Article
Geosciences, Multidisciplinary
J. Javier Alvaro, Mansoureh Ghobadi Pour, Teresa Sanchez-Garcia, Mohammad-Reza Kebria-ee Zadeh, Vachik Hairapetian, Leonid E. Popov
Summary: Recent geological mapping and chronostratigraphic dating in the eastern Alborz Mountains have revealed episodes of synsedimentary uplift and erosion associated with volcanic activities. The study also identified continuous magmatic pulses with alkaline to subalkaline activities, suggesting an intraplate field affinity compatible with OIB-like mantle sources. These findings provide insights into the geological history of the region, including lithospheric doming and rift pulses that shaped a large igneous province.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Adrian W. A. Rushton, Mansoureh Ghobadi Pour, Leonid E. Popov, Hadi Jahangir, Arash Amini
Summary: Graptolites have been discovered in Lower Ordovician strata in northern Iran, with different species found in different regions. The sedimentary characteristics in some areas suggest a relationship with sea level changes.
GEOLOGICAL MAGAZINE
(2021)
Article
Geosciences, Multidisciplinary
Dulce Raquel Reyes-Montoya, Francisco Javier Cuen-Romero, Nohemi Gamez-Meza, Juan Jose Palafox-Reyes, Rogelio Monreal, Pilar Navas-Parejo, Fernando Enriquez-Ocana, Frederick A. Sundberg, Francisco Javier Grijalva-Noriega
Summary: The Cambrian-Ordovician transition in Mexico is poorly documented. The most complete succession from middle-upper Cambrian to Lower Ordovician is found near the town of Arivechi in northeastern Sonora. The sedimentary succession is approximately 900 m thick and consists of seven lithostratigraphic units.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2023)
Article
Paleontology
Jcrg Maletz, Xiao-Feng Wang, Chuan-Shang Wang
Summary: A revision of early Tremadocian graptolites of the genus Rhabdinopora revealed that Rhabdinopora proparabola from Xiaoyang-qiao section in North China is the oldest species of the genus. These early Tremadocian species of Rhabdinopora can be distinguished based on the presence or absence and branching pattern of their nemata. The biozones of Rhabdinopora proparabola, Rhabdinopora campanulatum, Rhabdinopora flabelliformis (Anisograptus matanensis Biozone), and Rhabdinopora anglica show global correlation. However, there are no planktic graptolites in a short interval at the base of the Ordovician System.
Article
Geosciences, Multidisciplinary
Hamid Nazari, Jean-Francois Ritz, Jean-Pierre Burg, Mohamadali Shokri, Negar Haghipour, Mehdi Mohammadi Vizheh, Ara Avagyan, Hasan Fazeli Nashli, Mohamadreza Ensani
Summary: This study focuses on the active structural characteristics of the Alborz Mountain region, with a particular emphasis on the activity of the Khazar Fault. By analyzing the morphology of the fault and using methods such as radiocarbon dating, the study provides new constraints on the fault's activity rates and regional seismic hazard.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Ming Li, Lixia Li, Wenhui Wang
Summary: Well-preserved graptolites of the genus Kiaerograptus are reported for the first time in the Nanba section, Yiyang, Hunan Province, South China. Based on these new specimens, the Kiaerograptus biozone is established for the first time in South China, which has significant implications for biostratigraphical correlation.
ACTA GEOLOGICA SINICA-ENGLISH EDITION
(2023)
Article
Geology
Amelia Lindsay-Kaufman, Stephanie A. Rosbach, Lauren S. Wright, Emily L. Edwards, Seyed Hamid Vaziri, Mahmoud Reza Majidifard, Tara Selly, Marc Laflamme, James D. Schiffbauer
Summary: This study investigates poorly preserved shelly tubicolous organisms in two fossiliferous slabs from the Soltanieh Formation, northern Iran. The taphonomy of the fossil assemblage suggests a two-part preservational pathway involving phosphatic replacement of the shell wall and separate, diagenetically later infillings of void space. Morphometric analysis reveals two morphologically distinct groups of conical and tubular forms.
