scholarly journals Tectonic History of the South Tannuol Fault Zone (Tuva Region of the Northern Central Asian Orogenic Belt, Russia): Constraints from Multi-Method Geochronology

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 56
Author(s):  
Evgeny Vetrov ◽  
Johan De Grave ◽  
Natalia Vetrova ◽  
Fedor Zhimulev ◽  
Simon Nachtergaele ◽  
...  
Keyword(s):  
Fault Zone ◽  
Volcanic Rocks ◽  
The South ◽  
Mafic Rocks ◽  
Tectonic History ◽  
Central Asian ◽  
Igneous Provinces ◽  
Late Neogene ◽  
History Of ◽  
Felsic Volcanic

In this study, we present zircon U/Pb, plagioclase and K-feldspar 40Ar/39Ar and apatite fission track (AFT) data along the South Tannuol Fault Zone (STFZ). Integrating geochronology and multi-method thermochronology places constraints on the formation and subsequent reactivation of the STFZ. Cambrian (~510 Ma) zircon U/Pb ages obtained for felsic volcanic rocks date the final stage of STFZ basement formation. Ordovician (~460–450 Ma) zircon U/Pb ages were obtained for felsic rocks along the structure, dating their emplacement and marking post-formational local magmatic activity along the STFZ. 40Ar/39Ar stepwise heating plateau-ages (~410–400 Ma, ~365 and ~340 Ma) reveal Early Devonian and Late Devonian–Mississippian intrusion and/or post-magmatic cooling episodes of mafic rocks in the basement. Permian (~290 Ma) zircon U/Pb age of mafic rocks documents for the first time Permian magmatism in the study area creating prerequisites for revising the spread of Permian large igneous provinces of Central Asia. The AFT dating and Thermal history modeling based on the AFT data reveals two intracontinental tectonic reactivation episodes of the STFZ: (1) a period of Cretaceous–Eocene (~100–40 Ma) reactivation and (2) the late Neogene (from ~10 Ma onwards) impulse after a period of tectonic stability during the Eocene–Miocene (~40–10 Ma).

Deposition and imbrication of a 2670-2629 Ma supracrustal sequence in the Indin Lake area, southwestern Slave Province, Canada

1999 ◽  
Vol 36 (7) ◽  
pp. 1149-1168 ◽  
Author(s):  
S J Pehrsson ◽  
M E Villeneuve
Keyword(s):  
Volcanic Rocks ◽  
Lake Area ◽  
Regional Deformation ◽  
Tectonic History ◽  
Slave Province ◽  
Gneiss Complex ◽  
Supracrustal Belt ◽  
History Of ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks

New U-Pb age data from the southwestern Slave Province demonstrate that units of the Indin Lake supracrustal belt form an imbricated structural stack. The oldest rocks of the belt are undated mafic volcanic flows of the Hewitt Lake group that are crosscut by a 2670 Ma felsic sill, itself coeval with mafic through felsic volcanic rocks of the 2668-2671 Ma Leta Arm group. The youngest rocks of the belt are 2647-2629 Ma turbidites and felsic volcanic rocks of the unconformably overlying Chalco Lake group. Tonalite orthogneiss of the adjacent Cotterill gneiss complex is 2680 Ma, suggesting that it does not represent in situ basement to the supracrustal belt. Intercalation of the older Hewitt Lake and Leta Arm groups with the younger Chalco Lake group is interpreted to result from D1 imbrication and folding between 2629 and 2609 Ma, the age of a crosscutting tonalite intrusion. Subsequent D2 folding and regional low-pressure metamorphism occurred between 2609 Ma and ca. 2590 Ma. D3 normal faulting between the belt and Cotterill gneisses, ca. 2590 Ma, is interpreted to overlap with retrograde amphibolite-facies metamorphism and decompression of the gneiss complex. Comparisons between the tectonic history of the Indin Lake area and the central Slave Province show that turbidite deposition was regionally diachronous and overlapped with regional deformation elsewhere, supporting existing models favouring some form of accretionary orogenesis. The imbricated and intercalated 2670-2629 Ma supracrustal sequence may characterize a distinct crustal block in the southwestern Slave Province.

