Highly siderophile element geochemistry and tectonic setting of ultramafic rocks from Haiyangsuo in eastern Shandong

2021 ◽  
Vol 37 (8) ◽  
pp. 2562-2578
Author(s):  
MA XueYing ◽  
◽  
LIU Qing ◽  
YAN FangChao ◽  
HE Miao ◽  
...  
Author(s):  
M. M. Singh ◽  
Vinod K. Singh

Supracrustal rocks (mafics and ultramafics) occurs along with banded iron formation, and felsic volcanics around Babina, Dhaura, and Mauranipur linear east-west trends in central part of the Bundelkhand craton represent Archean crust. The mafic and ultramafic rocks geochemically classified into Komatiite and Basaltic Komatiite and have high-Fe Tholeiitic in composition which may relate with the primitive mantle. The major and trace element geochemistry of mafic and ultramafic rocks correspond to hydrated mantle with wedge tectonic sources and ocean ridge geological characteristics.


Author(s):  
Henrik Rasmussen ◽  
Lars Frimodt Pedersen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, H., & Frimodt Pedersen, L. (1999). Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 65-78. https://doi.org/10.34194/ggub.v181.5114 _______________ Two Archaean supracrustal sequences in the area north-east of Disko Bugt, c. 1950 and c. 800 m in thickness, are dominated by pelitic and semipelitic mica schists, interlayered with basic metavolcanic rocks. A polymict conglomerate occurs locally at the base of one of the sequences. One of the supracrustal sequences has undergone four phases of deformation; the other three phases. In both sequences an early phase, now represented by isoclinal folds, was followed by north-west-directed thrusting. A penetrative deformation represented by upright to steeply inclined folds is only recognised in one of the sequences. Steep, brittle N–S and NW–SE striking faults transect all rock units including late stage dolerites and lamprophyres. Investigation of major- and trace-element geochemistry based on discrimination diagrams for tectonic setting suggests that both metasediments and metavolcanic rocks were deposited in an environment similar to a modern back-arc setting.


2020 ◽  
Vol 22 ◽  
Author(s):  
Claudia Banks

The Singhbhum craton is one of five Archean nuclei comprising Peninsular India. It is a composite Archean block that includes the Older Metamorphic Group, the Older Metamorphic Tonalite Gneisses, the Singhbhum Granite, and the Iron Ore Group as its major units. The ages of these components range from ~3.5 to ~3.1 Ga, although overlapping ages and similar rock types confound their genetic relationships. Plutonic felsic rocks from the southeastern Singhbhum craton (BK1: a foliated tonalite, KP1: a non-foliated granite, and SG14: a non-foliated granite) yield U-Pb (zircon) ages of 3321 ± 2 Ma (BK1), 3301 ± 1 Ma (KP1), and  3261 ± 1 Ma (SG14) that coincide with a pulse of Singhbhum Granite emplacement at 3.27 to 3.33 Ga. REE patterns and tectonic discrimination diagrams based on major and trace element ratios suggest a subduction zone setting for these rocks. We report major and trace element data for and compare them to previous works in order to characterize the Archean felsic plutonic history of the craton.


2013 ◽  
Vol 32 (1) ◽  
pp. 55-85 ◽  
Author(s):  
Wolf Mayer

William Noel Benson was one of the most renowned geologists in Australia and New Zealand during the first half of the twentieth century. He studied geology at the Universities of Sydney and Cambridge and occupied the Chair of Geology at the University of Otago with great distinction for thirty-three years. His research work extended across the greater part of the geological spectrum and gained him world-wide recognition and a reputation as a scholar in the classical mode. His name is today most closely associated with his pioneering work on the composition, origin and tectonic setting of the mafic and ultramafic rocks of the Great Serpentine Belt of New South Wales, and with his unfinished study of the Tertiary volcanic rocks of the Dunedin district, in New Zealand. He also made important contributions in such diverse fields as palaeontology, geomorphology, engineering geology and medical geology. Benson was a highly respected teacher and a compassionate man with deep religious convictions.


2016 ◽  
Vol 35 ◽  
pp. 338-356 ◽  
Author(s):  
Musen Lin ◽  
Songbai Peng ◽  
Xingfu Jiang ◽  
Ali Polat ◽  
Timothy Kusky ◽  
...  

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