• dr hab. Ashley Gumsley
Position: adiunkt
Unit: Wydział Nauk Przyrodniczych
Adress: 41-200 Sosnowiec, ul. Będzińska 60
Floor: XII
Room: 1221
Phone: (32) 3689 418
E-mail: ashley.gumsley@us.edu.pl
Publications list: Publications by CINiBA
Publications list: Publications by OPUS
Scopus Author ID: 55319071400
Publications from the Scopus database
2024
Gumsley, A.; Słaby, E.; Dey, S.; Chew, D.; Gmochowska, W.; Wudarska, A.; Gumsley, A. P.; Szopa, K.; Krzykawski, T.; Marciniak-Maliszewska, B.; Drakou, F.
The evolution of Archean crust undisturbed for three billion years: A case study from the Bahalda Pluton, Singhbhum Craton, eastern India Journal Article
In: Precambrian Research, vol. 406, 2024, ISSN: 03019268.
@article{2-s2.0-85189797583,
title = {The evolution of Archean crust undisturbed for three billion years: A case study from the Bahalda Pluton, Singhbhum Craton, eastern India},
author = { A. Gumsley and E. Słaby and S. Dey and D. Chew and W. Gmochowska and A. Wudarska and A.P. Gumsley and K. Szopa and T. Krzykawski and B. Marciniak-Maliszewska and F. Drakou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85189797583&doi=10.1016%2fj.precamres.2024.107385&partnerID=40&md5=687787a56ef1d505f72773d12d7906f0},
doi = {10.1016/j.precamres.2024.107385},
issn = {03019268},
year = {2024},
date = {2024-01-01},
journal = {Precambrian Research},
volume = {406},
publisher = {Elsevier B.V.},
abstract = {The Archean Bahalda Pluton (Singhbhum Craton; eastern India) is an I-type mafic granodiorite, surrounded by Paleoarchean TTG and TTG-derived granites of the Singhbhum Suite. The Singhbhum Suite is highly unusual amongst Eo- and Paleo-Archean terranes because most of the Singhbhum Craton escaped post-Archean deformation and metamorphism. The Bahalda granodiorite contains accessory zircon, titanite, and fluorapatite, which are rarely studied together but are a powerful tool for exploring magmatic and post-magmatic processes. U-Pb zircon and titanite dating indicate a ca. 3.35 Ga emplacement age of the Bahalda granodiorite. Subsequent ca. 3.27–3.05 Ga U-Pb fluorapatite ages are interpreted as recording low-grade metamorphic or hydrothermal event(s). The Bahalda fluorapatite and titanite are LREE-enriched compared to the HREE. The complex zonation of fluorapatite suggests that primary igneous fluorapatite was recrystallised with the removal of REE and overgrown by REE-depleted rims. This is in agreement with the apatite trace element systematics which imply fluorapatite cores are of mafic I-type granitoid affinity, with rims of low- and medium-grade metamorphic / metasomatic affinity. No textural evidence of titanite alteration was detected, but some domains have minor REE depletion compared to crystal interiors. The titanite and fluorapatite data display similar trends in LREE vs Sr/Y space due to metamorphic/hydrothermal alteration. The evolution of the Bahalda Pluton, which did not exceed greenschist facies for 3 Gyr, invites comparison with other stabilized cratons from the Mesoarchean. © 2024},
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Gumsley, A. P.; Kock, M. O. De; Ernst, R. E.; Gumsley, A.; Hanson, R.; Kamo, S. L.; Knoper, M. W.; Lewandowski, M.; Luks, B.; Mamuse, A.; Söderlund, U.
The Mutare–Fingeren dyke swarm: the enigma of the Kalahari Craton’s exit from supercontinent Rodinia Journal Article
In: Geological Society Special Publication, vol. 537, pp. 359-380, 2024, ISSN: 03058719, (2).
@article{2-s2.0-85177566674,
title = {The Mutare–Fingeren dyke swarm: the enigma of the Kalahari Craton’s exit from supercontinent Rodinia},
author = { A.P. Gumsley and M.O. De Kock and R.E. Ernst and A. Gumsley and R. Hanson and S.L. Kamo and M.W. Knoper and M. Lewandowski and B. Luks and A. Mamuse and U. Söderlund},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85177566674&doi=10.1144%2fSP537-2022-206&partnerID=40&md5=c4e62b9025ad2895773946377bf87214},
doi = {10.1144/SP537-2022-206},
issn = {03058719},
year = {2024},
date = {2024-01-01},
journal = {Geological Society Special Publication},
volume = {537},
pages = {359-380},
publisher = {Geological Society of London},
abstract = {The Rodinia supercontinent broke apart during the Neoproterozoic. Rodinia break-up is associated with widespread intraplate magmatism on many cratons, including the c. 720–719 Ma Franklin large igneous province (LIP) of Laurentia. Coeval magmatism has also been identified recently in Siberia and South China. This extensive magmatism terminates ∼1 myr before the onset of the Sturtian Snowball Earth. However, LIP-scale magmatism and global glaciation are probably related. U–Pb isotope dilution–thermal ionization mass spectrometry (ID-TIMS) baddeleyite dating herein identifies remnants of a new c. 724–712 Ma LIP on the eastern Kalahari Craton in southern Africa and East Antarctica: the combined Mutare–Fingeren Dyke Swarm. This dyke swarm occurs in northeastern Zimbabwe (Mutare Dyke Swarm) and western Dronning Maud Land (Fin-geren Dyke Swarm). It has incompatible element-enriched mid-ocean ridge basalt-like geochemistry, suggest-ing an asthenospheric mantle source for the LIP. The Mutare–Fingeren LIP probably formed during rifting. This rifting would have occurred almost ∼100 myr earlier than previous estimates in eastern Kalahari. The placement of Kalahari against southeastern Laurentia in Rodinia is also questioned. Proposed alternatives, invoking link-ing terranes between Kalahari and southwestern Laurentia or close to northwestern Laurentia, also present chal-lenges with no discernible resolution. Nevertheless, LIP-scale magmatism being responsible for the Sturtian Snowball Earth significantly increases. © 2023 The Author(s).},
note = {2},
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2023
Senger, M. H.; Davies, J. H.; Ovtcharova, M.; Beukes, N. J.; Gumsley, A. P.; Gaynor, S. P.; Ulianov, A.; Ngobeli, R.; Schaltegger, U.
Improving the chronostratigraphic framework of the Transvaal Supergroup (South Africa) through in-situ and high-precision U-Pb geochronology Journal Article
In: Precambrian Research, vol. 392, 2023, ISSN: 03019268, (1).
