Crustal evolution of the Paleoproterozoic Ubendian Belt (SW Tanzania) western margin: A Central African Shield amalgamation tale

Ganbat, Ariuntsetseg; Tsujimori, Tatsuki; Boniface, Nelson; Pastor‐Galán, Daniel; Aoki, Shogo; Aoki, Kazumasa

doi:10.1016/j.gr.2020.12.009

Cited by 25 publications

(13 citation statements)

References 118 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The geochronology, geochemistry, and metamorphic structure of the Ubendian Belt suggests that it formed in response to multiple episodes of wrench tectonic events (Theunissen et al, 1996) with phases of subduction extending from the Paleoproterozoic to the Neoproterozoic (Ganbat et al, 2021). The orogenic belt first developed during a phase of collisional orogeny along the SW margin of the Tanzanian Craton (ca 2.1-2.0 Ga), after which the belt experienced two episodes of wrench tectonics consisting of an initial phase of dextral strike-slip shear at ca.…”

Section: Geological Settingmentioning

confidence: 99%

“…More detailed petrographic and geochemical investigation of the eclogites reveal striking similarities with oceanic island-arc volcanic rocks . Geochronologic analyses indicate a clustering of Paleoproterozoic eclogites to the northern segment of the structure (near Lake Tanganyika) and Neoproterozoic eclogites to the south (e.g., Chisi area and northern Malawi) (Figure 1B), suggesting multiple cycles of subduction-related orogenic events along the structure Ganbat et al, 2021). Thus, the "Ikulu" domain was proposed to be the primary Late Proterozoic (Pan African Orogeny) suture zone between the Tanzania and Bangweulu Cratons along the Ubendian Belt .…”

Section: The Chisi Shear Zonementioning

confidence: 99%

See 1 more Smart Citation

Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift

Kolawole¹,

Phillips²,

Atekwana³

et al. 2021

Front. Earth Sci.

View full text Add to dashboard Cite

Little is known about rift kinematics and strain distribution during the earliest phase of extension due to the deep burial of the pre-rift and earliest rift structures beneath younger, rift-related deposits. Yet, this exact phase of basin development ultimately sets the stage for the location of continental plate divergence and breakup. Here, we investigate the structure and strain distribution in the multiphase Late Paleozoic-Cenozoic magma-poor Rukwa Rift, East Africa during the earliest phase of extension. We utilize aeromagnetic data that image the Precambrian Chisi Shear Zone (CSZ) and bounding terranes, and interpretations of 2-D seismic reflection data to show that, during the earliest rift phase (Permo-Triassic ‘Karoo’): 1) the rift was defined by the Lupa border fault, which exploited colinear basement terrane boundaries, and a prominent intra-basinal fault cluster (329° ± 9.6) that trends parallel to and whose location was controlled by the CSZ (326°); 2) extensional strain in the NW section of the rift was accommodated by both the intra-basinal fault cluster and the border fault, where the intra-basinal faulting account for up to 64% of extension; in the SE where the CSZ is absent, strain is primarily focused on the Lupa Fault. Here, the early-rift strain is thus, not accommodated only by border the fault as suggested by existing magma-poor early-rift models; instead, strain focuses relatively quickly on a large border fault and intra-basinal fault clusters that follow pre-existing intra-basement structures; 3) two styles of early-rift strain localization are evident, in which strain is localized onto a narrow discrete zone of basement weakness in the form of a large rift fault (Style-1 localization), and onto a broader discrete zone of basement weakness in the form of a fault cluster (Style-2 localization). We argue that the CSZ and adjacent terrane boundaries represent zones of mechanical weakness that controlled the first-order strain distribution and rift development during the earliest phase of extension. The established early-rift structure, modulated by structural inheritance, then persisted through the subsequent rift phases. The results of our study, in a juvenile and relatively well-exposed and data-rich rift, are applicable to understanding the structural evolution of deeper, buried ancient rifts.

show abstract

Section: Geological Settingmentioning

confidence: 99%

Section: The Chisi Shear Zonementioning

confidence: 99%

Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift

Kolawole¹,

Phillips²,

Atekwana³

et al. 2021

Front. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…. Besides, Zr as a stable element has an obvious linear correlation with REE (represented by Sm), HFSE (represented by Hf) and LILE (represented by Rb) (Figure 7), indicating that the lamprophyres are not affected by alteration (Ganbat et al, 2021). Therefore, we believe that the high LOI is the intrinsically trait of the lamprophyres, which does not affect the geochemical features of the lamprophyres.…”

Section: Discussionmentioning

confidence: 99%

Geochemistry and Sr–Nd isotopes of the Late Mesozoic lamprophyres in the Chaohu area, eastern China: Petrogenesis and tectonic implications

