Elemental, lead and sulfur isotopic compositions of galena from Kola carbonatites, Russia – implications for melt and mantle evolution

2015 ◽  
Vol 79 (2) ◽  
pp. 219-241 ◽  
Author(s):  
K. Bell ◽  
A. N. Zaitsev ◽  
J. Spratt ◽  
S. Fröjdö ◽  
A. S. Rukhlov
Keyword(s):  
Isotopic Composition ◽  
Mantle Source ◽  
Noble Gas ◽  
Isotope Ratios ◽  
Pb Isotope ◽  
Mantle Evolution ◽  
Isotopic Compositions ◽  
Kola Alkaline Province ◽  
Mantle Sources ◽  
Heterogeneous Mantle

AbstractGalena from four REE-rich (Khibina, Sallanlatvi, Seblyavr, Vuoriyarvi) and REE-poor (Kovdor) carbonatites, as well as hydrothermal veins (Khibina) all from the Devonian Kola Alkaline Province of northwestern Russia was analysed for trace elements and Pb and S isotope compositions. Microprobe analyses show that the only detectable elements in galena are Bi and Ag and these vary from not detectable to 2.23 and not detectable to 0.43 wt.% respectively. Three distinct galena groups can be recognized using Bi and Ag contents, which differ from groupings based on Pb isotope data. The Pb isotope ratios show significant spread with 206Pb/204Pb ratios (16.79 to 18.99), 207Pb/204Pb (15.22 to 15.58) and 208Pb/204Pb ratios (36.75 to 38.62). A near-linear array in a 207Pb/204Pb vs.206Pb/204Pb ratio diagram is consistent with mixing between distinct mantle sources, one of which formed during a major differentiation event in the late Archaean or earlier. The S isotopic composition (δ34S) of galena from carbonatites is significantly lighter (–6.7 to –10.3% Canyon Diablo Troilite (CDT) from REE-rich Khibina, Seblyavr and Vuoriyarvi carbonatites, and – 3.2% CDT from REE-poor Kovdor carbonatites) than the mantle value of 0%. Although there is no correlation between S and any of the Pb isotope ratios, Bi and Ag abundances correlate negatively with δ34S values. The variations in the isotopic composition of Pb are attributed to partial melting of an isotopically heterogeneous mantle source, while those of δ34S (together with Bi and Ag abundances) are considered to be process driven. Although variation in Pb isotope values between complexes might reflect different degrees of interaction between carbonatitic melts and continental crust or metasomatized lithosphere, the published noble gas and C, O, Sr, Nd and Hf isotopic data suggest that the variable Pb isotope ratios are best attributed to isotopic differences preserved within a sub-lithospheric mantle source. Different Pb isotopic compositions of galena from the same complex are consistent with a model of magma replenishment by carbonatitic melts/fluids each marked by quite different Pb isotopic compositions.

Isotopic composition of lead in galena and Ni-arsenides of the Midwest deposit, northern Saskatchewan

1984 ◽  
Vol 21 (6) ◽  
pp. 649-656 ◽  
Author(s):  
G. L. Cumming ◽  
D. Krstic ◽  
J. M. Worden ◽  
H. Baadsgaard
Keyword(s):  
Isotopic Composition ◽  
Close Association ◽  
Isotope Ratios ◽  
Pb Isotope ◽  
Macroscopic Scale ◽  
Loss Mechanism ◽  
The Third ◽  
The Past ◽  
Isotopic Compositions ◽  
Basement Rocks

Pb-isotope ratios from galenas and Ni-arsenides of the Midwest deposit indicate that there are three classes of Pb present. The first, with 206Pb/204Pb ratios of about 22.5 and 208Pb/204Pb ratios of about 43.5, occurs only in galenas and is restricted to the basal Athabasca Formation. The second occurs from about 35 m above the unconformity to the deepest samples available to us (60 m into the basement rocks). Characteristically the 206Pb/204Pb ratios are 30–35 and the 208Pb/204Pb ratios are about 50, and this Pb occurs in both galenas and Ni-arsenides. The third class has elevated 206Pb/204Pb ratios ranging up to 350 and occurs within about 10 m of the unconformity in close association with U minerals.A model is developed in which radiogenic additions to galena have occurred during at least two different events. The first added U and Th daughters to "sandstone-type" Pb at 265 ± 50 Ma, and the second added U daughter only to the "basement-type" Pb in the past 50 Ma or less. These events are consistent with Pb loss recorded in the U minerals and indicate that the lead-loss mechanism from these U minerals is catastrophic rather than continuous diffusion.Some trace Pb isotopic compositions in Ni-arsenides suggest to us the occurrence of disequilibrium migration of 238U daughter products, but there is no clear evidence that this occurred on a macroscopic scale in the galena.The model implies that some galena predates the U mineralization, and thus that there is a potential for Pb–(Zn?) mineralization in the basal Athabasca Formation.

