赣南八仙脑钨矿区氟磷锰矿的发现及地质意义初析

对赣南八仙脑钨矿区发现的氟磷铁锰矿进行了激光拉曼光谱、X射线粉晶衍射和电子探针成分研究,显示该种矿物为接近锰端元的氟磷锰矿。氟磷锰矿中含有丰富的气液两相包裹体,大者超过150μm,且多为气/液比小于1的富液相包裹体。拉曼光谱显示,气相组分中不仅含有H2O,还含有CH4、CO2,而液相组分则以H2O为主。氟磷锰矿在含钨石英脉中出现,且空间上与石英、萤石等脉石矿物密切共生,说明八仙脑钨矿床成矿流体具有富氟富磷的特征。此外,根据矿石中氟磷锰矿的存在,也可以初步判断相关的花岗岩体可能是富氟的花岗岩。     

Rare Earth Element and Trace Element Features of Gold-bearing Pyrite in the Jinshan Gold Deposit, Jiangxi Province

<正>Jinshan gold deposit is located in northeastern Jiangxi,South China,which is related to the ductile shear zone.It has a gold reserve of more than 200 tons,with 80%of gold occurring in pyrite. The LREE of gold-bearing pyrite is as higher as 171.664 ppm on average,with relatively higher light rare earth elements(LREE;159.556 ppm) and lower HREE(12.108 ppm).TheΣLREE/ΣHREE ratio is 12.612 and(La/Yb)_N is 11.765.These indicate that pyrite is rich in LREE.The(La/Sm)_N ratio is 3.758 and that of(Gd/Yb)_N is 1.695.These are obvious LREE fractionations.The rare earth element(REE) distribution patterns show obvious Eu anomaly with averageδEu values of 0.664,andδCe anomalies of 1.044.REE characteristics are similar to those of wall rocks(regional metamorphic rocks),but different from those of the Dexing granodiorite porphyry and Damaoshan biotite granite.These features indicate that the ore-forming materials in the Jinshan gold deposit derived from the wall rocks, and the ore-forming fluids derived from metamorphic water.The Co/Ni ratio(average value 0.38) of pyrite suggests that the Jinshan gold deposit formed under a medium-low temperature.It is inferred from the values of high-field strength elements,LREE,Hf/Sm,Nb/La,and Th/La of the pyrite that the ore-forming fluids of the Jinshan gold deposit derived from metamorphic water with ClF.     

青海大柴旦双口山铅锌矿地质特征及控矿因素分析

通过对双口山铅锌矿以往地质资料的整理、研究及野外实地调查,系统地分析了该矿床的控矿因素,并总结了找矿标志。     

aiNet- and GIS-based regional prediction system for the spatial and temporal probability of rainfall-triggered landslides

We developed a real-time forecasting system, aiNet-GISPSRIL, for evaluating the spatiotemporal probability of occurrence of rainfall-triggered landslides. In this system, the aiNet (a kind of artificial neutral network based on a self-organizing system) and GIS are merged for integrating the rainfall conditions into various environmental factors that influence the landslide occurrence and for simulating the complex non-linear relationships between landslide occurrence and its related conditions. Zhejiang Province (101,800 km² in area), located in the southeast coastal region of China, is highly prone to the occurrence of landslides during intensive rainfall. Since 2003, the aiNet-GISPSRIL has been used to predict landslides during the rainy seasons in the region. The aiNet-GISPSRIL uses the regional 24-h forecast rainfall information and the real-time rainfall monitoring data from the rain-gauge network as its inputs, and then provides 24-h forecast of the landslide probability for every 1 × 1-km grid cell within the region. Verification studies on the performance of the aiNet-GISPSRIL show that the system has successfully predicted the dates and localities of 304 landslides (accounting for 66.2% of reported landslides during the period). During the period from 2003 to 2007, because the system provided the probability levels of landslide occurrences up to 24-h in advance, gave locations of potential landslides, and timely warned those individuals at high-risk areas, more than 1700 persons living in the risk sites had been evacuated to safe ground before the landslides occurred and thus casualty was avoided. This highly computerized, easy-operating system can be used as a prototype for developing forecasting systems in other regions that are prone to rainfall-triggered landslides.     