Chen

Kan

et al. 2022

Island Arc

View full text Add to dashboard Cite

Late Mesozoic lamprophyres are widespread in the Chaohu area of the Lower Yangtze region, eastern China. These mantle‐derived rocks are of great significance for understanding the characteristics of mantle source and tectonic environment of eastern China during the Late Mesozoic. The lamprophyres from the Chaohu area can be divided into two types. The type‐I lamprophyres have low SiO2 (43.8–44.5 wt.%) and TiO2 (1.06–1.14 wt.%), high MgO (13.5–17.5 wt.%) and high contents of compatible elements, and are enriched in LREE and LILE but depleted in HFSE. They have high initial 87Sr/86Sr (0.70767–0.70904) and negative εNd (t) (−4.8 to −4.4). The type‐II lamprophyres are characterized by low contents of SiO2 (43.0–45.4 wt.%), high TiO2 (1.74–2.55 wt.%), MgO (9.17–15.4 wt.%), and compatible elements. They are also enriched in LREE and LILE but depleted in HFSE. They show enriched Sr‐Nd isotopic compositions with initial 87Sr/86Sr values (0.70773–0.70886) and εNd (t) values (−8.6 to −7.8). The type‐I lamprophyres show higher Mg# and MgO contents but significant lower TiO2 than the type‐II lamprophyres. In addition, the type‐I lamprophyres have relatively similar initial 87Sr/86Sr ratios but higher εNd(t) values than the type‐II lamprophyres. The difference of geochemical characteristics between the type‐I and type‐II lamprophyres may be caused by different degrees of partial melting of an amphibole‐bearing garnet lherzolite mantle. The lithospheric mantle was metasomatised by the fluids caused by the rollback of the Paleo‐Pacific plate subduction during the Late Cretaceous.

show abstract

“…Detrital zircons from pelitic gneiss of the Tateyama area have a strong age peak at 1.8 Ga (Takahashi et al, 2018). Such Orosirian zircons are widespread in East Asian continental basements (e.g., Geng, 2015;Kim et al, 2020;Zhao & Zhai, 2013) as well as many continental shields as fragments of the Columbia/Nuna supercontinent (e.g., Ganbat et al, 2021). Moreover, Horie et al (2010Horie et al ( , 2018 reported Eoarchean-Paleoproterozoic inherited zircons in granitic rocks from the Unazuki "sub-belt.…”

Section: Geology Of the Hida Beltmentioning

confidence: 99%

The δ¹³C–δ¹⁸O variations in marble in the Hida Belt, Japan

et al. 2021

Self Cite

View full text Add to dashboard Cite

Marble has a great potential to understand a history of various geological events occurring during tectonic processes. In order to decode metamorphic-metasomatic records on C-O isotope compositions of marble at mid-crustal conditions, we conducted a C-O-Sr isotope study on upper amphibolite-facies marbles and a carbonate-silicate rock from the Hida Belt, which was once a part of the crustal basement of the East Asian continental margin. Carbon and oxygen isotope analyses of calcite from marbles (Kamioka area) and a carbonate-silicate rock (Wadagawa area) show a large variation of δ 13 C [VPDB] and δ 18 O [VSMOW] values (from −4.4 to +4.2 ‰ and +1.6 to +20.8 ‰, respectively). The low δ 13 C values of calcites from the carbonate-silicate rock (from −4.4 to −2.9 ‰) can be explained by decarbonation (CO 2 releasing) reactions; carbon-oxygen isotope modeling suggests that a decrease of δ 13 C strongly depends on the amount of silicate reacting with carbonates. The occurrence of metamorphic clinopyroxene in marbles indicates that all samples have been affected by decarbonation reactions. All δ 18 O values of calcites are remarkably lower than the marine-carbonate values. The large δ 18 O variation can be explained by the isotope exchange via interactions between marble, external fluids, and/or silicates. Remarkably low δ 18 O values of marbles that are lower than mantle value (+5 ‰) suggest the interaction with meteoric water at a later stage. Sr isotope ratios ( 87 Sr/ 86 Sr = 0.707255-0.708220) might be close to their protolith values.One zircon associated with wollastonite in a marble thin-section yields a U-Pb age of 222 ± 3 Ma, which represents the timing of the recrystallization of marble, triggered by H 2 O-rich fluid infiltration at a relatively high-temperature condition. Our isotope study implies that the upper amphibolite-facies condition, like the Hida Belt, might be appropriate to cause decarbonation reactions which can modify original isotope compositions of marble if carbonates react with silicates.

show abstract

Crustal evolution of the Paleoproterozoic Ubendian Belt (SW Tanzania) western margin: A Central African Shield amalgamation tale

Cited by 25 publications

References 118 publications

Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift

Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift

Geochemistry and Sr–Nd isotopes of the Late Mesozoic lamprophyres in the Chaohu area, eastern China: Petrogenesis and tectonic implications

The δ¹³C–δ¹⁸O variations in marble in the Hida Belt, Japan

Contact Info

Product

Resources

About

Crustal evolution of the Paleoproterozoic Ubendian Belt (SW Tanzania) western margin: A Central African Shield amalgamation tale

Cited by 25 publications

References 118 publications

Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift

Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift

Geochemistry and Sr–Nd isotopes of the Late Mesozoic lamprophyres in the Chaohu area, eastern China: Petrogenesis and tectonic implications

The δ13C–δ18O variations in marble in the Hida Belt, Japan

Contact Info

Product

Resources

About

The δ¹³C–δ¹⁸O variations in marble in the Hida Belt, Japan