Crust-mantle systems of magmatic complexes of Sikhote-Alin' (Far East, Russia)

2020 ◽  
Author(s):  
Nina Gorelikova ◽  
Nikolay Bortnikov ◽  
Aleksandr Khanchuk ◽  
Valeriy Gonevchuk ◽  
Irina Chizhova ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Regional Distribution ◽  
Crustal Contamination ◽  
Orogenic Belt ◽  
Geochemical Data ◽  
High Water Content ◽  
Crustal Material ◽  
Sikhote Alin ◽  
Margin Setting ◽  
Transform Margin

<p>Geochemical, isotope-geochemical, geochronolochical and thermobarometric study showed that the Badzhal, Mayo-Chan and Kavalerovo zones from Sikhote-Alin-Northern Sakhalin orogenic belt comprise: (1) oldest and geochemically and isotopically distinctive alkali mafic rocks, whose formation was related to mantle (asthenospheric) diapir. The possible regional distribution of the diapir is likely marked by subalkaline rocks (monzonites) having mantle Sr (0,7050) and Nd (0,5125) isotopic compositions at the Central (Tigrinoe deposit) and Southern (Kavalerovo district) Sikhote-Alin; (2) Tin-bearing ore-magmatic systems of the studied zones at the “ore region” level have similar intricate multi-root structure of generation area. 3) Magmatic evolution accompanying by increasing ore-bearing potential results in the final appearance of Li-F granites in the Badzhal Complex, and tourmaline granites in the Silinka Complex of the Myao-chan zone (Gonevchuk, 2002).</p><p>The elevated F and Cl contents and high water content as parameters responsible for ore potential of melt were confirmed by thermobarometric data (Bortnikov et al, 2019). Some associations of fluid and melt inclusions indicate that magma crystallization was accompanied by degassing with exsolution of water-rich fluids, which is required to form ore bodies in OMS. These data confirm significant role of mantle in the formation of the Myao-Chan and Badzhal zones, as well as early cassiterite—stannite—sulfide stage of the Arsen’evskoe deposit of the Kavalerovo district.</p><p>Numerical simulation of granitoids of the studied zones performed using logical-information method by I.A. Chizhova (2010) confirms crustal-mantle nature of magmatic complexes formed under transform continental margin and subduction settings. These systems are characterized by different geochemical features, in particular, different proportions of high-field strength (Sc, Y, Zr, Hf, Pb, U, Th, Nb), REE, and siderophile (Co, Ni, Cr, V, Cu) elements.</p><p>Obtained results in combination with previous data indicate that the Badzhal, Myao-Chain, and Kavalerovo zones were formed through several episodes of the growth and reworking of the Sikhote Alin’ Mesozoic continental crust, which were triggered by underplating. Granitoids and genetically related tin—base metal deposits were formed at final stage. The revealed difference in Sr-Nd composition of the granitoids could be caused by both initial geochemical crustal heterogeneity and the different degree of crustal contamination.</p><p>Geochemical and isotopic characteristics of the studied granitoids show that they were mainly derived through melting of juvenile metamafic crust, with subordinate contribution of metasedimentary rocks.</p><p>The ore-bearing magmatic complexes were formed during a change of transform margin setting by accretion of Early Cretaceous terranes of the Sikhote Alin—North Sakhalin orogenic belt.</p><p>Observed petrogeochemical diversirty of the granitoids from different zones could be caused by variations of sedimentary material, as well as by contamination of magmas by upper crustal material during emplacement, different contribution of mantle source, and diverse mechanisms of mantle-crustal interaction (Khanchuk et al, 2019). </p><p>Obtained petrochemical, geochemical, and isotopic-geochemical data on the granitoids from the studied zones provide better understanding of diversity of tin-bearing magmatism and conditions of magma generation and evolution in transform margin setting at the continent-ocean boundary.</p><p> </p>

Genesis of the Wuxing Pt–Pd-rich Cu–Ni sulfide deposit in the eastern Central Asian Orogenic Belt: evidences from geochronology, elemental geochemistry, and Sr–Nd–Hf isotopic data

2019 ◽  
Vol 56 (4) ◽  
pp. 380-398 ◽  
Author(s):  
Jing-gui Sun ◽  
Yun-peng He ◽  
Ji-long Han ◽  
Zhong-yu Wang
Keyword(s):  
Crustal Contamination ◽  
Early Period ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Geochemical Data ◽  
Sulfide Deposit ◽  
Late Period ◽  
Enriched Mantle ◽  
Central Asian ◽  
T Values

