Journal articles: 'Palaeo- Mesoproterozoic'

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ZHAI, MINGGUO, JINGHUI GUO, PENG PENG, and BO HU. "U–Pb zircon age dating of a rapakivi granite batholith in Rangnim massif, North Korea." Geological Magazine 144, no. 3 (March 9, 2007): 547–52. http://dx.doi.org/10.1017/s0016756807003287.

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Rapakivi granites and several small leucogabbroic and gabbroic bodies are located in the Rangnim Massif, North Korea. The largest batholith in the Myohyang Mountains covers an area of 300 km2 and was intruded into Precambrian metamorphosed rocks. It has a SHRIMP U–Pb zircon weighted mean 207Pb/206Pb age of 1861 ± 7 Ma. The country rocks of rapakivi granites are Neoarchaean orthogneisses and Palaeo-Mesoproterozoic graphite-bearing metasedimentary rocks of granulite facies, and they are similar to those of the rapakivi granites and anorthosites exposed in South Korea and in the North China Craton. We conclude that the three massifs in the Korean Peninsula commonly record an identical Palaeo-Mesoproterozoic anorogenic magmatic event, indicating that they have a common Precambrian basement with the North China Craton.

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Sergeev, Vladimir N., Mukund Sharma, and Yogmaya Shukla. "Mesoproterozoic silicified microbiotas of Russia and India's Characteristics and Contrasts." Journal of Palaeosciences 57, no. (1-3) (December 31, 2008): 323–58. http://dx.doi.org/10.54991/jop.2008.251.

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The paper analyses eight silicified Mesoproterozoic microbiotas of peritidal and shallow subtidal settings from Siberia, Ural and India. These microbiotas, subdivided into three main types - Kotuikan, Satka and Kataskin-are characterized by different taxonomic composition of microfossils. Mat-building entophysalidacean algae Eoentophysalis, ellipsoidal akinetes of nostocalean cyanobacteria genus Archaeoellipsoides and spherical large planktic microfossils Myxococcoides grandis of uncertain affinities dominate the Kotuikan-type microbiotas, the short trichomes are a rare but a distinctive element of these assemblages. The Satka type microbiotas are dominated by mat-building hormogonian cyanobacteria of genus Siphonophycus and chroococcacean dwellers genera Gloeodiniopsis, Eosynechococcus, Sphaerophycus, whereas entophysalidacean cyanobacteria are conspicuously missing and akinetes of genus Archaeoellipsoides occur but never abundant. Besides, microbiotas of Satka type include morphologically simple remains of phytoplanktic eukaryotic microorganisms-sphaeromorphic acritarchs genera Satka, Pterospermopsimorpha, Granomarginata? and Leiosphaeridia. The late Mesoproterozoic Kataskin-type microbiotas contain mat-forming entophysalidacean, oscillatoriacean and nostocalean as well as mat-dwelling and planktic chroococcacean cyanobacteria, but the most typical feature of these microfossil assemblages is the presence of a stalked cyanobacterium, Polybessurus bipartitus. Almost all-available data on relevant silicified Mesoproterozoic microbiotas from China, Greenland and North America have been analysed. Further different types of Mesoproterozoic silicified microbiotas have been compared with Palaeo- and Neoproterozoic microbiotas in cherts as well as with the assemblages of organic-walled microfossils throughout the world and explained differences and similarities in their composition. The analysis indicate that the Mesoproterozoic microbiotas have their own specific taxonomic composition and differ from the Palaeo- and Neoproterozoic microfossils occurring in the same and different palaeoenvironmental setting. The presence of newly evolved type of cyanobacteria, red algae and acanthomorphic acritarchs in the Kataskin-type microbiotas and contemporaneous open-shelf facies suggest that the terminal Mesoproterozoic can be separated as an independent biostratigraphical unit.

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Mitra, Rahul, Gopal Chakrabarti, and Debasish Shome. "Sedimentation history and depositional model of Palaeo-Mesoproterozoic Tadpatri Formation, Cuddapah Basin, India." Journal of Sedimentary Environments 5, no. 1 (February 6, 2020): 87–100. http://dx.doi.org/10.1007/s43217-020-00004-9.

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Idnurm, M., J. W. Giddings, and K. A. Plumb. "Apparent polar wander and reversal stratigraphy of the Palaeo-Mesoproterozoic southeastern McArthur Basin, Australia." Precambrian Research 72, no. 1-2 (March 1995): 1–41. http://dx.doi.org/10.1016/0301-9268(94)00051-r.

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Kaur, Parampreet, and Naveen Chaudhri. "Metallogeny associated with the Palaeo-Mesoproterozoic Columbia supercontinent cycle: A synthesis of major metallic deposits." Ore Geology Reviews 56 (January 2014): 415–22. http://dx.doi.org/10.1016/j.oregeorev.2013.03.005.

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Yao, Jinlong, Liangshu Shu, Peter A. Cawood, and Guochun Zhao. "Differentiating continental and oceanic arc systems and retro-arc basins in the Jiangnan orogenic belt, South China." Geological Magazine 156, no. 12 (May 17, 2019): 2001–16. http://dx.doi.org/10.1017/s001675681900027x.

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AbstractThe Neoproterozoic Jiangnan orogenic belt records the accretion and collision between the Yangtze and Cathaysia blocks in South China. The orogen is divisible into three units: a northeastern domain (also referred to as the Huaiyu or Shuangxiwu domain), a central domain (Jiuling domain) and an undifferentiated southwestern domain. Detrital zircons from the oldest sequences (Shuangqiaoshan, Lengjiaxi, Fanjingshan and Sibao groups) in the central and southwest domains yield similar age spectra with major age populations at c. 875–820 Ma, along with minor Palaeo- to Mesoproterozoic and Archaean ages. The dominance of detrital ages close to the deposition ages of the units, along with juvenile zircon Hf isotopic compositions and arc-like whole-rock compositional data, indicate the sedimentary units accumulated adjacent to a convergent plate margin magmatic arc. The presence of Mesoproterozoic and older zircons, both as detritus in the units and as xenocrysts within igneous rocks displaying a subduction-related signature, along with the compositional data, place the magmatic arc along a continental margin. In the northeastern domain, the oldest coeval sequence (Shuangxiwu and Qigong groups) and arc igneous suites are dated at c. 970–850 Ma, and lack older detritus and xenocrysts, indicating they represent an accreted oceanic arc system.

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Miao, Xiu-Quan, Yi-Xin Liu, Yi-Wei Liu, Jin-Rong Wang, and Jian-Lin Chen. "Petrogenesis of (meta-) basalts from the North Qilian Orogenic Belt, NW China: implications for the Palaeoproterozoic–Mesoproterozoic tectonic evolution of the North Qilian Block." Geological Magazine 158, no. 10 (May 12, 2021): 1795–810. http://dx.doi.org/10.1017/s0016756821000340.

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AbstractThe North Qilian Orogenic Belt is surrounded by the Tarim Craton to the NW and the North China Craton to the NE. The Precambrian continental crust remnants that are distributed in the North Qilian Orogenic Belt are termed the North Qilian Block (NQB), and their tectonic evolution has profound implications for the evolution of the Columbia Supercontinent. Here we present major- and trace-element and Sr–Nd–Hf isotope data for (meta-) basalts from the Beidahe Group (BDHG) and Zhulongguan Group (ZLGG) in the western North Qilian Orogenic Belt, to investigate the tectonic evolution of the NQB during the Proterozoic Eon. The protoliths of Palaeoproterozoic amphibole gneisses and plagioclase amphibolites from the BDHG are calc-alkaline series basalts. These metabasalts show island-arc-basalt affinities with variable Nd and Hf isotopes (ϵNd(t) = −5.0–0.6 and 2.7–4.3; ϵHf(t) = −14.2–2.0 and 6.9–8.8) and were generated by partial melting of the asthenospheric mantle that was metasomatized by aqueous fluid and sediment melt in a continental-arc setting. The early Mesoproterozoic ZLGG basalts show features of shoshonite-series basalts and are geochemically similar to ocean-island basalts. These basalts show variable (87Sr/86Sr)i, ϵNd(t) and ϵHf(t) values of 0.70464–0.70699, −1–2.6 and −1.5–5.7, and are products of mantle plume magmatism that participated with subducted oceanic crust in an intracontinental rift setting. This study suggests that the NQB underwent tectonic evolution from palaeo-oceanic subduction to intracontinental rifting during the Palaeoproterozoic–Mesoproterozoic eras. Furthermore, the above tectonomagmatic events were in response to convergence–splitting events of the Columbia Supercontinent during the Palaeoproterozoic–Mesoproterozoic eras.

