夹皮沟金矿北西向剪切带存在着长英质和镁铁质两类糜棱岩系列岩石，韧性变形中伴随的大量流体与糜棱岩之间发生了强烈的水岩反应：斜长石绢云母化和钠化，暗色矿物绿泥石化，以及大范围强烈的碳酸盐化。韧性剪切变形为一近等体积过程（fv≈1）。 随韧性剪切作用增强，两类糜棱岩系列岩石中SiO2均带出，而CO2和H2O等挥发分及Au、S等成矿元素明显富集。释放出的SiO2呈胶体态赋存在流体中，并吸附Au等成矿物质，后在脆性构造中重结晶为含金石英脉。流体包裹体研究显示成矿流体主要由大气降水组成，其温度、压力和盐度分别为245～292℃、95.4～131.7M Pa和12.88～16.33wt%NaCl。

Zhijin County in Western Guizhou is one of the most important production areas of phosphorites in China. In order to investigate genesis of the phosphorites, their REE compositions were analyzed by using inductively coupled plasma emission mass spectrometry (ICP-MS) method. For comparison, phosphorites from the Lower Cambrian black rock series in Southern China, such as Zunyi in Guizhou and Zhangjiajie in Hunan Province, were also analyzed. The analytical data show that: (1) Xinhua phosphorites possess a quite high and greatly varied total rare earth elements (ΣREE), which varying between 164.23×10-6 and 1395.01×10-6 with average of 642.54×10-6, remarkable differentiation between light (LREE) and heavy rare earth elements (HREE), and the ΣLREEPΣHREE ratios varying between 5.04 and 6.52. The ΣREE and ΣLREEPΣHREE ratios of the Zunyi and Zhangjiajie phosphorites are 156.69×10-6～637.41×10-6 with average of 431.75×10-6 and 3.17～6.95 with average of 4.37 respectively; (2) All the phosphorites from Xinhua, Zunyi and Zhangjiajie show remarkable negative Ce anomalies. Besides, the Xinhua phosphorites possess lower δCe, which varying between 0.26 and 0.53 with average of 0.35, while δCe of the Zunyi and Zhangjiajie phosphorites are 0.30～0.66 with average of 0.47, suggesting that all of the phosphorites are typical marine sediments deposited mainly in ancient pericontinental seas, and the depositional position of the Xinhua phosphorite might be deeper; (3) Most phosphorites from Xinhua, Zunyi and Zhangjiajie possess unremarkable positive Eu anomaly, and only a few of samples show obvious ones. The δEu varies between 0.98 and 2.4, suggesting that hot (>200℃) and strong reductive hydrothermal fluids might have been involved in genesis of the phosphorites; (4) The Xinhua phosphorite is relatively depleted in HREE, and LaNPNdN and δYof most samples are>1 and >1.5 respectively. Besides, there exists no correlation between δY and δCe, suggesting that the phosphorite was subjected to quite strong weathering and leaching processes, and catagenesis do not greatly modify its REE compositions .

Two kinds of mylonite series rocks, felsic and mafic, have been recognized in the NW-striking shear zone of the Jiapigou gold belt. During ductile deformation, a large amount of fluid interacted intensively with the mylonite series rocks: plagioclases were sericitized and the An values declined rapidly, finally all of them were transformed to albites; dark minerals were gradually replaced by chlorites (mostly ripidolite). Meanwhile, large-scale and extensive carbonation also took place, and the carbonatization minerals varied from calcite to dolomite and ankerite with the development of deformation. The δ13C values of the carbonates are -3.0%0 -5.6%0 suggesting a deep source of carbon. The ductile deformation is nearly an iso-volume one (fv≈1). With the enhancement of shear deformation, SiO2 in the two mylonite series rocks was depleted, while volatile components such as CO2 and H2O, and some ore-forming elements such as Au and S were obviously enriched. But it is noted that the enrichment of Au in both the mylonite series rocks did not reach the paygrade of gold. The released SiO2 from water-rock interactions occurred in the form of colloids and absorbed gold in the fluid. When brittle structures were formed locally in the ductile shear zone, the ore-forming fluids migrated to the structures along microfractures, and precipitated auriferous quartz because of reduction of pressure and temperature. Fluid inclusion study shows that the temperature and pressure of the ore-forming fluids are 245-292℃ and 95.4-131.7 MPa respectively; the salinity is 12.88-16.33 wt% NaC1; the fluid-phase is rich in Ca2+, K+, Na+, Mg2+, F- and C1-, while the gaseous phases are rich in CO2 and CH4. The δD and δ18o values of the ore-forming fluid are -84.48%0-91.73%0 and -0.247%0 -+2.715%0 respectively, suggesting that the fluid is composed predominantly of meteoric water.

较系统的流体包裹体观测显示：①华南黑色岩系铂多金属矿中存在两种不同体系的流体包裹体，一为具中低盐度、NaCl-H2O体系者（Ⅰ型）；二为具中高盐度、CaCl2-NaCl-H2O体系者（Ⅱ型）；其中后者为该类矿床中首次确定；②存在2个不同期次的成矿流体，其中铂多金属矿层和其下伏磷块岩中碳酸盐石英网脉的流体包裹体特征基本一致，可能代表主成矿期流体，其均一温度峰值为170℃左右，而盐度具双峰式特征，峰值分别为27%～31%和4%～6%；矿层之上碳酸盐石英脉中流体包裹体可能代表了晚期成矿流体，其均一温度多为130～170℃左右，盐度峰值在12%～14%；③在早寒武世，接受了巨厚沉积的扬子克拉通南缘加里东冒地槽中的盆地热卤水受挤压而顺层侧向迁移，从地层中汲取Ni、Mo、V和PGE等成矿元素，形成中高盐度的CaCl2-NaCl-H2O体系成矿热液，沿断裂上升并与NaCl-H2O体系海水混合，形成黑色岩系中的铂多金属矿床（点）。

利用惰性气体同位素质谱仪测定了华南下寒武统具代表性的黑色岩系铂多金属矿中黄铁矿流体包裹体的He-Ar同位素组成，发现其3He/4He均较低，为0.43×10-8～26.39×10-8，R/Ra为0.003～0.189，而40Ar/Ar为258～287，接近大气饱和水。同位素地球化学示踪研究显示，该矿成矿流体主要由建造水（盆地热卤水）和大气饱和水（海水）组成，基本不含地幔流体或深源岩浆水。黑色岩系铂多金属矿的成矿可能与华南克拉通南缘加里东冒地槽的演化有关。在早寒武世，接受了巨厚沉积的加里东盆地中的建造水由于上覆沉积物的压力，顺层侧向迁移，并沿断裂上升与海水混合而成矿。