Background and Objective: Jahrum Formation has long been of special interest due to its wide distribution, Biostratigraphic and Lithostratigraphic differences in different areas, and the existence of hydrocarbon reserves. The purpose of this study is to investigate the Jahrum Formation in the study areas, in terms of stratigraphic position (thickness and lithology) and geology (contact with upper and lower formations) and its paleontology. Material and Methodology: The study conducted on Jahrum formation (lower and Middle Eocene) of interior Fars, Zagros. The 465 samples were collected from Gushenekan, kuh-e-Chehel Cheshme and Tong garm. Thin sections were used to study of stratigraghy, microfacies and Microfossils. Findings: According to them, two sedimentery sequences identified. The main aims of the research are Identification of the Jahrum formation borders that connected to the Asmari at the top as discotinuty and the Sachun formation at bottom as concordant. Discussion and Conclusions: Based on this study Jahrum formation has deposited in the internal ramp and consisting two sequences. Additionaly, sedimentary environment, geochemical analysis and Paleontological ecology of the Jahrum were studied too. Also, the tectonic position of the sedimentary basin of Jahrum Formation in comparison with the adjacent basins was presented in the form of a conceptual design for the first time.

The late Pleistocene period witnessed significant shifts in human lifestyle and behaviour across various regions in the Old World, as indicated by prehistoric archaeological evidence. These shifts reflect a transition from hunting to a greater emphasis on activities related to gathering plants. Archaeological findings demonstrate the utilization of plants in diverse forms, including the emergence of Bedrock Ground Stone (BGS) at prehistoric sites. In the realm of archaeological research, these remains are deemed crucial man-made artefacts, shedding light on essential aspects such as nutrition, culture, vegetation, food processing, and the presence of medicinal and toxic substances within ancient human societies. Given the existing research gap and the paramount significance of these artefacts in archaeological and anthropological studies, the Diyarmehr Institute for Paleolithic Research, for the first time in Iran, has committed to undertaking comprehensive and scientific investigations of the BGS in the Nawadrwn valley in the  Kermanshah region. Owing to its geographical positioning and environmental abundance, the west-central Zagros range has historically attracted and served as a conducive habitat for diverse human groups across various epochs. This study represents a multi-disciplinary research endeavour focused on 24 bedrock groundstones (BGS) discovered in the Prehistoric Bawa Yawan rockshelters within Nawdarwan valley. Detailed morphological and geochemical analyses have unveiled their multifaceted utility, encompassing purposes such as herbal processing and extraction, and their use in three instances as stone lamps.

The area is located in 25 Km southwest of kazerun city in the Zagros folded zone. The Phosphate beds have been deposited in the core of the Sarbalesh-Baznak anticline with NW-SE trend. Stratigraphically, the Gurpi, Pabdeh, Asmari, Gachsaran, and Bakhtiyari Formations are outcropped in this area. Petrographic studies show that phosphate-bearing layers are composed of calcite, phosphate, glauconite and iron oxide with packstone to wackestone texture. Microfossil studies proved the age of Oligocene for the phosphate layers. The XRF and XRD analyses demonstrated that the phosphate-bearing mineral is fluor-apatite (Ca (PO4)3F). Sedimentary phosphate in this area was formed under the high energetic environment condition, phosphate saturated waters, and in the boundary of oxidation-reduction zone.

The present article is a review of a palaeobiogeographic analysis of Jurassic Ostracods from East Africa, India and Madagascar and includes also some general remarks on palaeobiogeography, biodiversity and Ostracod ecology.The palaeobiogeographic study shows the high significance of this Microfossil group for the reconstruction of palaeogeographic processes, particularly plate tectonic developments and sea level changes. The “South Gondwana Fauna” (SGF) was established in the early Middle Jurassic in a shallow marine rift basin between Madagascar, India and East Africa (Gulf of Madagascar) which was a result of early rifting processes between East- and West Gondwana. The maximum diversity of this fauna was reached during the late Middle Jurassic due to geographic expansion of the basin caused by successive rifting and rising sea level. The strong endemic character of the fauna was related to the peripheral geographic position of the Gulf of Madagascar at the southern Tethyan margin. In the late Middle and Upper Jurassic the SGF shows a biogeographic separation between East Africa and Madagascar/India and increasing endemism which may be affected by a deepening of the gulf and/or by the appearance of other environmental migration barriers between these areas.