Tectono-stratigraphic evolution of the Early Proterozoic Wisconsin magmatic terranes of the Penokean Orogen

1989 ◽  
Vol 26 (10) ◽  
pp. 2145-2158 ◽  
Author(s):  
P. K. Sims ◽  
W. R. Van Schmus ◽  
K. J. Schulz ◽  
Z. E. Peterman
Keyword(s):  
Subduction Zone ◽  
Continental Margin ◽  
Volcanic Rocks ◽  
Alkali Feldspar ◽  
Suture Zone ◽  
Island Arcs ◽  
Calc Alkaline ◽  
The South ◽  
Early Proterozoic ◽  
Felsic Volcanic

The Early Proterozoic Penokean Orogen developed along the southern margin of the Archean Superior craton. The orogen consists of a northern deformed continental margin prism overlying an Archean basement and a southern assemblage of oceanic arcs, the Wisconsin magmatic terranes. The south-dipping Niagara fault (suture) zone separates the south-facing continental margin from the accreted arc terranes. The suture zone contains a dismembered ophiolite.The Wisconsin magmatic terranes consist of two terranes that are distinguished on the basis of lithology and structure. The northern Pembine–Wausau terrane contains a major succession of tholeiitic and calc-alkaline volcanic rocks deposited in the interval 1860–1889 Ma and a more restricted succession of calc-alkaline volcanic rocks deposited about 1835 – 1845 Ma. Granitoid rocks ranging in age from about 1870 to 1760 Ma intrude the volcanic rocks. The older succession was generated as island arcs and (or) closed back-arc basins above the south-dipping subduction zone (Niagara fault zone), whereas the younger one developed as island arcs above a north-dipping subduction zone, the Eau Pleine shear zone. The northward subduction followed deformation related to arc–continent collision at the Niagara suture at about 1860 Ma. The southern Marshfield terrane contains remnants of mafic to felsic volcanic rocks about 1860 Ma that were deposited on Archean gneiss basement, foliated tonalite to granite bodies ranging in age from about 1890 to 1870 Ma, and younger undated granite plutons. Following amalgamation of the two arc terranes along the Eau Pleine suture at about 1840 Ma, intraplate magmatism (1835 Ma) produced rhyolite and anorogenic alkali-feldspar granite that straddled the internal suture.

Contributions to thermo-tectonic history of the Rio Grande Rise (South Atlantic Ocean) as revealed by apatite (U-Th-Sm)/He thermochronology

2020 ◽  
Author(s):  
Peter Christian Hackspacher ◽  
Bruno Venancio da Silva ◽  
Ulrich Anton Glasmacher ◽  
Gustavo Soldado Peres
Keyword(s):  
Atlantic Ocean ◽  
Rio Grande ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
The South ◽  
South American Plate ◽  
Tectonic History ◽  
Tectonically Active ◽  
History Of ◽  
Uplift And Erosion

