-East Iranian microcontinent (west of the Yazd block). The field studies show that the Eocene volcanic rocks in this area present two lithologies of gray-colored dacite and light-colored rhyolite. Dacite lavas cross-cut the rhyolite ones and are younger. Petrography indicates that dacites contain the major minerals of plagioclase (labradorite and bytownite), clinopyroxene (augite) and quartz, and rhyolites are mainly composed of plagioclase, sanidine and quartz. Chlorite, calcite, hematite and limonite are the secondary minerals in both rock units, formed by the alteration of clinopyroxene, plagioclase and magnetite. The main textures of these rocks are porphyritic, glomeroporphyritic, anti-rapakivi, sieved and poikilitic. The crystallization order of minerals in dacites is magnetite, clinopyroxene, plagioclase and quartz, and in rhyolites, is plagioclase, sanidine and quartz. Whole rock geochemical analyses show that the studied volcanic rocks of the Gooreh Mountain are sub-alkaline (calc-alkaline magma series) in nature. Moreover, the chondrite and primitive mantle-normalized diagrams are characterized by the enrichment of LREEs and LILEs and depletion of HFS elements (e.g., Ti, Nb and Ta). The negative TNT (Ti, Nb and Ta) anomalies probably indicate subduction-related volcanic arc magmatism. The dehydration of subducting slab and partial melting of the mantle wedge spinel peridotites produced a basic magma that, during ascent through the lower and middle continental crust, led to melting of amphibolites and formation of acidic magmas.

Miandasht copper deposit is located in 110 km east of Shahrood, 24km north west of Abbasabad, and in the Cenozoic volcanic belt of north of Central Iran zone. The major rock units of the study area have Eocene age and include submarine flows (andesite, basalt, and trachyandesit), pyroclastic (tuff breccia and agglomerate) and sedimentary complex (Nomullitic limestone, tuffacous limestone, shale, sandstone and conglomerate). Mineralization in the Miandasht copper deposit occurred as parallel to layering of the host rocks (tuff breccia and agglomerate), and also along with cross- cutting faults of the host rocks in form of stratabound and epigenetic ores. The main ore textures include vein- veinlets, open space filling, disseminated and replacement. The Ores contain primary pyrite, chalcopyrite, chalcocite, bornit, and secondary covellite, chalcocite, malachite, hematite and limonite. The most important wall rock alterations accompanied with mineralization are carbonatic- silicic, sericitic, argillic, and chloritic, and that the amound of carbonatization and silicification increases with closing to mineralization zones. According to geochemical studies, tectonic setting of the deposit was extensional environment formed in a continental margin volcanic arc. Based on essential characteristics of the copper mineralization such as tectonic setting, host rocks, mineralogy, and type of alterations, the Miandasht copper deposit shows many similarities with Manto- type deposits, dominantly formed during orogeny, folding and faulting of the host sequence. It should be mentiond that some charachteristic features of the Miandasht copper deposit including development of argillic alteration, and lack of extensive zeolitic alteration, distinguishes it from other copper deposits in the region including Abbasabad deposit.

In the northeastern part of the Isfahan province and 65 km northeast of the Anarak city (Kal-e-Kafi area), an I-type granitoid pluton cross cut the Paleozoic metamorphic rocks and Eocene volcanic rocks. In the contact of this granitoid body with sourrounding rock units, skarn and hornfels have been formed (Ahmadian, 2012; Ranjbar, 2010). The Kal-e-Kafi Eocene intrusive body presents a wide range of mineralogical and petrological compositions, from gabbro to alkali-feldspar granite. Presence of mafic to acidic rocks in this mostly-granitoid body indicates that fractional crystallisation has played an important role during magma evolution. The field and petrographical studies indicate the presence of anorthosite veins within the gabbro section. The mafic and basic parts of this pluton have not been studied yet. The mineralogy and chemistry of rock-forming minerals in the anorthosites and gabbros are the subject of this research study.