Tracing the Origins of the Ice Giants through Noble Gas Isotopic Composition

2021 ◽  
Author(s):  
Kathleen Mandt ◽  
Olivier Mousis ◽  
Jonathan Lunine ◽  
Bernard Marty ◽  
Thomas Smith ◽  
...  
Keyword(s):  
Solar System ◽  
Isotopic Composition ◽  
Heavy Element ◽  
Noble Gas ◽  
Giant Planet ◽  
Isotope Ratios ◽  
Building Blocks ◽  
Giant Planets ◽  
Element Abundances ◽  
Current State

<p>The current composition of giant planet atmospheres provides information on how such planets formed, and on the origin of the solid building blocks that contributed to their formation. Noble gas abundances and their isotope ratios are among the most valuable pieces of evidence for tracing the origin of the materials from which the giant planets formed. In this review we first outline the current state of knowledge for heavy element abundances in the giant planets and explain what is currently understood about the reservoirs of icy building blocks that could have contributed to the formation of the Ice Giants. We then outline how noble gas isotope ratios have provided details on the original sources of noble gases in various materials throughout the solar system. We follow this with a discussion on how noble gases are trapped in ice and rock that later became the building blocks for the giant planets and how the heavy element abundances could have been locally enriched in the protosolar nebula. We then provide a review of the current state of knowledge of noble gas abundances and isotope ratios in various solar system reservoirs, and discuss measurements needed to understand the origin of the ice giants. Finally, we outline how formation and interior evolution will influence the noble gas abundances and isotope ratios observed in the ice giants today. Measurements that a future atmospheric probe will need to make include (1) the <sup>3</sup>He/<sup>4</sup>He isotope ratio to help constrain the protosolar D/H and <sup>3</sup>He/<sup>4</sup>He; (2) the <sup>20</sup>Ne/<sup>22</sup>Ne and <sup>21</sup>Ne/<sup>22</sup>Ne to separate primordial noble gas reservoirs similar to the approach used in studying meteorites; (3) the Kr/Ar and Xe/Ar to determine if the building blocks were Jupiter-like or similar to 67P/C-G and Chondrites; (4) the krypton isotope ratios for the first giant planet observations of these isotopes; and (5) the xenon isotopes for comparison with the wide range of values represented by solar system reservoirs.</p><p>Mandt, K. E., Mousis, O., Lunine, J., Marty, B., Smith, T., Luspay-Kuti, A., & Aguichine, A. (2020). Tracing the origins of the ice giants through noble gas isotopic composition. Space Science Reviews, 216(5), 1-37.</p>

scholarly journals The Petrogenesis of the Permian Podong Ultramafic Intrusion in the Tarim Craton, Western China: Constraints from C-He-Ne-Ar Isotopes

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Mingjie Zhang ◽  
Pengyu Feng ◽  
Tong Li ◽  
Liwu Li ◽  
Juerong Fu ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Mantle Plume ◽  
Mantle Source ◽  
Noble Gas ◽  
Western China ◽  
Crustal Material ◽  
Sulfide Mineralization ◽  
Hydrocarbon Gases ◽  
Isotopic Compositions ◽  
Ultramafic Intrusion

