Strike-slip tectonics and subalkaline mafic magmatism in the Early Paleozoic collisional system of the western Baikal region

Fedorovsky, V.S.; Sklyarov, E. V.; Изох, А. Э.; Kotov, A. B.; Лавренчук, А. В.; Мазукабзов, А. М.

doi:10.1016/j.rgg.2010.04.009

Cited by 40 publications

(26 citation statements)

References 14 publications

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“…During this activity, several terranes accreted along the margins of the Siberian Craton (Donskaya et al 2000). The structure of the Olkhon region is considered to be a stack of shear slabs composed of metamorphic and magmatic rocks (Fedorovsky et al 2010;Fedorovsky and Sklyarov 2010).…”

Section: Occurrencementioning

confidence: 99%

Pavlovskyite Ca8(SiO4)2(Si3O10): A new mineral of altered silicate-carbonate xenoliths from the two Russian type localities, Birkhin massif, Baikal Lake area and Upper Chegem caldera, North Caucasus

Galuskin¹,

Gfeller²,

Savelyeva³

et al. 2012

American Mineralogist

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The new mineral pavlovskyite Ca 8 (SiO 4 ) 2 (Si 3 O 10 ) forms rims together with dellaite Ca 6 (Si 2 O 7 )(SiO 4 ) (OH) 2 around galuskinite Ca 7 (SiO 4 ) 3 CO 3 veins cutting calcio-olivine skarns in the Birkhin gabbro massif. In addition, skeletal pavlovskyite occurs in cuspidine zones of altered carbonate xenoliths in the ignimbrites of the Upper Chegem caldera (North Caucasus). The synthetic analog of pavlovskyite has been synthesized before and is known from cement-like materials. Isotypic to pavlovskyite is the synthetic germanate analog Ca 8 (GeO 4 ) 2 (Ge 3 O 10 ). The crystal structure of pavlovskyite, space group Pbcn, a = 5.0851(1), b = 11.4165(3), c = 28.6408(8) Å, V = 1662.71(7) Å 3 , Z = 4, has been refined from X-ray single-crystal data to R1 = 3.87%. The new colorless mineral has a Mohs hardness of 6-6.5, biaxial (-), α = 1.656(2), β = 1.658(2), γ = 1.660(2) (589 nm), 2V (meas) = 80(5)°, 2V (calc) = 89.9°, medium dispersion: r > v, optical orientation: X = b, Y = c, Z = a.For comparison with pavlovskyite, the crystal structure of kilchoanite Ca 6 (SiO 4 )(Si 3 O 10 ) from the Birkhin massif [space group I2cm, a = 11.4525(2), b = 5.0867(1), c = 21.996(3) Å, V = 1281.40(4) Å 3 , Z = 4] has been refined from single-crystal X-ray data to R1 = 2.00%.Pavlovskyite represents a 1:1 member of a polysomatic series with calcio-olivine γ-Ca 2 SiO 4 and kilchoanite Ca 6 (SiO 4 )(Si 3 O 10 ) as end-member modules. The structure is characterized by strongly folded trisilicate units (Si 3 O 10 ) interwoven with a framework of CaO 6 and CaO 8 polyhedra. Olivine-like slices with orthosilicate groups are interstratified with the characteristic trisilicate module of Ca 4 (Si 3 O 10 ) composition. Although the optical properties of pavlovskyite and kilchoanite are similar, both minerals can be distinguished by chemical analyses (different Ca/Si ratio), X-ray diffraction, and Raman spectroscopy. The new mineral is named after V.E. Pavlovsky , an outstanding geologist in the area of Eastern Siberia, in particular of the Baikal region.

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Section: Occurrencementioning

confidence: 99%

Pavlovskyite Ca8(SiO4)2(Si3O10): A new mineral of altered silicate-carbonate xenoliths from the two Russian type localities, Birkhin massif, Baikal Lake area and Upper Chegem caldera, North Caucasus

Galuskin¹,

Gfeller²,

Savelyeva³

et al. 2012

American Mineralogist

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“…С магматизмом Метешихинской островодужной системы связано формирование Ольхон-Урбикан-Намаминского задугового ареала плюмового магматизма [Tsydypov et al, 2006;Fedorovsky et al, 2010]. Данный ареал субдукционного и связанного с ним плюмового магматизма выделяется нами пока условно.…”

Section: Fig 14unclassified

Relationship Between Subduction‐related and Plume Magmatism at the Active Boundaries of Lithospheric Plates in the Interaction Zone of the Siberian Continent and Paleoasian Ocean in the Neoproterozoic and Paleozoic

Гордиенко

2019

Geodin. tektonofiz.