@article{2-s2.0-85159468680,
title = {Improving the chronostratigraphic framework of the Transvaal Supergroup (South Africa) through in-situ and high-precision U-Pb geochronology},
author = { M.H. Senger and J.H. Davies and M. Ovtcharova and N.J. Beukes and A.P. Gumsley and S.P. Gaynor and A. Ulianov and R. Ngobeli and U. Schaltegger},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85159468680&doi=10.1016%2fj.precamres.2023.107070&partnerID=40&md5=0ccfcf45c136f01ab98483c42d1946de},
doi = {10.1016/j.precamres.2023.107070},
issn = {03019268},
year = {2023},
date = {2023-01-01},
journal = {Precambrian Research},
volume = {392},
publisher = {Elsevier B.V.},
abstract = {The Transvaal Supergroup, on the Kaapvaal Craton in South Africa, is widely accepted as one of the best-preserved sedimentary archives to constrain planetary-scale environmental changes during the late Archean and early Proterozoic, yet the sedimentation age for certain stratigraphic intervals remains poorly constrained. To improve the temporal control on some of the first-order global changes recorded in these rocks, we carried out U-Pb analyses of detrital zircon populations from several clastic and volcano-clastic sedimentary units of the Transvaal Supergroup. We applied the Chemical Abrasion-Isotope Dilution-Thermal Ionization Mass Spectrometry (CA-ID-TIMS) technique on detrital and volcanic zircon populations that had been previously screened using the Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) technique. We report new maximum depositional age estimates for the Pannetjie (2456.6 ± 7.0 Ma), the Heynskop (2451.5 ± 2.5 Ma), the Makganyene (2423.1 ± 1.0 Ma) and the Hekpoort formations (2248.0 ± 1.1 Ma). A ca. 2.25 Ga-old cluster of LA-ICP-MS analyses in the Makganyene Formation was identified to be spurious, since it was completely removed during the chemical abrasion. Thus, we speculate that circulation of hydrothermal fluids and associated Pb-loss from a radiation-damaged lattice during the emplacement of the much younger Hekpoort Formation or possibly the Ophthalmia Orogeny, recorded in Western Australia, may have reset the U-Pb system of this zircon population. This implies that the accurate maximum depositional age of the Makganyene Formation is ca. 2.42 Ga instead, which denotes the age of the oldest glacial event of global extent during the Paleoproterozoic. Therefore, we suggest that the combination of both dating techniques is essential to ensure accurate maximum depositional age constraints for ancient detrital sedimentary rocks. Additionally, our data provides temporal constraints on a period characterized by major fluctuations in atmospheric oxygen. Finally, and supporting the complex nature of the Paleoproterozoic, linkages between widespread glaciations and atmospheric oxygen fluctuations remain to be explored. © 2023 The Authors},
note = {1},
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Ncube, S.; Wabo, H.; Owen-Smith, T. M.; Gumsley, A. P.; Beukes, N. J.
The Puduhush gabbro in Griqualand West, South Africa: extending ca. 1.89 to 1.83 Ga intraplate magmatism across the proto-Kalahari Craton Journal Article
In: South African Journal of Geology, vol. 126, no. 1, pp. 75-92, 2023, ISSN: 10120750.
@article{2-s2.0-85164140411,
title = {The Puduhush gabbro in Griqualand West, South Africa: extending ca. 1.89 to 1.83 Ga intraplate magmatism across the proto-Kalahari Craton},
author = { S. Ncube and H. Wabo and T.M. Owen-Smith and A.P. Gumsley and N.J. Beukes},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85164140411&doi=10.25131%2fsajg.126.0006&partnerID=40&md5=db2aab3ecf29901fb6bc28d5e3b67883},
doi = {10.25131/sajg.126.0006},
issn = {10120750},
year = {2023},
date = {2023-01-01},
journal = {South African Journal of Geology},
volume = {126},
number = {1},
pages = {75-92},
publisher = {Geological Society of South Africa},
abstract = {The Puduhush gabbro is located on the western margin of the proto-Kalahari Craton in Southern Africa. This gabbro intrudes the Volop Formation, which conformably overlies the Hartley Formation lava of the late Palaeoproterozoic Olifantshoek Group. Here we report a new U-Pb ID-TIMS baddeleyite age as well as petrographic, whole-rock geochemical and palaeomagnetic results for the Puduhush gabbro. The gabbro shows a well-preserved sub-ophitic texture between clinopyroxene and plagioclase, with minor amounts of amphibole, olivine, biotite and Fe-Ti oxides. The new U-Pb ID-TIMS baddeleyite age of 1 881 ± 1 Ma reported here for the Puduhush gabbro, together with existing ages for the Hartley Formation, define a ca.1 916 to 1 881 Ma age bracket for the Volop Formation. Our 1 881 ± 1 Ma age is also within error of ages reported for the oldest episode (so-called Episode 1) of the ca.1.89 to 1.83 Ga magmatism in the eastern and northern parts of the proto-Kalahari Craton. Our geochemical results also suggest compositional similarities between the Puduhush gabbro and Episode 1 magmatism, particularly the post-Waterberg sills. The virtual geomagnetic pole calculated here for the Puduhush gabbro (VGP: 1.6°N; 352.0°E; A95 = 14.2°) is consistent with the Episode 1 pole. All data are therefore combined to produce a new palaeomagnetic pole (11.7°N; 8.8°E; A95 = 9.3°) for Episode 1 magmatism. The present study provides the first evidence that the ca.1.89 to 1.83 Ga magmatism had a wider footprint that previously thought, extending to the western margin of the proto-Kalahari Craton. This wide-scale magmatism, previously proposed to be related to a back-arc extension setting, is here re-interpreted in the context of a mantle plume. Our results are consistent with the lithostratigraphic-based notion that at least parts of the red-bed successions (i.e.; Olifantshoek and Waterberg Groups) that are hosts to the ca.1.89 to 1.83 Ga magmatism could be correlative units, representing an extensive sedimentary sequence that once covered large expanses of the proto-Kalahari Craton. © 2023 Geological Society of South Africa. All rights reserved.},
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}
2022
Sałacińska, A.; Gerdjikov, I.; Kounov, A.; Chew, D.; Szopa, K.; Gumsley, A. P.; Kocjan, I.; Marciniak-Maliszewska, B.; Drakou, F.
In: Gondwana Research, vol. 109, pp. 253-273, 2022, ISSN: 1342937X, (5).
@article{2-s2.0-85130200700,
title = {Variscan magmatic evolution of the Strandja Zone (Southeast Bulgaria and northwest Turkey) and its relationship to other north Gondwanan margin terranes},
author = { A. Sałacińska and I. Gerdjikov and A. Kounov and D. Chew and K. Szopa and A.P. Gumsley and I. Kocjan and B. Marciniak-Maliszewska and F. Drakou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130200700&doi=10.1016%2fj.gr.2022.04.013&partnerID=40&md5=962e8d9b524bf404aeea23955b64735f},
doi = {10.1016/j.gr.2022.04.013},
issn = {1342937X},
year = {2022},
date = {2022-01-01},
journal = {Gondwana Research},
volume = {109},
pages = {253-273},
publisher = {Elsevier Inc.},
abstract = {The Strandja Zone, straddling the border between Bulgaria and Turkey, is often assigned to either the Balkanide or the Pontide thrust belts of the Alpine orogen in the Black Sea region. Previous studies have considered this zone, which originated on the North Gondwanan margin, as part of a Late Carboniferous to Triassic magmatic arc associated with the subduction of the Paleo-Tethys Ocean beneath Eurasia. Magmatism has been regarded as representing one continuous or two separate stages occurring under different tectonic settings. We present new LA-ICP-MS U-Pb zircon ages together with field, petrographic and geochemical studies of variably deformed granites from the Sakar Batholith and Levka Pluton of the Sakar Unit in the Strandja Zone. The new U-Pb ages from Sakar Batholith (ca. 306 Ma) and Levka Pluton (ca. 319 Ma) demand a re-evaluation of previously published U-Pb crystallisation ages from these magmatic bodies. The U-Pb age reported for the Levka Pluton also provides an upper age limit for the timing of Variscan metamorphism. The Late Carboniferous to Early Permian magmatic evolution of the Strandja Zone displays a strong resemblance to that of the Sredna Gora Zone. Both units, probably together with Serbo-Macedonian Metamorphic Complex and Sakarya Zone, were part of the metamorphic core of the Variscan Orogen. © 2022 The Authors},
note = {5},
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pubstate = {published},
tppubtype = {article}
}
Lempart-Drozd, M.; Błachowski, A.; Gumsley, A. P.; Ciesielska, Z.
Thermal decomposition of minnesotaite and dehydrogenation during Fe2+ oxidation, with implications for redox reactions in Banded Iron Formations Journal Article
In: Chemical Geology, vol. 601, 2022, ISSN: 00092541, (1).