The Podong Permian ultramafic intrusion is only one ultramafic intrusion with massif Ni-Cu sulfide mineralization in the Pobei layered mafic-ultramafic complex, western China. It is obviously different in sulfide mineralization from the nearby coeval Poyi ultramafic intrusion with the largest disseminated Ni-Cu sulfide mineralization and mantle plume contribution (Zhang et al., 2017). The type and addition mechanism of the confirmed crustal contaminations and possible mantle plume involved in the intrusion formation require evidences from carbon and noble gas isotopic compositions. In the present study, we have measured C, He, Ne, and Ar isotopic compositions of volatiles from magmatic minerals in the Podong ultramafic intrusion. The results show that olivine, pyroxene, and plagioclase minerals in the Podong intrusion have variable δ13C of CO2 (-24.5‰ to -3.2‰). The CH4, C2H6, C3H8, and C4H10 hydrocarbon gases show normal or partial reversal distribution patterns of carbon isotope with carbon number and light δ13C1 value of CH4, indicating the hydrocarbon gases of biogenic origin. The δ13C of CO2 and CH4 suggested the magmatic volatile of the mantle mixed with the volatiles of thermogenic and crustal origins. Carbon and noble gas isotopes indicated that the Podong intrusion could have a different petrogenesis from the Poyi ultramafic intrusion. Two types of contaminated crustal materials can be identified as crustal fluids from subducted altered oceanic crust (AOC) in the lithospheric mantle source and a part of the siliceous crust. The carbon isotopes for different minerals show that magma spent some time crystallizing in a magma chamber during which assimilation of crustal material occurred. Subduction-devolatilization of altered oceanic crust could be the best mechanism that transported large proportion of ASF (air-saturated fluid) and crustal components into the mantle source. The mantle plume existing beneath the Poyi intrusion could provide less contribution of real materials of silicate and fluid components.

A preliminary assessment of the application of Sr, Nd, Pb, He and N isotope analysis to fluid inclusions in kimberlite olivine: A new approach to trace deep-mantle sources

2020 ◽  
Author(s):  
Andrea Giuliani ◽  
Janne M. Koornneef ◽  
Peter Barry ◽  
Patrizia Will ◽  
Henner Busemann ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Trace Element ◽  
Mass Spectrometer ◽  
Fluid Inclusions ◽  
Noble Gas ◽  
Isotope Analysis ◽  
Helium Isotope ◽  
New Approach ◽  
Deep Mantle ◽  
Mantle Sources

<p>Kimberlites are the deepest melts that reach Earth’s surface and, therefore, can provide unique insights into the composition and evolution of the convective mantle through time. Application of isotope geochemistry to trace the composition of kimberlite sources has thus far been hindered by the ubiquitous alteration and incorporation of xenocrystic material in kimberlite rocks. Bulk-kimberlite analyses are typically considered reliable for Nd and Hf isotopes due to their overwhelmingly higher concentrations in kimberlite melts compared to common mantle and crustal contaminants. Conversely, Sr and Pb isotope compositions of bulk kimberlite samples are seldom considered representative of their parental melts thus requiring analysis of robust magmatic phases, primarily perovskite. Addressing the primary (i.e. magmatic) isotopic composition of volatile elements, such as N and noble gases, requires analyses of volatile-rich phases, and fluid inclusions in olivine represent a typical primary target in mantle-derived magmas. However, fluid inclusions in kimberlitic olivine are dominantly secondary in origin. Secondary inclusions can form at any time after crystallisation of their mineral host, which requires assessment of the origin of trapped fluids (i.e. pristine magmatic fluids, crustal fluids of external derivation, or combination thereof) before their isotopic composition can be used to make inferences about kimberlite mantle sources.</p><p>Here we present trace-element and Sr-Nd-Pb-He-N isotopic compositions of multiple olivine aliquots representing two different magmatic units of the ~88 Ma Wesselton kimberlite (Kimberley, South Africa). The Sr and Nd isotopic composition of olivine analysed by isotope-dilution (ID) TIMS are within the narrow range of perovskite <sup>87</sup>Sr/<sup>86</sup>Sr (0.7043-0.7046) and whole-rock <sup>143</sup>Nd/<sup>144</sup>Nd (eNd<sub>i</sub> = 0.4–2.2) for the Kimberley kimberlites. These results indicate that the secondary fluid inclusions, which dominate the incompatible trace-element budget of olivine separates, have a pristine magmatic origin devoid of crustal contribution.</p><p>Helium isotope compositions were measured by laser heating of 1.6 to 9.8 mg of olivine using an ultrahigh-sensitivity compressor-source noble gas mass spectrometer. <sup>3</sup>He/<sup>4</sup>He ratios are between 1.6 R<sub>A</sub> and 3.7 R<sub>A</sub> (where R<sub>A</sub> indicates the atmospheric <sup>3</sup>He/<sup>4</sup>He ratio), values more radiogenic than MORBs but comparable to HIMU OIBs. These results indicate a high time-integrated (U+Th)/He ratio in the source of the Kimberley kimberlites, which is consistent with the moderately high (i.e. HIMU-like) time-integrated U/Pb ratio implied by elevated initial <sup>206</sup>Pb/<sup>204</sup>Pb in Wesselton olivine (19.1-19.5), Kimberley kimberlites (up to 19.9) and megacrysts in southern African Cretaceous kimberlites (up to 20.5). The combination of low <sup>3</sup>He/<sup>4</sup>He, moderately radiogenic <sup>87</sup>Sr/<sup>86</sup>Sr, and negative d<sup>34</sup>S values (-2.6‰ to -5.7‰) require a contribution from subducted recycled material in the source of the Kimberley kimberlites. Conversely, a preliminary N isotope analysis of Wesselton olivine by in-vacuo crushing using a noble gas mass spectrometer returned a mantle-like d<sup>15</sup>N of -2.9‰, which might suggest limited recycling of surface N (d<sup>15</sup>N >0‰) in the source of these kimberlites. We conclude that the combination of Sr-Nd-Pb and He-N isotope tracing of fluid inclusions in olivine can provide a robust new approach to address the composition of kimberlite sources and, therefore, the evolution of the deep mantle through time.</p>

