Article
Geochemistry & Geophysics
Fred T. Bowyer, Collen-Issia Uahengo, Kavevaza Kaputuaza, Junias Ndeunyema, Mariana Yilales, Ruaridh D. Alexander, Andrew Curtis, Rachel A. Wood
Summary: The advent of animal biomineralization fundamentally changed Earth's history, allowing for the diversification of body plans and the control of carbonate sediment production, resulting in a permanent restructuring of the global carbon cycle.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Rachel Wood, Fred. T. Bowyer, Ruaridh Alexander, Mariana Yilales, Collen-Issia Uahengo, Kavevaza Kaputuaza, Junias Ndeunyema, Andrew Curtis
Summary: The Nama Group in Namibia preserves a rich record of metazoan fossils from the terminal Ediacaran Period. This study reports the discovery of potential body fossils, trace fossils, and sedimentary surface textures in the lowermost Mara Member, which represent the oldest documented macrofossils in the Nama Group. By proposing a re-definition of the Nama Assemblage and emphasizing the importance of non-destructive excavation, this study contributes to our understanding of early metazoan evolution.
GEOLOGICAL MAGAZINE
(2023)
Article
Geosciences, Multidisciplinary
Biao Gao, Jitao Chen, Xing Huang, Hao Xin, Quanfeng Zheng
Summary: The tectonic setting of South China during the late Paleozoic is crucial for understanding the geodynamics of the eastern margin of the Pangea supercontinent. By studying the late Carboniferous siliciclastic rocks in southeast South China, it is revealed that there was episodic lithospheric delamination and subduction of the paleo-Pacific plate beneath the South China Block in the late Paleozoic.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Bianca R. Spiering, Ajani Bissick, Simon A. F. Darroch, Joshua H. F. L. Davies, Brandt M. Gibson, Galen P. Halverson, Marc Laflamme, Frederik J. Hilgen
Summary: This study examines the sedimentary variations in the middle Nama Group in southern Namibia and proposes an astronomical origin for these variations. The findings suggest that astronomical forcing may have played a role in the distribution of early complex life and provide insights into the evolutionary trends and climatic variations during the Ediacaran Period.
PRECAMBRIAN RESEARCH
(2023)
Article
Paleontology
Katherine A. Turk, Katie M. Maloney, Marc Laflamme, Simon A. F. Darroch
Summary: This study examines the Nasep and Huns members of the Urusis Formation in southern Namibia, which contain diverse trace-fossil assemblages from the latest Ediacaran. The researchers discover potentially the world's oldest complex vertical sediment-penetrating burrows in these sediments. The findings provide insights into the diverse communities of bilaterian metazoans existing before the Cambrian period and the impact of increased metazoan ecosystem engineering behaviors. The study also establishes a biostratigraphic link between Namibia, Brazil, Paraguay, Iran, and the southwestern United States. Additionally, the researchers identify a possible late Ediacaran preservational window that hints at the timing of the first appearance of key bilaterian behaviors.
JOURNAL OF PALEONTOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Juan Moises Casas-Pena, Juan Alonso Ramirez-Fernandez, Fernando Velasco-Tapia, Eduardo Alejandro Aleman-Gallardo, Carita Augustsson, Bodo Weber, Dirk Frei, Uwe Jenchen
Summary: The study describes the Tamatan Group in the Huizachal-Peregrina Anticlinorium in northeastern Mexico, proposing a provenance model based on new petrological and geochemical data. The sediments show derivation from various rock types, intense weathering, and high recycling of the source area.
Article
Geochemistry & Geophysics
Lyle L. Nelson, Jahandar Ramezani, John E. E. Almond, Simon A. F. Darroch, Wendy L. Taylor, Dana C. Brenner, Ryan P. Furey, Madison Turner, Emily F. Smith
Summary: The Nama Group in northwestern Republic of South Africa is recognized as an important record of the Ediacaran-Cambrian transition. Through the study of volcanic ash beds in this area, the depositional history and carbon isotope record have been revealed. Young occurrences of Ediacaran-type fossils and a shift in chemostratigraphic trends were observed. However, the exact definition of the base of the Cambrian and the first appearance datum of the index fossil Treptichnus pedum remain challenging.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geology
Zongdong Pan, Hesheng Hou, Jianbo Zhou, Wei Fu, Xingzhou Zhang, Shiqi Huang, Dongzhao An, Wenyu Liu, Jin Yang, Rui Guo
Summary: The Duobaoshan ore district in Northeast China is home to the largest Early Paleozoic porphyry Cu (Mo) deposit in the region, with its crustal structure and mineralization playing a key role in reconstructing the Early Paleozoic setting of the Central Asian Orogenic Belt. New seismic and geochemical data collected in this study reveal the deep structure and mineralization features of the area, aiding in the identification of a relict ancient subduction belt and the most plausible suture location between the Xing'an and Songnen blocks.
