| 1. |
- Gladkochub, Dmitry P., et al.
(author)
-
Proterozoic mafic magmatism in Siberian craton: An overview and implications for paleocontinental reconstruction
- 2010
-
In: Precambrian Research. - : Elsevier BV. - 0301-9268. ; 183:3, s. 660-668
-
Journal article (peer-reviewed)abstract
- We present a summary of late Paleoproterozoic to Neoproterozoic mafic magmatism in the Siberian craton, including recently published U-Pb and Ar-40-Ar-39 dates. These new precise ages suggest that at least some of the previously published K-Ar ages of Siberian mafic bodies should be ignored. The time-space geochronological chart, or the 'barcode' of mafic magmatic events shows significant differences between northern and southern Siberia. Both are characterized by similar to 1900-1700 Ma magmatic events, but then there was an almost 1 Ga mafic magmatic 'pause' in south Siberia until similar to 800 Ma. Meanwhile there are indications of multiple mafic magmatic events in North Siberia (Anabar shield and Olenek uplift) between similar to 1600 and 1000 Ma. A series of magmatic events probably related to the breakup of Rodinia occurred in southern Siberia after similar to 800 Ma. So far, there are no indications of late Neoproterozoic mafic magmatism in North Siberia. Ca. 1000-950 Ma mafic sills were reported from Meso- to Neo-Proterozoic sedimentary successions in the Sette-Daban area on the east side of the Siberian craton, but their tectonic setting is debated. Recent Ar-Ar dates of similar to 1750 Ma for NW-trending dykes in the Aldan and Anabar shields, together with similar-age NNE-trending Baikal uplift dykes in south-eastern Siberia suggest the existence of a giant radial dyke swarm possibly related to a mantle plume centred in the Vilyui River area. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 2. |
|
|
| 3. |
- Evans, David A.D., et al.
(author)
-
An expanding list of reliable paleomagnetic poles for Precambrian tectonic reconstructions
- 2021
-
In: Ancient Supercontinents and the Paleogeography of Earth. - : Elsevier. ; , s. 605-639
-
Book chapter (peer-reviewed)abstract
- We present a compilation of reliable Precambrian paleomagnetic poles from three successive international workshops (in years 2009, 2014, 2017), comprising paleomagnetists specializing in Precambrian tectonic reconstructions. The working groups compiled lists of two global classes of poles, published through the end of 2017. “Grade-A” results are judged to provide essential constraints on tectonic reconstructions; “Grade-B” poles are judged to be suggestive of high-quality, but not yet demonstrated to be primary, or perhaps lacking precise geochronologic or other constraints. Our catalog documents a resurgence of high-quality data acquisition in recent years, and highlights specific cratons and time intervals that are most lacking in the data needed to reconstruct those blocks through supercontinental cycles.
|
|
| 4. |
- Meert, Joseph G., et al.
(author)
-
The magnificent seven : A proposal for modest revision of the Van der Voo (1990) quality index
- 2020
-
In: Tectonophysics. - : Elsevier. - 0040-1951 .- 1879-3266. ; 790
-
Journal article (peer-reviewed)abstract
- Thirty years ago, Rob Van der Voo proposed an elegant and simple system for evaluating the quality of paleomagnetic data. As a second-year Ph.D. student, the lead author remembers Rob waxing philosophical about the need to have an appropriate, but not overly rigid evaluation system. The end result was a 7-point system that assigned a (1) or (0) for any paleomagnetic result based on objective criteria. The goal was never to reject or blindly accept any particular result, but merely to indicate the degree of quality for any paleomagnetic pole. At the time, the global paleomagnetic database was burgeoning and it was deemed useful to rank older paleomagnetic results with the newer data being developed in modern laboratories. Van der Voo's, 1990 paper launched a silent revolution in paleomagnetism. Researchers began to evaluate their data against those seven criteria with the anticipation that reviewers would be similarly critical.Today, paleomagnetism is a mature science. Our methods, analyses, and results are more sophisticated than they were 30 years ago. Therefore, we feel it is appropriate to revisit the Van der Voo (1990) criteria in light of those developments. We hope to honor the intention of the original paper by keeping the criteria simple and easy to evaluate while also acknowledging the advances in science. This paper aims to update the criteria and modernize the process. We base our changes on advances in paleomagnetism and geochronology with a faithful adherence to the simplicity of the original publication. We offer the “Reliability” or “R” index as the next generation of the Van der Voo “Quality” or “Q” index. The new R-criteria evaluate seven different information items for each paleomagnetic pole including age, statistical requirements, identification of magnetic carriers, field tests, structural integrity, presence of reversals and an evaluation for possible remagnetization.
|
|
| 5. |
- Pisarevsky, Sergei A., et al.
