scholarly journals Enlargement of the area of the Timpton Large Igneous Province (ca. 1.75 ga) of the Siberian craton

2019 ◽  
Vol 10 (4) ◽  
pp. 829-839
Author(s):  
D. P. Gladkochub ◽  
T. V. Donskaya ◽  
R. E. Ernst ◽  
U. Söderlund ◽  
A. M. Mazukabzov ◽  
...  

We present new geochronological data on dolerites from the Chaya dyke swarm of the Baikal inlier of the Siberian craton. The U‐Pb dating of baddeleyite from one dyke located at the SW end of the Chaya dyke swarm yielded an age of 1752±6 Ma, similar to the previously obtained age of a dyke in the NE end of this swarm. These ages estab‐ lish an age of 1752 Ma for a unified Chaya dyke swarm that extends for more than 200 km in the Baikal inlier of the Siberian craton. These new data confirm that the entire Chaya dyke swarm (as well as the Timpton‐Algamay and Eastern Anabar swarms) is a part of an overall radiating dyke swarm belonging to the Late Paleoproterozoic Timpton Large Igneous Province (LIP), the center of which is located in the middle section of the Vilyuy river flow. Thus, the LIP is enlarged to include the area further west in the Siberian craton.

2019 ◽  
Vol 486 (3) ◽  
pp. 326-330
Author(s):  
D. P. Gladkochub ◽  
T. V. Donskaya ◽  
R. E. Ernst ◽  
M. A. Hamilton ◽  
A. M. Mazukabzov ◽  
...  

On the basis of U-Pb dating of zircon and baddeleyite from gabbro-dolerite of the Goloustnaya dyke swarm (southern margin of the Siberian Craton), the age of basites was established as 1338.0 ± 2.9 Ma. It is shown that the basite intrusions of close ages from the Goloustnaya and Listvyanka areas (southern Siberian Craton) and Victoria Island (northern Laurentia, Barking Dog complex) could have been formed under the influence of the same mantle plume and belong to the same Large Igneous Province of Ectasian (Middle Mesoproterozoic) age.


2009 ◽  
Vol 46 (3) ◽  
pp. 155-167 ◽  
Author(s):  
Steven W. Denyszyn ◽  
Don W. Davis ◽  
Henry C. Halls

The north–south-trending Clarence Head dyke swarm, located on Devon and Ellesmere Islands in the Canadian High Arctic, has a trend orthogonal to that of the Neoproterozoic Franklin swarm that surrounds it. The Clarence Head dykes are dated by the U–Pb method on baddeleyite to between 716 ± 1 and 713 ± 1 Ma, ages apparently younger than, but within the published age range of, the Franklin dykes. Alpha recoil in baddeleyite is considered as a possible explanation for the difference in ages, but a comparison of the U–Pb ages of grains of equal size from both swarms suggests that recoil distances in baddeleyite are lower than those in zircon and that the Clarence Head dykes are indeed a distinctly younger event within the period of Franklin magmatism. The Clarence Head dykes represent a large swarm tangential to, and cogenetic with, a giant radiating dyke swarm ∼800 km from the indicated source. The preferred mechanism for the emplacement of the Clarence Head dykes is the exploitation of concentric zones of extension around a depleting and collapsing plume source. While the paleomagnetism of most Clarence Head dykes agrees with that of the Franklin dykes, two dykes have anomalous remanence directions, interpreted to be a chemical remanent magnetization carried by pyrrhotite. The pyrrhotite was likely deposited from fluids mobilized southward from the Devonian Ellesmerian Orogeny to the north that used the interiors of the dykes as conduits and precipitated pyrrhotite en route.


Lithos ◽  
2008 ◽  
Vol 101 (3-4) ◽  
pp. 260-280 ◽  
Author(s):  
Peng Peng ◽  
Mingguo Zhai ◽  
Richard E. Ernst ◽  
Jinghui Guo ◽  
Fu Liu ◽  
...  

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 545 ◽  
Author(s):  
T. Donskaya ◽  
D. Gladkochub ◽  
R. Ernst ◽  
S. Pisarevsky ◽  
A. Mazukabzov ◽  
...  

We present new geochemical and Nd isotopic data on two Mesoproterozoic Listvyanka (1350 ± 6 Ma) and Goloustnaya (1338 ± 3 Ma) mafic dyke swarms located in the Irkutsk Promontory of the southern part of the Siberian craton. Listvyanka dykes are sub-vertical with NNE trend, while Goloustnaya dykes are characterized by prevailing W trend. Listvyanka and Goloustnaya dykes are composed of medium to coarse grained dolerites. All dolerites correspond to sub-alkaline tholeiitic basalts according to their major-element compositions with lower to moderate mg#, varying from 36 to 54. The trace and rare earth element abundances in Listvyanka and Goloustnaya dolerites are generally close to basalts of the oceanic island basalts (OIB) type. The Listvyanka dolerites demonstrate slightly positive εNd(t) values varying from +1.1 to +1.5, while the Goloustnaya dolerites are characterized by lower εNd(t) values ranging from −0.9 to +0.1. Geochemical and isotopic affinities of the Listvyanka dolerites suggest their enrichment by a mantle plume related source. For the Goloustnaya dolerites, we assume also some additional lithospheric input to their mantle plume-related source. The emplacement of both studied dolerites took place in intracontinental extensional setting, caused by a single rising mantle plume. Listvyanka and Goloustnaya dolerites are coeval to several mafic magmatic events in northern Laurentia and likely represent part of the Mesoproterozoic plumbing system of a Siberian–Laurentian Large Igneous Province.