@article{2-s2.0-85129692690,
title = {Thermal decomposition of minnesotaite and dehydrogenation during Fe2+ oxidation, with implications for redox reactions in Banded Iron Formations},
author = { M. Lempart-Drozd and A. Błachowski and A.P. Gumsley and Z. Ciesielska},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129692690&doi=10.1016%2fj.chemgeo.2022.120867&partnerID=40&md5=c9597e6fa15d062f34ee1dfcc7fca39d},
doi = {10.1016/j.chemgeo.2022.120867},
issn = {00092541},
year = {2022},
date = {2022-01-01},
journal = {Chemical Geology},
volume = {601},
publisher = {Elsevier B.V.},
abstract = {The study of the thermal decomposition of Fe2+-phyllosilicates and –silicates plays a crucial role in understanding the redox processes contributing to the global iron and hydrological cycles. In contrast to the widely accepted model of oxidation by incorporation of oxygen, Fe2+ oxidation of phyllosilicates and silicates studied under laboratory conditions is driven by a thermally induced dehydrogenation reaction, which proceeds as follows: Fe2+ + OH- → Fe3+ + Or2- + ½ H2↑. The processes of oxidation in Banded Iron Formation (BIF), both before and after the Great Oxidation Event, are debated between biotic and abiotic, and/or primary and secondary oxidation. Most BIFs have undergone various grades of metamorphism, including thermal events that support secondary oxidation and which control redox conditions. Here, Fe2+-rich minnesotaite, (Fe2+Mg)3Si4O10(OH)3, a common Fe2+-silicate occurring in BIFs, from an unaltered and unoxidized unit of the Biwabik Iron Formation (Minnesota; USA), was selected to study dehydrogenation as a potential secondary oxidation reaction of Fe-silicates in BIFs. The sample was heated thermogravimetrically (TG) under dynamic and isothermal conditions up to 1050 °C in dry N2 and synthetic air. Volatiles that evolved during heating were measured by a quadrupole mass spectrometer. The transitional and final heating products were examined by Mössbauer spectroscopy and X-ray powder diffraction (XRD). During the dynamic and isothermal heating, under inert and oxidizing atmospheric conditions, the minnesotaite structure underwent two reactions: dehydroxylation and oxidative dehydrogenation, producing H2O and H2 gas, respectively. Under dynamic heating in dry N2, dehydrogenation resulted in oxidation of ~16% of Fe2+ and ~0.09 wt.% H2 liberation. However, heating at 300, 350 and 400 °C for 48–80 hours in an inert atmosphere enhanced the progress of the reaction leading to the complete substitution of OH-Fe2+ by O-Fe3+, before dehydroxylation. When the sample was heated in synthetic air, despite high oxygen activity, oxidation by dehydrogenation occurredand the liberation of H2 in the presence of oxygen produced an excess of H2O at the sample surface. Dehydrogenation led to the formation of oxyminnesotaite, which is depleted in OH-, that showed greater thermal stability than Fe2+–minnesotaite. The final alteration products of minnesotaite (at 700–1050 °C) were hematite and maghemite when fully dehydrogenated in the presence of oxygen and ferric pyroxene and magnetite when the structure was partially dehydrogenated in the absence of oxygen. In this study, the mechanism of thermally induced oxidation of minnesotaite was thoroughly described and refers to the state of knowledge of thermal decomposition of other Fe-silicates and -phyllosilicates for the first time. Our results, together with other comprehensive studies regarding dehydrogenation, allows for a critical discussion of the reaction as one of the potential process of abiotic, secondary oxidation of Fe2+–silicates in BIFs to take place. A theoretical model of a dehydration sequence of minnesotaite during prograde metamorphism is proposed in the context of co-occurring dehydrogenation. A high Fe3+/Fet ratio corresponding to low OH/H2O content is diagnostic for dehydrogenated minerals; hence methodological and geological implementation may indicate and trace the reaction in geological environments. © 2022 Elsevier B.V.},
note = {1},
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pubstate = {published},
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2021
Sałacińska, A.; Gerdjikov, I.; Gumsley, A. P.; Szopa, K.; Chew, D.; Gawęda, A.; Kocjan, I.
Two stages of Late Carboniferous to Triassic magmatism in the Strandja Zone of Bulgaria and Turkey Journal Article
In: Geological Magazine, vol. 158, no. 12, pp. 2151-2164, 2021, ISSN: 00167568, (2).
@article{2-s2.0-85111029040,
title = {Two stages of Late Carboniferous to Triassic magmatism in the Strandja Zone of Bulgaria and Turkey},
author = { A. Sałacińska and I. Gerdjikov and A.P. Gumsley and K. Szopa and D. Chew and A. Gawęda and I. Kocjan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111029040&doi=10.1017%2fS0016756821000650&partnerID=40&md5=471c5bcc488234b3535f3dbe80c8a3f6},
doi = {10.1017/S0016756821000650},
issn = {00167568},
year = {2021},
date = {2021-01-01},
journal = {Geological Magazine},
volume = {158},
number = {12},
pages = {2151-2164},
publisher = {Cambridge University Press},
abstract = {Although Variscan terranes have been documented from the Balkans to the Caucasus, the southeastern portion of the Variscan Belt is not well understood. The Strandja Zone along the border between Bulgaria and Turkey encompasses one such terrane linking the Balkanides and the Pontides. However, the evolution of this terrane, and the Late Carboniferous to Triassic granitoids within it, is poorly resolved. Here we present laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) U-Pb zircon ages, coupled with petrography and geochemistry from the Izvorovo Pluton within the Sakar Unit (Strandja Zone). This pluton is composed of variably metamorphosed and deformed granites which yield crystallization ages of c. 251-256 Ma. These ages are older than the previously assumed age of the Izvorovo Pluton based on a postulated genetic relationship between the Izvorovo Pluton and Late Jurassic to Early Cretaceous metamorphism. A better understanding of units across the Strandja Zone can now be achieved, revealing two age groups of plutons within it. An extensive magmatic episode occurred c. 312-295 Ma, and a longer-lived episode between c. 275 and 230 Ma. Intrusions associated with both magmatic events were emplaced into pre-Late Carboniferous basement, and were overprinted by Early Alpine metamorphism and deformation. These two stages of magmatism can likely be attributed to changes in tectonic setting in the Strandja Zone. Such a change in tectonic setting is likely related to the collision between Gondwana-derived terranes and Laurussia, followed by either subduction of the Palaeo-Tethys Ocean beneath Laurussia or rifting in the southern margin of Laurussia, with granitoids forming in different tectonic environments. ©},
note = {2},
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Djeutchou, C.; Kock, M. O. De; Wabo, H.; Gaitán, C. E.; Söderlund, U.; Gumsley, A. P.
Late Paleoproterozoic mafic magmatism and the Kalahari craton during Columbia assembly Journal Article
In: Geology, vol. 49, no. 11, pp. 1375-1380, 2021, ISSN: 00917613, (1).
@article{2-s2.0-85118656332,
title = {Late Paleoproterozoic mafic magmatism and the Kalahari craton during Columbia assembly},
author = { C. Djeutchou and M.O. De Kock and H. Wabo and C.E. Gaitán and U. Söderlund and A.P. Gumsley},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118656332&doi=10.1130%2fG48811.1&partnerID=40&md5=f9012415c7128a9fca34dd740782becd},
doi = {10.1130/G48811.1},
issn = {00917613},
year = {2021},
date = {2021-01-01},
journal = {Geology},
volume = {49},
number = {11},
pages = {1375-1380},
publisher = {Geological Society of America},
abstract = {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 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license},
note = {1},
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pubstate = {published},
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Pandey, O. P.; Mezger, K.; Upadhyay, D.; Paul, D.; Singh, A. K.; Söderlund, U.; Gumsley, A. P.
Major-trace element and Sr-Nd isotope compositions of mafic dykes of the Singhbhum Craton: Insights into evolution of the lithospheric mantle Journal Article
In: Lithos, vol. 382-383, 2021, ISSN: 00244937, (9).
