Mantle sources of the Cenozoic volcanic rocks of East Asia: Derivatives of slabs, the sublithospheric convection, and the lithosphere

Abstract

The spatial temporal variations of the trace element and Sr isotope composition were analyzed in the Middle-Late Cenozoic volcanic rocks of the East Asian continental margin. The heterogeneity of the sublithospheric mantle was characterized, the active sources of the supraslab mantle were distinguished, and the Southern and Northern sublithospheric convective subdomains of the Transbaikalian low velocity domain at a depth of 410-200 km were distinguished. The supply of isotopically homogenous mantle from the convective subdomains was replaced in space and time by their mixtures. Isotopically highly depleted material was derived from the mantle above the Kula Izanagi and Pacific slabs ~43.5, 23-17, and <15 Ma, while moderately depleted mantle was derived from the Northern and Southern subdomains ~37, 31-23, and 16 Ma and 19-12 Ma, respectively. Similar convective but shallower isotopically enriched material was determined in mixtures from the Southern convective subdomain in the Northeast Japanese arc within 30-9 Ma and in mixtures with isotopically enriched lithospheric mantle in the central Heilongjiang Province <9.6 Ma. Lithospheric melts erupted during drastic changes in the dynamics of the sublithospheric convective subdomains.

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

“…Об источниках ее вулканизма высказывались различные суждения [Tatsumi et al, 1990;Zonenshain et al, 1991;Maruyama et al, 2007;и др.]. Изотопногеохимические исследования вулканических пород отдельных регионов [Chandrasekharam et al, 1999;Chen et al, 2007;Choi et al, 2006;Kuritani et al, 2013;Melluso et al, 2006;Park et al, 2005;Peng et al, 1994;Rasskazov, Chuvashova, 2018;Rasskazov et al, 2002Rasskazov et al, , 2005Rasskazov et al, , 2014Rasskazov et al, , 2019Song et al, 1990;Tatsumi et al, 2005;Tatsumoto et al, 1992;Wee, 1999;Zartman et al, 1991;Zhang et al, 1995Zhang et al, , 2018Zhang, Guo, 2016;Zou et al, 2000] выявили различный характер компонентов источников, для которых были предложены частные интерпретации. Излившиеся мантийные расплавы контаминированы коровым материалом лишь в исключительных случаях, что открывает возможность исследования характера мантийных источников.…”

Trace-Element and Pb Isotope Evidence on Extracting Sulfides from Potassic Melts beneath Longmenshan and Molabushan Volcanoes, Wudalianchi, Northeast China

“…The field of East China basalts and data of Pb isotopic ratios of rocks from Linju, Shandong Province are shown after [47]. The East Asian common reservoir ( 206 Pb/ 204 Pb = 17.55; 207 Pb/ 204 Pb = 15.52; 208 Pb/ 204 Pb = 37.76) is indicated after [9]. Slopes of reference lines, which approximate data points of sources, are explained in the text.…”

“…Both low-and moderate-Mg rocks from Wudalianchi revealed no Ce/Pb signatures specific for oceanic or convergent continental margin sources (~25 or 2.5, respectively), but showed Ce/Pb typical of the primordial mantle (PM = 10.7 ± 0.5). Therefore, the Wudalianchi source material represents the ESCM that never passed the oceanic stage, but could originate through processing of the evolved PM material, which was likely retained in the East Asian common reservoir [9]. Therefore, there is no reason to refer to Wudalianchi rocks as EM1 OIB end-member as was previously thought [1,2,4,5].…”

“…Both potassic and potassic-sodic rocks have been regarded as a single continuum, the Minerals 2020, 10 55,208 Pb/ 204 Pb~36.5) [6]. In most studies, K-rich magmas have been referred to the uppermost part of the asthenosphere and lithosphere [7][8][9][10]. The Wudalianchi volcanic field is of particular interest due to the historical 1720 to 1776 AD eruptions of the Laoheishan and Huoshaoshan volcanoes.…”

“…The field of East China basalts and data of Pb isotopic ratios of rocks from Linju, Shandong Province are shown after[47]. The East Asian common reservoir ( 206 Pb/ 204 Pb = 17.55; 207 Pb/ 204 Pb = 15.52; 208 Pb/ 204 Pb = 37.76) is indicated after[9]. Slopes of reference lines, which approximate data points of sources, are explained in the text.In contrast to moderate-Mg rocks of the Molabushan cone, low-Mg compositions of the Molabushan flow showed Pb isotopic ratios similar to values of the Gelaqiu source and a mixing trend directed toward the Molabu one.…”