Derivation of Large Igneous Provinces of the past 200 million years from long-term heterogeneities in the deep mantle

2004 ◽  
Vol 227 (3-4) ◽  
pp. 531-538 ◽  
Author(s):  
Kevin Burke ◽  
Trond H. Torsvik
2018 ◽  
Vol 470 (1) ◽  
pp. 39-64 ◽  
Author(s):  
Daniel Pastor-Galán ◽  
R. Damian Nance ◽  
J. Brendan Murphy ◽  
Christopher J. Spencer

AbstractThere is an emerging consensus that Earth's landmasses amalgamate quasi-periodically into supercontinents, interpreted to be rigid super-plates essentially lacking tectonically active inner boundaries and showing little internal lithosphere–mantle interactions. The formation and disruption of supercontinents have been linked to changes in sea-level, biogeochemical cycles, global climate change, continental margin sedimentation, large igneous provinces, deep mantle circulation, outer core dynamics and Earth's magnetic field. If these hypotheses are correct, long-term mantle dynamics and much of the geological record, including the distribution of natural resources, may be largely controlled by these cycles. Despite their potential importance, however, many of these proposed links are, to date, permissive rather than proven. Sufficient data are not yet available to verify or fully understand the implications of the supercontinent cycle. Recent advances in many fields of geoscience provide clear directions for investigating the supercontinent cycle hypothesis and its corollaries but they need to be vigorously pursued if these far-reaching ideas are to be substantiated.


Elements ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 319-324 ◽  
Author(s):  
Benjamin A. Black ◽  
Sally A. Gibson

Carbon is central to the formation and environmental impact of large igneous provinces (LIPs). These vast magmatic events occur over geologically short timescales and include voluminous flood basalts, along with silicic and low-volume alkaline magmas. Surface outgassing of CO2 from flood basalts may average up to 3,000 Mt per year during LIP emplacement and is subsidized by fractionating magmas deep in the crust. The large quantities of carbon mobilized in LIPs may be sourced from the convecting mantle, lithospheric mantle and crust. The relative significance of each potential carbon source is poorly known and probably varies between LIPs. Because LIPs draw on mantle reservoirs typically untapped during plate boundary magmatism, they are integral to Earth's long-term carbon cycle.


Geology ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Luc S. Doucet ◽  
Zheng-Xiang Li ◽  
Richard E. Ernst ◽  
Uwe Kirscher ◽  
Hamed Gamal El Dien ◽  
...  

Abstract The most dominant features in the present-day lower mantle are the two antipodal African and Pacific large low-shear-velocity provinces (LLSVPs). How and when these two structures formed, and whether they are fixed and long lived through Earth history or dynamic and linked to the supercontinent cycles, remain first-order geodynamic questions. Hotspots and large igneous provinces (LIPs) are mostly generated above LLSVPs, and it is widely accepted that the African LLSVP existed by at least ca. 200 Ma beneath the supercontinent Pangea. Whereas the continental LIP record has been used to decipher the spatial and temporal variations of plume activity under the continents, plume records of the oceanic realm before ca. 170 Ma are mostly missing due to oceanic subduction. Here, we present the first compilation of an Oceanic Large Igneous Provinces database (O-LIPdb), which represents the preserved oceanic LIP and oceanic island basalt occurrences preserved in ophiolites. Using this database, we are able to reconstruct and compare the record of mantle plume activity in both the continental and oceanic realms for the past 2 b.y., spanning three supercontinent cycles. Time-series analysis reveals hints of similar cyclicity of the plume activity in the continent and oceanic realms, both exhibiting a periodicity of ∼500 m.y. that is comparable to the supercontinent cycle, albeit with a slight phase delay. Our results argue for dynamic LLSVPs where the supercontinent cycle and global subduction geometry control the formation and locations of the plumes.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicolas Luca Celli ◽  
Sergei Lebedev ◽  
Andrew J. Schaeffer ◽  
Carmen Gaina

AbstractHow cratons, the ancient cores of continents, evolved since their formation over 2.5 Ga ago is debated. Seismic tomography can map the thick lithosphere of cratons, but its resolution is low in sparsely sampled continents. Here we show, using waveform tomography with a large, newly available dataset, that cratonic lithosphere beneath Africa is more complex and fragmented than seen previously. Most known diamondiferous kimberlites, indicative of thick lithosphere at the time of eruption, are where the lithosphere is thin today, implying surprisingly widespread lithospheric erosion over the last 200 Ma. Large igneous provinces, attributed to deep-mantle plumes, were emplaced near all lithosphere-loss locations, concurrently with or preceding the loss. This suggests that the cratonic roots foundered once modified by mantle plumes. Our results imply that the total volume of cratonic lithosphere has decreased since its Archean formation, with the fate of each craton depending on its movements relative to plumes.


Author(s):  
Nasrrddine Youbi ◽  
Richard E. Ernst ◽  
Ross N. Mitchell ◽  
Moulay A. Boumehdi ◽  
Warda El Moume ◽  
...  

2006 ◽  
Vol 167 (3) ◽  
pp. 1447-1460 ◽  
Author(s):  
Trond H. Torsvik ◽  
Mark A. Smethurst ◽  
Kevin Burke ◽  
Bernhard Steinberger

2021 ◽  
pp. SP518-2021-53
Author(s):  
Rajesh K. Srivastava ◽  
Richard E. Ernst ◽  
Ulf Söderlund ◽  
Amiya K. Samal ◽  
Om Prakash Pandey ◽  
...  

AbstractWe propose a Precambrian megacraton (consisting of two or more ancient cratons) ‘DHABASI’ in the Indian Shield that includes the Dharwar, Bastar and Singhbhum cratons. This interpretation is mainly based on seven large igneous provinces (LIPs) that are identified in these three cratons over the age range of ca. 3.35-1.77 Ga, a period of at least 1.6 Gyr. The absence of any subsequent breakup of ‘DHABASI’ since 1.77 Ga suggests that this megacraton has existed for the past 3.35 Gyr.In addition to their use in recognizing this megacraton, these LIP events may also provide likely targets for Cu-Ni-Cr-Co-PGE deposits. We suggest that the megacraton ‘DHABASI’ was an integral part of supercontinents/supercratons through Earth's history, and that it should be utilized as a distinct building block for paleocontinental reconstructions rather than using the individual Dharwar, Bastar and Singhbhum cratons.


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