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Search Results: 1 - 10 of 268 matches for " Permian "
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A New Approach to Permian System in the Section of Gahkum Mountain (Zagros-Iran)  [PDF]
Maryam Abedini, Ali Aghanabati, Ali Meisami, Davoud Jahani
Open Journal of Geology (OJG) , 2017, DOI: 10.4236/ojg.2017.77065
Abstract:
The deposits of Permian system in Kuh-e-Gahkum consist of 480 m clastic subdiffusion of Faraghan Formation and carbonates of Dalan Formation. In this section, the sediments of Faraghan Formation, which is gradationally overlain by Dalan formation, unconformably overlies Zakin Formation (Lower Carboniferous). In the upper part, Kangan Formation rests on the Permian deposits with an erosional and unconformable contact. Studying the microscopic thin sections led to the identification of 37 genera and 37 species of Foraminifera as well as 14 genera and 15 species of algae. According to the identified foraminifera in Faraghan and Dalan Formations, the age of the rock units in Permian system is assigned to Julfian-Asselian.
A new species:Szea (Cladophlebis) henanense sp. nov. in Henan Province and its evolutional significance
Guanxiu Yang,Axing Sheng,Hongshan Wang
Chinese Science Bulletin , 1997, DOI: 10.1007/BF02882625
Abstract:
The first record of Helicoprion Karpinsky (Helicoprionidae) from China
XiaoHong Chen,Long Cheng,KaiGuo Yin
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0321-y
Abstract: A new species, Helicoprion jingmenense sp. nov., from the Lower Permian Qixia Formation of Hubei Province, China, is described based on a nearly complete symphyseal tooth spiral preserved as part and counterpart. The specimen is a large elliptical symphyseal tooth spiral with $$ 4{\raise0.5ex\hbox{$\scriptstyle 1$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}} $$ volutions, with cutting blade being relatively wide, and its width being greater than the height after 3 volution, middle portion being higher than the cutting blade, narrowed base being short. There is a distinct space not covered by enameloid in two adjacent tooth crowns in the outermost two volutions; the height of the compound root is moderate, and the ventral groove is about 1/10 of the same tooth crown. In comparison with other known Helicoprion species of the world, the new species resembles H. ferrieri and H. bessonowi. However, it can be easily distinguished from H. ferrieri by the wider cutting blade, the shorter narrowed base and lower compound root, and also from H. bessonowi by its more narrowed compound root and less than 39 tooth crowns per volution. Helicoprion jingmenense sp. nov. is obviously different from helicoprionid species previously found in China in general shape, size and histology. However, it is very difficult to identify their relationships because of the fragmentary nature of holotypes of the latter. Because the new specimen is the first record of Helicoprion and the most complete fossil dentition of helicoprionids from China, the new species is of significance for biostratigraphy and paleobiogeography.
Oligocarpia kepingensis sp. nov. from the Lower Permian of the northern Tarim Basin, Xinjiang and itsin situ spores
Yongdong Wang,Xiuyuan Wu
Chinese Science Bulletin , 1999, DOI: 10.1007/BF02884728
Abstract: A Palaeozoic gleicheniaceous fernOligocarpia kepingensis sp. nov. is described from the Lower Permian of the northern Tarim Basin, Xinjiang, China. The material comprises fertile organs including sori, sporangia, spores and associated sterile leaf of theSphenopteris type. The sori are circular and 0.6–0.8 mm in diameter, and each sorus consists of 4–6 oval sporangia without an indusium. A transverse annulus completely encircles the sporangium. Each sporangium produces probably 256 trilete spores resembling the dispersed genusLeiotriletes. Comparisons are made betweenO. kepingensis and other species ofOligocarpia in the soral organization and spores. It is reasonable to includeOligocarpia in Gleicheniaceae based on its similarities of fertile character to the extant gleicheniaceous members.
OCCURRENCE OF EARLIEST CYCADS IN THE PERMIAN OF CHINA AND ITS BEARING ON THEIR EVOLUTION

科学通报(英文版) , 1989,
Abstract:
Facies Interpretation, Depositional Environment and Sequence Stratigraphy of the Sartakht Formation in the Bakhshi Section, Located in Kalmard Block, East-Central Iran  [PDF]
Bibi Haniyeh Emraninasab, Mohammad Hossein Adabi, Mahmoodreza Majidifard, Nader Kohansal Ghadimvand
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.65027
Abstract: Permian rocks in Kalmard block are recognized with Khan Group, enjoying various characteristics in different outcrops. This group is made up of three informal formations, namely Chili, Sartakht and Hermez. Middle Permian deposits (Sartakht formation) are composed chiefly of sandstone and carbonate rocks. This formation is composed of 58.6 m sandstone and dolomitic limestone in the Bakhshi section. Lower Permian carbonate deposits (Chili formation) unconformably underlie this formation while lateritic paleosols of upper Permian (Hermez formation) are depicted overlying an erosional unconformity above this formation. According to lithologic and microscopic investigations, the deposits of Sartakht formation can be divided into 2 siliciclastic petrofacies and 12 carbonate microfacies. Field observations, along with microscopic examinations, have resulted in identifying tidal flat, lagoon, shoal and open marine environments in the rocks of the studied formation. Vertical changes of microfacies and depth variation curve point to the high thickness of the microfacies of lagoon and shoal environments and low thickness of the microfacies of tidal flat and open marine environments. The carbonate-siliciclastic sequence of Sartakht formation is made up of a third-order depositional sequence, separated from carbonate depositions of lower Permian (Chili formation) and lateritic paleosols of upper Permian by type 1 sequence boundary (SB1). Siliciclastic deposits include LST system tract, and carbonate microfacies involve TST and HST system tracts, separated from each other by MFS. Sartakht formation rocks in Bakhshi section are deposited in a low-angle homoclinal ramp, mostly in the inner ramp, located in the south of Paleotethys Ocean. The depositional sequence identified in Sartakht formation points to the age of middle Permian, conforming to middle Absaroka II supersequence. The upper erosional boundary between Sartakht and Hermez formations conforms to the global-scale sea level fall.