The principal rock units are a gabbro sequence, late intrusive rocks that consist largely of the plagiogranite and volcanic rocks, which are largely pillow basalts interbedded with pelagic sedimentary rocks, including radiolarian cherts. Chondrite-and primitive mantle-normalized incompatible trace element data indicate that the Lahroud ophiolite was derived from a within plate basalt-like mantle source. All rocks are cogenetic geochemically and were derived by fractionation from melts with a composition similar to average E-MORB with calc-alkaline signatures. Plate reconstructions suggest that the rocks appear to be approximately contemporaneous with the Mashhad ophiolites and Rasht ophiolite, which has a crystallization age of ~380 Ma. Rocks from the Lahroud ophiolite complex represent northern Paleo-Tethyan ocean crust that was formed distinctly earlier than crust preserved in the Ma Paleo-Tethys suture zone ophiolite from upper Paleozoic to Later Teriassic. The results from Microfossil studies show the presence of Paleozoic biostratigraphy (e. g., Paleotextularia, Nodosinella cf. concinna, Pseudokahlerina, Cylindrica, Earlandia, Endothyra baileyi, pachyphloia, Fusulinella Stafella and Bivalve, Paratikhine). The data suggest that although the initial rifting and crystallization of the oceanic crust of the Lahroud ophiolite began in the Carboniferous, with volcanic activities continuing through to the late Triassic.

In order to reconstruction of sedimentary conditions and paleogeography of Qom Formation, one stratigraphic outcrop in the Northeast of Mahneshan has been studied. In this study, microfacies analysis and Microfossil investigations have been carried out on Forty-seven samples from one hundred sixty-two meters of sedimentary rock layers. Qom Formation in this section, is composed of carbonate, clastic and volcanoclastic layers that covers the andesitic strata of the Karaj Formation with a disconformity boundary and overlayed by clastic strata of the Upper Red Formation with gradual boundary. Microfacies analysis led to identification of one lithofacies (grain supported conglomerate) and three microfacies (1- Algal coral bioclast packstone, 2- Carbonate volcaniclastic and 3-Pelagic wack/packstone) that are related to the open carbonate shelf, submarine channels and submarine volcano in this section. Fossil investigations lead to identification if seventeen species of foraminifera fossils and two biostratigraphical zones. Based on foraminiferal index fossils (Borelis melo curdica, Meandropsina iranica, Praeorbulina glomerosa), Burdigalian-Langhian have been proposed as relative age for these strata. Facies change throw the stratigraphic column show deepening upward trend (during Langhian) in this study that can be correlated with paleogeographic events and relative sea level rise in Langhian age in this area.

The Mobarak Formation with 347.5 m, thickness is well exposed in Valyabad section, at the Karaj-Chalus road. The lower contact with underlying Laloon Formation is disconformable, whereas stratigraphic relation to the overlying Dozdeband formation is transitional. According to the lithological character, the studied section can be subdivided into 11 rock units. The lower part of the fm. consist of dark- gray to black limestone as well as marly limestone, while upper part consist mainly of sandy limestone with interbeds of marlstone. According to the Microfossil investigation, 14 genius and species have been recognized, which leads 2 conodont biozones. The both conodont biozones correspond to the international standard conodont biozonation which suggest an Early Tournisian to Middle Visean time interval. in addition, a Namurian age is suggested for deposites of informal Dozdeband formation, based on foraminifers. Received conodont bizones are as:Neopriniodus peracutus-Polygnathus longiposticus Assemblage- ZoneHibbardella roundya-Gnathodus girtyi Assemblage-ZoneMore over, 5 Holotorian species as well as 6 genuse, 72 species Foraminifers in form of 5 biozone have been distinguished. These biozones are as:Eotuberitina retligener-Endothyra spirilloformis Assemblage-ZoneArchaediscus permodiscus-Archaediscus(Paraarchaediscus) mixtus Assemblage-ZoneEndostaffella parva-Brunsina pulchera Assemblage-ZoneTuberitina bulbacea-Kammaena sp. Barren Interval ZoneLipinella notata-Archaediscus planoarchaediscus Assemblage-ZoneThe studied foraminifers support the given age. Conodonts the Color Alteration Index (CAI) correspond 190 to 300oC which indicate dry gas stage or empty of any hydrocarbon.