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Wendorff, Marek, and Andrzej Świąder. "Lithostratigraphic classification of the Tsodilo Hills Group: a Palaeo- to Mesoproterozoic metasedimentary succession in NW Botswana." Geology, Geophysics and Environment 45, no. 4 (January 25, 2020): 305. http://dx.doi.org/10.7494/geol.2019.45.4.305.

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The Tsodilo Hills Group strata exposed in the Tsodilo Hills are an association of meta-arenites, meta-conglomerates, quartz-mica schists, sandstone, red siltstone and sedimentary breccia deposited on an open siliciclastic marine shelf between the Late Palaeoproterozic and Late Mesoproterozoic, and outcropping in NW Botswana. The succession is dominated by three micaceous quartzite units interlayered with subordinate lenses and wedges of other rock types. Facies gradients from S to N are expressed by decreasing content of muscovite at all levels of metasediment organisation from thin wedge-shaped units to thick quartzite complexes, as well as a decrease in pebble content and increase in the arenaceous matrix in some metal conglomerate beds, matching regional palaeotransport direction. Well-rounded pebbles of rocks are flat, suggesting redeposition from a beach environment. Lenticular conglomeratic bodies with erosional lower boundaries represent infills of local incisions in the sandy bottom sediments. The abundance of laterally discontinuous lithological units reflects shelf palaeotopography controlled and modified by deposition and migration of large bed forms, ranging from megaripple marks (or submarine dunes) to sand waves. Deposition was influenced by tides and two regressive events. The older regression resulted in a marker unit of tidal mudflat-related red-bed facies: mudstone, siltstone, channel-fill sandstone and sedimentary breccia. The second regression is indicated by a tabular conglomerate marker reflect-ing increased input of coarse terrigenous material.

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Spikings, R. A., D. A. Foster, B. P. Kohn, and G. S. Lister. "Post-orogenic (<1500 Ma) thermal history of the Palaeo-Mesoproterozoic, Mt. Isa province, NE Australia." Tectonophysics 349, no. 1-4 (May 2002): 327–65. http://dx.doi.org/10.1016/s0040-1951(02)00060-4.

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10

Verlekar, Purushottam Anil, and Mahender Kotha. "Provenance, tectonics and palaeo environment of Mesoproterozoic Saundatti Quartzite Member of Kaladgi Basin, India: A petrographic view." Journal of The Indian Association of Sedimentologists 37, no. 2 (December 31, 2020): 91–102. http://dx.doi.org/10.51710/jias.v37i2.101.

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The Kaladgi Basin, one of the important Proterozoic Sedimentary basins of Peninsular India, exposes a thick sequence of Proterozoic succession composed of a variety of lithologies with predominance of arenaceous rocks interrupted with Carbonate sediments at different stratigraphic levels. The present work focuses mainly on understanding the Sedimentological nature and diagenetic character of the Lower part of the Lokapur sub-group rocks that are exposed in and around Savadatti Town, Belagavi District of Karnataka. These rocks are mainly composed of Arenite sequences of varying grain size. The clastic succession comprises lithologies Sandstones with minor conglomeratic facies at the lower regimes. An attempt is made to identify the detailed petrographic character of the sandstones to understand the provenance and depositional environments based on the detailed petrographic observation. The study suggests that the coarse clastic conglomerates are essentially polymictic types and the sandstones are sub-mature to mature (mineralogically), medium to coarse grained and can be categorized mainly into lithic/feldspathic and quartz arenites. Minor occurance of feldspars as the framework constituent also suggests that the rock have undergone considerable transport. However with their variable degree of alteration (from fresh to partially alter to completely altered grains) associated with textural maturity and nature of Quartz point towards the possibility of derivation of these sediments from two different sources. Palaeocurrent data that indicate a NW palaeoslope suggest the derivation of sediments from a variety of granitic and gnesssic crystalline complexes occurring along the basin margin. The maturity of the sandstones (Quartz Arenites) is attributed to the recycling and re-working of the older sediments. Analysis of Textural parameters of these rocks pointed towards deposition under beach environments. The lack in preservation of much amount of feldspar in these sandstones is indicates a remote source and relatively dry-arid climate of the source area.

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Mitra, Rahul, Gopal Chakrabarti, and Debasish Shome. "Geochemistry of the Palaeo–Mesoproterozoic Tadpatri shales, Cuddapah basin, India: implications on provenance, paleoweathering and paleoredox conditions." Acta Geochimica 37, no. 5 (December 5, 2017): 715–33. http://dx.doi.org/10.1007/s11631-017-0254-3.

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Hartley, Adrian, Bartosz Kurjanski, Jessica Pugsley, and Joseph Armstrong. "Ice-rafting in lakes in the early Neoproterozoic: dropstones in the Diabaig Formation, Torridon Group, NW Scotland." Scottish Journal of Geology 56, no. 1 (December 18, 2019): 47–53. http://dx.doi.org/10.1144/sjg2019-017.

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A dropstone horizon is described from lake deposits in a palaeo-valley from the c. 1000 Ma Diabaig Formation, Torridon Group, NW Scotland. Dropstones occur in wave-rippled, fine-grained sandstones and siltstones that contain desiccation and syneresis cracks indicative of fluctuating lake levels. Five locally derived dropstones occur at the same horizon over lateral distance of 250 m and display clear evidence of deflection and penetration of laminae at the base, with thinning, onlap and draping of laminae on to clast margins and tops. Mechanisms of dropstone formation are discussed, with ice-rafting considered the most likely explanation. It is suggested that rafting was promoted by cold winters at 35° S in the early Neoproterozoic, possibly in an upland setting. Interpretation of the dropstones as ice-rafted debris provides the first physical record of evidence for ice at the Earth's surface during the late Mesoproterozoic to early Neoproterozoic.

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Chalapathi Rao, N. V., Fu-Yuan Wu, and M. Srinivas. "Mesoproterozoic emplacement and enriched mantle derivation of the Racherla alkali syenite, Palaeo-Mesoproterozoic Cuddapah Basin, southern India: insights from in situ Sr–Nd isotopic analysis on apatite." Geological Society, London, Special Publications 365, no. 1 (2012): 185–95. http://dx.doi.org/10.1144/sp365.10.

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14

GASSER, DETA, and ARILD ANDRESEN. "Caledonian terrane amalgamation of Svalbard: detrital zircon provenance of Mesoproterozoic to Carboniferous strata from Oscar II Land, western Spitsbergen." Geological Magazine 150, no. 6 (June 4, 2013): 1103–26. http://dx.doi.org/10.1017/s0016756813000174.