<p>The Rio Grande Rise (RGR) consists of an aseismic, basaltic plateau currently submerged in the southwestern side of the South Atlantic Ocean. Its origin is still a matter of considerable debate, ranging from a microcontinent formed by fragmentation of the South American plate (1) to a basaltic ridge formed by expressive intra-plate magmatism triggered by the arrival of the Tristan da Cunha plume in the Cretaceous (2). The western portion of the RGR (WRGR) is crossed by a major rift-like structure known as the Cruzeiro do Sul Lineament (CSL) interpreted as tectonically active mainly from Upper Cretaceous to Middle Eocene (3). So far, understanding the development of the CSL is central to deciphering the thermo-tectonic history of the RGR with implications for the understanding of opening of the South Atlantic Ocean and the evolution of associated lithospheric plate margins. For this purpose, basaltic rocks from the northern and southern flanks of the CSL dredged during the Rio Grande Rise Project expedition (PROERG) carried out by the Geological Survey of Brazil (CPRM) were analysed for apatite (U-Th-Sm)/He (AHe) thermochronology. Thermal histories for these rocks (time-temperature paths) were obtained by the QTQt software (4). Single-grain AHe ages vary from ~ 5 to 65 Ma and the thermal histories indicate a phase of cooling at the southern flank in the Eocene, and three phases of cooling at the northern flank: in the Eocene, Miocene, and Pliocene, respectively. Based on published seismic and stratigraphic data (3,5,6), the Eocene cooling is mainly interpreted in terms of magmatic cooling and basement uplift and erosion, whereas the Miocene and the Pliocene cooling probably reflect tectonic driven basement uplift and erosion. The preliminary AHe data suggest that the CSL was tectonically active at least until the Pliocene. Plumes evolution also must be considered to explain these reactivations and uplifts.  </p><p> </p><ol><li>Kumar, N., 1979. Origin of “paired” aseismic rises: Ceará and Sierra Leone rises in the equatorial, and the Rio Grande Rise and Walvis Ridge in the South Atlantic. Mar. Geol. 30, 175–191. https://doi.org/10.1016/0025-3227(79)90014-8</li> <li>O’Connor, J.M., Duncan, R.A., 1990. Evolution of the Walvis Ridge-Rio Grande Rise Hot Spot System: Implications for African and South American Plate motions over plumes. J. Geophys. Res. 95, 17475. https://doi.org/10.1029/JB095iB11p17475</li> <li>Praxedes AGP, Castro DL, Torres LC, et al., 2019. New insights of the tectonic and sedimentary evolution of the Rio Grande Rise, South Atlantic Ocean. Marine and Petroleum Geology. https://doi.org/10.1016/j.marpetgeo.2019.07.035</li> <li>Gallagher K., 2012. Transdimensional inverse thermal history modeling for quantitative thermochronology. Journal of Geophysical Research: Solid Earth 117:1–16. https://doi.org/10.1029/2011JB008825</li> <li>Barker, P.F., 1983. Tectonic evolution and subsidence history of the Rio Grande Rise. In: Barker, P.F., Carlson, R.L., et al. (Eds.), Initial Reports of the Deep Sea Drilling Project, vol 72. US Government Printing Office, Washington, DC, pp. 953-976.</li> </ol><p>6. Mohriak, W.U., Nobrega, M., Odegard, M.E., Gomes, B.S., Dickson, W.G., 2010. Geological and geophysical interpretation of the Rio Grande Rise, south-eastern Brazilian margin: extensional tectonics and rifting of continental and oceanic crusts. Pet. Geosci. 16, 231–245. https://doi.org/10.1144/1354-079309-910</p>

Origin of the Piché Structural Complex and implications for the early evolution of the Archean crustal-scale Cadillac – Larder Lake Fault Zone, Canada

2018 ◽  
Vol 55 (8) ◽  
pp. 905-922 ◽  
Author(s):  
Pierre Bedeaux ◽  
Lucie Mathieu ◽  
Pierre Pilote ◽  
Silvain Rafini ◽  
Réal Daigneault
Keyword(s):  
Fault Zone ◽  
Cross Sections ◽  
Volcanic Rocks ◽  
Sedimentary Basins ◽  
Drill Hole ◽  
Gold Deposits ◽  
Ductile Deformation ◽  
Chemical Compositions ◽  
Abitibi Subprovince ◽  
Felsic Volcanic