scholarly journals Upper Cretaceous to Pleistocene melilitic volcanic rocks of the Bohemian Massif: petrology and mineral chemistry

2015 ◽  
Vol 66 (3) ◽  
pp. 197-216 ◽  
Author(s):  
Roman Skála ◽  
Jaromír Ulrych ◽  
Lukáš Ackerman ◽  
Lukáš Krmíček ◽  
Ferry Fediuk ◽  
...  
Keyword(s):  
Mantle Source ◽  
Bohemian Massif ◽  
Upper Cretaceous ◽  
Volcanic Rocks ◽  
Mineral Chemistry ◽  
Primitive Mantle ◽  
Mantle Sources ◽  
Heterogeneous Mantle ◽  
Central European Volcanic Province ◽  
Scoria Cones

Abstract Upper Cretaceous to Pleistocene volcanic rocks of the Bohemian Massif represent the easternmost part of the Central European Volcanic Province. These alkaline volcanic series include rare melilitic rocks occurring as dykes, sills, scoria cones and flows. They occur in three volcanic periods: (i) the Late Cretaceous to Paleocene period (80–59 Ma) in northern Bohemia including adjacent territories of Saxony and Lusatia, (ii) the Mid Eocene to Late Miocene (32.3–5.9 Ma) period disseminated in the Ohře Rift, the Cheb–Domažlice Graben, Vogtland, and Silesia and (iii) the Early to Late Pleistocene period (1.0–0.26 Ma) in western Bohemia. Melilitic magmas of the Eocene to Miocene and Pleistocene periods show a primitive mantle source [(143Nd/144Nd)t=0.51280–0.51287; (87Sr/86Sr)t=0.7034–0.7038)] while those of the Upper Cretaceous to Paleocene period display a broad scatter of Sr–Nd ratios. The (143Nd/144Nd)t ratios (0.51272–0.51282) of the Upper Cretaceous to Paleocene rocks suggest a partly heterogeneous mantle source, and their (87Sr/86Sr)t ratios (0.7033–0.7049) point to an additional late- to post-magmatic hydrothermal contribution. Major rock-forming minerals include forsterite, diopside, melilite, nepheline, sodalite group minerals, phlogopite, Cr- and Ti-bearing spinels. Crystallization pressures and temperatures of clinopyroxene vary widely between ~1 to 2 GPa and between 1000 to 1200 °C, respectively. Nepheline crystallized at about 500 to 770 °C. Geochemical and isotopic similarities of these rocks occurring from the Upper Cretaceous to Pleistocene suggest that they had similar mantle sources and similar processes of magma development by partial melting of a heterogeneous carbonatized mantle source.

scholarly journals The mantle source of basalts from Reunion Island is not more oxidized than the MORB source mantle