(author)
-
Palaeomagnetic, geochronological and geochemical study of Mesoproterozoic Lakhna Dykes in the Bastar Craton, India: Implications for the Mesoproterozoic supercontinent
- 2013
-
In: Lithos. - : Elsevier BV. - 0024-4937. ; 174, s. 125-143
-
Journal article (peer-reviewed)abstract
- Palaeomagnetic analysis of the Lakhna Dykes (Bastar Craton, India) yields a palaeopole at 36.6 degrees N, 132.8 degrees E, dp=12.4 degrees, dm=15.9 degrees, and the U-Pb zircon age obtained from one of the rhyolitic dykes is 1466.4 +/- 2.6 Ma (MSWD = 0.21, concordia age based on two analyses with identical Pb/U ages), similar to previously published U-Pb ages. Major and trace element analyses of the Lakhna Dykes show shoshonitic and high-K calc-alkaline affinities consistent with a subduction related characteristics suggesting an active continental margin setting. This is in keeping with the Palaeo- to Mesoproterozoic tectonic environments in the eastern Indian margin. The new 1460 Ma Indian palaeopole was used to test possible palaeopositions of India within the Mesoproterozoic supercontinent Columbia. Of the four palaeomagnetically permissible reconstructions, juxtaposing western India against south-west Baltica is geologically the most reliably constrained and best fitting model. Our preferred reconstruction implies a long Palaeo- to Mesoproterozoic accretionary orogen stretching from south-eastern Laurentia through south-western Baltica to south-eastern India. Breakup of India and Baltica probably occurred in the Late Mesoproterozoic, but additional constraints are needed. (C) 2012 Elsevier B.V. All rights reserved.
|
|
| 6. |
- Cederberg, Julia, et al.
(author)
-
U-Pb baddeleyite dating of the Proterozoic Pará de Minas dyke swarm in the São Francisco craton (Brazil) – implications for tectonic correlation with the Siberian, Congo and North China cratons
- 2016
-
In: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 138:1, s. 219-240
-
Journal article (peer-reviewed)abstract
- U–Pb baddeleyite ages demonstrate the presence of three dyke generations within the NW-trending Pará de Minas swarm (São Francisco craton, South America), dated at ca. 1795 Ma (1798 ± 4, 1791 ± 7 and 1793 ± 18 Ma), ca. 1710 Ma (1702 ± 13 and 1717 ± 11 Ma) and 766 ± 36 Ma. These ages have implications for the São Francisco-Congo (SF-Congo) craton within the Rodinia and Columbia supercontinent configurations. At 1795 Ma, the Rio de la Plata craton (1790 ± 5 Ma Uruguayan dykes), Amazonian craton (1790–1780 Ma Avanavero LIP), Sarmatia (1789 ± 3 Ma Tomashgorod dyke), North Australia (1790 ± 4 Ma Hart dolerites) and the North China craton (1790–1770 Ma Taihang-Xiong’er event) could potentially have been “next-door neighbours” to the SF-Congo craton. Possible matches at 1710 Ma are the 1750–1700 Ma Bilyakchan-Ulkan complex and coeval dykes in the Siberian craton and the 1730 Ma Miyun dyke swarm in NCC. Given large uncertainties, the 766 ± 36 Ma age may be compared with the age of the 790 Ma Niquelândia complex in adjacent Goias state, the 799 Ma Gannakouriep dykes in the Kalahari craton, the 780 Ma Gunbarrel LIP of western Laurentia, the 760 Ma Mount Rogers LIP of eastern Laurentia and the 755 Ma Mundine Well event (western Australia). We propose a reconstruction in which the SF-Congo is attached to North China and Siberia, which existed from 1790 to 1380 Ma when SF-Congo and North China broke away from Siberia, and until 930 Ma when North China separated from SF-Congo.
|
|
| 7. |
- Elming, Sten-åke, et al.
