scholarly journals Geochemistry and Petrogenesis of Mesoproterozoic Dykes of the Irkutsk Promontory, Southern Part of the Siberian Craton

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 545 ◽  
Author(s):  
T. Donskaya ◽  
D. Gladkochub ◽  
R. Ernst ◽  
S. Pisarevsky ◽  
A. Mazukabzov ◽  
...  
Keyword(s):  
Mantle Plume ◽  
Siberian Craton ◽  
Coarse Grained ◽  
Large Igneous Province ◽  
Element Abundances ◽  
Igneous Province ◽  
Oceanic Island Basalts ◽  
T Values ◽  
Dyke Swarms ◽  
Extensional Setting

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

scholarly journals А new ectasian event of basitic magmatism in the southern Siberian craton

2019 ◽  
Vol 486 (3) ◽  
pp. 326-330
Author(s):  
D. P. Gladkochub ◽  
T. V. Donskaya ◽  
R. E. Ernst ◽  
M. A. Hamilton ◽  
A. M. Mazukabzov ◽  
...  
Keyword(s):  
Mantle Plume ◽  
Siberian Craton ◽  
Large Igneous Province ◽  
Dyke Swarm ◽  
Southern Margin ◽  
Igneous Province ◽  
Victoria Island

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

scholarly journals Geochemical, isotopic, and U–Pb zircon study of the central and southern portions of the 780 Ma Gunbarrel Large Igneous Province in western Laurentia

2019 ◽  
Vol 56 (7) ◽  
pp. 738-755 ◽  
Author(s):  
Alana Mackinder ◽  
Brian L. Cousens ◽  
Richard E. Ernst ◽  
Kevin R. Chamberlain
Keyword(s):  
Mantle Plume ◽  
Magma Mixing ◽  
Volcanic Rocks ◽  
Parental Magma ◽  
Coarse Grained ◽  
Large Igneous Province ◽  
Magma Reservoirs ◽  
Igneous Province ◽  
Local Host ◽  
Host Rocks

Spanning 2500 km along the western margin of North America are 780 Ma dykes, sills, and minor volcanic packages of the Gunbarrel Large Igneous Province. This study focuses on southern (northwestern United States) and central (northern British Columbia) Gunbarrel intrusions and metavolcanics rocks of the Irene and Huckleberry formation (Washington State). Southern Gunbarrel U–Pb ages range from 780 to 769 Ma and new U–Pb zircon dates for the Turah and Rogers Pass sills are 778.6 ± 0.7 and 778.7 ± 0.9 Ma, respectively. Southern Gunbarrel intrusions are medium- to coarse-grained diabases that are moderately evolved basaltic, continental tholeiites. Intrusions display negative Nb–Ta and positive Pb anomalies in normalized multielement plots, and εNd780 values vary from +3.6 to +1.5. The Irene and Huckleberry volcanic rocks are E-MORB in composition with higher εNd780 (+5 to +6) and likely represent partial melts of a mantle plume responsible for the Gunbarrel event. Assuming an Irene and Huckleberry parental magma, mixing models indicate that the southern Gunbarrel magmas were crustally contaminated, but local host rocks are not appropriate crustal contaminants. The modeling points to average upper crust as the crustal contaminant, with an εNd780 of approximately –2. This crustal contaminant likely resides on the craton impinged upon by the mantle plume. The remarkable geochemical homogeneity of Gunbarrel intrusions from the Yukon to Wyoming is best explained if primary, plume-derived E-MORB magmas were contaminated in large magma reservoirs near the plume centre and were then injected laterally into the crust 100s to 1000s of kilometres from the reservoir.

Ultramafic-alkaline-carbonatite complexes as a result of two-stage melting of mantle plume: evidence from the mid-paleoproterozoic Tiksheozero intrusion, Northern Karelia, Russia

2019 ◽  
Vol 486 (4) ◽  
pp. 460-465
Author(s):  
E. V. Sharkov ◽  
A. V. Chistyakov ◽  
M. M. Bogina ◽  
O. A. Bogatikov ◽  
V. V. Shchiptsov ◽  
...  
Keyword(s):  
Fractional Crystallization ◽  
Mantle Plume ◽  
Large Igneous Province ◽  
Intrusive Complex ◽  
Incongruent Melting ◽  
Isotopic Data ◽  
Two Stage ◽  
Similar Composition ◽  
Igneous Province ◽  
Alkaline Magmas

Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of large igneous province, related to the ascent of thermochemical mantle plume. Our geochemical and isotopic data evidence that ultramafites and alkaline rocks are joined by fractional crystallization, whereas carbonatitic magmas has independent origin. We suggest that origin of parental magmas of the Tiksheozero complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: 1) adiabatic melting of its inner part, which produced moderately-alkaline picrites, which fractional crystallization led to appearance of alkaline magmas, and 2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids  that arrived from underlying zone of adiabatic melting gave rise to carbonatite magmas.