@article{2-s2.0-85098960491,
title = {Major-trace element and Sr-Nd isotope compositions of mafic dykes of the Singhbhum Craton: Insights into evolution of the lithospheric mantle},
author = { O.P. Pandey and K. Mezger and D. Upadhyay and D. Paul and A.K. Singh and U. Söderlund and A.P. Gumsley},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098960491&doi=10.1016%2fj.lithos.2020.105959&partnerID=40&md5=a535f92dcf2754c8a202646f9494e59f},
doi = {10.1016/j.lithos.2020.105959},
issn = {00244937},
year = {2021},
date = {2021-01-01},
journal = {Lithos},
volume = {382-383},
publisher = {Elsevier B.V.},
abstract = {The Singhbhum Craton in eastern India is host to at least seven sets of mafic dyke swarms. Four previously dated swarms (studied here) include the NNE-trending Keshargaria (ca. 2.80 Ga) and Ghatgaon (ca. 2.76 - 2.75 Ga) swarms, the ENE-trending Kaptipada swarm (ca. 2.26 Ga), and the ESE-trending Pipilia swarm (ca.1.76 Ga). The dykes range in composition from basalt to andesite and have transitional tholeiitic to calc-alkaline affinities. They show intra- and inter-swarm geochemical and Sr-Nd isotopic heterogeneities and have SiO2 content ranging from 47 to 60 wt.%. The chondrite normalized REE patterns show enrichment in LREE and the Primitive-Mantle normalized multi-element patterns show elevated U, Th, Cs, Rb, K, and Pb; and depletion in Nb, Ta, and Ti. These characteristics indicate involvement of crustal component in the petrogenesis of these dykes. The dykes of different swarms have variable 87Sr/86Sri and εNd(i) values, which define a crust-like isotopic growth trajectory with time from a common chondritic to depleted source that was enriched contemporaneously with the formation of the crustal rocks of the Singhbhum Craton. The isotope data indicate involvement of older enriched crustal material in the petrogenesis of these dykes. Variable but mostly high (compared to similarly evolved magmas) Ni (40 - 590 ppm), Cr (40 - 1110 ppm), and V (120 - 434 ppm) contents particularly of the most primitive dykes indicate that parental melts were in equilibrium with mantle peridotite and experienced only minor fractional crystallization of olivine, pyroxene, and magnetite. The Sr-Nd isotope ratios do not show any correlation with differentiation indices which indicates that the melts were not modified significantly by crustal assimilation during ascent and emplacement. The crust-like secular trend of the Sr and Nd isotopic compositions suggests that the enriched crustal material was incubated in the mantle (i.e.; metasomatized lithospheric mantle) for a long time and this source was periodically tapped leading to multiple dyke emplacement events over at least 1 Gyr. The recycled crustal material played a role in metasomatizing the subcontinental lithospheric mantle prior to ca. 2.80 Ga. Mantle plume activity triggered melting of the metasomatized lithospheric mantle many times, leading to the emplacement of mafic dykes of different generations across the craton. © 2020 The Author(s)},
note = {9},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2020
Gumsley, A. P.; Stamsnijder, J.; Larsson, E. R.; Söderlund, U.; Naeraa, T.; Kock, M. O. De; Sałacińska, A.; Gawęda, A.; Humbert, F.; Ernst, R. E.
In: Bulletin of the Geological Society of America, vol. 132, no. 9-10, pp. 1829-1844, 2020, ISSN: 00167606, (27).
@article{2-s2.0-85082011023,
title = {Neoarchean large igneous provinces on the Kaapvaal Craton in southern Africa re-define the formation of the Ventersdorp Supergroup and its temporal equivalents},
author = { A.P. Gumsley and J. Stamsnijder and E.R. Larsson and U. Söderlund and T. Naeraa and M.O. De Kock and A. Sałacińska and A. Gawęda and F. Humbert and R.E. Ernst},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082011023&doi=10.1130%2fB35237.1&partnerID=40&md5=2ed39d0db711af749679673ccdfca3c7},
doi = {10.1130/B35237.1},
issn = {00167606},
year = {2020},
date = {2020-01-01},
journal = {Bulletin of the Geological Society of America},
volume = {132},
number = {9-10},
pages = {1829-1844},
publisher = {Geological Society of America},
abstract = {U-Pb geochronology on baddeleyite is a powerful technique that can be applied effectively to chronostratigraphy. In southern Africa, the Kaapvaal Craton hosts a well-preserved Mesoarchean to Paleoproterozoic geological record, including the Neoarchean Ventersdorp Supergroup. It overlies the Witwatersrand Supergroup and its world-class gold deposits. The Ventersdorp Supergroup comprises the Klipriviersberg Group, Platberg Group, and Pniel Group. However, the exact timing of formation of the Ventersdorp Supergroup is controversial. Here we present 2789 ± 4 Ma and 2787 ± 2 Ma U-Pb isotope dilution- thermal ionization mass spectrometry (ID-TIMS) baddeleyite ages and geochemistry on mafic sills intruding the Witwatersrand Supergroup, and we interpret these sills as feeders to the overlying Klipriviersberg Group flood basalts. This constrains the age of the Witwatersrand Supergroup and gold mineralization to at least ca. 2.79 Ga. We also report 2729 ± 5 Ma and 2724 ± 7 Ma U-Pb ID-TIMS baddeleyite ages and geochemistry from a mafic sill intruding the Pongola Supergroup and on an east-northeast-trending mafic dike, respectively. These new ages distinguish two of the Ventersdorp Supergroup magmatic events: the Klipriviersberg and Platberg. The Ventersdorp Supergroup can now be shown to initiate and terminate with two large igneous provinces (LIPs), the Klipriviersberg and Allanridge, which are separated by Platberg volcanism and sedimentation. The age of the Klipriviersberg LIP is 2791-2779 Ma, and Platberg volcanism occurred at 2754-2709 Ma. The Allanridge LIP occurred between 2709-2683 Ma. Klipriviersberg, Platberg, and Allanridge magmatism may be genetically related to mantle plume(s). Higher heat flow and crustal melting resulted as a mantle plume impinged below the Kaapvaal Craton lithosphere, and this was associated with rifting and the formation of LIPs. © 2019 Geological Society of America.},
note = {27},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gumsley, A. P.; Manby, G.; Domańska-Siuda, J.; Nejbert, K.; Michalski, K.
In: Precambrian Research, vol. 341, 2020, ISSN: 03019268, (7).