2021 ◽  
Vol 177 (1) ◽  
Author(s):  
Maryjo Brounce ◽  
Edward Stolper ◽  
John Eiler
Keyword(s):  
Indian Ocean ◽  
Canary Islands ◽  
Mantle Source ◽  
Reunion Island ◽  
Near Surface ◽  
Isotopic Compositions ◽  
Mantle Sources ◽  
Réunion Island ◽  
Mantle Component ◽  
The Indian Ocean

AbstractGlasses quenched from relatively undegassed ocean island magmas erupted from volcanoes at Iceland, Hawaii, the Canary Islands, and Erebus have elevated Fe3+/∑Fe ratios compared to glasses quenched from mid-ocean ridge basalts. This has been ascribed to elevated fO2 of their mantle sources, plausibly due to subducted, oxidized near-surface-derived components in their mantle sources. The basaltic magmas from Reunion Island in the Indian ocean have Sr–Nd-Hf-Pb-Os isotopic compositions suggesting that their mantle sources contain little or no subducted near-surface materials and contain the C/FOZO/PREMA mantle component. To constrain the fO2 of the C/FOZO/PREMA mantle component and test the link between oxidized OIB and recycled surface-derived materials in their sources, we measured major and volatile element abundances and Fe3+/∑Fe ratios of naturally glassy, olivine-hosted melt inclusions from Piton de La Fournaise volcano, La Reunion. We conclude that the fO2 of the mantle source of these Reunion lavas is lower than of the mantle sources of primitive, undegassed magmas from Hawaii, Iceland, the Canary Islands, and Mt. Erebus, and indistinguishable from that of the Indian-ocean upper mantle. This finding is consistent with previous suggestions that the source of Reunion lavas (and the C/FOZO/PREMA mantle component) contains little or no recycled materials and with the suggestion that recycled oxidized materials contribute to the high fO2 of some other OIBs, especially those from incompatible-element-enriched mantle sources. Simple mixing models between oxidized melts of EM1 and HIMU components and relatively reduced melts of DMM can explain the isotopic compositions and Fe3+/∑Fe ratios of lavas from Hawaii, Iceland, the Canary Islands, and Mount Erebus; this model can be tested by study of additional OIB magmas, including those rich in the EM2 component.

scholarly journals Lead isotope constraints on the mantle sources involved in the genesis of Mesozoic high-Ti tholeiite dykes (Urubici type) from the São Francisco Craton (Southern Espinhaço, Brazil)

2016 ◽  
Vol 46 (suppl 1) ◽  
pp. 105-122 ◽  
Author(s):  
Leila Soares Marques ◽  
Eduardo Reis Viana Rocha-Júnior ◽  
Marly Babinski ◽  
Karine Zuccolan Carvas ◽  
Liliane Aparecida Petronilho ◽  
...  
Keyword(s):  
Mantle Source ◽  
Crustal Contamination ◽  
Experimental Tests ◽  
Pb Isotope ◽  
Flood Basalts ◽  
Nd Isotope ◽  
Continental Flood Basalts ◽  
Rock Fragments ◽  
Mantle Sources ◽  
First Results

ABSTRACT: The first results of Pb isotope compositions of the high-Ti Mesozoic dykes of the Southern Espinhaço are presented. The results do not show large variations and are significantly more radiogenic than the Pb isotope compositions of the high-Ti tholeiites from the Paraná Continental Flood Basalts. The data combined with published geochemical and Sr-Nd isotope results rule out crustal contamination processes in the genesis of the dykes, requiring magma generation in metasomatized subcontinental lithospheric mantle with the involvement of HIMU-type and carbonatite components. The magmas may have been also derived from a mantle source containing ~4 - 5% of pyroxenite and ~1% of carbonatite melts, agreeing with published Os isotope compositions of high-Ti rocks from the Paraná Continental Flood Basalts. These metasomatizing agents could be responsible for mantle source refertilization, as was also proposed in the literature to explain the characteristics of xenoliths of the Goiás Alkaline Province, which also occurs in the border of the São Francisco Craton. Additionally, to evaluate the risks of Pb contamination during sample preparation for analysis, several experimental tests were accomplished, which indicate the need of sawed surface removal and a careful washing of small-sized rock fragments before powdering, especially for rocks with [Pb] < 7 µg/g.