The Tethyan Himalaya igneous province: Early melting products of the Kerguelen mantle plume

2021 ◽  
Author(s):  
Sheng-Sheng Chen ◽  
Wei-Ming Fan ◽  
Ren-Deng Shi ◽  
Ji-Feng Xu ◽  
Yong-Min Liu
Keyword(s):  
Mantle Plume ◽  
Crustal Contamination ◽  
Large Igneous Province ◽  
Mafic Rocks ◽  
Os Isotopes ◽  
Igneous Province ◽  
Break Up ◽  
Low Degrees ◽  
The Relationship ◽  
Tethyan Himalaya

Abstract The Kerguelen large igneous province (LIP) has been related to mantle plume activity since at least 120 Ma. There are some older (147–130 Ma) magmatic provinces on circum-eastern Gondwana, but the relationship between these provinces and the Kerguelen mantle plume remains controversial. Here we present petrological, geochronological, geochemical, and Sr–Nd–Hf–Pb–Os isotopic data for high-Ti mafic rocks from two localities (Cuona and Jiangzi) in the eastern Tethyan Himalaya igneous province (147–130 Ma). Zircon grains from these two localities yielded concordant weighted mean 206Pb/238U ages of 137.25 ± 0.98 and 131.28 ± 0.78 Ma (2σ), respectively. The analyzed mafic rocks are enriched in high field strength elements and have positive Nb–Ta anomalies relative to Th and La, which have ocean island basalt-like characteristics. The Cuona basalts were generated by low degrees of melting (3–5%) of garnet lherzolites (3–5 vol.% garnet), and elsewhere the Jiangzi diabases were formed by relatively lower degrees of melting (1–3%) of garnet lherzolite (1–5 vol.% garnet). The highly radiogenic Os and Pb isotopic compositions of the Jiangzi diabases were produced by crustal contamination, but the Cuona basalts experienced the least crustal contamination given their relatively low γOs(t), 206Pb/204Pbi, 207Pb/204Pbi, and 208Pb/204Pbi values. Major and trace element geochemical and Sr–Nd–Hf–Pb–Os isotope data for the Cuona basalts are similar to products of the Kerguelen mantle plume head. Together with high mantle potential temperatures (>1500°C), this suggests that the eastern Tethyan Himalaya igneous province (147–130 Ma) was an early magmatic product of the Kerguelen plume. A mantle plume initiation model can explain the temporal and spatial evolution of the Kerguelen LIP, and pre-continental break-up played a role in the breakup of eastern Gondwana, given the >10 Myr between initial mantle plume activity (147–130 Ma) and continental break-up (132–130 Ma). Like studies of Re-Os isotopes in other LIPs, the increasing amount of crustal assimilation with distance from the plume stem can explain the variations in radiogenic Os.

scholarly journals Introduction: from the British Tertiary into the future – modern perspectives on the British Palaeogene and North Atlantic Igneous provinces

2009 ◽  
Vol 146 (3) ◽  
pp. 305-308 ◽  
Author(s):  
DOUGAL A. JERRAM ◽  
KATHRYN M. GOODENOUGH ◽  
VALENTIN R. TROLL
Keyword(s):  
North Atlantic ◽  
18Th Century ◽  
North Atlantic Ocean ◽  
Volcanic Rocks ◽  
Large Igneous Province ◽  
The North ◽  
Igneous Provinces ◽  
Starting Point ◽  
Igneous Province ◽  
Dyke Swarms

The study of volcanic rocks and igneous centres has long been a classic part of geological research. Despite the lack of active volcanism, the British Isles have been a key centre for the study of igneous rocks ever since ancient lava flows and excavated igneous centres were recognized there in the 18th century (Hutton, 1788). This led to some of the earliest detailed studies of petrology. The starting point for many of these studies was the British Palaeogene Igneous Province (BPIP; formerly known as the ‘British Tertiary’ (Judd, 1889), and still recognized by this name by many geologists around the globe). This collection of lavas, volcanic centres and sill/dyke swarms covers much of the west of Scotland and the Antrim plateau of Northern Ireland, and together with similar rocks in the Faroe Islands, Iceland and Greenland forms a world-class Large Igneous Province. This North Atlantic Igneous Province (NAIP) began to form through continental rifting above a mantle plume at c. 60 Ma, and subsequently evolved as North America separated from Europe, creating the North Atlantic Ocean.

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