@article{2-s2.0-85079902810,
title = {Caught between two continents: First identification of the Ediacaran Central Iapetus Magmatic Province in Western Svalbard with palaeogeographic implications during final Rodinia breakup},
author = { A.P. Gumsley and G. Manby and J. Domańska-Siuda and K. Nejbert and K. Michalski},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85079902810&doi=10.1016%2fj.precamres.2020.105622&partnerID=40&md5=5ef3d4530e2d2dd8f1a5ec14c0fea954},
doi = {10.1016/j.precamres.2020.105622},
issn = {03019268},
year = {2020},
date = {2020-01-01},
journal = {Precambrian Research},
volume = {341},
publisher = {Elsevier B.V.},
abstract = {The final fragmentation of Rodinia occurred during the Ediacaran period as the continental blocks of Baltica and Laurentia, as well as Amazonia and West Africa, rifted and drifted apart. It was along this progressively rifted margin that the Iapetus Ocean opened and subsequently closed, creating the Caledonian orogeny (sensu lato), some 100 and 200 million years later. The 0.62–0.54 Ga Central Iapetus Magmatic Province (CIMP), accompanying this break-up, is variously manifested in northern Europe and north-eastern North America as mafic dykes and sills, volcanic rocks, as well as carbonatites. This magmatism is interpreted to be broadly coincident with the so-called Marinoan and Gaskiers glaciations, and the subsequent evolution of metazoans. While the various Precambrian basement blocks of Svalbard are known to carry a Caledonian overprint, the proximity of various parts of Svalbard to either Baltica or Laurentia during final Rodinia breakup in the Ediacaran has yet to be established. Petrographic, geochronological and geochemical data from the variably deformed and metamorphosed coarse-grained mafic units of Oscar II Land (OIIL) from Spitsbergen, Svalbard, are presented here to determine the source of the magma and to elucidate on their palaeogeographic affinity with adjacent crustal blocks/units. An alkali and OIB-like affinity of the mafic units is confirmed by their whole-rock geochemical composition. An ID-TIMS U-Pb baddeleyite crystallisation age determination of 560 ± 12 Ma, obtained from one such mafic unit, contrasts with the published Caledonian (sensu lato) age determinations. These data for OIIL compare well with the broadly coeval and geochemically similar 570–560 Ma Norwegian Seiland Igneous Province, which may have formed a part of Baltica. Temporally and compositionally similar mafic units also occur within the North American Appalachian Belt, as well as the Sept-Îles intrusion, which is part of Laurentia. However, any links between these intrusions with those of Svalbard are yet to be unequivocally demonstrated. © 2020 The Authors},
note = {7},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Szopa, K.; Sałacińska, A.; Gumsley, A. P.; Chew, D.; Petrov, P.; Gawęda, A.; Zagórska, A.; Deput, E.; Gospodinov, N.; Banasik, K.
Two‐stage late jurassic to early cretaceous hydrothermal activity in the sakar unit of southeastern bulgaria Journal Article
In: Minerals, vol. 10, no. 3, 2020, ISSN: 2075163X, (8).
@article{2-s2.0-85082117169,
title = {Two‐stage late jurassic to early cretaceous hydrothermal activity in the sakar unit of southeastern bulgaria},
author = { K. Szopa and A. Sałacińska and A.P. Gumsley and D. Chew and P. Petrov and A. Gawęda and A. Zagórska and E. Deput and N. Gospodinov and K. Banasik},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082117169&doi=10.3390%2fmin10030266&partnerID=40&md5=c1031e19ad2e90069967da74468af388},
doi = {10.3390/min10030266},
issn = {2075163X},
year = {2020},
date = {2020-01-01},
journal = {Minerals},
volume = {10},
number = {3},
publisher = {MDPI AG},
abstract = {Southeastern Bulgaria is composed of a variety of rocks from pre‐Variscan (ca. 0.3 Ga) to pre‐Alpine sensu lato (ca. 0.15 Ga) time. The Sakar Unit in this region comprises a series of granitoids and gneisses formed or metamorphosed during these events. It is cut by a series of post‐Variscan hydrothermal veins, yet lacks pervasive Alpine deformation. It thus represents a key unit for detecting potential tectonism associated with the enigmatic Cimmerian Orogenic episode, but limited geochronology has been undertaken on this unit. Here we report age constraints on hydrothermal activity in the Sakar Pluton. The investigated veins contain mainly albite–actinolite– chlorite–apatite–titanite–quartz–tourmaline–epidote and accessory minerals. The most common accessory minerals are rutile and molybdenite. Apatite and titanite from the same vein were dated by U–Pb LA–ICP‐MS geochronology. These dates are interpreted as crystallization ages and are 149 ± 7 Ma on apatite and 114 ± 1 Ma on titanite, respectively. These crystallization ages are the first to document two stages of hydrothermal activity during the late Jurassic to early Cretaceous, using U– Pb geochronology, and its association with the Cimmerian orogenesis. The Cimmerian tectonothermal episode is well‐documented further to the east in the Eastern Strandja Massif granitoids. However, these are the first documented ages from the western parts of the Strandja Massif, in the Sakar Unit. These ages also temporally overlap with previously published Ar–Ar and K–Ar cooling ages, and firmly establish that the Cimmerian orogeny in the studied area included both tectonic and hydrothermal activity. Such hydrothermal activity likely accounted for the intense albitization found in the Sakar Unit. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.},
note = {8},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2019
Kock, M. O. De; Gumsley, A. P.; Klausen, M. B.; Söderlund, U.; Djeutchou, C.
In: pp. 155-214, Springer, 2019, ISSN: 21979545, (11).
@inbook{2-s2.0-85068005832,
title = {The precambrian mafic magmatic record, including large igneous provinces of the kalahari craton and its constituents: A paleogeographic review},
author = { M.O. De Kock and A.P. Gumsley and M.B. Klausen and U. Söderlund and C. Djeutchou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068005832&doi=10.1007%2f978-981-13-1666-1_5&partnerID=40&md5=08d90570f9b60bd2d8346374a912331d},
doi = {10.1007/978-981-13-1666-1_5},
issn = {21979545},
year = {2019},
date = {2019-01-01},
journal = {Springer Geology},
pages = {155-214},
publisher = {Springer},
abstract = {The study of Precambrian dyke swarms, sill provinces and large igneous provinces on the Kalahari craton in southern Africa has expanded greatly since the pioneering work initiated almost four decades ago. The main contributors to this progress have been a large number of precise U–Pb crystallization ages of mafic rocks, published in a number of recent papers. This information is compiled here into a series of maps that provide a nearly 3 billion year intraplate magmatic record of the Kalahari craton and its earlier constituents, the proto-Kalahari, Kaapvaal and Zimbabwe cratons. We also review their possible paleogeographic relations to other cratons or supercontinents. This review provides a more accessible overview of individual magmatic events, and mostly includes precise U–Pb ages of mafic dykes and sills, some of which can be linked to stratigraphically well-constrained volcanic rocks. The extrusion ages of these volcanic units are also starting to be refined by, among others, in situ dating of baddeleyite. Some mafic dyke swarms, previously characterized entirely on similarity in dyke trends within a swarm, are found to be temporally composite and sometimes consist of up to three different generations. Other mafic dyke swarms, with different trends, can now be linked to protracted volcanic events like the stratigraphically well preserved Mesoarchean Nsuze Group (Pongola Supergroup) and Neoarchean Ventersdorp Supergroup. Following upon these Archean events, shorter-lived Proterozoic large igneous provinces also intrude the Transvaal Supergroup, Olifantshoek Supergroup and Umkondo Group, and include the world’s largest layered intrusion, the Bushveld Complex. Longer-lived late Paleoproterozoic magmatic events are also preserved as mafic intrusions and lava units within the Waterberg and Soutpansberg groups as well as the granitic basement. Many gaps in our knowledge of the Precambrian mafic record of the Kalahari craton remain, but further multi-disciplinary studies combining the latest advances in U–Pb geochronology and both paleomagnetism and geochemistry will help solve the Precambrian paleogeographic puzzle. © Springer Nature Singapore Pte Ltd. 2019.},
note = {11},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
Beukes, N. J.; Kock, M. O. De; Vorster, C.; Ravhura, L. G.; Frei, D.; Gumsley, A. P.; Harris, C.
The age and country rock provenance of the Molopo farms complex: Implications for transvaal supergroup correlation in southern Africa Journal Article
In: South African Journal of Geology, vol. 122, no. 1, pp. 39-56, 2019, ISSN: 10120750, (20).