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AbstractThe tectonic origin of pre-Devonian rocks of Svalbard has long been a matter of debate. In particular, the origin and assemblage of pre-Devonian rocks of western Spitsbergen, including a blueschist-eclogite complex in Oscar II Land, are enigmatic. We present detrital zircon U–Pb LA-ICP-MS data from six Mesoproterozoic to Carboniferous samples and one U–Pb TIMS zircon age from an orthogneiss from Oscar II Land in order to discuss tectonic models for this region. Variable proportions of Palaeo- to Neoproterozoic detritus dominate the metasedimentary samples. The orthogneiss has an intrusion age of 927 ± 3 Ma. Comparison with detrital zircon age spectra from other units of similar depositional age within the North Atlantic region indicates that Oscar II Land experienced the following tectonic history: (1) the latest Mesoproterozoic sequence was part of a successor basin which originated close to the Grenvillian–Sveconorwegian orogen, and which was intruded byc. 980–920 Ma plutons; (2) the Neoproterozoic sediments were deposited in a large-scale basin which stretched along the Baltoscandian margin; (3) the eclogite-blueschist complex and the overlying Ordovician–Silurian sediments probably formed to the north of the Grampian/Taconian arc; (4) strike-slip movements assembled the western coast of Spitsbergen outside of, and prior to, the main Scandian collision; and (5) the remaining parts of Svalbard were assembled by strike-slip movements during the Devonian. Our study confirms previous models of complex Caledonian terrane amalgamation with contrasting tectonic histories for the different pre-Devonian terranes of Svalbard and particularly highlights the non-Laurentian origin of Oscar II Land.

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Mishra, Meenal, Shinjana Sen, and Kiran Kumari. "Explosive felsic volcanism at Palaeo-Mesoproterozoic boundary from Vindhyan Supergroup, Son Valley, Central India—Evidences of crustal contamination." Geochemistry International 55, no. 5 (May 2017): 474–88. http://dx.doi.org/10.1134/s0016702917050093.

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Zhao, Guochun, Sanzhong Li, Min Sun, and Simon A. Wilde. "Assembly, accretion, and break-up of the Palaeo-Mesoproterozoic Columbia supercontinent: record in the North China Craton revisited." International Geology Review 53, no. 11-12 (February 8, 2011): 1331–56. http://dx.doi.org/10.1080/00206814.2010.527631.

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Singh, Birendra Pratap, Krishna Mondal, Akanksha Singh, Preeti Mittal, Rohit Kumar Singh, and Shyam Kanhaiya. "Seismic origin of the soft‐sediment deformation structures in the upper Palaeo‐Mesoproterozoic Semri Group, Vindhyan Supergroup, Central India." Geological Journal 55, no. 11 (June 2, 2020): 7474–88. http://dx.doi.org/10.1002/gj.3872.

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Wang, Xiangdong, Xinbiao Lv, Xiaofeng Cao, Yifan Wang, and Wen Liu. "Palaeo-Mesoproterozoic magmatic and metamorphic events from the Kuluketage block, northeast Tarim Craton: geochronology, geochemistry and implications for evolution of Columbia." Geological Journal 53, no. 1 (January 25, 2017): 120–38. http://dx.doi.org/10.1002/gj.2881.

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Chakraborty, Maitrayee, Sayan Biswas, Nandini Sengupta, and Pulak Sengupta. "First Report of Florencite from the Singhbhum Shear Zone of the East Indian Craton." International Journal of Mineralogy 2014 (February 3, 2014): 1–8. http://dx.doi.org/10.1155/2014/978793.

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Metamorphic florencite is being reported from kyanite-rich rocks from the eastern part of the Palaeo- to Mesoproterozoic Singhbhum shear zone. This is the first report of florencite from the Precambrian rocks of the Indian Shield. Host rock of florencite is a kyanite-rich rock (>80 vol%) with small and variable amounts of quartz, lazulite, augelite, and rutile. Florencite forms small (<20 microns) idioblastic-to-subhedral crystals that are included in large kyanite grains. Rarely, florencite replaces kyanite. The florencite has small proportion of crandallite (8.7–11.8 mol%) and goyazite (<2 mol%) components. Florencite of this study is dominated by Ce (~49 mol%) with significant La (~30 mol%) and Nd (~21 mol%). Compared to other florencite occurrences of the world, florencite of the studied rock is impoverished in S, Sr, and Ba and rich in P. Stability of the assemblage florencite-kyanite-augelite-lazulite and the quantitative thermobarometry in the adjoining rocks suggest that florencite was formed during Palaeoproterozoic metamorphism that culminated at the P-T range of 490±40∘C and 6.3±1 kbar. Integrating all the geological features it is postulated that florencite was formed due to metasomatism of some aluminous protolith by infiltration of acidic fluids charged with PO4-3 and LREE.

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Mazumder, Rajat, Shuvabrata De, Tohru Ohta, David Flannery, Leena Mallik, Trisrota Chaudhury, Priyanka Chatterjee, Marinah A. Ranaivoson, and Makoto Arima. "Chapter 10 Palaeo-Mesoproterozoic sedimentation and tectonics of the Singhbhum Craton, eastern India, and implications for global and craton-specific geological events." Geological Society, London, Memoirs 43, no. 1 (2015): 139–49. http://dx.doi.org/10.1144/m43.10.

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McConachie, B. A., M. G. Barlow, J. N. Dunster, R. A. Meaney, and A. O. Schaap. "THE MOUNT ISA BASIN—DEFINITION, STRUCTURE AND PETROLEUM GEOLOGY." APPEA Journal 33, no. 1 (1993): 237. http://dx.doi.org/10.1071/aj92018.

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The Mount Isa Basin is a new concept to describe the area of Palaeo- to Mesoproterozoic rocks south of the Murphy Inlier (not the Murphy Tectonic Ridge) and inappropriately described as the Mount Isa Inlier. The new basin concept presented in this paper allows the characterisation of basin-wide structural deformation and the recognition of areas with petroleum exploration potential.The northern depositional margin of the Mount Isa Basin is the metamorphic, intrusive and volcanic complex referred to as the Murphy Inlier. The eastern, southern and western boundaries of the basin are obscured by younger basins (Carpentaria, Eromanga and Georgina Basins). The Murphy Inlier rocks comprise the seismic basement to the Mount Isa Basin sequence. Evidence for the continuity of the Mount Isa Basin with the McArthur Basin to the northwest and the Willyama Block (Basin) at Broken Hill to the south is presented. These areas combined with several other areas of similar age are believed to have comprised the Carpentarian Superbasin.The application of seismic exploration within Authority to Prospect (ATP) 423P at the northern margin of the basin was critical to the recognition and definition of the Mount Isa Basin. The northern Mount Isa Basin is structurally analogous to the Palaeozoic Arkoma Basin of Oklahoma and Arkansas in the southern USA but as with all basins it contains unique characteristics, a function of its individual development history. The northern Mount Isa Basin is defined as the basin area northwest of the Mount Gordon Fault.

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Xu, Zhi-Tao, Jing-Gui Sun, Feng-Zhi Lei, Ji-Long Han, and Ke-Yao Zhang. "Geochronology, geochemistry, and Pb–Hf isotopes of mineralization-related magmatism in the Dongyang gold deposit, Fujian Province, southeastern China." Canadian Journal of Earth Sciences 57, no. 5 (May 2020): 553–74. http://dx.doi.org/10.1139/cjes-2019-0006.

