Major Characteristics of the Lajishan Orogenic Belt of the South Qilian Mountains and Its Geotectonic Attribute

The Lajishan orogenic belt is one of the E-W-trending Caledonian orogenicbelts within the Qinling-Qilian orogenic system. It was formed upon the Jiningian basement byintensive taphrogenesis. Its major characteristics comprise the prominent faulting along the northand south boundaries, the highly complicated petrological and petro-geochemical features of thevolcanic rock series, and the development of a new type of ophiolite suite. In terms of tectonicanalysis and the sequential analysis of tectonic settings of magmatic rocks, it is suggested thatthe Lajishan orogenic belt has undergone a complete 'opening-closing' cycle, which can be furtherdivided into 3 second-order 'opening-closing' cycles. The composite characteristics of the'opening-closing' movement show that Laji Mountain is a typical fault orogenic belt. The faultorogenic belt is one of the most important types of intracontinental orogens. It is of criticaltheoretical and practical significance to summarize the characteristics and the diagnostic criteriaof this kind of orogenic belts, and study the mechanism of their formation and build models of theirevolution.

Discovery of Radiolarian Fossils from the Aiketik Group at the Western End of the South Tianshan Mountains of Chinaand Its Implications

The Aiketik Group, distributed at the western end of the South TianshanMountains, China, is an important lithostratigraphic unit involved in the South Tianshan orogen. Itis separated from the adjacent rocks by faults. Generally, the geologists ascribed it to the UpperCarboniferous according to Pseudostaffella sp., Profusulinella sp. and Fusulinella sp. found fromthe limestone and sandy limestone of Aiketik. Our radiolarian fossils were obtained from the chertsamples collected from the Haladaok section located at the upper Tuoshihan River. The fossils mainlyinclude Albaillella undulata Deflandre, Albaillella paradoxa Deflandre, Albaillella sp. aff. A.paradoxa Deflandre, Albaillella sp. cf. A. deflandrei Gourmelon, Albaillella sp., Albaillellaexcelsa Ishiga, Kito and Imoto (?), Belowea variabilis (Ormiston et Lane), Callella cf. C.parvispinosa Won, Entactinia cf. E. tortispina Ormiston et Lane, Entactinia aff. E. tortispinaOrmiston et Lane, Entactinia variospina Won, Entactinia sp., Eostylodictya rota (Won),Latentifistula impella (Ormistone et Lane) (?), Latentifistula turgita Omiston et Lane,Latentifistulidae gen. et. sp. indet. and Polyentactinia cf. aranea Gourmelon. Among them,Albaillella excelsa Ishiga, Kito and Imoto (?) is a Late Permian species with some elementsuncertain as there is only one poorly-preserved fossil of this species found so far. And tworadiolarian assemblages can be identified from the other fossils. One is the early EarlyCarboniferous assemblage represented by Albaillella undulata Deflandre, Albaillella paradoxa andAlbaillella sp. cf. A. deflandrei Gourmelon. And the other is the late Early Carboniferousassemblage represented by Eostylodictya rota (Won). This is the first discovery of radiolarianfossils in the Aiketik Group, also the first discovery of Late Permian radiolarian fossils in theSouth Tianshan Mountains. Meanwhile, this is the current westernmost sampling site of radiolarianfossils in the South Tianshan Mountains.

Types of uranium deposits in central Zhuguang Mountains in Hunan Province,South China and their metallogenic regularity and prospecting directions

The central Zhuguang Mountains in Hunan Province is located at the junction of the three provinces,namely Hunan,Jiangxi,and Guangdong,where the famous Lujing uranium ore field lies.The uranium deposits occurring in this area are all granite-related and they can be divided into three types,namely endogranitic ones,perigranitic ones,and contact zone types.The endogranitic uranium deposits are mainly controlled by the structural alteration zones developing within granites,with fragmentation,hematitization,and alkali metasomatism as their main mineralization characteristics.The perigranitic uranium deposits are mainly produced in the carbonaceous,siliceous,and argillaceous composite layers of epimetamorphic rocks and are controlled by fractured zones formed due to interlayer compression.The contact zone type uranium deposits mainly occur in the contact parts between the granites and favorable horizons.They have developed in favorable sections where multiple sets of structures are combined and intersected.The main metallogenic regularities of uranium in the central Zhuguang Mountains are as follows.The basic conditions for the uranium mineralization in this area include the framework consisting of regional deep large faults and their associated multi-set multi-direction favorable metallogenic structures,multi-cycle and multi-stage uranium-rich rock masses,and uranium-rich folded basement.Meanwhile,the uranium deposits in this area are closely related to granites in terms of genesis and space and they are formed in different structural parts subject to the same metallization.Furthermore,based on the summary of the characteristics and regularities of uranium mineralization in this area,the controlling factors of different types of uranium deposits in the area were explored and six metallogenic target areas were predicted.All these will provide references for the exploration of uranium deposits in this area.

