A comparison study of tungsten-bearing granite and related mineralization in the northern Jiangxi-southern Anhui provinces and southern Jiangxi Province in South China

The southern Jiangxi Province(SJP) and northern Jiangxi-southern Anhui provinces(NJSAP) are the two most important tungsten metallogenic districts in South China. The SJP district is a well-known tungsten producer in South China where distributes several ore concentrated areas such as the "Chongyi-Dayu-Shangyou", "Yudu" and "Longnan-Quanan-Dingnan"areas, with many large and super large tungsten deposits including the famous Xihuashan, Piaotang, Pangushan and Dajishan deposits. In recent years, major prospecting breakthrough for W-polymetallic resources has been made in the NJSAP district.Several large and super large W-Cu(Mo) deposits, such as the Dahutang, Zhuxi, Dongyuan and Baizhangyan deposits, are discovered. These deposits are all genetically associated with the Yanshanian(Mesozoic) granitic magmatism. In this study, a systematic comparison of the temporal and spatial distribution, petrology, geochronology, and geochemical characteristics of the tungsten-bearing granites between the SJP and NJSAP districts has been made, with an aim to improving the understanding of the petrogenesis of the granites and associated metal enrichment mechanisms in the two tungsten ore districts in South China. The following conclusions can be drawn:(1) The ages of the tungsten-bearing granites and associated mineralization are different in the two districts, in the SJP district the ages are mainly concentrated in 165–150 Ma, whereas in the NJSAP district it displays two age periods, one is 150–140 Ma(Late Jurassic-Early Cretaceous), and the other is 135–120 Ma(Early Cretaceous).(2) The tungsten-bearing granites from both the NJSAP and SJP districts are highly fractionated granitic rocks, but the SJP granites have experienced higher degree of fractional crystallization and more extensive fluid metasomatism than the NJSAP granites.(3) The petrogeneses of the tungsten-bearing granites from the two districts are different, those from the NJSAP district originated from partial melting of less mature sandstone-mudstone intercalated with meta-volcanic rocks of the Neoproterozoic Shuangqiaoshan Group which are both W and Cu enriched, in contrast those from the SJP district were likely derived from the highly mature,clay-rich mudstones of the Mesoproterozoic age which are only W enriched. In summary, the different source rocks with different metal enrichment features and different magmatic evolution and fractional degrees for the granites in the two districts might be the key factors that controlled the different matallogenic characteristics of tungsten ore deposits in the two districts in South China.

Multiple-aged granitoids and related tungsten-tin mineralization in the Nanling Range, South China

The Nanling metallogenic belt in South China is characterized by well-developed tungsten-tin mineralization related to multi- ple-aged granitoids. This belt is one of the 5 key prospecting and exploration areas among the 19 important metallogenic tar- gets in China. Important progress has been made in recent years in understanding the Nanling granitoids and associated miner- alization, and this paper introduces the latest major findings as follows： （1） there exists a series of Caledonian, Indosinian, and Yanshanian W-Sn-bearing granites; （2） the Sn-bearing Yanshanian granites in the Nanling Range form an NE-SW trending aluminous A-type granite belt that stretches over 350 km. The granites typically belong to the magnetite series, and dioritic micro-granular enclaves with mingling features are very common; （3） the Early Yanshanian Sn- and W-bearing granites pos- sess different petrological and geochemical features to each other： most Sn-bearing granites are metaluminous to weakly per- aluminous biotite （hornblende） granites, with zircon tHe（t） values of ca. -2 to -8, whereas most W-bearing granites are peralu- minous two-mica granites or muscovite granites with CHf（t） values of ca. -8 to -12; （4） based on the petrology and geochemis- try of the W-Sn-bearing granites, mineralogical studies have shown that common minerals such as titanite, magnetite, and bio- tite may be used as indicators for discriminating the mineralizing potential of the Sn-bearing granites. Similarly, W-bearing minerals such as wolframite may indicate the mineralizing potential of the W-bearing granites. Future studies should be fo- cused on examining the internal relationships between the multiple-aged granites in composite bodies, the metallogenic pecu- liarities of multiple-aged W-Sn-bearing granites, the links between melt evolution and highly evolved ore-bearing felsic dykes, and the connections between granite domes and mineralization.