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The recently discovered Dongyang low-sulphidation epithermal Au deposit is located in Fujian Province. The Au mineralization hosted in rhyolite porphyry and the Lower Jurassic Nayuan Formation continental volcanic rocks is considered to be related to intermediate–acidic intrusions (rhyolite porphyry, quartz diorite porphyry, and dacite porphyry). The zircon U–Pb ages of these samples are 160.3 ± 0.8, 156.6 ± 0.8, and 154.1 ± 0.6 Ma, respectively, and the sulphide Rb–Sr isotope isochron age is 152.4 ± 1.7 Ma, indicating a temporal link between porphyry emplacement and Au mineralization. Porphyries are enriched in large-ion lithophile elements and light rare earth elements and slightly depleted in heavy rare earth elements and high field strength elements, belong to the high-potassium calc-alkaline or shoshonitic series, and show characteristics of volcanic arcs or active continental margins. Moreover, the εHf(t) values of the porphyries range from −11.6 to −7.6, −11.2 to −5.4, and −9.8 to −4.6, respectively. The 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb values of the ore minerals are from 38.417 to 38.406, 15.603, and from 18.179 to 18.175, respectively. Pb and Hf isotopes indicate that the intermediate–acidic magma related to mineralization originated from Mesoproterozoic lower crust. Consequently, these data favour an intermediate–acidic magma origin for Au mineralization in the Dongyang deposit. Integrating new and published data on the tectonic evolution, we suggest that the rhyolite porphyry, quartz diorite porphyry, dacite porphyry, and associated Au mineralization in the Dongyang deposit formed at 160–152 Ma in an extensional environment related to subduction of the Palaeo-Pacific Plate beneath the South China block.

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de Wit, M. J., S. Bowring, R. Buchwaldt, F. Ö. Dudas, D. MacPhee, G. Tagne-Kamga, N. Dunn, A. M. Salet, and D. Nambatingar. "Geochemical reconnaissance of the Guéra and Ouaddaï Massifs in Chad: evolution of Proterozoic crust in the Central Sahara Shield." South African Journal of Geology 124, no. 2 (June 1, 2021): 353–82. http://dx.doi.org/10.25131/sajg.124.0048.

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Abstract In 1964, W.Q. Kennedy suggested that the crust of Saharan Africa is different from the rest of Africa. To date, the geologic evolution of this region remains obscure because the age and composition of crystalline basement are unknown across large sectors of the Sahara. Most of Africa comprises Archaean cratons surrounded by Palaeo- to Mesoproterozoic orogenic belts, which together constitute Africa’s three major shields (the Southern, Central and West African Shields), finally assembled along belts of Pan-African rocks. By contrast, central Saharan Africa (5.3x106 km2), an area just over half the size of Europe, is considered either as a Neoproterozoic region constructed of relatively juvenile crust (0.5 to 1.0 Ga), or as an older (North African) shield that was reactivated and re-stabilized during that time, a period commonly referred to as “Pan African”. Here, using U-Pb zircon age determinations and Nd isotopic data, we show that remote areas in Chad, part of the undated Darfur Plateau stretching across ¾ million km2 of the central Sahara, comprise an extensive Neoproterozoic crystalline basement of pre-tectonic gabbro-tonalite-granodiorite and predominantly post-tectonic alkali feldspar granites and syenites that intruded between ca. 550 to 1050 Ma. This basement is flanked along its western margin by a Neoproterozoic continental calc-alkaline magmatic arc coupled to a cryptic suture zone that can be traced for ~2400 km from Tibesti through western Darfur into Cameroon. We refer to this as the Central Saharan Belt. This, in a Gondwana framework, is part of a greater arc structure, which we here term the Great Central Gondwana Arc (GCGA). Inherited zircons and Nd isotopic ratios indicate the Neoproterozoic magmas in the central Sahara were predominantly derived from Mesoproterozoic continental lithosphere. Regional deformation between 613 to 623 Ma marks the onset of late alkaline granite magmatism that was widespread across a much larger area of North Africa until about 550 Ma. During this magmatism, the region was exhumed and eroded, leaving a regional peneplain on which early Palaeozoic (Lower-Middle Cambrian) siliciclastic sediments were subsequently deposited, as part of a thick and widespread cover that stretched across much of North Africa and the Arabian Peninsula. Detrital zircons in these cover sequences provide evidence that a substantial volume of detritus was derived from the central Sahara region, because these sequences include ‘Kibaran-age’ zircons (ca. 1000 Ma) for which a source terrain has hitherto been lacking. We propose that, in preference to calling the central Sahara a “ghost” or “meta” craton, it should be called the Central Sahara Shield.

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JIANG, YAO-HUI, SHAO-YONG JIANG, KUI-DONG ZHAO, and HONG-FEI LING. "Petrogenesis of Late Jurassic Qianlishan granites and mafic dykes, Southeast China: implications for a back-arc extension setting." Geological Magazine 143, no. 4 (April 26, 2006): 457–74. http://dx.doi.org/10.1017/s0016756805001652.

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A late Mesozoic belt of volcanic-intrusive complexes occurs in Southeast China. The Qianlishan granites are distributed in the northwest of the belt. The pluton is composed of porphyritic biotite granite (153 Ma) and equigranular biotite granite (151 Ma) and was intruded by granite-porphyry dykes (144 Ma) and mafic dykes such as lamprophyre and diabase (142 Ma). The granitic rocks, consisting mainly of K-feldspar, plagioclase, quartz and Fe-rich biotite, have SiO2 contents of 72.9–76.9%, and are enriched in alkalis, rare earth elements (REE), high field strength elements (HFSE) and Ga with high Ga/Al ratios, but depleted in Ba, Sr and transition metals. Trace-element geochemistry and Sr–Nd isotope systematics further imply that the Qianlishan granitic magmas were most probably derived by partial melting of Palaeo- to Mesoproterozoic metamorphic lower-crustal rocks that had been granulitized during an earlier thermal event. These features suggest an A-type affinity. The Qianlishan lamprophyre and neighbouring coeval mafic dykes (SiO2 = 47.9–53.8 wt%) have high MgO and compatible element contents. These rocks also have high K2O contents and are enriched in alkalis, light REE, large ion lithophile elements, and depleted in HFSE. They have low initial εNd values and relatively high initial 87Sr/86Sr ratios. We suggest a subduction-modified refractory lithospheric mantle (phlogopite-bearing harzburgite or lherzolite) for these high-Mg potassic magmas. The Qianlishan diabases (SiO2 = 48.4–48.7 wt%) are alkaline and have high TiO2 and total Fe2O3 contents, together with the positive initial εNd value, suggesting derivation from fertile asthenopheric mantle (phlogopite-bearing lherzolite). A back-arc extensional setting, related to subduction of the Palaeo-Pacific plate, is favoured to explain the petrogenesis of the Qianlishan granites and associated mafic dykes. Between 180 and 160 Ma, Southeast China was a continental arc, forming the 180–160 Ma plutons of the late Mesozoic volcanic-intrusive complex belt, and the lower-crust was granulitized. Since 160 Ma the northwestern belt has been in a back-arc extensional setting as a consequence of slab roll-back, resulting in the lithosphere thinning and an influx of asthenophere. The upwelling asthenosphere, on the one hand, induced the local lithospheric mantle to melt partially, forming high-Mg potassic magmas, and on the other hand it underwent decompression melting itself to form alkaline diabase magma. Pulsatory injection of such high-temperature magmas into the granulitized crustal source region induced them to partially melt and generate the A-type magmas of the Qianlishan granitic rocks.

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Kroner, S. "U-Pb and Pb-Pb zircon ages for metamorphic rocks in the Kaoko Belt of Northwestern Namibia: A Palaeo- to Mesoproterozoic basement reworked during the Pan-African orogeny." South African Journal of Geology 107, no. 3 (September 1, 2004): 455–76. http://dx.doi.org/10.2113/107.3.455.

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Wang, Andong, Xiaocong Li, Xianwen Luo, M. Santosh, Yurong Cui, Quanzhong Li, Dongrong Lai, Jianjun Wan, and Xuefen Zhang. "Crustal growth as revealed by integrated U–Pb and Lu–Hf isotope analyses of detrital zircons from the Ganjiang River, southeastern China." Geological Magazine 157, no. 4 (November 14, 2019): 666–76. http://dx.doi.org/10.1017/s001675681900116x.