@article{2-s2.0-85061086086,
title = {The age and country rock provenance of the Molopo farms complex: Implications for transvaal supergroup correlation in southern Africa},
author = { N.J. Beukes and M.O. De Kock and C. Vorster and L.G. Ravhura and D. Frei and A.P. Gumsley and C. Harris},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061086086&doi=10.25131%2fsajg.122.0003&partnerID=40&md5=bf9781c11033b995bb6a779b5041708a},
doi = {10.25131/sajg.122.0003},
issn = {10120750},
year = {2019},
date = {2019-01-01},
journal = {South African Journal of Geology},
volume = {122},
number = {1},
pages = {39-56},
publisher = {Geological Society of South Africa},
abstract = {The ultramafic-mafic layered igneous Molopo Farms Complex straddles the border between South Africa and Botswana. Younger cover obscures this igneous complex and its country rocks, which are generally assigned to the Paleoproterozoic Transvaal Supergroup. The area intruded by the complex is characterized by abutting and contrasting successions of the upper Transvaal Supergroup (i.e.; the Pretoria and Postmasburg groups), the correlation of which is critical to understanding the first significant build-up in atmospheric oxygen, also known as the Great Oxidation Event. Recent dating of the Postmasburg Group necessitates a reinterpretation of Transvaal Supergroup stratigraphy involving a 200 million year downward revision of the Postmasburg Group relative to the Pretoria Group. The geology of the area intruded by the Molopo Farms Complex may provide important insights into this correlation model. Here we report a207Pb/206Pb ID-TIMS baddeleyite date of 2 054 ± 5 Ma from a gabbroic sample from the Molopo Farms Complex in South Africa, and an U-Pb zircon date of 2 056 ± 10 Ma from a highly altered and metamorphosed quartzite in direct contact with ultramafic rocks of the complex in Botswana. We interpret these as crystallization ages of the Complex, which are within error of the 2 056 to 2 055 Ma age of the Bushveld Complex. Also reported from drill core intersections are U-Pb LA-ICP-MS detrital zircon age data from quartzite samples of both the floor and roof country rock. The roof rock detrital zircon age populations are comparable to those of the Paleoproterozoic Waterberg Group. Age populations in floor rocks are generally similar to those of the Pretoria Group, with the addition of ~2 050 Ma populations, which likely reflect the metamorphic aureole of the complex on distinctly recrystallized country rock. A revised pre-Kalahari regional geology of the Molopo Farms Complex in South Africa, that incorporates the Pretoria Group in the area, implies an unconformable relationship with the Potsmasburg Group. Future recognition of such an unconformable relationship in drill core will ultimately resolve the problem of Transvaal strata correlation. © 2019 March Geological Society of South Africa.},
note = {20},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2018
Salminen, J.; Hanson, R.; Evans, D. A. D.; Gong, Z.; Larson, T.; Walker, O.; Gumsley, A. P.; Söderlund, U.; Ernst, R. E.
Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa: Strange attractors across supercontinental cycles Journal Article
In: Geology, vol. 46, no. 11, pp. 1011-1014, 2018, ISSN: 00917613, (21).
@article{2-s2.0-85055904062,
title = {Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa: Strange attractors across supercontinental cycles},
author = { J. Salminen and R. Hanson and D.A.D. Evans and Z. Gong and T. Larson and O. Walker and A.P. Gumsley and U. Söderlund and R.E. Ernst},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055904062&doi=10.1130%2fG45294.1&partnerID=40&md5=69f06d86f08eab226b360a27c78442a9},
doi = {10.1130/G45294.1},
issn = {00917613},
year = {2018},
date = {2018-01-01},
journal = {Geology},
volume = {46},
number = {11},
pages = {1011-1014},
publisher = {Geological Society of America},
abstract = {Mobilistic plate-tectonic interpretation of Precambrian orogens requires that two conjoined crustal blocks may derive from distant portions of the globe. Nonetheless, many proposed Precambrian cratonic juxtapositions are broadly similar to those of younger times (socalled "strange attractors"), raising the specter of bias in their construction. We evaluated the possibility that the Congo and Kalahari cratons (Africa) were joined together prior to their amalgamation along the Damara-Lufilian-Zambezi orogen in Cambrian time by studying diabase dikes of the Huila-Epembe swarm and sills in the southern part of the Congo craton in Angola and in Namibia. We present geologic, U-Pb geochronologic, and paleomagnetic evidence showing that these two cratons were directly juxtaposed at ca. 1.1 Ga, but in a slightly modified relative orientation compared to today. Recurring persistence in cratonic connections, with slight variations from one supercontinent to the next, may signify a style of supercontinental transition similar to the northward motion of Gondwana fragments across the Tethys-Indian oceanic tract, reuniting in Eurasia. © 2018 Geological Society of America.},
note = {21},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2017
Gumsley, A. P.; Chamberlain, K. R.; Bleeker, W.; Söderlund, U.; Kock, M. O. De; Larsson, E. R.; Bekker, A.
Timing and tempo of the great oxidation event Journal Article
In: Proceedings of the National Academy of Sciences of the United States of America, vol. 114, no. 8, pp. 1811-1816, 2017, ISSN: 00278424, (265).
@article{2-s2.0-85013422830,
title = {Timing and tempo of the great oxidation event},
author = { A.P. Gumsley and K.R. Chamberlain and W. Bleeker and U. Söderlund and M.O. De Kock and E.R. Larsson and A. Bekker},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85013422830&doi=10.1073%2fpnas.1608824114&partnerID=40&md5=0d878041af2a6685327fe11fc190e31d},
doi = {10.1073/pnas.1608824114},
issn = {00278424},
year = {2017},
date = {2017-01-01},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {114},
number = {8},
pages = {1811-1816},
publisher = {National Academy of Sciences},
abstract = {The first significant buildup in atmospheric oxygen, the Great Oxidation Event (GOE), began in the early Paleoproterozoic in association with global glaciations and continued until the end of the Lomagundi carbon isotope excursion ca. 2,060 Ma. The exact timing of and relationships among these events are debated because of poor age constraints and contradictory stratigraphic correlations. Here, we show that the first Paleoproterozoic global glaciation and the onset of the GOE occurred between ca. 2,460 and 2,426 Ma, ∼100 My earlier than previously estimated, based on an age of 2,426 ± 3 Ma for Ongeluk Formation magmatism from the Kaapvaal Craton of southern Africa. This age helps define a key paleomagnetic pole that positions the Kaapvaal Craton at equatorial latitudes of 11° ± 6° at this time. Furthermore, the rise of atmospheric oxygen was not monotonic, but was instead characterized by oscillations, which together with climatic instabilities may have continued over the next ∼200 My until ≤2,250-2,240 Ma. Ongeluk Formation volcanism at ca. 2,426 Ma was part of a large igneous province (LIP) and represents a waning stage in the emplacement of several temporally discrete LIPs across a large low-latitude continental landmass. These LIPs played critical, albeit complex, roles in the rise of oxygen and in both initiating and terminating global glaciations. This series of events invites comparison with the Neoproterozoic oxygen increase and Sturtian Snowball Earth glaciation, which accompanied emplacement of LIPs across supercontinent Rodinia, also positioned at low latitude.},
note = {265},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Evans, D. A. D.; Smirnov, A. V.; Gumsley, A. P.
Paleomagnetism and U–Pb geochronology of the Black Range dykes, Pilbara Craton, Western Australia: a Neoarchean crossing of the polar circle Journal Article
In: Australian Journal of Earth Sciences, vol. 64, no. 2, pp. 225-237, 2017, ISSN: 08120099, (16).