The Wuxing Pt–Pd-rich Cu–Ni sulfide deposit in Heilongjiang Province, Northeast China, is located to the northeast of the Dunhua–Mishan fracture of the eastern Central Asian Orogenic Belt. The mafic–ultramafic complex consist of early-period hornblende–olivine pyroxenite, diopsidite, and hornblende pyroxenite and late-period gabbro and diabase units. An early-period hornblende pyroxenite yielded a zircon U–Pb age of 208.2 ± 2.6 Ma and a late-period diabase yielded a U–Pb age of 205.6 ± 1.1 Ma, with zircon εHf(t) values of +1.24 to +8.13. The early- and late-period lithofacies are relatively enriched in LILE (Rb, Ba, and Sr) and LREE, and variably depleted in HFSE (Nb, Ta). The whole-rock and single-mineral analyses of the early-period lithofacies yield (87Sr/86Sr)i ratios of 0.7055–0.7083 and εNd(t) ratios of −7.98–+3.10. These geochemical data suggest that the parental magmas of the Wuxing complex are high-Mg subalkaline basaltic in nature and were derived from an enriched mantle source. The magmas chamber formed after the injection of magma into the crust along with crustal contamination, producing early crystalline minerals and ore-bearing magmas. The rupturing of the magma chamber released evolved magmas, which then ascended and generated Pt–Pd-bearing lithofacies and Cu–Ni sulfide orebodies by fractional crystallization, accumulation, and liquation. During the late period, the residual magma invaded the early lithofacies and Cu–Ni orebodies. The fluids exsolved from the gabbroic magmas concentrated the mineralized metal elements and enhanced the precipitation of Pt–Pd-bearing veinlet-disseminated orebodies and Pt–Pd–Cu–Ni orebodies.

On the volcanic architecture, petrology and geodynamic setting of the 3.48 Ga Barberton komatiite suite, South Africa

2021 ◽  
Author(s):  
E.G. Grosch ◽  
J. Slama
Keyword(s):  
South Africa ◽  
Mantle Plume ◽  
Source Region ◽  
Crustal Contamination ◽  
Primitive Mantle ◽  
Geochemical Data ◽  
Geodynamic Setting ◽  
Crustal Material ◽  
Type Section ◽  
Formation Type

Abstract This study presents new field and petrological observations combined with geochemical data on a range of komatiitic to tholeiitic volcanic rocks from the ca. 3.48 Ga mid-lower Komati Formation type-section of the Barberton Greenstone Belt, South Africa. A range of mafic-ultramafic rocks is identified across a 1.44 km profile, leading to the proposition of a new preliminary volcanic architecture for the mid-lower Komati Formation type-section. Major, trace and rare earth element (REE) data in conjunction with Lu-Hf isotopic constraints indicate that the tholeiites, newly recognized high-magnesium basalts, basaltic komatiites and komatiites in the volcanic sequence have a primitive mantle signature with no geochemical affinity to Archaean or modern-day supra-subduction zone boninites. The whole rock initial εHf values of spinifex and massive komatiite flows in the lowermost part of the Komati type-section are negative, ranging between -1.9 and -3.1, whereas the second overlying spinifex and massive flow unit records positive initial εHf values between +0.5 and +4.7. A new geodynamic model involving crustal contamination of the mafic-ultramafic lavas is proposed for the Barberton mid-lower Komati Formation type-section, involving mantle plume-crust interaction. The new observations and data indicate that the komatiites erupted as a result of a mantle plume from a hot (>1 600oC) mid-Archaean mantle, in which the earliest volcanic flows were variably affected by crustal contamination during their ascent and eruption. The possibility of incorporation of lower crustal material and/or recycled crust residing in the mantle source region cannot be excluded. This indicates that modern-style plate tectonic processes, such as subduction, may not have been a requirement for the formation of the 3.48 Ga Barberton komatiite suite, with implications for the hydration state, geodynamic processes and secular thermal evolution of the Archaean mantle.

scholarly journals Ore-Bearing Magmatic Systems with Complex Sn–Au–Ag Mineralization in the North-Eastern Verkhoyansk–Kolyma Orogenic Belt, Russia

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 266
Author(s):  
Vera A. Trunilina ◽  
Andrei V. Prokopiev
Keyword(s):  
Active Continental Margin ◽  
Orogenic Belt ◽  
Crustal Extension ◽  
Margin Setting ◽  
The North ◽  
Magmatic Rocks ◽  
Isotopic Methods ◽  
North Eastern ◽  
Magmatic Stage ◽  
Mineral Compositions