2009 ◽  
Vol 73 (2) ◽  
pp. 206-226 ◽  
Author(s):  
T. R. Riley ◽  
M. L. Curtis ◽  
P. T. Leat ◽  
I. L. Millar

AbstractJurassic dykes of western Dronning Maud Land (Antarctica) form a minor component of the Karoo large igneous province. An extensive local dyke swarm intrudes Neoproterozoic gneisses and Jurassic syenite plutons on the margins of the Jutulstraumen palaeo rift in the Svedrupfjella region. The dykes were intruded in three distinct episodes (~204, ~176 and ~170 Ma). The 204 Ma dykes are overwhelminglylow-Ti, olivine tholeiites including some primitive (picritic) compositions (MgO >12 wt.%; Fe2O3 >12 wt.%; Cr >1000 ppm; Ni >600 ppm). This 204 Ma event precedes the main Karoo volcanic event by~25 Ma, so anycorrelations to the wider province are difficult to make. However, it mayrecord the earliest phase of rift activity along the Jutulstraumen. The 176 Ma dyke event is more intimately associated with the two syenite plutons. The dykes are alkaline (basanite/ tephrite) and were small-degree melts from an enriched, locallyderived source and underwent at least some degree of interaction with a syenitic contaminant. This ~176 Ma dyke event is widespread elsewhere in the Karoo (southern Africa and Dronning Maud Land). Later-stage (170 Ma) felsic (phonolite–comendite) dykes intrude the 176 Ma basanite–tephrite suite and represent the last phase of magmatic activityin the region.


Geology ◽  
2021 ◽  
Author(s):  
Cedric Djeutchou ◽  
Michiel O. de Kock ◽  
Hervé Wabo ◽  
Camilo E. Gaitán ◽  
Ulf Söderlund ◽  
...  

The 1.87–1.84 Ga Black Hills dike swarm of the Kalahari craton (South Africa) is coeval with several regional magmatic provinces used here to resolve the craton’s position during Columbia assembly. We report a new 1850 ± 4 Ma (U-Pb isotope dilution–thermal ionization mass spectrometry [ID-TIMS] on baddeleyite) crystallization age for one dike and new paleomagnetic data for 34 dikes of which 8 have precise U-Pb ages. Results are constrained by positive baked-contact and reversal tests, which combined with existing data produce a 1.87–1.84 Ga mean pole from 63 individual dikes. By integrating paleomagnetic and geochronological data sets, we calculate poles for three magmatic episodes and produce a magnetostratigraphic record. At 1.88 Ga, the Kalahari craton is reconstructed next to the Superior craton so that their ca. 2.0 Ga poles align. As such, magmatism forms part of a radiating pattern with the coeval ca. 1.88 Ga Circum-Superior large igneous province.


2021 ◽  
Author(s):  
Johanna Salminen

<p>Currently three supercontinent cycles have been identified and existed supercontinents named from youngest to oldest: Pangea, Rodinia and Nuna/Columbia. Recently Wang et al. (2020) suggested that supercontinent amalgamation were each preceded by ~200 Myr by the assembly of long-lasting <em>megacontinent</em> aking to Gondwana.</p><p>The Congo-São Francisco (C/SF) craton is a main building block in Gondwana due to its central location, but its participation to Rodinia is controversial. Salminen et al. (2018) presented 1.11 Ga paleomagnetic and geochronological data from a prominent Epembe-Huila swarm of gabbronoritic dykes in the southern part of the Congo craton in Namibia and in Angola. This paleomagnetic pole yields a relatively low paleolatitude for the C/SF craton at ca. 1.11 Ga and permits a direct connection between Congo and Kalahari cratons. This connection supports an earlier qualitative comparison (Ernst et al., 2013), that the mafic Epembe-Huila swarm was an integral component of the Umkondo Large Igneous Province (LIP). The 1.11 Ga Umkondo LIP is widespread across Kalahari craton, and coeval mafic magmatism has been identified in several of the world’s other late Mesoproterozoic cratons: Laurentia, India, Amazonia, and Antarctica (Grunehogna). Were these coeval provinces spatially linked at the time of emplacement during the amalgamation of Rodinia? Robust paleomagnetic and geochronological data from Laurentia and Kalahari have demonstrated substantial separation between those two blocks at 1.11 Ga (Swanson-Hysell et al., 2015). However, based on similar tholeiitic magmatism Choudhary et al. (2019) proposed that Kalahari and C/SF together with Amazonia and northern India constituted “Umkondia” at 1.11 Ga. It has been proposed that Umkondia occupied an intermediary “megacontinental” role in the Nuna-Rodinia transition analogous to Gondwana in Rodinia-Pangea evolution (Wang et al., 2020). Contradicting Gondwana the proposed Umkondia was not long-lasting, since it has been proposed that Kalahari and Congo separated after 1.10 Ga to form a vast ocean (ca. 6000 km) during the formation of Rodinia and widespread juvenile intra-oceanic magmatism along the present-day central Brazil indicates a large ca. 0.94 Ga ocean between C/SF and Amazonia (Cordani et al., 2003).</p><p> </p><p>Choudhary et al. 2019. Precambrian Research 332, 105382.</p><p>Cordani et al. 2003. Gondwana Research 6, 275-283.</p><p>Ernst et al. 2003. Lithos 174 1-14.</p><p>Salminen et al. 2018. Geology 46, 1011-1014.</p><p>Swanson-Hysell et al. 2015. Geophysical Journal International 203, 2237-2247.</p><p>Wang et al. 2020. Geology 49, https://doi.org/10.1130/G47988.1</p><p> </p>


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