Permian deposits, including Doroud and Ruteh Formations, have extensive outcrops in Central Alborz. The Gaduk Section, east of Firuzkuh city provides a good example from these exposures. The siliciclastic and carbonate deposits of Permian in this section, about 348 meters thick, overlie the Lower Carboniferous limestones of Mobarak Formation and are unconformably overlain by Lower Triassic carbonate rocks of Elikah Formation. Detailed description of geometry, fossil content, sedimentary structures, and stratal surfaces in the field along with lithological characteristics, textural properties, and Microfossil components of the rocks in the lab led to identification of 4 terrigenous and 13 carbonate facies. Using major characteristics of the facies, diversity of fossil content especially foraminifra and green algae, and eodiagenetic siliceous cement; these facies were formed in the 7 depositional sequences. Depositional environment of the facies were determined as a continental shelf in the Paleotethyan passive margin (North of Gondwanaland). This environment shows the characteristics of a siliciclastic shelf for Lower Permian deposits and a carbonate ramp for the Middle Permian rocks. Comparing with sequences from other parts of the world, the studied sequences were classified in second and third order types. Relative sea level fall in the Late Permian led to development of cherty–lateritic unconformity in the Permo-Triassic boundary. Cherty nodule bearing strata can be related to maximum sea level fall as an indicator for type one sequence boundary determination.

The carbonate-dominated Taleh Zang Formation is one of the exclusive formations of the Lurestan area, which was deposited in a shallow carbonate platform in the Amiran foreland basin during the Late Thanetian-Middle Cuisian and is rich in swarms of the Early Paleogene larger benthic foraminifera. Despite of short distance between the examined sections in the Rit and Daryagirveh anticlines, there are major differences in thickness, the Paleogene LBF assemblages and their ages as well as the platform evolution settings. From the Rit anticline toward the Daryageriveh anticline, thickness increases significantly and the sedimentary processes being younger.The identified SBZs and comparing the detected platform evulotion stages with the global scale, revealed that, Taleh Zang Formation can be attributed to SBZ4 and SBZ10-SBZ11, in the Rit and Daryagirveh anticlines, respectively. According this data, the Taleh Zang Formation platform evolution settings can be defined as follow; the Rit section is similar to the platform evolution stage II or coral-agal and the first larger foraminiferal platform and the Daryagirveh section resembles the platform evolution stage III or larger foraminiferal platform of the Early Paleogene low paleolatitude platforms of the Tethys. In the studied area, the reasons for the obvious age difference, Microfossil assemblages, microfacies, and platform evolution settings in Taleh Zang Formation can be attributed not only to the depositional processes but also to the tectonic activities. The processes which caused obvious thickness and facies variations and record the diachronicity of the lithostratigraphic units across the basin.

In the eastern part of an ophiolitic complex in Sulabest area (in south east of Birjand) has exposed a metamorphic series including eclogite, blueschist, garnet bearing blueschist, amphibolite, epidote amphibolite, greenschist and micaschist. In addition to basaltic pillow lavas and cherts which have changed to eclogite and blueschist, were also metamorphosed most of gabbroic cumulate series to overlaying sheeted diabasic dykes. This metamorphism is within the limit of prehnite-actinolite(sub greenschist) to greenschist facieses. Presence of orbitoides Microfossil within micritic limestones in ophiolitic complex, indicates Maastrichtian age of emplacement for ophiolitic complex. Thermobarometry results of eclogites showing that peak temperature of eclogites from Sulabest varies from 496 to 592°C and their peak pressures ranging from 22.0 to 26.4 Kbars. Epidote amphibolite retrograde metamorphism of these eclogites has been done in a temperature of 549 to 592°C and a pressure of 6.7 to 7.4 Kbars. Textural evidences and analyses results showing that, the second stage of metmorphism were taken place during ascending root of these rocks on to the surface. Coexisting of eclogites in studied area with blueschists, amphibolites and garnet amphibolites in the eastern part of an ophiolitic complex and combination of field observations and laboratory works, indicates that a subduction activity with a late Cretaceous age were responsible for the studied area and consequently for east of Iran, which were followed by an thrusting process during colliding of Afghan(Helmand) and Lut-Block plates.