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AbstractThe Ganjiang River, one of eight major tributaries of the Yangtze River, located in the western hinterland of the Cathaysia Block, SE China, has a length of 823 km and a drainage area of 82 809 km2, whose detrital zircons provide a valuable means to trace sediment provenances of the river and explore the crustal growth and evolution of the Cathaysia Block. In the current study, 389 concordia zircon U–Pb age spots and rare earth element (REE) contents, in combination with 201 Lu–Hf isotope analyses, have been determined. Oscillatory zoning, high Th/U ratios and REE distribution patterns indicate that most detrital zircon grains are of magmatic origin. The age can be further divided into seven groups: 130–185 Ma with a peak at 153 Ma (7 %); 217–379 Ma with a peak at 224 Ma (16 %); 390–494 Ma with a peak at 424 Ma (37 %); 500–698 Ma with a peak at 624 Ma (5 %); 716–897 Ma with a peak at 812 Ma (10 %); 902–1191 Ma with a peak at 976 Ma (13 %); and 2232–2614 Ma with a peak at 2471 Ma (5 %). The sources of almost all the zircon age groups can be found from the exposed rocks. In particular, Yanshanian, Hercynian to Indosinian, Pan-African, Grenvillian and Palaeoproterozoic–Archaean zircons can be mainly sourced from the northern Guangdong – southern Jiangxi – western Fujian region, while Caledonian zircons come from southern and central Jiangxi, and Jinningian zircons are from central and northern Jiangxi. Most determined zircon grains exhibit negative εHf(t) values and TDM2 ages of 797 to 4016 Ma with a wide peak at 1500–2100 Ma and a keen peak at 1824 Ma, suggesting that most zircons are sourced from the reworked ancient crustal materials or crust–mantle mixing. The zircon Hf model age cumulative probability diagram shows that rapid crustal growth took place at the Palaeo- to Mesoproterozoic and that about 90 % of the crust of the Cathaysia Block was formed before 1.5 Ga.

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Robb, L. J., L. A. Freeman, and R. A. Armstrong. "Nature and longevity of hydrothermal fluid flow and mineralisation in granites of the Bushveld Complex, South Africa." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 91, no. 1-2 (2000): 269–81. http://dx.doi.org/10.1017/s0263593300007434.

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The Lebowa Granite Suite of the Bushveld Complex is a large, 2054 Ma old, A-type batholith, characterised by numerous relatively small magmato-hydrothermal, polymetallic ore deposits. The mineralisation is represented by a three-stage paragenetic sequence: early magmatic Sn-W-Mo-F ores (600°C > T > 400°C), followed by a Cu-Pb-Zn-As-Ag-Au paragenesis (400°C > T > 200°C) and then late-stage Fe-F-U mineralisation (< 200°C). The first stage of mineralisation (typified by the endogranitic Zaaiplaats tin deposit) is related to incompatible trace element concentration during crystal fractionation and subsequent fluid saturation of the magma. Evolution of the late magmatic fluids as they were channelled along fractures, as well as mingling with externally derived connate or meteoric fluids, resulted in the deposition of the second stage of mineralisation (typified by the fracture-related, endogranitic Spoedwel and Albert deposits and the exogranitic, sediment-hosted Rooiberg mine) which is dominated by polymetallic sulphide ores. As the externally derived fluid component became progressively more dominant, oxidation of the polymetallic sulphide assemblage and precipitation of hematite, pitchblende and fluorite occurred generally along the same fracture systems that hosted the earlier sulphide paragenesis.Small hydrothermal zircons trapped along quartz growth zones from the Spoedwel deposit yield a U-Pb concordia age of 1957 ± 15 Ma. Whole-rock Rb-Sr age determinations from the Lebowa Granite Suite fall in the range 1790 ± 114 Ma to 1604 ± 70 Ma and are interpreted to reflect alkali element mobility and isotopic resetting during exhumation of the Bushveld granite. In contrast to thermal modelling which indicates that hydrothermal activity should have ceased within 4 my of emplacement, isotopic evidence suggests that mineralisation was long-lived, but episodic, and that fluid flow events were linked to major periods of Palaeo- and Mesoproterozoic orogenic activity along the margins of the Kaapvaal Craton. During these orogenic episodes, fluid flow was enhanced by tectonically induced fluid over-pressuring and/or exhumation of the Bushveld Complex.

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Sayab, Mohammad. "Tectonic significance of structural successions preserved within low-strain pods: Implications for thin- to thick-skinned tectonics vs. multiple near-orthogonal folding events in the Palaeo-Mesoproterozoic Mount Isa Inlier (NE Australia)." Precambrian Research 175, no. 1-4 (December 2009): 169–86. http://dx.doi.org/10.1016/j.precamres.2009.09.007.

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TaiPing, ZHAO, PANG LanYin, QIU YiFan, ZHU XiYan, WANG ShiYan, and GENG YuanSheng. "The Paleo-Mesoproterozoic boundary: 1.8Ga." Acta Petrologica Sinica 35, no. 8 (2019): 2281–98. http://dx.doi.org/10.18654/1000-0569/2019.08.01.

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Tang, Youjun, Meijun Li, Qiuge Zhu, Daxiang He, Xingchao Jiang, Hong Xiao, Junfeng Shan, Wujiang Kang, Junying Leng, and Wenqiang Wang. "Geochemical characteristics and origin of hydrocarbons in the Mesoproterozoic reservoirs in the Liaoxi Depression, NE China." Energy Exploration & Exploitation 38, no. 2 (July 12, 2019): 333–47. http://dx.doi.org/10.1177/0144598719862922.

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Oil reservoirs have been discovered in the Mesoproterozoic strata in the Liaoxi Depression, NE China. In order to determine the source of oil shows of the Mesoproterozoic Gaoyuzhuang Formation and their organic geochemical characteristics, eight source rocks and reservoir cores from the Mesoproterozoic Gaoyuzhuang Formation and four source rocks from the overlying Middle Jurassic Haifanggou Formation were geochemically analysed. The distribution patterns of normal alkanes, acyclic isoprenoids, hopanes, steranes and triaromatic steroids of the Mesoproterozoic hydrocarbons from Well N-1 are consistent with those of source rock extracts from the Mesoproterozoic Gaoyuzhuang Formation in the Well L-1. The molecular marker compositions of source rock extracts from the overlying Middle Jurassic Haifanggou Formation are distinctively different from those of the Mesoproterozoic hydrocarbons. The results suggest that the Mesoproterozoic source rocks have significant petroleum generation potential. The Mesoproterozoic paleo-reservoir may be prospecting exploration targets in the Liaoxi Depression, NE China.

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Meert, Joseph G. "Paleomagnetic Evidence for a Paleo-Mesoproterozoic Supercontinent Columbia." Gondwana Research 5, no. 1 (January 2002): 207–15. http://dx.doi.org/10.1016/s1342-937x(05)70904-7.

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32

Zhao, Guochun, Min Sun, Simon A. Wilde, and Sanzhong Li. "A Paleo-Mesoproterozoic supercontinent: assembly, growth and breakup." Earth-Science Reviews 67, no. 1-2 (September 2004): 91–123. http://dx.doi.org/10.1016/j.earscirev.2004.02.003.

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33

Sang, Miao, Wenjiao Xiao, Brian F. Windley, Qigui Mao, Zhiyong Zhang, Hao Wang, He Yang, et al. "From Middle Neoproterozoic Extension to Paleozoic Accretion and Collision of the Eastern Tiklik Belt (the Western Kunlun Orogen, NW China)." Minerals 12, no. 2 (January 28, 2022): 166. http://dx.doi.org/10.3390/min12020166.