The Piché Structural Complex (PSC) extends over 150 km within the Cadillac – Larder Lake Fault Zone (CLLFZ), a gold-endowed, east-trending, and high-strain corridor located along the southern edge of the Archean Abitibi Subprovince. The PSC consists of discontinuous units of volcanic rocks (<1 km thick) that host multiple gold deposits. It is spatially associated with molasse-type Timiskaming sedimentary basins. This study describes and interprets the origin of structures and lithologies within the poorly understood PSC to unravel the tectonic evolution of the CLLFZ. Field mapping, chemical analyses, as well as interpretations of cross-sections from drill-hole data, were used to interpret the geometry and structure of the PSC. The PSC is subdivided into six homogeneous fault-bounded segments or slivers. These slivers consist mostly of ultramafic to intermediate volcanic rocks and include some felsic volcanic flows and intrusions. Volcanic facies, chemical compositions, and isotopic ages confirm that these slivers are derived from the early volcanic units of the southern Abitibi greenstone belt, which are located north of the CLLFZ. Cross-cutting relationships between volcanic rocks of the PSC and the Timiskaming-aged intrusions suggest that the slivers were inserted into the CLLFZ during the early stages of the accretion-related deformation (<2686 Ma) and prior to Timiskaming sedimentation and ductile deformation (>2676 Ma). The abundant ultramafic rocks located within the CLLFZ may have focused strain, thereby facilitating the nucleation of the fault as well as the displacements along this crustal-scale structure.

Faulting of a Middle Jurassic, ultramafic dyke in the Picton Quarry, Picton, southern Ontario

1990 ◽  
Vol 27 (11) ◽  
pp. 1536-1540 ◽  
Author(s):  
G. H. McFall
Keyword(s):  
Fault Zone ◽  
Middle Jurassic ◽  
Southern Ontario ◽  
Prince Edward County ◽  
Dyke Rock ◽  
Tectonic History ◽  
History Of ◽  
East West

A fault zone coinciding with a Middle Jurassic, ultramafic dyke exposed in the Picton Quarry in Prince Edward County, Ontario, is marked by steeply dipping, generally east–west-striking fractures. The dyke has been affected by faulting, as evidenced by the presence of subhorizontal slickensides on fractures cutting the dyke rock. This discovery constitutes the first known example of Middle Jurassic or younger faulting having affected Paleozoic strata of southern Ontario and indicates that the structural and tectonic history of the region is more complex than commonly believed.

scholarly journals Zur Tal- und Reliefgeschichte des Churfirsten-Alvier-Gebietes (Kanton St. Gallen)

1987 ◽  
Vol 42 (2) ◽  
pp. 159-168
Author(s):  
R. Hantke
Keyword(s):  
Southern Slope ◽  
The South ◽  
Helvetic Nappes ◽  
Early Stages ◽  
Tectonic History ◽  
Early Tertiary ◽  
History Of

Abstract. The valley and relief history of the Churfirsten-Alvier ränge (Ct. St. Gallen): Valley formation in the Churfirsten-Alvier range, between the Linth and Rhine rivers. began at the end of the Miocene with the tectonic history of the Helvetic nappes. In early stages. the Cretaceaous sequences became independent of their Jurassic substratums and these from their Verrucano-Tnassic basement. The valley of Lake Walenstadt in the south was initiated between this basement and north-moving younger sequences. The Thur valley, north of the Churfirsten range, which follows a syncline in the highest Helvetic nappe. was filled with early Tertiary Sediments and Pennine Flysch. The Valleys in the Alvier area are formed along synclmes and faults in the Cretaceous sequence; these structures dip towards the Rhme valley. The Churfirsten range forms a limestone shield in the Helvetic nappe. It broke up foUowing ±N/S-onented joints. There inbetween, excavation of kars (cirques) began already during pre-Ouaternary glaciation; they are still intact at the ends of the ränge, but in the middle the kar-walls broke down along the steeper southern slope. During the Mindel and Riss glaciations. no Rhine ice flowed through the saddles between the Churfirsten peaks into the Thur valley; however, this could have been possible in pre- Mindelian cold periods at high ice levels and still lower moun¬ tain relief.

Sign in / Sign up

Export Citation Format

Share Document