@article{2-s2.0-85014500337,
title = {Paleomagnetism and U–Pb geochronology of the Black Range dykes, Pilbara Craton, Western Australia: a Neoarchean crossing of the polar circle},
author = { D.A.D. Evans and A.V. Smirnov and A.P. Gumsley},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014500337&doi=10.1080%2f08120099.2017.1289981&partnerID=40&md5=7b4a8f1528923425e9e0affc41cabbc6},
doi = {10.1080/08120099.2017.1289981},
issn = {08120099},
year = {2017},
date = {2017-01-01},
journal = {Australian Journal of Earth Sciences},
volume = {64},
number = {2},
pages = {225-237},
publisher = {Taylor and Francis Ltd.},
abstract = {We report a new paleomagnetic pole for the Black Range Dolerite Suite of dykes, Pilbara craton, Western Australia. We replicate previous paleomagnetic results from the Black Range Dyke itself, but find that its magnetic remanence direction lies at the margin of a distribution of nine dyke mean directions. We also report two new minimum ID-TIMS 207Pb/206Pb baddeleyite ages from the swarm, one from the Black Range Dyke itself (>2769 ± 1 Ma) and another from a parallel dyke whose remanence direction lies near the centre of the dataset (>2764 ± 3 Ma). Both ages are slightly younger than a previous combined SHRIMP 207Pb/206Pb baddeleyite weighted mean date from the same swarm, with slight discordance interpreted as being caused by thin metamorphic zircon overgrowths. The updated Black Range suite mean remanence direction (D = 031.5°; I = 78.7°; k = 40; α95 = 8.3°) corresponds to a paleomagnetic pole calculated from the mean of nine virtual geomagnetic poles at 03.8°S, 130.4°E},
note = {16},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2016
Gumsley, A. P.; Chamberlain, K. R.; Bleeker, W.; Söderlund, U.; Kock, M. O. De; Kampmann, T. C.; Larsson, E. R.; Bekker, A.
In: Acta Geologica Sinica (English Edition), vol. 90, pp. 67-68, 2016, ISSN: 10009515, (1).
@article{2-s2.0-84994078082,
title = {The Timing of the Palaeoproterozoic Great Oxidation Event using Dykes, Sills and Bolcanics of the Ongeluk Large Igneous Province, Kaapvaal Craton},
author = { A.P. Gumsley and K.R. Chamberlain and W. Bleeker and U. Söderlund and M.O. De Kock and T.C. Kampmann and E.R. Larsson and A. Bekker},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84994078082&doi=10.1111%2f1755-6724.12891&partnerID=40&md5=7be46554a25eda6f7836e6610280b484},
doi = {10.1111/1755-6724.12891},
issn = {10009515},
year = {2016},
date = {2016-01-01},
journal = {Acta Geologica Sinica (English Edition)},
volume = {90},
pages = {67-68},
abstract = {[No abstract available]},
note = {1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kock, M. O. De; Ravhura, L. G.; Vorster, C.; Beukes, N. J.; Gumsley, A. P.
Constraining the Timing of the Molopo Farms Complex Emplacement and Provenance of Its Country Rock Journal Article
In: Acta Geologica Sinica (English Edition), vol. 90, pp. 78-, 2016, ISSN: 10009515, (1).
@article{2-s2.0-84994071265,
title = {Constraining the Timing of the Molopo Farms Complex Emplacement and Provenance of Its Country Rock},
author = { M.O. De Kock and L.G. Ravhura and C. Vorster and N.J. Beukes and A.P. Gumsley},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84994071265&doi=10.1111%2f1755-6724.12898&partnerID=40&md5=a3f04b8a9b544be003af4e7cbc03afdd},
doi = {10.1111/1755-6724.12898},
issn = {10009515},
year = {2016},
date = {2016-01-01},
journal = {Acta Geologica Sinica (English Edition)},
volume = {90},
pages = {78-},
abstract = {[No abstract available]},
note = {1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Semami, F. Alebouyeh; Kock, M. O. De; Söderlund, U.; Gumsley, A. P.; da Silva, R.; Beukes, N. J.; Armstrong, R.
In: GFF, vol. 138, no. 1, pp. 164-182, 2016, ISSN: 11035897, (21).
@article{2-s2.0-84959093409,
title = {New U–Pb geochronologic and palaeomagnetic constraints on the late Palaeoproterozoic Hartley magmatic event: evidence for a potential large igneous province in the Kaapvaal Craton during Kalahari assembly, South Africa},
author = { F. Alebouyeh Semami and M.O. De Kock and U. Söderlund and A.P. Gumsley and R. da Silva and N.J. Beukes and R. Armstrong},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959093409&doi=10.1080%2f11035897.2015.1124917&partnerID=40&md5=b89f8af417a97decaafd66c9282c59c1},
doi = {10.1080/11035897.2015.1124917},
issn = {11035897},
year = {2016},
date = {2016-01-01},
journal = {GFF},
volume = {138},
number = {1},
pages = {164-182},
publisher = {Taylor and Francis Ltd.},
abstract = {The volcanic Hartley Formation (part of the Olifantshoek Supergroup; which is dominated by red bed successions) in South Africa recorded depositional and tectonic conditions along the western Kaapvaal Craton during the late Palaeoproterozoic. It formed in association with red bed deposition elsewhere in the cratonic hinterland and along the craton’s northern margin. However, the exact correlation of the Olifantshoek Supergroup with these other red-bed successions is hindered by poor geochronological constraints. Herein, we refine the age and palaeopole of the Hartley Formation, and provide geochronological constraints for large-scale 1.93–1.91 Ga bimodal magmatism on the Kaapvaal Craton (herein named the Hartley large igneous province). We present new age constraints for the mafic and felsic phases of this event at 1923 ± 6 Ma and 1920 ± 4 Ma, respectively, which includes the first reported age dating of the Tsineng Dyke Swarm that has been linked to Hartley volcanism. A mean 1.93–1.91 Ga palaeomagnetic pole for the Hartley large igneous province at 22.7°N, 328.6°E with A95 = 11.7° represents a significant improvement on a previously published virtual geomagnetic pole. This improved pole is used to refine the late Palaeoproterozoic apparent polar wander path of the Kaapvaal Craton. This can assist in correlation of red-bed successions in southern Africa. © 2016 Geologiska Föreningen.},
note = {21},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gumsley, A. P.; Rådman, J.; Söderlund, U.; Klausen, M. B.
In: GFF, vol. 138, no. 1, pp. 115-132, 2016, ISSN: 11035897, (15).
@article{2-s2.0-84959078836,
title = {U–Pb baddeleyite geochronology and geochemistry of the White Mfolozi Dyke Swarm: unravelling the complexities of 2.70–2.66 Ga dyke swarms across the eastern Kaapvaal Craton, South Africa},
author = { A.P. Gumsley and J. Rådman and U. Söderlund and M.B. Klausen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959078836&doi=10.1080%2f11035897.2015.1122665&partnerID=40&md5=4d247ca27a0f6b3f2139b6906265fc2c},
doi = {10.1080/11035897.2015.1122665},
issn = {11035897},
year = {2016},
date = {2016-01-01},
journal = {GFF},
volume = {138},
number = {1},
pages = {115-132},
publisher = {Taylor and Francis Ltd.},
abstract = {On the south-easternmost Kaapvaal Craton, a NE-trending plagioclase-megacrystic dolerite dyke swarm, herein named the White Mfolozi Dyke Swarm (WMDS), has been identified. New U–Pb baddeleyite ages presented here indicate that the WMDS was emplaced within less than 10 million years, with our three most robust results yielding a weighted mean age of 2662 ± 2 Ma. The WMDS is coeval with the youngest dykes of a 2.70–2.66 Ga radiating dyke swarm already identified further north on the eastern side of the Kaapvaal Craton. This dyke swarm radiates out from the eastern lobe of the ca. 2.05 Ga Bushveld Complex. A clustering of ages from the WMDS and the 2.70–2.66 Ga radiating dyke swarm identify potential magmatic peaks at 2701–2692 Ma, 2686–2683 Ma and 2665–2659 Ma. Geochemical signatures of the dykes do not correlate with these age groups, but are rather unique to specific areas. The northern part of the eastern Kaapvaal Craton hosts relatively differentiated 2.70–2.66 Ga dolerite dykes that could have been derived from a moderately enriched mantle source, whereas the ca. 2.66 Ga WMDS from the southernmost area exhibit much more depleted signatures. In between these two margins, the central area hosts more andesitic 2.70–2.66 Ga dykes that may have assimilated substantial amounts of partly digested tonalite–trondhjemite–granodiorite crust from the basement. We investigate the evolution for the Kaapvaal Craton during a highly magmatic period that extends for over 60 million years from extensive Ventersdorp volcanism to the eruption of proto-basinal volcanic rocks at the base of the Transvaal Supergroup. © 2015 Geologiska Föreningen.},
note = {15},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2015
Kampmann, T. C.; Gumsley, A. P.; Kock, M. O. De; Söderlund, U.