Article
Geosciences, Multidisciplinary
Aram Bayet-Goll, Mahmoud Sharafi, Neda Jazimagh, Marco Brandano
Summary: This article discusses the changes in stacking patterns of facies, stratal architecture, and shoreline trajectory along depositional strike, which are mainly influenced by factors such as physical processes, tectonics, eustatic changes, sediment supply, and local physiography. The Lower-Upper Ordovician successions in a Peri-Gondwana shallow continental shelf were interpreted using sequence stratigraphic concepts, revealing significant differences along-strike in the co-existing depositional systems. The sedimentary units were divided into four facies associations based on their characteristics. Six depositional sequences were identified, each bounded by unconformities and shifts in facies. Changes in sediment supply and processes were the main controlling factors for stratigraphic architecture, while tectonic activity played a dominant role in later intervals.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Xinze Lu, Cole T. Edwards, Brian Kendall
Summary: This study investigates the role of ocean anoxia/euxinia on the base Stairsian mass extinction event by measuring elemental concentrations and uranium isotope compositions in carbonate samples from three sections in the Great Basin. The results show different uranium isotope trends in the three sections, with the distal sections better preserving global ocean signals. The study suggests that the small mass extinction event was not associated with an expansion of global ocean euxinia.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geology
Aram Bayet-Goll, Mahmoud Sharafi, Mehdi Daraei, Yaghub Nasiri
Summary: The distribution of conventional subichnofacies in deep-water fan systems can be influenced by changes in flow state between laminar and turbulent conditions. This study investigated the effects of hybrid sediment gravity flows on the distribution and composition of trace fossils in the Ordovician Ghelli Formation. It was found that the presence of cohesive flows reduced ichnodiversity and density of bioturbation, and trace fossils were limited to simple feeding strategies.
Review
Geosciences, Multidisciplinary
Jian-Po Wang, Qi-Jian Li, Stephen Kershaw, Yuan-Yuan Zhang, Shen-Yang Yu, Yue Li
Summary: This study provides an overview of the controls on the distribution of organic reefs during the Early Ordovician Period in the Yangtze Platform in South China. The composition of reefs was mainly driven by water depth, with a transition from microbial-dominated to metazoan-dominated reefs. Different environmental settings and water depths played a role in the formation of different types of biotic structures in different regions.
JOURNAL OF PALAEOGEOGRAPHY-ENGLISH
(2021)
Article
Geosciences, Multidisciplinary
Wei Dan, J. Brendan Murphy, Gong-Jian Tang, Xiu-Zheng Zhang, William M. White, Qiang Wang
Summary: The origin of the controversial Cambrian-Ordovician tectono-magmatic events in NE Gond-wana and adjacent peri-Gondwanan terranes is discussed. A potential silicic large igneous province (LIP) called the Pinghe silicic LIP is proposed, consisting of granitic rocks formed between ca. 510 Ma and 460 Ma. The recognition of this belt of granitic rocks helps refine tectonic reconstructions of Gondwana and models for the rifting of terranes from its northern margin.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2023)
Article
Geochemistry & Geophysics
Leibo Bian, Anthony Chappaz, Niels H. Schovsbo, Xiaomei Wang, Wenzhi Zhao, Hamed Sanei
Summary: The late Cambrian extinction - Early Ordovician biodiversification is a crucial lower Paleozoic biological change, but the mechanisms behind this transition are not well understood. This study reconstructed the paleoenvironmental changes and assessed the Cambro-Ordovician biological turnover. The results showed that depositional environments became extremely sulfidic with lower nutrient inputs, leading to the Steptoean Positive Carbon Isotope Excursion event. Intense volcanic activity in the early Jiangshanian contributed to recurrent bio-calamities. Later, enhanced terrestrial weathering and oceanic water upwelling facilitated biological recovery and laid the foundation for the Great Ordovician Biodiversification Event.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Xi Chen, Graham A. Shields, Morten B. Andersen, Chen Qiu, Si -Yu Min, Qing-Feng Shao, Hong-Fei Ling
Summary: Marine animal diversity during the late Cambrian was reduced due to extinctions attributed to oceanic anoxic events. Carbon and uranium isotope ratios from carbonate rocks in South China were used to analyze global carbon cycle and oceanic redox conditions. The study suggests a positive coupling between delta 13C and delta 238U, which relates to the existence of intermediate reducing settings and a greenhouse climate during the late Cambrian. The expansion of intermediate reducing conditions, rather than persistent anoxic euxinia, is consistent with the recovery of delta 13C and delta 238U.
Review
Geology
Afshin Zohdi, Adrian Immenhauser, Javad Rabbani
Summary: This study provides a detailed facies and depositional record from a distally steepened Middle Jurassic carbonate ramp in the northern Tethyan realm. The development of the Middle Callovian mounds is linked to minimum sedimentation rates and accommodation space resulting from a long-term sea-level rise, while the Upper Callovian conglomeratic deposits may have formed due to a relative sea-level fall.