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This paper is focused on the relationship between plate-and plume-tectonic processes during the formation of Neoproterozoic and Vendian-Paleozoic island-arc systems and active continental margins in the interaction zone of the Siberian continent and Paleoasian Ocean (PAO). In this study, we use our own materials collected in the long-term research of the Central Asian Orogenic Belt (CAOB) and the published models showing convection in the asthenosphere and mantle, subduction-related and plume magmatism at the Cenozoic active margins of the Western Pacific and California types. It is clearly shown that subduction-related magmatism of the Paleoasian Ocean active margins should not be considered separately from plume magmatism. These interrelated processes played a major role in the CAOB formation. Based on the reconstructed Neoproterozoic, Vendian-Early and Middle Paleozoic paleogeodynamic features, 25 island-arc systems of PAO are characterized. These island arcs are related to the occurrence of more than 30 plume magmatism areas. At the active margin of the Siberian continent, there are numerous fields of intraplate magmatism in riftogeneous structures. Such fields of various scales not related to subduction zones, especially at the final Late Paleozoic stage. All the major stages of the CAOB development, including the Cambrian-Ordovician collision stage, are clearly correlated with plume magmatism. Considering a revealed combination of the island arcs and the plume magmatism areas, there are grounds to suggest that the development of the entire Neoproterozoic-Paleozoic region of Central Asia was related to the activity of mantle plumes.

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“…Породные массивы в пределах юго-восточного крыла зоны Приморского разлома представлены образованиями нижнепалеозойского ольхонского метаморфического комплекса -преимущественно диоритами, габбро-диоритами, габброидами бирхинского комплекса с возрастом ≈500 млн лет [Fedorovsky et al, 2010]. В меньшей мере картируются в крыльях разлома метаморфические породы амфиболитовой фации: биотит-амфиболовые и амфиболовые гнейсы, кристаллосланцы, мраморы, а также небольшие тела гранитов.…”

Section: палеогеодинамические сведенияunclassified

On the structure and formation of earthquake sources in the faults located in the subsurface and deep levels of the crust. Part II. Deep level

Ruzhich

Kocharyan

Savelieva

et al. 2018

Geodin. tektonofiz.

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In the part 2 of the study [Ruzhich, Kocharyan, 2017, we aimed at identifying the elements of paleoearthquake sources in the crust, which formed at the hypocentral depths in the exhumed Primorsky segment of the ancient collisional suture. The study area covered the southeastern margin of the Siberian craton (Pribaikalie, East Siberia). Slickensides, pseudo-tachyllite (basaltic glass) and other petrological evidence of intensive tectonic movements were sampled. The structure of the deep segments of the collisional suture were reconstructed from on the data on coseismic ruptures and faults, and the PT parameters were estimated. In the past decades, similar research problems were actively investigated (e.g. [Sibson, 1973;Byerlee, 1978;Morrowetal., 1992;Hodges, 2004;Kirkpatricketal., 2012). In Russia, the interest in studying geological and geophysical features of the deeply denuded areas in ancient faults is still limited [Sherman, 1977;Ruzhich, 1989, 1992, 1997;Savel’eva et al., 2003;Ruzhich et al., 2015; Kocharyan, 2016. The deeply denuded Primorsky segment of the collisional suture of the Siberian Craton underwent the geological evolution of a billion years. In the analysis, we used additional geological data from the petrology studies of the Main Sayan fault zone and other exhumed fault segments, including the seismogenerating faults in the Mongolia-Baikal region [Zamaraev,Ruzhich, 1978;Zamaraev et al., 1979;Ruzhich et al., 2009. From the PT conditions for the occurrence of the slickensides, pseudo-tachylyte, and the Primorsky segment structure, the40Ar/39Ar method estimated the age of the slickensides containing tourmaline at 673±4.8 Ma, which may correspond to the Neoproterozoic stage of the breakdown of the megacontinent Rodinia. Another dating, 415.4±4.1 Ma, obtained for the muscovite sample from a decompressional rupture, refers to the Early Paleozoic stage in the development of the collisional suture, when accretion of the Siberian Craton and the Olkhon terrain took place [Donskaya et al., 2003;Fedorovsky et al., 2010. Based on these ages and other available petrological data, the depths of the heterochronous systems of coseismic ruptures were estimated:18 km in the Neoproterozoic, and12 km in the Middle Paleozoic stage of the seismotectonic evolution of the crust in Pribaikalie. The deep paleoseismological settings need to be further investigated in order to more thoroughly clarify the physical and chemical conditions that contributed to the occurrence of the ancient and recent sources of strong earthquakes in the deep segments of faults in the crust. Such information is a prerequisite for further progress towards resolving the problems of securing seismic safety in various regions.

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Strike-slip tectonics and subalkaline mafic magmatism in the Early Paleozoic collisional system of the western Baikal region

Cited by 40 publications

References 14 publications

Pavlovskyite Ca8(SiO4)2(Si3O10): A new mineral of altered silicate-carbonate xenoliths from the two Russian type localities, Birkhin massif, Baikal Lake area and Upper Chegem caldera, North Caucasus

Pavlovskyite Ca8(SiO4)2(Si3O10): A new mineral of altered silicate-carbonate xenoliths from the two Russian type localities, Birkhin massif, Baikal Lake area and Upper Chegem caldera, North Caucasus

Relationship Between Subduction‐related and Plume Magmatism at the Active Boundaries of Lithospheric Plates in the Interaction Zone of the Siberian Continent and Paleoasian Ocean in the Neoproterozoic and Paleozoic

On the structure and formation of earthquake sources in the faults located in the subsurface and deep levels of the crust. Part II. Deep level

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