ORE GEOLOGY REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Fabio Santos Pereira, Herbet Conceicao, Maria de Lourdes Silva Rosa, Moacyr Moura Marinho, Colombo Celso Gaeta Tassinari, Joao Marinho Milhomem Neto, Jean -Michel Lafon
Summary: This study investigates the Neoproterozoic plutonic rocks in the Sergipano Orogenic System (SOS) in the southern Borborema Province, NE Brazil, to understand their sources, petrogenesis, and tectonic setting. Three magmatic episodes are identified, reflecting the evolutionary stages of the orogen. The rocks in each episode exhibit distinct compositions and origins, including metasomatism of the lithospheric mantle, partial melting of graywacke protoliths, and reworking of ancient lower mafic crust.
GEOSCIENCE FRONTIERS
(2023)
Review
Geosciences, Multidisciplinary
Simon A. F. Darroch, Alison T. Cribb, Luis A. Buatois, Gerard J. B. Germs, Charlotte G. Kenchington, Emily F. Smith, Helke Mocke, Gretchen R. O'Neil, James D. Schiffbauer, Katie M. Maloney, Rachel A. Racicot, Katherine A. Turk, Brandt M. Gibson, John Almond, Bryce Koester, Tom H. Boag, Sarah M. Tweedt, Marc Laflamme
Summary: The Ediacaran-Cambrian transition is a significant geobiological revolution in Earth history, involving multiple waves of evolutionary radiation and apparent mass extinctions. Factors such as ecosystem engineering, trace fossils, and bioturbation may have played crucial roles during this period.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Liandang Zhao, Huayong Chen, Jinsheng Han, Jiangang Jiao
Summary: This study presents new geochronological and geochemical data to constrain the tectonic setting and evolution of the Central Tianshan Block. The results suggest that the Central Tianshan Block was a continental arc in the Ordovician to Carboniferous, formed by the subduction of the Kangguer oceanic slabs. The Devonian period saw the formation of the Central Tianshan continental arc to the south, accompanied by emplacement of multiphase arc-related granitoids in the Shuangqing district.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geology
He XiHeng, Zhang Jing, Deng XiaoHua, Long LingLi, Chen Lei, Yin YuanJun, Zhang ZhiChao
Summary: The East Tianshan copper metallogenic belt is a part of the Central Asian metallogenic belt and includes large, medium, and small-scale copper deposits. The belt is distributed along an island arc and experienced magmatic activities during the Silurian and Carboniferous periods. The host rocks are mainly Paleozoic volcanic rocks, granites, and sedimentary rocks. The ore-forming rocks are intermediate-acid calc-alkaline granites with island arc magmatic characteristics. The fluid inclusions indicate a high salinity H2O-NaCl +/- CO2 system, and the isotopic characteristics suggest a mixed source of juvenile crust and depleted mantle. The East Tianshan orogenic belt has gone through multiple transformations and magmatic activities, resulting in multi-stage mineralization.
ACTA PETROLOGICA SINICA
(2023)
Article
Geosciences, Multidisciplinary
Dongfang Song, Wenjiao Xiao, Brian F. Windley, Chunming Han
Summary: The study investigates the provenance and tectonic setting of late Paleozoic sedimentary rocks in the southern Central Asian Orogenic Belt through detrital zircon geochronological data. It reveals different age peaks in samples from the Devonian, Carboniferous, and Permian, indicating magmatic flare-ups and shifts in detritus sources. The data suggest an archipelago-style accretionary process during the late Paleozoic tectonic evolution of the southern Central Asian Orogenic Belt.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2021)
Article
Geochemistry & Geophysics
Sylvester Ofili, Alvar Soesoo, Elena G. Panova, Rutt Hints, Sigrid Hade, Leho Ainsaar
Summary: This study analyzed the major and trace elements of Lower Paleozoic black shales from Estonia, Sweden, and Russia to determine their provenance, tectonic setting, and paleoweathering conditions. The results suggest that the black shales were derived from rocks of intermediate to felsic composition, with input from recycled sediments. The study also revealed a passive margin tectonic setting and intense chemical weathering of the clastic material in the black shales.
Article
Geochemistry & Geophysics
Tushar Meshram, Shraddha Nannaware, Satya Narayana Mahapatro, M. L. Dora, Srinivasa Baswani, Kirtikumar Randive
Summary: The Proterozoic Chimalpahad Anorthosite Complex (CAC) in South India is a deformed and dismembered complex consisting of anorthosite-leucogabbro-gabbro-ultramafic rocks. The presence of iridium-like platinum-group minerals (IPGM) in the chromitites of CAC is reported for the first time. The geochemical and mineral chemical characteristics suggest an ophiolitic affinity of the CAC chromitites.