Analysis of Sedimentary Environment and Sequence Stratigraphy of Middle-Late Permian Sediments in Coastal Fars, Iran (Zireh Gas Field, Well ZH-A)  [PDF]
Nasser Rezavand, Davood Jahani, Hossein Asilian
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.612109
Abstract: The current paper is focused on the facies, sedimentary environment and depositional cycles study of the Middle-Late Permian sediments in the South Fars Zireh Gas Field, the subsurface section of well ZH-A. Four hundred thin-sections obtained from cores and cuttings were examined under standard petrographic microscope. For this study research, Corel Draw X6, Corel Photo-Paint, DN2 Microscopy Image Processing System, Scope Photo, Autodesk Map, Geocalc and Auto Cad 2014 were utilized. Based on microfacies analysis and significant founa and flora, fourteen major facies in four facies associations comprising tidal flat (A), lagoon (B), shoal (C) and open marine (D) identified in the well ZH-A. This formation was deposited in inner part of a homoclinal ramp. Based on depositional cycles, seven main 3rd order sequences were revealed in the Well ZH-A. The ooid grainstone facies with interparticle and oomoldic porosity has high reservoir potential. The diagenetic processes like dolomitization and dissolution have significant effect in the reservoir quality. Based on research results, a major framework can be weaved and used to correlate reservoir layering.
Estimation of Species Richness of Permian Foraminifera in Non-Parametric Methods and Investigation of Its Change Trend in Central Alborz, Western Tethys  [PDF]
Mohammad Medadi, Hossein Mosaddegh, Seyed Mohsen Aleali, Mahmoud Reza Majidifard
Open Journal of Geology (OJG) , 2017, DOI: 10.4236/ojg.2017.75045
Abstract: Species richness of foraminifera assemblages in the Permian succession, contains Dorud, Ruteh and Nessen Formations, in Central Alborz—North of Iran, was estimated and studied based on lithostratigraphy and microbiostratigraphy of Permian. We used four non-parametric estimators to investigate the species richness: Chao 2, Jackknife 1, Jackknife 2 and bootstrap. These methods estimates the species richness based on the presence/absence data of each taxon identified in the samples. We use the submenu of quadrat richness in “Past” [1] software to estimate richness in regional chronostratigraphic stages.The results show that the estimated diversity of foraminiferal assemblages with the exception of late Yakhtashian, increased constantly from Asselian to Murgabian with the highest diversity of foraminifera seen in the Murgabian. The main decrease in foraminiferal species richness happened during the Midian which corresponds to the kamura cooling event.
Maderas gimnospérmicas de la Formación Solca (Pérmico Inferior), provincia de La Rioja, Argentina
Crisafulli,Alexandra; Herbst,Rafael;
Ameghiniana , 2008,
Abstract: for the first time gymnospermous woods from the solca formation (lower permian) from the olta and parque guasamayo localities are described. the conifers agathoxylon kumarpurensis (bajpai and singh) crisafulli and herbst nov.comb. and agathoxylon ningahense (maheshwari) crisafulli and herbst nov. comb. have been transferred from araucarioxylon; also podocarpoxylon indicum (bhardwaj) bose and maheshwari, chapmanoxylon jamuriense pant and singh and the new species chapmanoxylon oltaense crisafulli and herbst are described. chapmanoxylon preserves homogeneous pith, primary and secondary xylem; the other taxa only have secondary xylem all of which present interruptions in the growth and distorsion in transverse sections. these picnoxylic woods based on tracheidal characters are clasified in three groups: with araucarioid pits, with araucarioid-abietinoid pits and finally with araucarioid, mixed and tending to abietinoid pits. chapmanoxylon jamuriense, agathoxylon kumarpurensis and agathoxylon ningahense were found in the raniganj formation in india. the latter species was also recorded in the mount glossopteris (antarctica) and melo (uruguay) formations while agathoxylon kumarpurensis together with podocarpoxylon indicum were found in springfontain (south africa) , all from the permian. genus podocarpoxylon is also present in the triassic el tranquilo group (patagonia) and jurassic of rajmahal (india).
Permian plants from the Chutani Formation (Titicaca Group, Northern Altiplano of Bolivia): I. Genera Pecopteris and Asterotheca
Vieira, Carlos E. L.;Iannuzzi, Roberto;Guerra-Sommer, Margot;Díaz-Matrínez, Enrique;Grader, George W.;
Anais da Academia Brasileira de Ciências , 2004, DOI: 10.1590/S0001-37652004000100010
Abstract: fossil plants belonging to the morphogenera glossopteris, pecopteris and asterotheca were collected from the upper part of the chutani formation (titicaca group), near the town of san pablo de tiquina, on the southeastern shore of lake titicaca (northern altiplano, bolivia). here we report the analysis of fern-type foliage found at this location. three species of pecopterid fronds are identified: pecopteris dolianitii rohn and r?sler, p. cf. p. cadeadensis rohn and r?sler, and p. cf. p. pedrasica read. all these species are typically found in permian deposits of the paraná basin in southern brazil. despite the poor preservation of the material, a fertile specimen could be studied and was determined as asterotheca sp. the paleoenvironmental and paleoecological implications of this new find are briefly analyzed.
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