This paper reports the results of a study of magmatic rocks with Sn–W–Au–Ag mineralization from the Kuranakh, Elikchan, and Istekh ore fields in the Northern batholith belt of the north-eastern Verkhoyansk–Kolyma orogenic belt in Eastern Russia. Using petrographic, mineralogical, geochemical, and isotopic methods, we determined the mineral compositions, petrochemistry, and geochemistry of magmatic rocks, the P–T conditions of their generation and crystallization, and their geodynamic affinity. The studied magmatic rocks have common geochemical characteristics that likely reflect the influence of fluids supplied from a long-lived, deep-seated mantle source. The ore fields are characterized by Sn–W–Au–Ag–Pb polygenetic mineralization. The magmatic and metallogenic evolution comprised five stages for the formation of magmatic rocks and ores. During the first stage (Berriasian–Barremian), arc-related magmatic rocks formed in an active continental margin setting and were associated with Au–Ag mineralization. The second, third, and fourth stages (Aptian–Campanian) took place in a crustal extension and rift setting, and were accompanied by Au–Ag and Sn–W mineralization. During the fifth (post-magmatic) stage, Sn–Ag–Sb and Pb–Ag mineralization occurred.

scholarly journals Mass-transport deposits and fluid venting in a transform margin setting, the eastern Demerara Plateau (French Guiana)

2013 ◽  
Vol 46 ◽  
pp. 287-303 ◽  
Author(s):  
F. Pattier ◽  
L. Loncke ◽  
V. Gaullier ◽  
C. Basile ◽  
A. Maillard ◽  
...  
Keyword(s):  
Mass Transport ◽  
French Guiana ◽  
Margin Setting ◽  
Transform Margin ◽  
Fluid Venting ◽  
Mass Transport Deposits

Late Cretaceous granitoids of the Sikhote–Alin orogenic belt, southeastern Russia: implications for the Mesozoic geodynamic history of the eastern Asian continental margin

2021 ◽  
pp. jgs2021-109
Author(s):  
Igor V. Kemkin ◽  
Andrei V. Grebennikov ◽  
Xing-Hua Ma ◽  
Ke-Ke Sun
Keyword(s):  
Late Cretaceous ◽  
Pacific Plate ◽  
Orogenic Belt ◽  
Sikhote Alin ◽  
Asian Continent ◽  
Content Type ◽  
Eastern Margin ◽  
Continental Plate ◽  
Supplementary Material ◽  
Cretaceous Magmatism

We present new U–Pb age data for granitoids in the Central Sikhote–Alin orogenic belt in SE Russia, which refute the established opinion about the absence of the Late Cretaceous magmatism at the eastern margin of the Paleo-Asian continent. It was previously thought that a period of magmatic quiescence occurred from 88 to 50 Ma, related to subduction of the Paleo-Pacific Plate under the eastern margin of the Paleo-Asian continent, although this is inconsistent with evidence from the Sikhote–Alin, Sakhalin, and Japan regions. Three suites of plutonic rocks with different ages were identified in this study. The first suite has ages of 105–92 Ma and formed in a syn-orogenic setting. The second (86–83 Ma) and third (ca. 73 Ma) suites formed during the post-orogenic stage of the Sikhote–Alin orogenic belt. The second and third suites were coeval with Late Cretaceous granitoids that formed in a suprasubduction continental arc known as the Eastern Sikhote–Alin volcanic–plutonic belt (ESAVPB). However, the studied rocks are located far inland from the ESAVPB. The ages of the studied granitoids coincide with the timing of a change in the angle of convergence between the Paleo-Pacific Plate and eastern margin of the Paleo-Asian continent. This change in motion of the oceanic plate with respect to the continental plate was probably caused by a rupture in the subducted slab (i.e., a slab tear), followed by asthenospheric upwelling and partial melting of the overlying crust, which ultimately generated post-orogenic intrusive magmatism.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5738616

Origin of the Ordovician Mansehra granite in the NW Himalaya, Pakistan: constraints from Sr–Nd isotopic data, zircon U–Pb age and Hf isotopes

2018 ◽  
Vol 481 (1) ◽  
pp. 277-298 ◽  
Author(s):  
Masatsugu Ogasawara ◽  
Mayuko Fukuyama ◽  
Rehanul Haq Siddiqui ◽  
Ye Zhao
Keyword(s):  
Granitic Magma ◽  
Geochemical Data ◽  
Large Contribution ◽  
Crustal Material ◽  
Sr Isotope ◽  
Nw Himalaya ◽  
Nd Isotope ◽  
Isotope Data ◽  
Late Neoproterozoic ◽  
T Values