The mineralogical and petrographical studies have been done by using Olympus BH-2 polarizing microscope in the mineralogy laboratory of the University of Isfahan. EPMA and LA-ICP-MS analyses were used to obtain chemical characteristics of rock-forming minerals. Major-elements composition of minerals were performed by JEOL JXA-8800, WDS microprobe electron analyzer with accelerator voltage of 15 kV, current of 15 nmA, diameter of 3 μm, and a counting time of 40 seconds at the Kanazawa University of Japan. Natural and synthetic minerals and compounds were used as standards. The ZAF program was used for data correction.Trace element values of plagioclases and clinopyroxenes were analyzed by LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry) using an ArF 193 nm Excimer Laser coupled to an Agilent 7500S at the Earth Science Department of the Kanazawa University, Japan. The diameter of the analyzed points was 110 µm at 10 Hz with energy density of 8 J/cm2 per pulse.Mineral abbreviations in tables and photomicrographs are adopted from Whitney and Evans (2010). 

The Eocene Kal-e-Kafi pluton includes a wide range of rocks from gabbro to alkali-feldspar granite, which points to an extensive magmatic differntiation. Field relationships indicate presence of at least 4 magmatic phases, and gabbro is the first and oldest phase. The most predominant rock unit in the Kal-e-Kafi intrusive body is granitoid. However,  in the northern parts, the gabbro and anorthosite present substantial exposures. The anorthosites and gabbros are associated with each other in the field. Anorthositic veins with up to 15 cm thickness cut the gabbro.Gabbro is composed of bytownite and anorthite plagioclase (An= 84 – 94 %; some of them have been altered to bytownite, andesine and oligoclase), clinopyroxene (diopside, Mg#= 0.75), orthoclase (Or0.88), apatite, magnetite, and prehnite. Anorthosite rock-forming minerals are anorthite plagioclase (An= 89 – 95 %; some anorthite plagioclase have been altered to bytownite and labradorite), sphene and zircon. The main texture of these rocks are granular, intergranular and poikilitic. Field studies suggest that anorthosites are associated with gabbros which have filled the fractures of gabbros.Very simmilar petrography and chemical composition of plagioclases in the anorthosites and gabbros possibly reveal their cogenetic nature. It seems that the primary magma in the magma chamber, first crystallized the clinopyroxene and plagioclase, which caused formation of gabbros. In the next stage, by occurrence of a tectonic activity, the gabbros have broken and the remaining magma which was rich in plagioclase components, crystallized the anorthosites in the fractures. This reveals that the anorthosites of the study area are the plagioclase rich part of the primary basic magma which have formed the gabbros.According to the field relationships, it is generally believed that anorthosites are differentiates of gabbroic magmas. The studied anorthosite veins and gabbros of the Kal-e-Kafi area are consanguineous. These anorthosites are perhaps generated by the process of collection of plagioclase crystals from a gabbroic magma under the action of gravity and tectonic activity (filter pressing).Pyroxene is one of the common minerals. The chemical composition of this mineral provides valuable information about the nature of magma, H2O content, Oxygen fugacity, type of magmatic series, tectonic setting, as well as temperature and pressure of crystallisation (Schweitzer et al., 1979; Leterrier et al., 1982; D’Antonio and Kristensen, 2005).Chemistry of clinopyroxens within the gabbros of the Kal-e-Kafi  area shows that the parental magma belongs to the sub-alkaline and calc-alkaline magmatic series and these rocks are similar to those of volcanic arcs. The time and place of formation of these plutonic rocks possibly indicate that they are formed by subduction of the Central-East Iranian Microcontinent (CEIM) – confining oceanic crust beneath the CEIM. AcknowledgmentsThe authors thank the University of Isfahan for financial supports.

Subduction-related magmas are characterized by enrichment of large ion lithophile elements (LILEs), light rare earth elements (LREEs) and depletion in high field strength elements (HFSEs) (Harangi et al., 2007). These geochemical signatures of magmatic rocks are commonly explained by the addition of hydrous fluids from subducting oceanic lithosphere combined with the flux of melts from subducted sediments to the mantle wedge, lowering the mantle solidus and leading to magma generation (Aydınçakır, 2016). Asthenospheric mantle, subcontinental lithospheric mantle and/or lower crust may be the principal source of these rocks (Eyuboglu et al., 2018). In addition, magma differentiation processes, such as fractional crystallization, crustal contamination, and magma mixing may also play an important role in the genesis of these rocks.This research study presents new petrological and geochemical data from the volcanic rocks with NW–SE trending, which are situated in the northwestern margin of the Central –East Iranian Microcontinent (CEIM) (south-east of Khur, Isfahan Province) which have been formed during the peak activity of Eocene. Study of this typical small volume subduction- related magmatism will be useful in understanding the origin and geological evolution of the Central Iran in Cenozoic.