华北地区冬季降水时空分布特征分析

利用华北地区29个测站,57年冬季降水量资料,采用EOF,REOF,小波分析等方法,对华北地区冬季降水量的空间分布特征和时间演变规律进行了诊断分析研究.结果表明:华北地区冬季降水的空间分布在整体一致的基础上,即存在南北分布差异,又有着环渤海湾地区与其它地区的差异;冬季整个华北地区可以划分为五个主要的降水异常区:黄河中下游区、京津唐区、呼伦贝东盟区、黄河河套区、冀北山地区;整个华北在70年代末期有明显的降水减少趋势;各区域冬季降水有不同尺度的年际和年代际周期变化,但基本上都存在着准12～14年、准3～5年的周期振荡.     

粤北梅子窝钨矿区隐伏花岗闪长岩锆石SHRIMP U-Pb年龄与~(40)Ar/~(39)Ar成矿年龄及其地质意义

梅子窝钨矿位于粤北瑶岭—梅子窝钨矿带的东部,成矿作用同期形成白云母的40Ar/39Ar年龄为(155.9±0.6)Ma,与华南中生代燕山期大规模W,Sn成矿作用的年龄一致,代表梅子窝钨矿的成矿年龄。矿床下部600m中段附近出现的隐伏黑云母花岗闪长岩体的锆石SHRIMPU-Pb年龄为(430.4±3.6)Ma,为加里东期,与成矿作用无关。因此,矿区不存在前人提出的两套叠加的"五层楼"成矿模式。成矿年龄与隐伏花岗闪长岩的年龄显示梅子窝钨矿的形成可能与更深部的隐伏燕山期花岗岩有关,矿床向深部可能延伸更大。     

深度学习支持下的宅基地复垦项目真实性智能审查技术研究与应用

全域综合整治背景下的宅基地复垦项目审查是保证复垦项目合法性合规性的有效手段,针对当前宅基地复垦项目审查效率低的问题,本文提出了基于遥感影像的农村宅基地复垦项目立项真实性审查方法。首先以重庆市农村宅基地复垦项目为例,建立宅基地复垦项目立项真实性审查模型,利用改进的U-Net模型准确提取建筑物,然后与复垦红线叠加实现复垦项目真实性的智能审查。试验结果表明,该方法能够快速准确地审查复垦项目真实性,对优化土地结构、促进土地流转、实现乡村振兴具有重要意义,可为全域综合整治背景下宅基地复垦项目真实性审查提供技术参考。     

云南剑川新民铁矿地质及成因

新民铁矿位于北北西—南南东向雪龙山—桥后断裂（弥沙河断裂）东侧之云岭褶皱束三级构造单元中,赋矿层位为中三叠统上兰组下亚段泥质灰岩.地层、构造控矿,为沉积—后期改造型铁矿床.     

Determining the optimal pumping duration of transient pumping tests for estimating hydraulic properties of leaky aquifers using global curve-fitting method: a simulation approach

Global curve-fitting method (GCFM) is regarded as an effective approach in hydrogeological parameter estimation, as it integrates and uses pumping data and water recovery data of a transient pumping test for parameter estimation. The impacts of pumping duration on hydrogeological parameter estimation by GCFM were investigated in the present study using 2 in situ pumping tests and 24 simulated transient pumping tests. Empirical formulas for determining the optimal pumping duration were derived. The study results suggest that pumping duration will have impacts on the accuracy of hydrogeological parameter estimation. When pumping duration is longer than a certain period, relative errors of hydrogeological parameter estimation keep relatively stable within an acceptable limit. Therefore, it is unnecessary to continue the pumping for a very long time after the groundwater level has become stable. When the change rate of drawdown over time (γ) in an observation well located within a distance of 100 m to the pumping well reaches 0.134, the pumping can be stopped. If there are more than one observation wells in a pumping test, the smallest γ value should be selected to determine the optimal pumping duration. This research is meaningful in the instruction of pumping tests, and will reduce test costs greatly.