Fluid Inclusion Geochemistry of Metallic Ore Deposits in the South- Central Sector of theDa Hinggan Mountains in China

Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to the minerogenetic series of deposits.

Geomorphic features of Quaternary glaciation in the Taniantaweng Mountain, on the southeastern Qinghai-Tibet Plateau

We present geomorphological evidence for multiple glacial fluctuations during the Quaternary in the Taniantaweng Mountain, which is situated at the transition zone of the southeastern Qinghai-Tibet Plateau and the Yunnan-Guizhou Plateau. To reconstruct the history of glacial evolution during the Quaternary Glaciation, we present a ~13000 km^2 geomorphologic map(1:440,000) for the Quaternary glaciations, as well as three electron spin resonance(ESR) ages and three optically stimulated luminescence(OSL) ages from the landforms. By integrating these with ages from previous studies, four major glacial advances are identified during marine oxygen isotope stages(MIS) 6, 3, 2 and 1. This glacial chronology is in reasonable agreement with existing glacial chronologies from other parts of the Hengduan Mountains and surrounding mountains. Glaciers had extended to the Yuqu River during the glacial maximum advance(MIS 6), but became successively more restricted from MIS 3 to MIS 1. The glacial distribution show that precipitation brought by the south Asian monsoon might play a primary role in driving glacial advances during the last glacial period in the southeastern Qinghai-Tibet Plateau.

Analysis on the Climatic Characteristics of Hail in the South Mountain Area of Ningxia

[Objective] The research aimed to study the climatic characteristics of hail in the southern mountain area of Ningxia in recent 50 years. [Method] Based on the hail observation data of 5 surface meteorological stations (Guyuan, Xiji, Jingyuan, Longde, Liupanshan) in the south of Ningxia during 1960-2009, the spatial distribution rule, the interannual and monthly climatic characteristics and variation trends of hail in the south mountain area of Ningxia were analyzed by using the statistical method. Moreover, the hail disaster prevention and reduction measures in Guyuan were put forward. [Result] The hail in the south mountain area of Ningxia in recent 50 years had the obvious annual, seasonal, monthly and daily variation characteristics. The hail might occur from March to October and mainly concentrated during May-August which occupied 72% in the whole year. The occurrence probability of hail in June was the biggest and occupied 21.7% in the whole year. It was the typical multi-hail zone in summer. The interannual variation of hail occurrence in Guyuan was big and had 3-year periodicity. The secondary-order time trend of hail in Guyuan was the anti-parabolic type, and the hail occurrence times during the 1960s-1980s presented the increase trend. It was the hail multi-occurrence period in the 1970s and 1980s. After the 1990s, the hail presented the decrease trend. In recent 20 years, the hail significantly decreased. The hail in Guyuan mainly concentrated during 12:00-21:00, and the hail occurrence times occupied 85% of total times. The hail distribution in Guyuan area had the obvious regional characteristics. The hail in the mountain area, hilly area was more and in the stream valley, north Pingchuan area was less. The hail cloud mainly derived from the mountain areas, such as Liupanshan, Nanhua Mountain, Yueliang Mountain, Xifeng Mountain and Yunwu Mountain, etc. The move direction of hail cloud was mainly from northwest to southeast or from north to south. Part of hail cloud disappeared in the original place. According to the regional distribution of hail, the hail risk in Guyuan City was divided into the high, moderate and low occurrence zones by combining with the hail disaster data. [Conclusion] The research provided the scientific basis for the forecast, early-warning of hail weather and the artificial hail suppression.

Land degradation in the subtropical hilly andmountain regions of South China

Land degradation, caused by water erosion. closely related to inherent vulnerabilities of itseco-environment in South China. Spatial variation of land degradation from top to foot of a slope wasmainly induced by differentiation of surface materials and their erodibility, nutrient and moisture dueto downslope variation of land erosion. It was showed by comparing maps of land degradationbetween the 1950s and the 1980s that changes of land degradation varied from one area to anotherbecause of differences of human activities, including land reclamation and vegetation depletion.

