Early Paleozoic Adakitic Granitoids from the Xingshuping Gold Deposit of East Qinling, China: Petrogenesis and Tectonic Significance

Pei Zan,Shengli Li,Jinduo Chen,Shouyu Chen

doi:10.3390/min11101032

Abstract

This study discussed the pertrological classification, geochronology, petrogenesis and tectonic evolution of early Paleozoic granites from the Xingshuping gold deposit in the East Qinling orogenic belt. In order to achieve this target, we carried out an integrated study of zircon U–Pb age, whole-rock major and trace elements, as well as Sr–Nd–Hf isotope compositions for the Xingshuping granites (part of the Wuduoshan pluton) from the Erlangping unit. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb dating constrains the emplacement age of the Xingshuping granites at 446.2 ± 1.2 Ma. The rocks at Xingshuping can be divided into two types: mainly biotite granite and monzonitic granite. The biotite granites are typical adakitic rocks, while the monzonitic granites show characteristics similar to normal arc volcanic rocks. The geochemical compositions reveal that they were derived from a clay-rich, plagioclase-rich and biotite-rich psammitic lower continental crust source, with contributions of mantle-derived magmas. The distinction is that the biotite granites were primarily derived from partial melting in a syn-collision extension setting, whereas the monzonitic granite went through a fractional crystallization process in an intraplate anorogenic setting.

Highlights

The East Qinling orogenic belt (EQOB) is part of the Central China orogenic belt (CCOB), where the North China Craton (NCC) is adjacent to the north and South ChinaCraton (SCC) to the south [1,2] (Figure 1A)
Au reserves are associated with late Mesozoic (Late Jurassic to Middle Cretaceous) granites at the southern margin of the NCC [16,17,18,19,20], and only a few deposits are located within the neighbor terranes of the EQOB [20,21] or associated with other orogenic processes [13,22]
In order to clarify these problems and to provide a basis for further study, in this paper, we report the pertrological classification, geochronology and petrogenesis of granites from the Xingshuping gold deposit combined with the amount of geochronological, Minerals 2021, 11, 1032 geochemical and isotopic data that have been obtained for the Wuduoshan pluton in order to systematically study orogeny-related magmatic events and tectonic evolution

Summary

Introduction

The East Qinling orogenic belt (EQOB) is part of the Central China orogenic belt (CCOB), where the North China Craton (NCC) is adjacent to the north and South ChinaCraton (SCC) to the south [1,2] (Figure 1A). The EQOB records complex geological and tectonic history, including continental rifting, ocean basins opening and closure along convergent margins, continental growth and recycling, continental collision and intraplate tectonics [3,4,5,6,7]. It is formed by multiple stages (Neoproterozoic, Paleozoic and Mesozoic) of tectonism since Neoproterozoic and formed by collision of the NCC and SCC during the Early Mesozoic; most granitoid magmatism or plutons have been intensively studied [8,9,10,11]. Au reserves are associated with late Mesozoic (Late Jurassic to Middle Cretaceous) granites at the southern margin of the NCC [16,17,18,19,20], and only a few deposits are located within the neighbor terranes of the EQOB [20,21] or associated with other orogenic processes [13,22].

Methods

Results

Discussion

Conclusion