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The eastern Tiklik belt is mainly composed of meta-sedimentary rocks of the Ailiankate and Sailajiazitage Groups that were previously interpreted as Palaeoproterozoic, Mesoproterozic and Neoproterozoic stratigraphic units, which are part of the Tarim Precambrian basement. Our new detrital (U-Pb) zircon ages yield a dominant single peak with a major range between ca. 700 Ma and 800 Ma for meta-sedimentary rocks from both the Ailiankate and Sailajiazitage Groups, which demonstrates that they were mainly derived from an independent Neoproterozoic terrane. There are several ages of 444–659 Ma, of which, the youngest has an age of 444 ± 6 Ma, indicating that the time of deposition of the meta-sedimentary rocks could have been in the Early Silurian. The porphyritic granite sample has a weighted mean crystallization age of 442 ± 2 Ma. The adakite-like geochemical characteristics of the porphytitic granite suggest derivation from the melting of the oceanic slab and formation in a subduction, arc-related tectonic setting. After integration with relevant published data, our work suggests that the Ailiankate and Sailajiazitage Groups belong to a tectonic mosaic that contains Middle Neoproterozoic extensional and Paleozoic accretionary and collisional complexes, rather than the Paleoproterozoic or Mesoproterozoic basement, as previously regarded. We propose a new tectonic model for the eastern Tiklik belt that started with a Middle Neoproterozoic extension and ended with Paleozoic continuous accretion and collision in a Paleo-Tethys archipelago, which contributed to the considerable continental growth of the southern Tarim Block.

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Anderson, J. L. "Paleo- and Mesoproterozoic granite plutonism of Colorado and Wyoming." Rocky Mountain Geology 34, no. 2 (November 1, 1999): 149–64. http://dx.doi.org/10.2113/34.2.149.

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PIMENTEL, MÁRCIO M., ELTON L. DANTAS, REINHARDT A. FUCK, and RICHARD A. ARMSTRONG. "Shrimp and conventional U-Pb age, Sm-Nd isotopic characteristics and tectonic significance of the K-rich Itapuranga suite in Goiás, Central Brazil." Anais da Academia Brasileira de Ciências 75, no. 1 (March 2003): 97–108. http://dx.doi.org/10.1590/s0001-37652003000100011.

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The Itapuranga alkali granite and Uruana quartz syenite are large K-rich EW-elongated intrusions, in the central part of the Neoproterozoic Brasília Belt, central Brazil. They are associated with Pireneus lineaments, which cut the regional NNW-SSE structures of the southern part of the belt. SHRIMP and conventional U-Pb data for the Itapuranga and Uruana intrusions indicate crystallization ages of 624 ± 10 Ma and 618 ± 4 Ma, respectively. Three zircon cores from the Itapuranga granite yielded U-Pb ages between 1.79 and 1.49 Ga. Sm-Nd T DM ages for both intrusions are 1.44 Ga and epsilonNd(T) values are -5.1 and -5.7, suggesting the input of material derived from older (Paleo- to Mesoproterozoic) sialic crust in the origin of the parental magmas. Magma mixing structures indicate co-existence of mafic and felsic end-members. The felsic end-member of the intrusions is dominantly represented by crust-derived melts, formed in response to the invasion of Paleo/Mesoproterozoic sialic crust by alkali-rich mafic magmas at ca. 620 Ma. These intrusions are roughly contemporaneous with, or perhaps slightly younger than, the peak of regional metamorphism in the southern Brasília Belt. Their emplacement along the Pireneus lineament suggest a syn-tectonic origin for them, most probably in transtensional settings along these faults.

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Giri, Rohit Kumar, Praveer Pankaj, N. V. Chalapathi Rao, Ramananda Chakrabarti, and Dinesh Pandit. "Petrogenesis of an alkaline lamprophyre (camptonite) with ocean island basalt (OIB)-affinity at the NW margin of the Cuddapah basin, eastern Dharwar craton, southern India." Neues Jahrbuch für Mineralogie - Abhandlungen Journal of Mineralogy and Geochemistry 196, no. 2 (November 1, 2019): 149–77. http://dx.doi.org/10.1127/njma/2019/0179.

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We report petrology and geochemistry (including Sr and Nd isotopes) of a fresh lamprophyre at Ankiraopalli area at the north-western margin of Paleo-Mesoproterozoic Cuddapah basin, eastern Dharwar craton, southern India. Ankiraopalli samples possess a typical lamprophyre porphyritic-panidiomorphic texture with phenocrysts of kaersutite and diopside set in a plagioclase dominant groundmass. Combined mineralogy and geochemistry classify it as alkaline lampro- phyre in general and camptonite in particular. Contrary to the calc-alkaline and/or shoshonitic orogenic nature portrayed by lamprophyres occurring towards the western margin of the Cuddapah basin, the Ankiraopalli samples display trace element composition revealing striking similarity with those of ocean island basalts, Italian alkaline lamprophyres and highlights an anorogenic character. However, the87 Sr/86 Srinitial (0.710316 to 0.720016) and εNdinitial (– 9.54 to – 9.61) of the Ankiraopalli lamprophyre show derivation from an 'enriched' mantle source showing long term enrichment of incompatible trace elements and contrast from those of (i) OIB, and (ii) nearby Mahbubnagar alkaline mafic dykes of OIB affinity. Combining results of this study and recent advances made, multiple mantle domains are identified in the Eastern Dharwar craton which generated distinct Mesoproterozoic lamprophyre varieties. These include (i) Domain I, involving sub-continental lithospheric mantle source essentially metasomatized by subduction-derived melts/fluids (represented by orogenic calcalkaline and/or shoshonitic lamprophyres at the Mudigubba, the Udiripikonda and the Kadiri); (ii) Domain II, comprising a mixed sub-continental lithospheric and asthenospheric source (represented by orogenic-anorogenic, alkaline to calc-alkaline transitional lamprophyres at the Korakkodu), and (iii) Domain III, representing a sub-continental lithospheric source with a dominant overprint of an asthenospheric (plume) component (represented by essentially alkaline lamprophyres at the Ankiraopalli). Our study highlights the varied mantle source heterogeneities and complexity of geodynamic processes involved in the Neoarchean-Paleo/Mesoproterozoic evolution of the Eastern Dharwar craton.

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37

Malyshev, Sergey, Aleksander Pasenko, Aleksei Ivanov, Dmitrii Gladkochub, Valery Savatenkov, Sebastien Meffre, Adam Abersteiner, Vadim Kamenetsky, and Vasiliy Shcherbakov. "Geodynamic Significance of the Mesoproterozoic Magmatism of the Udzha Paleo-Rift (Northern Siberian Craton) Based on U-Pb Geochronology and Paleomagnetic Data." Minerals 8, no. 12 (November 29, 2018): 555. http://dx.doi.org/10.3390/min8120555.

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The emplacement age of the Great Udzha Dyke (northern Siberian Craton) was determined by the U-Pb dating of apatite using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). This produced an age of 1386 ± 30 Ma. This dyke along with two other adjacent intrusions, which cross-cut the sedimentary units of the Udzha paleo-rift, were subjected to paleomagnetic investigation. The paleomagnetic poles for the Udzha paleo-rift intrusions are consistent with previous results published for the Chieress dyke in the Anabar shield of the Siberian Craton (1384 ± 2 Ma). Our results suggest that there was a period of intense volcanism in the northern Siberian Craton, as well as allow us to reconstruct the apparent migration of the Siberian Craton during the Mesoproterozoic.

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Luo, Bing, Yu Yang, Gang Zhou, Wenjun Luo, Shujiao Shan, and Maolong Xia. "Basic characteristics and accumulation mechanism of Sinian−Cambrian giant highly mature and oil-cracking gas reservoirs in the Sichuan Basin, SW China." Energy Exploration & Exploitation 36, no. 4 (November 7, 2017): 568–90. http://dx.doi.org/10.1177/0144598717736856.

