Lateral change of sources for the Cretaceous-Paleogene magmatism of the Tian Shan

Rasskazov, S. V.; Chuvashova, Irina; Mikolaichuk, Alexander; Sobel, Edward R.; Yasnygina, T. A.; Фефелов, Н. Н.; Saranina, Elena

doi:10.1134/s0869591115010038

Cited by 6 publications

(4 citation statements)

References 35 publications

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“…A mafic sill intruded in the Hodzhiabad conglomerates yields an apatite U-Pb age of ca 140 Ma ( § 3.3). The presence of (sub)volcanic rocks along the Naryn river near Tash Komyr was previously described by Verzilin (1976) and Rasskazov et al (2015), who suggested an Early…”

Section: Accepted Manuscriptmentioning

confidence: 62%

Source-to-sink dynamics in the Kyrgyz Tien Shan from the Jurassic to the Paleogene: Insights from sedimentological and detrital zircon U-Pb analyses

et al. 2018

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International audienceNew insights in the Mesozoic geodynamic evolution and related basin-range interactions in the Kyrgyz Tien Shan were obtained based on new sedimentological and detrital zircon U-Pb (LA-ICP-MS) results from Jurassic to Paleogene sedimentary sequences. Studied sedimentary sections are located in the Fergana and Yarkand-Fergana basins to the west of the Talas-Fergana Fault (TFF) and in the Issyk-Kul and Ming-Kush-Kökömeren basins to the east. The ages of the Phanerozoic zircon grains found in 18 Jurassic to Paleogene sandstones can be divided into four groups: Caledonian (470–390 Ma), Hercynian (315–260 Ma), Triassic (250–210 Ma) and Jurassic (190–160 Ma) ages. The differences in sedimentation pattern and zircon U-Pb results suggest that the TFF played an important role in the distribution of the sedimentary deposits in the Mesozoic. During the Early - Middle Jurassic, the TFF was active and the strongest subsidence occurred in the Yarkand-Fergana Basin. The provenance of its sediments can be explained both by local sources close to the TFF and by more distal sources to the (south)west, probably stretching into the present-day Pamir. During the Late Jurassic – Early Cretaceous, renewed compression led to the inversion of the Yarkand-Fergana Basin. Around the Jurassic – Cretaceous transition, large alluvial fans developing in a semi-arid to arid climate traceable around the whole Tien Shan were also deposited in the Fergana Basin. A mafic sill intruded within these alluvial fans provides an emplacement age of 144 ± 8 Ma (apatite U-Pb) indicating (sub)volcanic activity during the Early Cretaceous. During the Late Cretaceous to early Paleogene, the area to the west of the TFF experienced marine incursions related to the proto-Paratethys Sea. The dominance of Caledonian ages in the Upper Cretaceous – lower Paleogene detrital samples indicates a change in provenance whereby the drainage areas became larger towards low-relief land area east of the TFF

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Section: Accepted Manuscriptmentioning

confidence: 62%

Source-to-sink dynamics in the Kyrgyz Tien Shan from the Jurassic to the Paleogene: Insights from sedimentological and detrital zircon U-Pb analyses

et al. 2018

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“…Во впадине Туюн (Китайский Тянь-Шань) извергалась вулканическая серия пикробазальт-трахибазальт-базанит-фонотефрит-фонолит на протяжении длительного временного интервала 122-46 млн лет назад. Вся вулканическая серия была производной плавления малоглубинного безгранатового мантийного источника [Rasskazov et al, 2015]. По изотопным отношениям Pb различаются два тренда.…”

Section: эволюционированные составы Elmuunclassified

General Pb‐isotope Systematics of Sources for Volcanic Rocks of the Latest Geodynamic Stage in Asia

Рассказов

Chuvashova

Ясныгина

et al. 2019

Geodin. tektonofiz.

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The modern theory of the evolving Earth is based on integrated isotopic data obtained for the accessible part of the planet and cosmic bodies, in which the U–Pb isotope system plays a key role. The theory is tested by the isotope systematics of oceanic basalt sources. The origin of continental volcanic rocks is often interpreted in terms of the isotopic systematics of oceanic basalts. However, such interpretations, as a rule, reveal contradictions arising from differences in the history and current mantle dynamics of oceans and continents. Under the oceans, a mantle material has long lost connection with the accessible Earth tectonic units; under the continents such a connection is often established. The nature of the evolution of deep‐seated processes under the continents remains uncertain and, by analogy with the oceans, requires deciphering in terms of the components of the mantle sources for volcanic rocks. In modern lithospheric plates of the Earth, there are regions ranging in width from hundreds to thousands of kilometers, which are characterized by high strain rates and, consequently, at least one to two orders of magnitude lower viscosity relative to that of the internal stable parts of the plates. This gives them a special structural status of “dispersed plate boundaries”. The isotope‐geochemical studies of volcanic rocks from regions of the unstable Asia revealed the different nature of components in sources, for which particular interpretations have been proposed. In this paper, a general systematics of sources is defined for volcanic rocks of the latest geodynamic stage in Asia through estimating the incubation time on the 207Pb/204Pb versus 206Pb/204Pb diagram. Two domains are designated: (1) low 238U/204Pb (LOMU) derived from the viscous protomantle (VIPMA), and (2) elevated 238U/204Pb (ELMU). The mantle domains evolved from the Earth's primary material between 4.51 and 4.36 Gyr ago, 4.0 and 3.7 Gyr ago, 2.9 and 2.6 Gyr ago, 2.0 and 1.8 Gyr ago, about 0.66 Gyr ago and <0.09 Gyr ago. Melting anomalies of ELMU sources characterize the unstable mantle of Southern Asia, and those of LOMU sources belong to the Japan‐Baikal geodynamic corridor of the transitional region between the unstable mantle of Asia and its stable core. The Late Cenozoic evolution of the Japan‐Baikal geodynamic corridor resulted in cutting the LOMU domain by the Jeju‐Vitim ELMU source line.

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“…Meanwhile, Sr isotope ratios may be overstated due to rock alteration. Although this effect can be reduced by acid treatment of a sample Rasskazov et al, 2015), no criterion for a strontium isotope ratio in an unaltered rock is substantiated and no true value of this parameter can be estimated.…”

Section: Crustal Contaminationmentioning

confidence: 96%

Mid-Miocene thermal impact on the lithosphere by sub-lithospheric convective mantle material: Transition from high- to moderate-Mg magmatism beneath Vitim Plateau, Siberia

Chuvashova

Rasskazov

Yasnygina

2017

Geoscience Frontiers

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Lateral change of sources for the Cretaceous-Paleogene magmatism of the Tian Shan

Cited by 6 publications

References 35 publications

Source-to-sink dynamics in the Kyrgyz Tien Shan from the Jurassic to the Paleogene: Insights from sedimentological and detrital zircon U-Pb analyses

Source-to-sink dynamics in the Kyrgyz Tien Shan from the Jurassic to the Paleogene: Insights from sedimentological and detrital zircon U-Pb analyses

General Pb‐isotope Systematics of Sources for Volcanic Rocks of the Latest Geodynamic Stage in Asia

Mid-Miocene thermal impact on the lithosphere by sub-lithospheric convective mantle material: Transition from high- to moderate-Mg magmatism beneath Vitim Plateau, Siberia

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