In: Precambrian Research, vol. 269, pp. 58-72, 2015, ISSN: 03019268, (15).
@article{2-s2.0-84939814521,
title = {U-Pb geochronology and paleomagnetism of the Westerberg Sill Suite, Kaapvaal Craton - Support for a coherent Kaapvaal-Pilbara Block (Vaalbara) into the Paleoproterozoic?},
author = { T.C. Kampmann and A.P. Gumsley and M.O. De Kock and U. Söderlund},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939814521&doi=10.1016%2fj.precamres.2015.08.011&partnerID=40&md5=d0139a99329e95f9263e3373615b41b8},
doi = {10.1016/j.precamres.2015.08.011},
issn = {03019268},
year = {2015},
date = {2015-01-01},
journal = {Precambrian Research},
volume = {269},
pages = {58-72},
publisher = {Elsevier},
abstract = {Precise geochronology, combined with paleomagnetism on mafic intrusions, provides first-order information for paleoreconstruction of crustal blocks, revealing the history of supercontinental formation and break-up. These techniques are used here to further constrain the apparent polar wander path of the Kaapvaal Craton across the Neoarchean-Paleoproterozoic boundary. U-Pb baddeleyite ages of 2441±6 Ma and 2426±1 Ma for a suite of mafic sills located on the western Kaapvaal Craton in South Africa (herein named the Westerberg Sill Suite), manifests a new event of magmatism within the Kaapvaal Craton of southern Africa. These ages fall within a ca. 450 Myr temporal gap in the paleomagnetic record between 2.66 and 2.22Ga on the craton. Our older Westerberg Suite age is broadly coeval with the Woongarra magmatic event on the Pilbara Craton in Western Australia. In addition, the Westerberg Suite on the Kaapvaal Craton intrudes a remarkably similar Archean-Proterozoic sedimentary succession to that on the Pilbara Craton, supporting a stratigraphic correlation between Kaapvaal and Pilbara (i.e.; Vaalbara). The broadly coeval Westerberg-Woongarra igneous event may represent a Large Igneous Province. The paleomagnetic results are more ambiguous, with several different possibilities existing. A Virtual Geomagnetic Pole obtained from four sites on the Westerberg sills is 18.9°N, 285.0°E},
note = {15},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gumsley, A. P.; Olsson, J.; Söderlund, U.; Kock, M. O. De; Hofmann, A.; Klausen, M. B.
In: Precambrian Research, vol. 267, pp. 174-185, 2015, ISSN: 03019268, (35).
@article{2-s2.0-84937002169,
title = {Precise U-Pb baddeleyite age dating of the Usushwana Complex, southern Africa - Implications for the Mesoarchaean magmatic and sedimentological evolution of the Pongola Supergroup, Kaapvaal Craton},
author = { A.P. Gumsley and J. Olsson and U. Söderlund and M.O. De Kock and A. Hofmann and M.B. Klausen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937002169&doi=10.1016%2fj.precamres.2015.06.010&partnerID=40&md5=f12a173f6b97abbc7a7c348031445aca},
doi = {10.1016/j.precamres.2015.06.010},
issn = {03019268},
year = {2015},
date = {2015-01-01},
journal = {Precambrian Research},
volume = {267},
pages = {174-185},
publisher = {Elsevier},
abstract = {The Usushwana Complex of the south-eastern Kaapvaal Craton (South Africa and Swaziland), intrudes the ca. 3.6-3.1. Ga basement of the craton, as well as the Mesoarchaean volcanic and sedimentary cover succession of the Pongola Supergroup. New high-precision U-Pb dating of gabbros belonging to the Piet Retief Suite of the Usushwana Complex yield ages of 2989 ± 1 Ma, 2990 ± 2 Ma and 2978 ± 2 Ma. The Piet Retief Suite represents part of an intricate magmatic feeder to a major volcanic event which gave rise to the oldest known continental flood basalts on Earth, the Nsuze volcanic rocks. Broadly coeval SE-trending dolerite dykes of the Barberton-Badplaas Dyke Swarm in the larger region of the south-eastern Kaapvaal Craton formed along the same structural trend as the Usushwana Complex. One such dyke is dated herein to 2980 ± 1. Ma. Using the high-precision U-Pb geochronological data, the Nsuze volcanic rocks can now be resolved into at least two magmatic episodes which can be correlated with parts of the Pongola Supergroup. The first episode at ca. 2.99-2.98 Ga is broadly coeval with the Pypklipberg (Nhlebela) volcanic rocks, whereas the second at ca. 2.97-2.96 Ga was near synchronous to the Agatha volcanic rocks. A dolerite sill intruding into the Mozaan Group of the Pongola Supergroup, thought to be part of the Usushwana Complex, was dated to 2869 ± 5 Ma, and is instead coeval with the Hlagothi Complex further to the south, and provides a new minimum age for deposition of the Mozaan Group. © 2015 Elsevier B.V.},
note = {35},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2013
Gumsley, A. P.; Kock, M. O. De; Rajesh, H. M.; Knoper, M. W.; Söderlund, U.; Ernst, R. E.
The Hlagothi Complex: The identification of fragments from a Mesoarchaean large igneous province on the Kaapvaal Craton Journal Article
In: Lithos, vol. 174, pp. 333-348, 2013, ISSN: 00244937, (26).
@article{2-s2.0-84878909766,
title = {The Hlagothi Complex: The identification of fragments from a Mesoarchaean large igneous province on the Kaapvaal Craton},
author = { A.P. Gumsley and M.O. De Kock and H.M. Rajesh and M.W. Knoper and U. Söderlund and R.E. Ernst},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878909766&doi=10.1016%2fj.lithos.2012.06.007&partnerID=40&md5=9ed65f268f1fab4aa3de65ceadc7ee14},
doi = {10.1016/j.lithos.2012.06.007},
issn = {00244937},
year = {2013},
date = {2013-01-01},
journal = {Lithos},
volume = {174},
pages = {333-348},
abstract = {In this paper, we present geochronological, geochemical and palaeomagnetic results from the Hlagothi Complex and a NW-trending dolerite dyke swarm on the southeastern region of the Kaapvaal Craton in northern KwaZulu-Natal, South Africa. The Hlagothi Complex consists of layered sills of meta-peridotite, pyroxenite and gabbro intruding into the Pongola Supergroup. U-Pb baddeleyite ages on the Hlagothi Complex and a NW-trending dyke of 2866. ±. 2. Ma and 2874. ±. 2. Ma, respectively, reveal a ca. 2.87. Ga magmatic event on the southeastern Kaapvaal Craton. The geochemical signature of the Hlagothi Complex recognises two discrete groupings, with a magmatic source that is chemically distinct from those of the older rift-related Nsuze and Dominion groups. Additional units on the Kaapvaal Craton can be linked with this new 'Hlagothi' event based on spatial and temporal association, and geochemistry: 1) the Thole Complex, 2) parts of the Usushwana Complex, and 3) flood basalts within the Mozaan Group and Central Rand Group. The association between all these units suggests a previously unrecognised large igneous province in the southeastern Kaapvaal Craton. Our palaeomagnetic data identifies a possible primary magnetisation within the least-altered lithologies of the Hlagothi Complex (with a virtual geographic pole at 23.4°N, 53.4°E},
note = {26},
keywords = {},
pubstate = {published},
tppubtype = {article}
}