Reconstructing Terrestrial Environments Using Stable Isotopes in Fossil Teeth and Paleosol Carbonates

2012 ◽  
Vol 18 ◽  
pp. 167-194 ◽  
Author(s):  
Benjamin H. Passey
Keyword(s):  
Isotopic Composition ◽  
Soil Temperature ◽  
Carbon Isotopes ◽  
Oxygen Isotopes ◽  
Precipitation Amount ◽  
Radiative Heating ◽  
Mammal Species ◽  
Isotopic Compositions ◽  
Heat Effects ◽  
Oxygen Isotopic

Carbon isotopes in Neogene-age fossil teeth and paleosol carbonates are commonly interpreted in the context of past distributions of C3 and C4 vegetation. These two plant types have very different distributions in relation to climate and ecology, and provide a robust basis for reconstructing terrestrial paleoclimates and paleoenvironments during the Neogene. Carbon isotopes in pre-Neogene fossil teeth are usually interpreted in the context of changes in the δ13C value of atmospheric CO2, and variable climate-dependent carbon-isotope discrimination in C3 plants. Carbon isotopes in pre-Neogene soil carbonates can be used to estimate past levels of atmospheric CO2. Oxygen isotopes in fossil teeth and paleosol carbonates primarily are influenced by the oxygen isotopic compositions of ancient rainfall and surface waters. The oxygen isotopic composition of rainfall is has a complex, but tractable, relationship with climate, and variably relates to temperature, elevation, precipitation amount, and other factors. Mammal species that rely on moisture in dietary plant tissues to satisfy their water requirements (rather than surface drinking water) may have oxygen isotopic compositions that track aridity. Thus, oxygen isotopes of fossil mammals can place broad constraints on paleoaridity. Carbonate clumped isotope thermometry allows for reconstruction of soil temperatures at the time of pedogenic carbonate mineralization. The method is unique because it is the only thermodynamically based isotopic paleothermometer that does not require assumptions about the isotopic composition of the fluid in which the archive mineral formed. Soil temperature reflects a complex interplay of air temperature, solar radiative heating, latent heat effects, soil thermal diffusivity, and seasonal variations of these parameters. Because plants and most animals live in and/or near the soil, soil temperature is an important aspect of terrestrial (paleo)climate.

Le terrane de Slide Mountain (Cordillères canadiennes) : une lithosphère océanique marquée par des points chauds

2003 ◽  
Vol 40 (6) ◽  
pp. 833-852 ◽  
Author(s):  
M Tardy ◽  
H Lapierre ◽  
D Bosch ◽  
A Cadoux ◽  
A Narros ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Oceanic Island ◽  
Light Rare Earth ◽  
Isotopic Compositions ◽  
Incompatible Elements ◽  
Depleted Mantle ◽  
Mantle Sources ◽  
British Colombia ◽  
Ultramafic Cumulates ◽  
Back Arc

The Slide Mountain Terrane consists of Devonian to Permian siliceous and detrital sediments in which are interbedded basalts and dolerites. Locally, ultramafic cumulates intrude these sediments. The Slide Mountain Terrane is considered to represent a back-arc basin related to the Quesnellia Paleozoic arc-terrane. However, the Slide Mountain mafic volcanic rocks exposed in central British Colombia do not exhibit features of back-arc basin basalts (BABB) but those of mid-oceanic ridge (MORB) and oceanic island (OIB) basalts. The N-MORB-type volcanic rocks are characterized by light rare-earth element (LREE)-depleted patterns, La/Nb ratios ranging between 1 and 2. Moreover, their Nd and Pb isotopic compositions suggest that they derived from a depleted mantle source. The within-plate basalts differ from those of MORB affinity by LREE-enriched patterns; higher TiO2, Nb, Ta, and Th abundances; lower εNd values; and correlatively higher isotopic Pb ratios. The Nd and Pb isotopic compositions of the ultramafic cumulates are similar to those of MORB-type volcanic rocks. The correlations between εNd and incompatible elements suggest that part of the Slide Mountain volcanic rocks derive from the mixing of two mantle sources: a depleted N-MORB type and an enriched OIB type. This indicates that some volcanic rocks of the Slide Mountain basin likely developed from a ridge-centered or near-ridge hotspot. The activity of this hotspot is probably related to the worldwide important mantle plume activity that occurred at the end of Permian times, notably in Siberia.

Sign in / Sign up

Export Citation Format

Share Document