SEDIMENTARY GEOLOGY
(2021)
Article
Paleontology
Lars E. Holmer, Leonid E. Popov, Mansoureh Ghobadi Pour, Tom Claybourn, Zhiliang Zhang, Glenn A. Brock, Zhifei Zhang
Article
Geology
Mansoureh Ghobadi Pour, Leonid E. Popov, Mehdi Omrani, Hadi Omrani
ESTONIAN JOURNAL OF EARTH SCIENCES
(2018)
Article
Paleontology
Mansoureh Ghobadi Pour
Article
Paleontology
Mansoureh Ghobadi Pour, Leonid E. Popov, Robert M. Owens, Elena A. Vinogradova, Inna A. Klishevich
Article
Geosciences, Multidisciplinary
John C. W. Cope, Mansoureh Ghobadi Pour
GEOLOGICAL JOURNAL
(2020)
Article
Multidisciplinary Sciences
Leonid E. Popov, J. Javier Alvaro, Lars E. Holmer, Heikki Bauert, Mansoureh Ghobadi Pour, Andrei Dronov, Oliver Lehnert, Olle Hints, Peep Mannik, Zhifei Zhang, Zhiliang Zhang
SCIENTIFIC REPORTS
(2019)
Article
Geosciences, Multidisciplinary
Adrian W. A. Rushton, Mansoureh Ghobadi Pour, Leonid E. Popov, Hadi Jahangir, Arash Amini
Summary: Graptolites have been discovered in Lower Ordovician strata in northern Iran, with different species found in different regions. The sedimentary characteristics in some areas suggest a relationship with sea level changes.
GEOLOGICAL MAGAZINE
(2021)
Article
Paleontology
Lars E. Holmer, Sebastien Clausen, Leonid E. Popov, Mansoureh Ghobadi Pour, Yue Liang, Zhifei Zhang, Juan Jose Palafox Reyes, Jesus Porfirio Sosa-Leon, Blanca Estela Buitron-Sanchez
Summary: The Cambrian successions at the Chihuarruita Hill outcrop in Sonora, Mexico, have revealed two consecutive linguliform brachiopod assemblages that bridge the gap between Cambrian Stage 4 and the newly recognized global Wuliuan Stage. These findings provide crucial insights into the Cambrian biostratigraphy of the region.
JOURNAL OF PALEONTOLOGY
(2022)
Article
Paleontology
Mansoureh Ghobadi Pour
Summary: Middle to Late Ordovician trilobites from the West Balkhash and North Betpak-Dala regions in Kazakhstan are documented for the first time. The newly discovered faunas show strong links to contemporaneous faunas of Tarim, South China, and the Australian sector of Gondwana, supporting Ordovician palaeogeographical reconstructions. Cluster analysis reveals the distinct trilobite associations between different biofacies, indicating their evolutionary and ecological differences.
PAPERS IN PALAEONTOLOGY
(2022)
Article
Evolutionary Biology
Leonid E. Popov, Shaahin Zaman, Valerii Baranov, Mansoureh Ghobadi Pour, Lars E. Holmer
Summary: The post-extinction recovery brachiopod fauna in Iran and Afghanistan during the Silurian (Aeronian) period is characterized by the Stegocornu Brachiopod Association. A new phylogenetic analysis reveals the major centres of biodiversification and dispersal for spiriferides during the Late Ordovician to Aeronian period. The study also highlights South China as a refuge for spiriferides and the Iranian terranes as a secondary centre of spiriferide biodiversification during the Aeronian Age.
JOURNAL OF SYSTEMATIC PALAEONTOLOGY
(2021)
Article
Paleontology
Lars E. Holmer, Leonid E. Popov, Mansoureh Ghobadi Pour, Inna A. Klishevich, Yue Liang, Zhifei Zhang
PAPERS IN PALAEONTOLOGY
(2020)
Article
Paleontology
Lars E. Holmer, Mohammad-Reza Kebria-Ee Zadeh, Leonid E. Popov, Mansoureh Ghobadi Pour, J. Javier Alvaro, Vachik Hairapetian, Zhifei Zhang
PAPERS IN PALAEONTOLOGY
(2019)
Article
Geosciences, Multidisciplinary
Leonid E. Popov, Philippe Legrand, Boumedienne Bouterfa, Mansoureh Ghobadi Pour
BULLETIN OF GEOSCIENCES
(2019)
Article
Paleontology
Lars E. Holmer, Mansoureh Ghobadi Pour, Leonid E. Popov, Zhiliang Zhang, Zhifei Zhang
PAPERS IN PALAEONTOLOGY
(2017)
Article
Geology
Vachik Hairapetian, Mansoureh Ghobadi Pour, Leonid E. Popov, Peep Mannik, C. Giles Miller
ACTA GEOLOGICA POLONICA
(2017)