scholarly journals Late Paleoproterozoic mafic magmatism and the Kalahari craton during Columbia assembly

Geology ◽  
2021 ◽  
Author(s):  
Cedric Djeutchou ◽  
Michiel O. de Kock ◽  
Hervé Wabo ◽  
Camilo E. Gaitán ◽  
Ulf Söderlund ◽  
...  
Keyword(s):  
Thermal Ionization Mass Spectrometry ◽  
Black Hills ◽  
Large Igneous Province ◽  
Ionization Mass ◽  
Data Sets ◽  
Geochronological Data ◽  
Pb Isotope ◽  
Kalahari Craton ◽  
Igneous Province ◽  
Superior Craton

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.

U–Pb geochronology of Cretaceous magmatism on Svalbard and Franz Josef Land, Barents Sea Large Igneous Province

2013 ◽  
Vol 150 (6) ◽  
pp. 1127-1135 ◽  
Author(s):  
FERNANDO CORFU ◽  
STÉPHANE POLTEAU ◽  
SVERRE PLANKE ◽  
JAN INGE FALEIDE ◽  
HENRIK SVENSEN ◽  
...  
Keyword(s):  
Thermal Ionization Mass Spectrometry ◽  
Barents Sea ◽  
Large Igneous Province ◽  
The Arctic ◽  
Ionization Mass ◽  
Franz Josef Land ◽  
Igneous Province ◽  
Stratigraphic Record ◽  
Single Grain ◽  
Cretaceous Magmatism

AbstractThe opening of the Arctic oceanic basins in the Mesozoic and Cenozoic proceeded in steps, with episodes of magmatism and sedimentation marking specific stages in this development. In addition to the stratigraphic record provided by sediments and fossils, the intrusive and extrusive rocks yield important information on this evolution. This study has determined the ages of mafic sills and a felsic tuff in Svalbard and Franz Josef Land using the isotope dilution thermal ionization mass spectrometry (ID-TIMS) U–Pb method on zircon, baddeleyite, titanite and rutile. The results indicate crystallization of the Diabasodden sill at 124.5 ± 0.2 Ma and the Linnévatn sill at 124.7 ± 0.3 Ma, the latter also containing slightly younger secondary titanite with an age of 123.9 ± 0.3 Ma. A bentonite in the Helvetiafjellet Formation, also on Svalbard, has an age of 123.3 ± 0.2 Ma. Zircon in mafic sills intersected by drill cores in Franz Josef Land indicate an age of 122.7 Ma for a thick sill on Severnaya Island and a single grain age of ≥122.2 ± 1.1 Ma for a thinner sill on Nagurskaya Island. These data emphasize the importance and relatively short-lived nature of the Cretaceous magmatic event in the region.

Magmatic duration of the Emeishan large igneous province: Insight from northern Vietnam

Geology ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 457-461 ◽  
Author(s):  
J. Gregory Shellnutt ◽  
Thuy Thanh Pham ◽  
Steven W. Denyszyn ◽  
Meng-Wan Yeh ◽  
Tuan-Anh Tran
Keyword(s):  
High Precision ◽  
Thermal Ionization Mass Spectrometry ◽  
Volcanic Rocks ◽  
Large Igneous Province ◽  
Ionization Mass ◽  
Emeishan Large Igneous Province ◽  
Northern Vietnam ◽  
Global Cooling ◽  
Igneous Province ◽  
Distinct Period

Abstract The eruption of Emeishan lava in southwestern China and northern Vietnam is considered to be a contributing factor to the Capitanian mass extinction and subsequent global cooling event, but the duration of volcanism is uncertain. The difficulty in assessing the termination age is, in part, due to the lack of high-precision age data for late-stage volcanic rocks. The Tu Le rhyolite of northern Vietnam is the most voluminous silicic unit of the Emeishan large igneous province (ELIP) and is spatially associated with the Muong Hum and Phan Si Pan hypabyssal plutons. Chemical abrasion–isotope dilution–thermal ionization mass spectrometry U-Pb dating of zircons from the Tu Le rhyolite (257.1 ± 0.6 Ma to 257.9 ± 0.3 Ma) and Muong Hum (257.3 ± 0.2 Ma) and Phan Si Pan (256.3 ± 0.4 Ma) plutons yielded the youngest high-precision ages of the ELIP yet determined. The results demonstrate that Emeishan lavas erupted over a period of ∼6 m.y,. with plutonism ending shortly thereafter. Thus, it is possible that Emeishan volcanism contributed to global cooling into the middle Wuchiapingian. It appears that these rocks represent a distinct period of ELIP magmatism, as they are young and were emplaced oblique to the main north-south–trending Panxi rift.

