Late to Post-Orogenic Brasiliano-Pan-African Volcano-Sedimentary Basins in the Dom Feliciano Belt, Southernmost Brazil

Terrane provenance and amalgamation: examples from the Caledonides

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1990.0092 ◽

1990 ◽

Vol 331 (1620) ◽

pp. 599-609 ◽

Cited By ~ 13

Keyword(s):

Sedimentary Basins ◽

Fault Zones ◽

River Systems ◽

Pan African ◽

Basin Formation ◽

Laurentian Margin

The Scottish Caledonides have grown by the accretion of terranes generated somewhere along the Laurentian margin. By the time these terranes had been emplaced along the Scottish sector, they were structurally truncated then reassembled to form an incomplete collage of indirectly related tectonic elements of a destructive margin. The basement to some of these tectonic elements and the basement blocks belonging to the previously accreted Precambrian are of uncertain provenance and a source in the Pan-African craton is possible. As terranes migrate along the orogen they generate in the fault zones and on their periphery a reservoir of mature sediment. This mature sediment is produced because of the recycling produced during the generation and destruction of sedimentary basins developing during terrane translation. At each period of recycling the mature sediments are mixed with less mature sediments yielded from local uplifts generated by the new basin formation. If a large part of the orogen suffers orthogonal closure, giant river systems may form and disperse sediment across terranes. This is likely to have happened during the Devonian-Carboniferous of parts of N. Europe.

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New insights into the Gondwana breakup at the Southern South America by apatite fission-track analyses

Advances in Geosciences ◽

10.5194/adgeo-47-1-2019 ◽

2019 ◽

Vol 47 ◽

pp. 1-15 ◽

Cited By ~ 6

Author(s):

Cristiane H. Gomes ◽

Delia Almeida

Keyword(s):

Fission Track ◽

Shear Zones ◽

Temperature History ◽

Early Paleozoic ◽

Apatite Fission Track ◽

Pan African ◽

History Of ◽

Dom Feliciano Belt ◽

Eastern Domain ◽

Exhumation History

Abstract. Apatite fission-track (AFT) analyses, applied to Southern Brazil and Uruguay samples, was employed aiming to understand the low temperature history of the Dom Feliciano Belt Segment. The Dom Feliciano Belt formed during the Neoproterozoic to Early Paleozoic, linked to the Brasiliano/Pan-African Orogeny. Twenty-four samples were dated, and confined track lengths of twenty samples were measured. The spatial distribution of ages shows three domains with different evolution cut by shear zones and, or suture zones in the Dom Feliciano Belt. The Western Domain exhibits AFT ages > 250 Ma (Permian to Devonian) while the Eastern Domain shows AFT ages < 230 Ma (Paleogene to Triassic). In the Central Domain, the AFT ages range from ∼196 to 130 Ma (Jurassic to Early Cretaceous). The thermal modeling in the domains revealed a complex evolution, with cooling and reheating phases, and a denudation of ∼2600 m. The AFT ages clearly postdate the Gondwanide, Paraná-Etendeka and Rio Grande Cone exhumation history of the Dom Feliciano Belt.

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A review of the Pan-African evolution of the Arabian Shield

GeoArabia ◽

10.2113/geoarabia0701103 ◽

2002 ◽

Vol 7 (1) ◽

pp. 103-124 ◽

Cited By ~ 6

Author(s):

Pierre Nehlig ◽

Antonin Genna ◽

Fawzia Asfirane ◽

C. Guerrot ◽

J.M. Eberlé ◽

...

Keyword(s):