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Old Mesoproterozoic−Cambrian successions have been regarded as an important frontier field for global oil and gas exploration in the 21st century. This has been confirmed by a recent natural gas exploration breakthrough in the Sinian and Cambrian strata, central Sichuan Uplift, Sichuan Basin of SW China. However, the accumulation mechanism and enrichment rule of these gases have not been well characterized. This was addressed in this work, with aims to provide important guidance for the further exploration while enriching the general studies of the oil and gas geology in the old Mesoproterozoic–Cambrian strata. Results show that the gas field in the study area is featured by old target layers (Sinian–Lower Cambrian), large burial depth (>4500 m), multiple gas-bearing intervals (the second and fourth members of the Sinian Dengying Formation and the Lower Cambrian Longwangmiao Formation), various gas reservoir types (structural type and structural–lithologic type), large scale (giant), and superimposing and ubiquitous distribution. The giant reserves could be attributed to the extensive intercalation of pervasive high quality source rocks and large-scale karst reservoirs, which enables a three-dimensional hydrocarbon migration and accumulation pattern. The origin of natural gas is oil cracking, and the three critical stages of accumulation include the formation of oil reservoirs in Triassic, the cracking of oil in Cretaceous, and the adjustment and reaccumulations in the Paleogene. The main controlling factor of oil and gas enrichment is the inherited development of large-scale stable paleo-uplift, and the high points in the eastern paleo-uplift are the favorable area for natural gas exploration.

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Hu, Chenlin, Changcheng Han, Jinghui Ma, Li Deng, and Lingfeng Zhao. "Paleowind Directions over the Tarim Block during the Mesoproterozoic, Northwestern China." Minerals 12, no. 11 (November 12, 2022): 1435. http://dx.doi.org/10.3390/min12111435.

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The Tarim Block is an ancient plate with a basement of ancient continental crust, which has been separated from the Rodinia supercontinent since the Neoproterozoic. During the Neoproterozoic, which lasted nearly 500 Myr, this block experienced significant evolutionary processes, such as proliferation, radioactive decay of elements, and gradual cooling and solidification. The investigation of Neoproterozoic paleogeography may shed light on the evolution of these geological events. In order to realize this potential, this study aimed to infer paleowind directions over the Tarim Block during each epoch of the Cryogenian–Ediacaran and to constrain the paleogeographic location of the Tarim Block. To this end, outcrop magnetic fabric data were employed to analyze the anisotropy of magnetic susceptibility within the Tarim Block. The anisotropy of magnetic susceptibility measurements yielded mean paleowind directions of 308° ± 69°, 277° ± 78°, and 256° ± 76° from the present north for the Early, Middle, and Late Cryogenian, respectively; the corresponding values for the Early and Late Ediacaran were 237° ± 77° and 254° ± 73° from the present north, respectively. Considering the rotation relationship of the Tarim Block from the Neoproterozoic to the present, the paleowind directions during the Early, Middle, and Late Cryogenian were ~55°, ~35°, and ~35° from the paleo-north, respectively. The paleowind directions during the Early and Late Ediacaran were ~35° and ~60° from paleo-north, respectively. By referring to the correspondence between the paleowind directions over the Tarim Block and trade winds in the Northern Hemisphere, this study provides evidence for the location of the Tarim Block during the Cryogenian–Ediacaran. The main contributions of this study can be summarized as follows: (1) paleowind patterns are established through the analysis of the anisotropy of magnetic susceptibility; (2) the paleogeographic location of the Tarim Block during the Cryogenian–Ediacaran is constrained; and (3) a reference for further study of the paleogeography of the Tarim Block during the Cryogenian–Ediacaran is provided.

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YuanSheng, GENG, KUANG HongWei, DU LiLin, LIU YongQing, and ZHAO TaiPing. "On the Paleo-Mesoproterozoic boundary from the breakup event of the Columbia supercontinent." Acta Petrologica Sinica 35, no. 8 (2019): 2299–324. http://dx.doi.org/10.18654/1000-0569/2019.08.02.

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RIZZOTTO, GILMAR J., LÉO A. HARTMANN, JOÃO O. S. SANTOS, and NEAL J. MCNAUGHTON. "Tectonic evolution of the southern margin of the Amazonian craton in the late Mesoproterozoic based on field relationships and zircon U-Pb geochronology." Anais da Academia Brasileira de Ciências 86, no. 1 (March 2014): 57–84. http://dx.doi.org/10.1590/0001-37652014104212.

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New U-Pb zircon geochronological data integrated with field relationships and an airborne geophysical survey suggest that the Nova Brasilândia and Aguapeí belts are part of the same monocyclic, metaigneous and metasedimentary belt formed in the late Mesoproterozoic (1150 Ma-1110 Ma). This geological history is very similar to the within-plate origin of the Sunsás belt, in eastern Bolivia. Thus, we propose that the Nova Brasilândia, Aguapeí and Sunsás belts represent a unique geotectonic unit (here termed the Western Amazon belt) that became amalgamated at the end of the Mesoproterozoic and originated through the reactivation of a paleo-suture (Guaporé suture zone) in an intracontinental rift environment. Therefore, its geological history involves a short, complete Wilson cycle of ca. 40 Ma. Globally, this tectonic evolution may be related with the final breakup of the supercontinent Columbia. Mafic rocks and trondhjemites in the northernmost portion of the belt yielded U-Pb zircon ages ca. 1110 Ma, which dates the high-grade metamorphism and the closure of the rift. This indicates that the breakup of supercontinent Columbia was followed in short sequence by the assembly of supercontinent Rodinia at ca. 1.1-1.0 Ga and that the Western Amazon belt was formed during the accretion of the Arequipa-Antofalla basement to the Amazonian craton.

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Uhlein, Alexandre, Fernanda Ersinzon, Gabriel Jubé Uhlein, and Davi Gobira de Alcântara. "Estratigrafia e sistemas deposicionais do Supergrupo Espinhaço e grupos Bambuí e Macaúbas." Terrae Didatica 13, no. 3 (January 22, 2018): 244–57. http://dx.doi.org/10.20396/td.v13i3.8650963.

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A Serra do Espinhaço Meridional e regiões limítrofes constituem áreas importantes do Brasil para treinamento de estudantes de geologia em nível de graduação e pós-graduação. Apresenta-se aqui um roteiro geológico destas regiões com afloramentos importantes que visam motivar o estudante de geologia e facilitar a compreensão de processos geológicos. São descritos e localizados afloramentos do Supergrupo Espinhaço (Paleo-Mesoproterozoico) e Grupos Macaúbas e Bambuí (Neoproterozoico) para um trabalho de campo de quatro a seis dias, com ênfase em estratigrafia e sedimentologia. Apresentam-se também diversos afloramentos que ilustram vários sistemas deposicionais siliciclásticos e carbonáticos do Pré-Cambriano.

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43

Waters-Tormey, Cheryl, Kyle T. Ashley, Daniel Jones, and Robert Tracy. "The Mount Hay block, central Australia: Another puzzle piece for Paleo-Mesoproterozoic tectonic history." Precambrian Research 281 (August 2016): 537–65. http://dx.doi.org/10.1016/j.precamres.2016.03.006.

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Chen, Xiaoyan, Menghan Li, Erik A. Sperling, Tonggang Zhang, Keqing Zong, Yongsheng Liu, and Yanan Shen. "Mesoproterozoic paleo-redox changes during 1500–1400 Ma in the Yanshan Basin, North China." Precambrian Research 347 (September 2020): 105835. http://dx.doi.org/10.1016/j.precamres.2020.105835.

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45

Martins-Neto, Marcelo A. "Tectonics and sedimentation in a paleo/mesoproterozoic rift-sag basin (Espinhaço basin, southeastern Brazil)." Precambrian Research 103, no. 3-4 (October 2000): 147–73. http://dx.doi.org/10.1016/s0301-9268(00)00080-2.