Constraining the duration of the Tarim flood basalts (northwestern China): CA-TIMS zircon U-Pb dating of tuffs

2021 ◽  
Author(s):  
Yu-Ting Zhong ◽  
Zhen-Yu Luo ◽  
Roland Mundil ◽  
Xun Wei ◽  
Hai-Quan Liu ◽  
...  
Keyword(s):  
Thermal Ionization Mass Spectrometry ◽  
Northwest China ◽  
Lava Flows ◽  
Northwestern China ◽  
Large Igneous Province ◽  
Ionization Mass ◽  
Flood Basalts ◽  
Eruption Rate ◽  
Long Duration ◽  
Igneous Province

The Early Permian Tarim large igneous province (LIP) in northwestern China comprises voluminous basaltic lava flows, as well as ultramafic and silicic intrusions. The age and duration of the Tarim LIP remains unclear, and thus the rate of magma production and models of potential environmental effects are uncertain. Here we present high-precision chemical abrasion−isotope dilution−thermal ionization mass spectrometry zircon U-Pb ages for three newly discovered tuff layers interlayered with lava flows in the Kupukuziman and Kaipaizileike formations in the Keping area (Xinjiang, northwest China). The volcanism of the Kupukuziman Formation is constrained to a short duration from 289.77 ± 0.95 to 289.41 ± 0.52 Ma. An age for the overlying Kaipaizileike Formation is 284.27 ± 0.39 Ma, bracketing the duration of the entire eruptive phase of the Tarim flood basalts at ∼5.5 m.y. The low eruption rate and relatively long duration of magmatism is consistent with a plume incubation model for the Tarim LIP.

Congo-São Francisco at 1.11 Ga and the megacontinent Umkondia 

2021 ◽  
Author(s):  
Johanna Salminen
Keyword(s):  
Large Igneous Province ◽  
Geochronological Data ◽  
Qualitative Comparison ◽  
Central Brazil ◽  
Northern India ◽  
Paleomagnetic Pole ◽  
Kalahari Craton ◽  
Igneous Province ◽  
The World ◽  
Tholeiitic Magmatism

<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>

scholarly journals The lead-up to the Sturtian Snowball Earth: Neoproterozoic chemostratigraphy time-calibrated by the Tambien Group of Ethiopia

2019 ◽  
Vol 132 (5-6) ◽  
pp. 1119-1149 ◽  
Author(s):  
Yuem Park ◽  
Nicholas L. Swanson-Hysell ◽  
Scott A. MacLennan ◽  
Adam C. Maloof ◽  
Mulubrhan Gebreslassie ◽  
...  
Keyword(s):  
Large Igneous Province ◽  
Snowball Earth ◽  
Ionization Mass ◽  
Data Sets ◽  
Northern Ethiopia ◽  
Glacial Deposits ◽  
Igneous Province ◽  
Low Latitudes ◽  
Back Arc ◽  
The Tropics

Abstract The Tonian-Cryogenian Tambien Group of northern Ethiopia is a mixed carbonate-siliciclastic sequence that culminates in glacial deposits associated with the first of the Cryogenian glaciations—the Sturtian “Snowball Earth.” Tambien Group deposition occurred atop arc volcanics and volcaniclastics of the Tsaliet Group. New U-Pb isotope dilution–thermal ionization mass spectrometry (ID-TIMS) dates demonstrate that the transition between the Tsaliet and Tambien Groups occurred at ca. 820 Ma in western exposures and ca. 795 Ma in eastern exposures, which is consistent with west to east arc migration and deposition in an evolving back-arc basin. The presence of intercalated tuffs suitable for high-precision geochronology within the Tambien Group enable temporal constraints on stratigraphic data sets of the interval preceding, and leading into, the Sturtian glaciation. Recently discovered exposures of Sturtian glacial deposits and underlying Tambien Group strata in the Samre Fold-Thrust Belt present the opportunity to further utilize this unique association of tuffs and carbonate lithofacies. U-Pb ID-TIMS ages from zircons indicate that Tambien Group carbonates were deposited from ca. 820 Ma until 0–2 m.y. before the onset of the Sturtian glaciation, making the group host to a relatively complete carbonate stratigraphy leading into this glaciation. New δ13C and 87Sr/86Sr data and U-Pb ID-TIMS ages from the Tambien Group are used in conjunction with previously published isotopic and geochronologic data to construct newly time-calibrated composite Tonian carbon and strontium isotope curves. Tambien Group δ13C data and U-Pb ID-TIMS ages reveal that a pre-Sturtian sharp negative δ13C excursion (referred to as the Islay anomaly in the literature) precedes the Sturtian glaciation by ∼18 m.y., is synchronous in at least two separate basins, and is followed by a prolonged interval of positive δ13C values. The composite Tonian 87Sr/86Sr curve shows that, following an extended interval of low and relatively invariant values, inferred seawater 87Sr/86Sr rose ca. 880–770 Ma, then subsequently decreased leading up to the ca. 717 Ma initiation of the Sturtian glaciation. These data, when combined with a simple global weathering model and analyses of the timing and paleolatitude of large igneous province eruptions and arc accretion events, suggest that the 87Sr/86Sr increase was influenced by increased subaerial weathering of radiogenic lithologies as Rodinia rifted apart at low latitudes. The following 87Sr/86Sr decrease is consistent with enhanced subaerial weathering of arc lithologies accreting in the tropics over tens of millions of years, lowering pCO2 and contributing to the initiation of the Sturtian glaciation.

