Petrogenesis and tectonic significance of the Mengjiaping beschtauite in the southern Taihang mountains

Haofei Tian,Mengqi Jin,Xian Liang,Jinyong Choi,Shen Wang,Wenlou Luan,Xiaofei Hu,Peijie Zou,Haotian Chen,Liang Zhao,Ganyu Li,Wenjing Chen,Sinan Han,Xingtao Cui,Chengjie Zou

doi:10.1515/geo-2020-0324

Abstract

Abstract The evolution process of the North China Craton has been discussed by many scholars; however, the frame for the timing of the Trans-North China Block has not been fully agreed upon. Related research has mostly focused on the northern and southern sections of the Trans-North China Block, and in-depth studies on intrusive rocks in the central region are lacking. In this study, we conduct a systematic study of the petrography, the whole-rock geochemistry, and the zircon U–Pb dating for the beschtauite intrusion, located in the Mengjiaping area of the Southern Taihang Mountains. Our results demonstrate that the dyke intrusion is mainly composed of beschtauite. Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating shows that the beschtauite intrusion occurred at ∼1,880 ± 69 Ma. The beschtauite belongs to I-type granite, Arc tholeiite series, and Cale-alkaline series, with low total alkali, low potassium, and high aluminum. They are also enriched in large-ion lithophile elements, relatively depleted in high-field strength elements, and low total rare-earth elements. Based on the abovementioned data, it is suggested that the magmas for the beschtauite intrusion were metasomatized by oceanic slab subduction in the Late Paleoproterozoic. The formation time of the North China Craton basement should be set to after 1,880 Ma.

Highlights

The North China Craton is one of the oldest cratons in the world [1]
Compared with the Earth’s crust, the high-field strength elements (HFSEs), such as P, Nb, Ce, Ta, Sr, and Ti, were relatively depleted, whereas the large-ion lithophile elements (LILEs), such as Rb, Th, and K, were relatively enriched, which is a characteristic of a volcanic-arc granite
The results indicate that beschtauite may originate from mantle-derived magma or mixed crust- and mantle-derived magma

Summary

Introduction

Compared with other cratons worldwide, the North China Craton has recorded almost all major tectonic events after 3.5 Ga during the early development of the Earth despite possessing a limited exposed area [2]. This craton exhibits a dual paleostructural geographic pattern comprising an early Precambrian metamorphic crystalline basement and a Mesoproterozoic sedimentary cap [3]. Related studies have mostly focused on the northern and southern sections of the Trans-North China Block [10,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68], and there is a lack of in-depth studies on intrusive rocks in the central region [18,69,70,71,72,73,74,75]

Methods

Results

Discussion

Conclusion