The petrographic investigations on Eocene volcanic rocks from the SE of Khur area were carried out with an optical microscope (Olympus-BH2) in the petrology Laboratory of the University of Isfahan, Iran. Major and trace element concentrations of samples from whole- rocks were obtained by a combination of inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) at the Als Chemex Laboratory of Ireland. The chemical compositions of 4 samples (B865, B866, B867, and B868) were determined by Neutron Activation Analysis (NAA) in the Isfahan Activation Center. The detection limit was 0.01% for all major element oxides and 0.01 ppm for rare earth elements. Mineral abbreviations were adopted from Whitney and Evans (2010).

Eocene volcanic rocks with trachy-basalt and trachy-basaltic andesite composition are exposed in the northwestern part of the Central-East Iranian Microcontinent (CEIM) (SE of Khur, Isfahan Province, Central Iran). These rocks which have a dominant northwest-southeast trend crosscut the Cretaceous sedimentary rocks.Petrography and mineral chemistry analyses indicate that the predominant rock-forming minerals of volcanic rocks are olivine, plagioclase, clinopyroxene and orthopyroxene. Phenocrysts set in a fine to medium grained matrix of the same minerals plus sanidine with minor amounts of opaque minerals. Secondary minerals are chlorite and calcite. The most common textures of these rocks are porphyritic, microlitic porphyritic, poikiolitic and glomeroporphyritic. Geochemical analyses of whole rock samples show that these rocks have been enriched in alkalies and large ion lithophile elements (Cs, K, Rb, Sr, Ba,), and have been depleted in high field strength elements (HFSE) (Ta, Nb, Ti). All samples indicate moderate to high fractionation in LREE patterns. These geochemical signatures point out to the subduction-related calc-alkaline nature of these rocks and their similarity to volcanic rocks of continental arcs or convergent margins (Yu et al., 2017). Pb enrichment and low values of Nb/La, Nb/U and Ce/Pb ratios reveal that crustal contamination has played an important role in magma evolution (Srivastava and Singh, 2004; Furman, 2007). The large volume of hydrous fluids coming from the subducted slab rather than sediments have caused enrichment and metasomatism of the subcontinental lithospheric mantle source. The geochemical characteristics of the studied rocks suggest that the parental magma have been derived from partial melting of a metasomatized spinel lherzolite of lithospheric mantle, which was previously modified by dehydration of a subducting slab. The tectonic environment, in which these rocks were formed has probably been a volcanic arc. Subduction of oceanic crust around the Central-East Iranian Microcontinent (CEIM) is the most reasonable mechanism which can be used to explain enrichment in volatiles of the mantle, and the calc-alkaline magmatism of the study area in Eocene times.

For the paleoecology study of Lower Paleogene deposits based on foraminifera fauna in the NW of Jiroft situated in the Central Iran zone, two Sabzevaran (230m) and Sad (45m) sections were selected. Lithology of these sections mostly contain marl, sandstone and siltstone. Based on the presence of index planktonic foraminifers, the Late Eocene age can be deduced for the studied sections. In this study parameters such as paleo depth, oxygen and nutrient level and EP/IN morphotype ratio were studied. Based on this study neritic paleodepth proposed for these sections. EP/IN morphotype ratio in this part indicate of oligotrophic conditions in the base of sections that turn to eutrophic conditions toward top of Eocene part.

In southwest of the Jandaq City (northeast of Isfahan Province) and northwest of the Central-East Iranian Microcontinent (CEIM), the Eocene dykes with trachy-andesitic composition cross cut the quartz monzodioritic intrusion. The texture of these dykes is granular, intergranular and porphyritic. The studied dykes are composed of plagioclase (andesine and labradorite), clinopyroxene (diopside and augite), sanidine, mica (Biotite), and quartz as primary minerals, and amphibole (tremolite-actinolite), chlorite, magnetite and calcite as secondary ones. Mineral chemistry and distribution of elements indicate that these minerals are formed in low to medium pressure (2-5 kbar), 1150 to 1200 °C, and the high Oxygen fugacity conditions. The source rock of the magma is a mantle peridotite which previously metasomatized by fluids and melts derived from subducting oceanic slab.  Mineral chemistry of clinopyroxene and biotite reveal that these dykes have calc-alkaline nature and are formed in a subduction-related environment.