AbstractThe Mansehra granite in the NW Himalaya is a typical Lesser Himalayan granite. We present here new whole-rock geochemistry, Rb–Sr and Sm–Nd isotope data, together with zircon U–Pb ages and Hf isotope data, for the Mansehra granite. Geochemical data for the granite show typical S-type characteristics. Zircon U–Pb dating yields 206Pb/238U crystallization ages of 483–476 Ma. The zircon grains contain abundant inherited cores and some of these show a clear detrital origin. The 206Pb/238U ages of the inherited cores in the granite cluster in the ranges 889–664, 1862–1595 and 2029 Ma. An age of 664 Ma is considered to be the maximum age of the sedimentary protoliths. Thus the Late Neoproterozoic to Cambrian sedimentary rocks must be the protolith of the Mansehra granitic magma. The initial Sr isotope ratios are high, ranging from 0.7324 to 0.7444, whereas the εNd(t) values range from −9.2 to −8.6, which strongly suggests a large contribution of old crustal material to the protoliths. The two-stage Nd model ages and zircon Hf model ages are Paleoproterozoic, indicating that the protolith sediments were derived from Paleoproterozoic crustal components.

scholarly journals Окислительно-восстановительный фон в земной коре Сихотэ-Алиньского орогенного пояса при кристаллизации магматитов мел-палеогенового возраста: связь с геодинамикой

2020 ◽  
pp. 24-38
Author(s):  
Yu. V. Taltykin ◽  
◽  
L. F. Mishin ◽  
E. A. Konovalova ◽  
◽  
...  
Keyword(s):  
Orogenic Belt ◽  
Redox Conditions ◽  
Western Pacific ◽  
Sikhote Alin ◽  
Mechanism Of Formation ◽  
Magma Crystallization ◽  
The Relationship

A new mechanism for the formation of ilmenite and magnetite series of granitoids in the Sikhote-Alin orogenic belt is proposed. The existing distribution zones of these magmatites are associated with the regional redox background, where magma crystallization occurs. The paper shows the relationship between the redox background in the lithosphere of the region and subduction processes in the Cretaceous-Paleogene time. The proposed mechanism of formation of the ilmenite and magnetite zones of Sikhote-Alin also explains the differences in redox conditions during the crystallization of Mesozoic magmatites in the orogens of the Eastern and Western Pacific coasts.

Geochronology, geochemistry, and Hf isotopic compositions of early Permian syenogranite and diabase from the northern Great Xing’an Range, northeastern China: petrogenesis and tectonic implications

2020 ◽  
Vol 57 (12) ◽  
pp. 1478-1491 ◽  
Author(s):  
Yong-gang Sun ◽  
Bi-le Li ◽  
Feng-yue Sun ◽  
Qing-feng Ding ◽  
Ye Qian ◽  
...  
Keyword(s):  
Early Carboniferous ◽  
Northeastern China ◽  
Geochemical Data ◽  
Late Paleozoic ◽  
Crustal Material ◽  
Early Permian ◽  
Geodynamic Evolution ◽  
Isotopic Compositions ◽  
Great Xing’An Range ◽  
T Values

Geodynamic evolution in the late Paleozoic is significant for understanding the final amalgamation of the Central Asian Orogenic Belt (CAOB). No consensus has yet been reached regarding the late Paleozoic geodynamic evolution of the northern Great Xing’an Range (GXR) in northeastern China, the eastern CAOB. Furthermore, late Paleozoic syenogranite–diabase dyke association is present in the Xiaokele area in northern GXR. It provides an important opportunity to understand the nature of magmatism and the geodynamic evolution during this period. This paper presents new zircon U–Pb ages, zircon Hf isotopic compositions, and geochemical data of whole rocks for Xiaokele syenogranite and diabase. Zircon U–Pb dating suggests that the Xiaokele syenogranite (292.5 ± 0.9 Ma) and diabase (298.3 ± 1.5 Ma) were emplaced during the early Permian. The Xiaokele syenogranites have high SiO2 contents, low MgO contents, and enriched zircon εHf(t) values, suggesting that their primary magma was generated by the partial melting of the juvenile crustal material. The Xiaokele diabases have low SiO2 contents, high MgO contents, are enriched in large-ion lithophile elements, depleted in high-field-strength elements, and exhibit enriched zircon εHf(t) values. They derived from a lithospheric mantle source that had previously been metasomatized by slab-derived fluids. Combined with previous research results, we believe that the continent–continent collision between the Xing’an and Songliao blocks occurred during the late early Carboniferous – early late Carboniferous (330–310 Ma), and the two blocks were transformed into a post-collisional extensional setting during the latest Carboniferous – early Permian.

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