A link between rift-related volcanism and end-Ediacaran extinction? Integrated chemostratigraphy, biostratigraphy, and U-Pb geochronology from Sonora, Mexico

Geology ◽  
2020 ◽  
Author(s):  
Eben B. Hodgin ◽  
Lyle L. Nelson ◽  
Corey J. Wall ◽  
Arturo J. Barrón-Díaz ◽  
Lucy C. Webb ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Thermal Ionization Mass Spectrometry ◽  
Flood Basalt ◽  
Large Igneous Province ◽  
Ionization Mass ◽  
Carbon Isotope Excursion ◽  
Igneous Province ◽  
First Occurrence ◽  
Thermal Ionization Mass ◽  
Depositional Age

We present chemostratigraphy, biostratigraphy, and geochronology from a succession that spans the Ediacaran-Cambrian boundary in Sonora, Mexico. A sandy hematite-rich dolostone bed, which occurs 20 m above carbonates that record the nadir of the basal Cambrian carbon isotope excursion within the La Ciénega Formation, yielded a maximum depositional age of 539.40 ± 0.23 Ma using U-Pb chemical abrasion–isotope dilution–thermal ionization mass spectrometry on a population of sharply faceted volcanic zircon crystals. This bed, interpreted to contain reworked tuffaceous material, is above the last occurrences of late Ediacaran body fossils and below the first occurrence of the Cambrian trace fossil Treptichnus pedum, and so the age calibrates key markers of the Ediacaran-Cambrian boundary. The temporal coincidence of rift-related flood basalt volcanism in southern Laurentia (>250,000 km3 of basalt), a negative carbon isotope excursion, and biological turnover is consistent with a mechanistic link between the eruption of a large igneous province and end-Ediacaran extinction.

Tectonic implications of new SHRIMP and TIMS U–Pb geochronology of rocks from the Sask Craton, Peter Lake Domain, and Hearne margin, Trans-Hudson Orogen, Saskatchewan

2005 ◽  
Vol 42 (4) ◽  
pp. 635-657 ◽  
Author(s):  
N M Rayner ◽  
R A Stern ◽  
M E Bickford
Keyword(s):  
Thermal Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Ion Microprobe ◽  
Geochronological Data ◽  
Zircon Growth ◽  
Precursor Material ◽  
Three Samples ◽  
Limited Support ◽  
Age Range ◽  
Superior Craton

This study reports new sensitive high-resolution ion microprobe (SHRIMP) and thermal ionization mass spectrometry (TIMS) U–Pb geochronological data for thirteen rocks from the Archean to Paleoproterozic Sask Craton, the Peter Lake Domain and Hearne margin, Saskatchewan. Seven samples from the exposed Sask Craton in both the Glennie Domain and Pelican Window record zircon growth between 2425 and 2525 Ma and at ~1800 Ma. Older precursor material has been identified, most notably a refined crystallization age of 3117 Ma for a sample of quartzofeldspatic gneiss ("Q-gneiss") in the Pelican Window, which also experienced ca. 2450 Ma zircon growth. Three samples from the Peter Lake Domain and a sample from the Linn Island inlier of the Wollaston Domain yield ages of ~2575 Ma. One sample from the Peter Lake Domain is distinctly older, yielding an age of 2640 Ma, but also displays zircon growth at 2575 Ma. The simplest interpretation of these data is that the Peter Lake Domain is likely a part of the Hearne margin, although the significance and distribution of 2575 Ma ages within the larger Hearne craton is unclear. Conversely, the age range of most samples from the Sask Craton is distinctly younger than those of the Peter Lake and Hearne margin rocks. We suggest that 2.45 Ga was a major episode of magmatic reworking of older material within the Sask Craton, which includes, but is not restricted to, 3.1 Ga precursors. These ages do not coincide with typical ages reported from the Superior craton and thus the data, although limited, support an exotic origin for the Sask Craton.

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 ◽  
...  
Keyword(s):  
Siberian Craton ◽  
River Flow ◽  
Large Igneous Province ◽  
Dyke Swarm ◽  
Middle Section ◽  
Geochronological Data ◽  
Igneous Province

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.

scholarly journals Major and Trace Element and Sr, Nd, Hf, and Pb Isotope Compositions of the Karoo Large Igneous Province, Botswana–Zimbabwe: Lithosphere vs Mantle Plume Contribution

2007 ◽  
Vol 48 (6) ◽  
pp. 1043-1077 ◽  
Author(s):  
F. Jourdan ◽  
H. Bertrand ◽  
U. Schärer ◽  
J. Blichert-Toft ◽  
G. Féraud ◽  
...  
Keyword(s):  
Trace Element ◽  
Mantle Plume ◽  
Large Igneous Province ◽  
Pb Isotope ◽  
Igneous Province
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