(author)
-
A palaeomagnetic and Ar-40/Ar-39 study of mafic dykes in southern Sweden: A new Early Neoproterozoic key-pole for the Baltic Shield and implications for Sveconorwegian and Grenville loops
- 2014
-
In: Precambrian Research. - : Elsevier BV. - 0301-9268 .- 1872-7433. ; 244, s. 192-206
-
Journal article (peer-reviewed)abstract
- We present the results of palaeomagnetic and Ar-40/Ar-39 studies of the Proterozoic mafic dykes in the Norrkoping and Falun areas of the southern Sweden. The primary remanence of two 939 +/- 3 Ma dykes is supported by the rigorous baked contact test. The remanence direction of two other dykes, one of which was previously U-Pb dated at 946 +/- 1 Ma is close to the reverse direction of 939 Ma dykes. Using these results together with previously published 935 +/- 5 Ma palaeomagnetic data from the Goteborg-Slussen mafic dykes and some dykes from the Falun area we calculated the mean 946-935 Ma palaeopole for Baltica (0.9 degrees S, 240.7 degrees E, A(95) = 6.7), which can be qualified as the key pole. Using this pole together with other date we conclude that the Grenville and Sveconorwegian loops of Laurentian and Baltican Apparent Polar Wander Paths are temporary displaced by 100-150 m.y. We propose new palaeogeographic reconstructions of Baltica and Laurentia at ca. 940 Ma and ca. 850 Ma. We also present two new Mesoproterozoic non-key poles from 1410 Ma and 1595 Ma dykes. 2014 Elsevier B.V. All rights reserved.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Pisarevsky, Sergei A., et al.
(author)
-
Mesoproterozoic paleogeography : Supercontinent and beyond
- 2014
-
In: Precambrian Research. - : Elsevier BV. - 0301-9268 .- 1872-7433. ; 244, s. 207-225
-
Journal article (peer-reviewed)abstract
- A set of global paleogeographic reconstructions for the 1770–1270 Ma time interval is presented here through a compilation of reliable paleomagnetic data (at the 2009 Nordic Paleomagnetic Workshop in Luleå, Sweden) and geological constraints. Although currently available paleomagnetic results do not rule out the possibility of the formation of a supercontinent as early as ca. 1750 Ma, our synthesis suggests that the supercontinent Nuna/Columbia was assembled by at least ca. 1650–1580 Ma through joining at least two stable continental landmasses formed by ca. 1.7 Ga: West Nuna (Laurentia, Baltica and possibly India) and East Nuna (North, West and South Australia, Mawson craton of Antarctica and North China). It is possible, but not convincingly proven, that Siberia and Congo/São Francisco were combined as a third rigid continental entity and collided with Nuna at ca.1500 Ma. Nuna is suggested to have broken up at ca. 1450–1380 Ma. West Nuna, Siberia and possibly Congo/São Francisco were rigidly connected until after 1270 Ma. East Nuna was deformed during the breakup, and North China separated from it. There is currently no strong evidence indicating that Amazonia, West Africa and Kalahari were parts of Nuna.
|
|
| 11. |
- Pisarevsky, Sergei A., et al.
(author)
-
Paleomagnetism and U-Pb age of the 2.4 Ga Erayinia mafic dykes in the south-western Yilgarn, Western Australia: Paleogeographic and geodynamic implications
- 2015
-
In: Precambrian Research. - : Elsevier BV. - 0301-9268. ; 259, s. 222-231
-
Journal article (peer-reviewed)abstract
- We present results from a paleomagnetic study of the previously undated Erayinia dykes intruding the south-western Yilgarn Craton. The U-Pb TIMs baddeleyite age of these dykes is now 2401 +/- 1 Ma, which is about 10 m.y. younger than the 2418-2410 Ma Widgiemooltha dyke swarm. The paleomagnetic study isolated a stable primary remanence with steep downward direction, and the paleomagnetic pole (22.7 degrees S. 150.5 degrees E, A(95) = 11.4 degrees) is similar, but not identical to that of the previously studied Widgiemooltha dykes. We interpret this difference as the result of the movement of the Yilgam Craton toward the pole at similar to 1 degrees/m.y. angular speed, which is comparable with tectonic plates' velocities during the Phanerozoic. Paleomagnetic polarities of Widgiemooltha and Erayinia dykes suggest that at least one geomagnetic reversal occurred between these two magmatic events. The estimated amplitude of geomagnetic secular variations at c. 2400 Ma is slightly higher than predicted by the existing models for the last 5 m.y. at the c. 64 degrees latitude. The paleomagnetic data and patterns of c. 2.6-2.1 Ga mafic dyke swarms permit the recently suggested reconstruction of the Paleoproterozoic supercontinent. (C) 2014 Elsevier B.V. All rights reserved.
|
|
| 12. |
- Pisarevsky, Sergei A., et al.
(author)
-
Preface
- 2015
-
In: Precambrian Research. - : Elsevier BV. - 0301-9268. ; 259, s. 1-4
-
Journal article (other academic/artistic)
|
|
