Petrogenesis of Neoproterozoic magmatic rocks in the Songnen Massif (northeastern China): Implications for basement composition and crustal growth

Luan，Jin–Peng P.1,2; Tang，Jie1; Xu，Wen–Liang L.1,3; Guo，Peng4; Long，Xin–Yu Y.1; Xiong，Shuai1

2022-07-15

10.1016/j.precamres.2022.106687

PRECAMBRIAN RESEARCH   Impact Factor & Quartile

0301-9268

1872-7433

This paper reports new zircon U-Pb geochronological, whole-rock geochemical, and zircon Hf isotopic data for Neoproterozoic intrusive rocks in the Songnen Massif in the eastern Central Asian Orogenic Belt (CAOB), with the aim of revealing the petrogenesis of the Neopmterozoic intrusive rocks, and constraining the basement composition and crustal growth process of the Songnen Massif. Dating results identify three episodes of Neopmterozoic magmatism at ca. 950, ca. 856, and ca. 790 Ma in the eastern Songnen Massif. The ca. 950 Ma magmatic rocks consist of syenogranites, the ca. 856 Ma magmatic rocks comprise mainly gneissic monzogranites, and the ca. 790 Ma magmatic rocks consist of gneissic monzonites and monzogranites. The Neopmterozoic granitoids have high contents of SiO2 and K2O, low contents of total Fe2O3 and MgO, and show characteristics of enrichment in large-ion lithophile elements (e.g., K and Rb), and depletion in high-fieldstrength elements, implying that their primary magmas could have been derived from partial melting of the lower crust. However, compared with the ca. 790 Ma monzogranites [epsilon(Hf(t))= +7.3 to +9.5] in the south of the Songnen Massif, the ca. 950 and ca. 856 Ma granitoids in the north have much lower zircon epsilon(Hf)(t) values (-2.0 to -0.2 and -10.6 to -8.9, respectively), suggesting that the ca. 950 and ca. 856 Ma magmas were generated by the reworking of ancient mafic lower crust, whereas the ca. 790 Ma granitic magma was generated by the reworking of juvenile mafic lower crust. In contrast, the ca. 790 Ma gneissic monzonites were formed by mixing of the mantle-derived and crust-derived melts. Considering the Precambrian magmatism, detrital and captured zircons, and zircon Hf model ages together, the Precambrian basement of the Songnen Massif includes not only the Neopmterozoic crustal materials, but also the Neoarchean-Mesopmterozoic components. Zircon epsilon(Hf)(t) values of the Neoproterozoic granitoids in the Songnen Massif appear to progressively decrease from south to north, reflecting a lateral heterogeneity of basement composition of the eastern Songnen Massif, and indicating that crustal growth occurred mainly during the late Mesoproterozoic and Neoproterozoic in the south, while during the late Paleoproterozoic in the north.

CAOB Songnen Massif Neoproterozoic magmatism Petrogenesis Basement composition Crustal growth

SCI

English

Others

National Natural Science Foundation of China["42072071","41772047"] ; Fundamental Research Funds for the Central Universities[N2123029] ; Natural Science Foundation of Hebei Province[D2020501002]

Geology

Geosciences, Multidisciplinary

WOS:000832727400002

ELSEVIER

GEOSCIENCES

2-s2.0-85134477924

Web of Science

1.College of Earth Sciences,Jilin University,Changchun,130061,China
2.Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang,110819,China
3.Key Laboratory of Mineral Resources Evaluation in Northeast Asia,Ministry of Land and Resources,Changchun,130061,China
4.Department of Earth and Space Science,Southern University of Science and Technology,Shenzhen,518055,China

Luan，Jin–Peng P.,Tang，Jie,Xu，Wen–Liang L.,et al. Petrogenesis of Neoproterozoic magmatic rocks in the Songnen Massif (northeastern China): Implications for basement composition and crustal growth[J]. PRECAMBRIAN RESEARCH,2022,376.

Luan，Jin–Peng P.,Tang，Jie,Xu，Wen–Liang L.,Guo，Peng,Long，Xin–Yu Y.,&Xiong，Shuai.(2022).Petrogenesis of Neoproterozoic magmatic rocks in the Songnen Massif (northeastern China): Implications for basement composition and crustal growth.PRECAMBRIAN RESEARCH,376.

Luan，Jin–Peng P.,et al."Petrogenesis of Neoproterozoic magmatic rocks in the Songnen Massif (northeastern China): Implications for basement composition and crustal growth".PRECAMBRIAN RESEARCH 376(2022).