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46

Zhang, Xiao-Tian, Jing-Gui Sun, Zheng-Tao Yu, and Quan-Heng Song. "LA-ICP-MS zircon U–Pb and sericite 40Ar/39Ar ages of the Songjianghe gold deposit in southeastern Jilin Province, Northeast China, and their geological significance." Canadian Journal of Earth Sciences 56, no. 6 (June 2019): 607–28. http://dx.doi.org/10.1139/cjes-2018-0254.

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The Songjianghe deposit is a newly discovered altered gold deposit in the southeastern Jiapigou-Haigou Gold Metallogenic Belt (JHGMB) in southeastern Jilin Province of NE China. The host rocks were considered to be the Mesoproterozoic Seluohe Group, and the metallogenic epoch lacked accurate isotopic constraints. To determine the age and metallogenic setting of the deposit, we describe the geologic characteristics of the deposit and present the results of petrographic and geochronologic analyses of the host rocks and ores. The ore bodies are hosted within a suite of amphibolite facies metamorphic rocks superimposed by greenschist facies indicative of retrograde metamorphism. Zircon U–Pb dating results indicate that the host rocks belong to the Jiapigou Group that formed at the end of the Neoarchean (2543–2527 Ma). Subsequently, the rocks successively underwent metamorphism during the late Neoarchean (2521–2506 Ma), retrograde metamorphism caused by the closure of the Paleo-Asian Ocean during the late Permian to Early Triassic (262–250 Ma), and extension after the closure of the Paleo-Asian Ocean during the Late Triassic (231–210 Ma). Sericite 40Ar/39Ar dating results suggest that the Songjianghe deposit formed during the Late Jurassic between 157 Ma and 156 Ma. By combining these new insights with those of previous studies, we propose that the Songjianghe deposit is a mesothermal gold deposit and that mineralization occurred during the extensional period in the intermittent stage that followed the first subduction of the Paleo-Pacific Plate. All the gold deposits in the JHGMB formed from the late Permian to Early Cretaceous by multi-stage mineralization events that corresponded temporally with the tectonic evolution of the Paleo-Asian Ocean and the episodic subduction of the Paleo-Pacific Plate.

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Sun, Shuai, Guiting Hou, K. R. Hari, Shuwen Liu, and Shuwei Guan. "Mechanism of Paleo-Mesoproterozoic rifts related to breakup of Columbia supercontinent: A paleostress field modeling." Journal of Geodynamics 107 (June 2017): 46–60. http://dx.doi.org/10.1016/j.jog.2017.04.002.

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BERALDI-CAMPESI, H., J. D. FARMER, and F. GARCIA-PICHEL. "MODERN TERRESTRIAL SEDIMENTARY BIOSTRUCTURES AND THEIR FOSSIL ANALOGS IN MESOPROTEROZOIC SUBAERIAL DEPOSITS." PALAIOS 29, no. 2 (June 12, 2014): 45–54. http://dx.doi.org/10.2110/palo.2013.084.

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Pan, Zhongcui, Fengyue Sun, Zhichao Cong, Nan Tian, Wei Xin, Li Wang, Yajing Zhang, and Dongqian Wu. "Petrogenesis and Tectonic Implications of the Triassic Granitoids in the Ela Mountain Area of the East Kunlun Orogenic Belt." Minerals 12, no. 7 (July 13, 2022): 880. http://dx.doi.org/10.3390/min12070880.

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Abstract:

The East Kunlun Orogenic Belt is located in the western part of the Central Orogenic Belt of China, with a large number of Triassic igneous rocks parallel to the Paleo-Tethys ophiolite belt, which provides a large amount of geological information for the tectonic evolution of the Paleo-Tethys Ocean. The granitoids studied in this paper are located in the Ela Mountain area in the eastern part of the East Kunlun Orogenic Belt. Zircon U-Pb dating results show that these different types of granitoids were crystallized in the Triassic. The 247.5 Ma porphyritic granites from Zairiri (ZRR) displayed calc-alkaline I-type granite affinities, with the zircon εHf(t) values being mainly positive (−0.5 to + 3.8, TDM2 of 1309–1031 Ma), indicating that they are derived from the partial melting of the juvenile crust and mixed with ancient crustal components. The 236.8 Ma Henqionggou (HQG) granodiorites and 237.5 Ma Daheba (DHB) granodiorites are high-K calc-alkaline I-type granite, and both have mafic microgranular enclaves (MMEs), showing higher and more varied Mg# (39.73–62.73), combined with their negative Hf isotopes (εHf(t) = −2.6 to −1.6, TDM2 = 1430–1369 Ma), suggesting that their primary magmas were the products of partial melting of the Mesoproterozoic lower crust that mixed with mantle-derived rocks. The 236.4 Ma DHB porphyritic diorites showed characteristics of high-K calc-alkaline I-type granitoids, with moderate SiO2 contents, medium Mg# values (40.41–40.65), with the Hf isotopes (εHf(t) = −2.9 to −0.5; TDM2 = 1451–1298 Ma) indistinguishably relative to contemporaneous host granodiorites and MMEs. The petrographic and geochemical characteristics indicate that the porphyritic diorites are the product of well-mixed magma derived from the Mesoproterozoic lower crust and lithospheric mantle. Based on the results of this paper and previous data, the chronology framework of Late Permian–Triassic magmatic rocks in the eastern part of the East Kunlun Orogenic Belt was constructed, and the magmatic activities in this area were divided into three peak periods, with each peak representing an extensional event in a particular tectonic setting, for example, P1 (slab roll-back in subduction period; 254–246 Ma), P2 (slab break-off in transition period of subduction and collision; 244–232 Ma), P3 (delamination after collision; 230–218 Ma).

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D'Agrella-Filho, Manoel Souza, Franklin Bispo-Santos, Ricardo Ivan Ferreira Trindade, and Paul Yves Jean Antonio. "Paleomagnetism of the Amazonian Craton and its role in paleocontinents." Brazilian Journal of Geology 46, no. 2 (June 2016): 275–99. http://dx.doi.org/10.1590/2317-4889201620160055.

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ABSTRACT: In the last decade, the participation of the Amazonian Craton on Precambrian supercontinents has been clarified thanks to a wealth of new paleomagnetic data. Paleo to Mesoproterozoic paleomagnetic data favored that the Amazonian Craton joined the Columbia supercontinent at 1780 Ma ago, in a scenario that resembled the South AMerica and BAltica (SAMBA) configuration. Then, the mismatch of paleomagnetic poles within the Craton implied that either dextral transcurrent movements occurred between Guiana and Brazil-Central Shield after 1400 Ma or internal rotation movements of the Amazonia-West African block took place between 1780 and 1400 Ma. The presently available late-Mesoproterozoic paleomagnetic data are compatible with two different scenarios for the Amazonian Craton in the Rodinia supercontinent. The first one involves an oblique collision of the Amazonian Craton with Laurentia at 1200 Ma ago, starting at the present-day Texas location, followed by transcurrent movements, until the final collision of the Amazonian Craton with Baltica at ca. 1000 Ma. The second one requires drifting of the Amazonian Craton and Baltica away from the other components of Columbia after 1260 Ma, followed by clockwise rotation and collision of these blocks with Laurentia along Grenvillian Belt at 1000 Ma. Finally, although the time Amazonian Craton collided with the Central African block is yet very disputed, the few late Neoproterozoic/Cambrian paleomagnetic poles available for the Amazonian Craton, Laurentia and other West Gondwana blocks suggest that the Clymene Ocean separating these blocks has only closed at late Ediacaran to Cambrian times, after the Amazonian Craton rifted apart from Laurentia at ca. 570 Ma.

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Journal articles on the topic 'Palaeo- Mesoproterozoic'

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