Structural Evolution ◽

Sedimentary Basins ◽

Fault Zones ◽

Fault System ◽

Arabian Shield ◽

Geologic History ◽

Lower Paleozoic ◽

The North ◽

Pan African ◽

History Of

ABSTRACT Recent fieldwork and the synthesis and reappraisal of aeromagnetic, geologic, structural, geochemical, and geochronologic data have provided a new perspective on the structural evolution and geologic history of the Arabian Shield. Although Paleoproterozoic rocks are present in the eastern part of the Shield, its geologic evolution was mainly concentrated in the period from 900 to 550 Ma during which the formation, amalgamation, and final Pan-African cratonization of several tectonostratigraphic terranes took place. The terranes are separated by major NW-trending faults and by N-, NW- and NE-oriented suture zones lined by serpentinized ultramafic rocks (ophiolites). Terrane analysis using the lithostratigraphy and geochronology of suture zones, fault zones, overlapping basins, and stitching plutons, has helped to constrain the geologic history of the Arabian Shield. Ophiolites and volcanic-arcs have been dated at between 900 and 680 Ma, with the southern terrane of Asir being older than the Midyan terrane in the north and the Ar Rayn terrane in the east. Final cratonization of the terranes between 680 and 610 Ma induced a network of anastomosing, strike-slip faults consisting of the N-trending Nabitah belt, the major NW-striking left-lateral transpressive faults (early Najd faults), lined by gneiss domes and associated with sedimentary basins, and N- to NE-trending right-lateral transpressive faults. Following the Pan-African cratonization, widespread alkaline granitization was contemporaneous with the deposition of the Jibalah volcanic and sedimentary rocks in transtensional pull-apart basins. Crustal thinning was governed by the Najd fault system of left-lateral transform faults that controlled the formation of the Jibalah basins and was synchronous with the emplacement of major E- to NW-trending dike swarms throughout the Arabian Shield. The extensional episode ended with a marine transgression in which carbonates were deposited in the Jibalah basins. Continuation of the thinning process may explain the subsequent deposition of the marine formations of the lower Paleozoic cover. Our interpretation of the distribution and chronology of orogenic zones does not correspond entirely to those proposed in earlier studies. In particular, the N-trending Nabitah and NW-trending Najd fault zones are shown to be part of the same history of oblique transpressional accretion rather than being two distinct events related to accretion and dispersion of the terranes.

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Magnetotelluric investigation of the Precambrian crust and intraplate Cenozoic volcanism in the Gour Oumelalen area, Central Hoggar, South Algeria

Geophysical Journal International ◽

10.1093/gji/ggaa432 ◽

2020 ◽

Vol 223 (3) ◽

pp. 1973-1986

Author(s):

Zakaria Boukhalfa ◽

Abderrezak Bouzid ◽

Yixian Xu ◽

Abderrahmane Bendaoud ◽

Bo Yang ◽

...

Keyword(s):

Cross Sections ◽

Lower Crust ◽

Broad Band ◽

Sedimentary Basins ◽

Shear Zones ◽

Mobile Belt ◽

Impedance Tensor ◽

Pan African ◽

Eastern Boundary ◽

Cenozoic Volcanism

SUMMARY The Tuareg Shield was assembled by oceanic closures and horizontal movements along mega-shear zones between approximately 20 terranes during the Pan-African Orogeny (750–550 Ma). Although there is an ongoing debate about its origin, the exhumation of the Tuareg Shield is assumed to be related to Cenozoic intraplate volcanism. The Gour Oumelalen is a key region of the Tuareg Shield and is located in the northeastern part of the Egéré-Aleksod terrane, corresponding to the eastern boundary of the Archean–Palaeoproterozoic microcontinent LATEA (Central Hoggar). The eastern boundary of the study area corresponds to a Neoproterozoic suture zone separating two old microcontinents, LATEA and the Orosirian Stripe. We deployed two magnetotelluric (MT) profiles consisting of 33 broad-band MT stations and combined these with aeromagnetic data, aiming to define the crustal structure in detail. The resistivity cross-sections obtained from the 3-D inversion of full impedance tensor and tipper data from stations along the profiles, confirm the main Precambrian faults, some of which are covered by Quaternary sediments and hence, have not yet been deciphered. The cross-sections also highlight the Cretaceous–Quaternary sedimentary basins represented by low resistivities. The upper crust is typically cratonic with a high electrical resistivity. On the contrary, the lower crust shows a drastic drop in resistivity (<10 Ωm). The most plausible hypothesis is that the study area corresponds to a Cretaceous rifting zone. The Cretaceous magmatic event and its related fluids and mineralization as well as the recent fluids associated with Cenozoic volcanism, are plausible causes of a very conductive lower crust. However, we cannot exclude other reasons such as: (i) a high-temperature and strongly sheared mobile belt or (ii) a contribution of inheritance involving Pan-African events that affected this former suture area.

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A possible model of the Paleozoic sedimentary basins evolution at the North African platform

Proceedings of higher educational establishments Geology and Exploration ◽

10.32454/0016-7762-2017-6-68-73 ◽

2017 ◽

pp. 68-73

Author(s):

M. Sh. Zamil

Keyword(s):

Sedimentary Basins ◽

Dual Model ◽

Magmatic Activity ◽

North African ◽

Early Precambrian ◽

Early Proterozoic ◽

Late Proterozoic ◽

The North ◽

Pan African

A dual model of the Paleozoic basins development, disposing on the Late Proterozoic (Pan-African) and the Early Proterozoic (Eburnean) crust, has been proposed. The formation of the first group basins is connected with the subsiding of the sections of the cooling gneissic-domes of«rejuvenated» (Early Precambrian but tectonically reworked at the end of the Proterozoic) Pan-African crust. Accordingly, the development of the second group basins is a result of the Precambrian deep sited (mantle) magmatic chambers cooling and subsiding together with the sites of the old lithosphere, covering them. The manifestation of the Vendian volcanic units on Anti-Atlas, Ugarta, Regibat-Eglab uplifts is the most possible evidence of the mantle magmatic activity, which could create those chambers.

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