Zircon U-Pb Age,Geochemical,and Sr-Nd-Pb-Hf Isotopic Constraints on the Time Frame and Origin of Early Cretaceous Mafic Dykes in the Wuling Mountain Gravity Lineament,South China

In view of the importance of mafic dyke swarms and their contribution to current scientific problems relating to South China,herein,we present the findings of studies on twenty–five representative mafic dykes cropping out in Hunan Province and Guangxi Zhuang Autonomous Region,within the southern Wuling Mountain gravity lineament,China.These results include new zircon LA-ICP-MS U-Pb age,whole rock geochemical,Sr-Nd-Pb isotopic,and zircon Hf isotopic data for these dykes.The dykes formed between 131.5±1.2 and 121.6±1.1 Ma,and have typical doleritic textures.They fall into the alkaline and shoshonitic series,are enriched in light rare earth elements(LREE),some large ion lithophile elements(LILE;e.g.,Rb,Ba,and Sr),Th,U,and Pb,and are depleted in Nb,Ta,Hf,and Ti.Moreover,the dolerites have high initial 87 Sr/86 Sr ratios(0.7055–0.7057),negativeεNd(t)and zirconεHf(t)values(-14.8 to-11.9,-30.4 to-14.9),and relatively constant initial Pb isotopic ratios(that are EM1-like,16.77–16.94,15.43–15.47,and 36.84–36.92 for 206 Pb/204 Pb,207 Pb/204 Pb,and 208 Pb/204 Pb,respectively).These results indicate that the dykes were likely derived from magma generated through low-degree partial melting(1.0%–10%)of an EM1-like garnet–lherzolite mantle source.The parental magmas fractionated olivine,clinopyroxene,plagioclase,and Ti-bearing phases with negligible crustal contamination,during ascent and dyke emplacement.Several possible models have been proposed to explain the origin of Mesozoic magmatism along the Wuling Mountain gravity lineament.Herein we propose a reasonable model for the origin of these mafic dykes,involving the collision between the paleo-Pacific Plate and South China,which led to subsequent lithospheric extension and asthenosphere upwelling,resulting in partial melting the underlying mantle lithosphere in the Early Cretaceous,to form the parental magmas to the WMGL mafic dykes,as studied.

Sensitivity of mountain runoff to climate change for Urumqi and Kaidu rivers originating from the Tianshan Mountains

The mountain watersheds of Kaidu River and Urumqi River, which separately originate from the south and north-side of the Tianshan Mountains in Xinjiang, are selected as the study area. The characteristics and trends on variation of temperature, precipitation and runoff, and the correlativity between temperature, precipitation, and runoffwere analyzed based on the past 40 years of observational data from the correlative hydrological and weather stations in the study areas. Various weather scene combinations are assumed and the response models of runoff to climate change are established in order to evaluate the sensitivity of runoff to climate change in the study areas based on the foregoing analysis, Results show that all variations of temperature, precipitation, and runoff overall present an oscillating and increasing trend since the 1960s and this increase are quite evident after 1990. There is a markedly positive correlation between mountain runoff, temperature, and precipitation while there are obvious regional differences of responding degree to precipitation and temperature between mountain runoff of Ummqi River and Kaidu River Basins Also, mountain runoff of Urumqi River Basin is more sensitive to precipitation change than that of Kaidu River Basin, and mountain runoff of Kaidu River Basin is more sensitive to temperature change than that of Ummqi River Basin.

山地地形下中江南塔地震响应特征试验

为研究山地地形对砖石古塔地震响应的影响,以位于四川中江县铜鱼山顶的中江南塔作为原型,选取了汶川地震发生时自贡台阵的加速度记录为基底输入,通过小型振动台试验研究了山底、山顶古塔自振频率随地震动幅值的变化趋势,分析了地形效应对古塔地震响应的影响及古塔破坏特征。结果表明:在低幅值地震动作用下古塔自振频率不变,当自由地表地震动峰值分别达到100 Gal和150 Gal时,山顶和山底古塔发生破坏;在古塔自振特性、输入地震动的频谱特征以及结构构造特点影响下,古塔发生了“上轻下重”的破坏特征;与山底古塔相较,山顶古塔地震反应明显更大,相同工况下山顶古塔各楼层峰值加速度、最大相对位移、最大层间位移角分别为山底古塔的2~3倍、1.5~4.5倍、1.5~4.5倍,其中最大相对位移和最大层间位移角的放大倍数与地震动幅值相关,因此需重视山顶古塔的地震安全性。

兰州市南北两山土壤水分遥感反演及植被需水量估算

探究西北干旱区土壤水分和植被需水量动态变化特征,可为生态恢复不同阶段所需水资源量及水资源优化配置提供科学依据。以兰州市南北两山为研究区,基于Sentinel-2 L2A和Landsat 8 OLI遥感影像,结合实测土壤0~10 cm的111个数据,分别构建垂直干旱指数(Perpendicular Drought Index,PDI)、改进型垂直干旱指数(Modified Perpendicular Drought Index,MPDI)和植被调整垂直干旱指数(Vegetation-adjusted Perpendicular Drought Index,VAPDI)土壤水分反演模型,并采用4种模型指标定量决定系数(R^(2))、平均绝对误差(MAE)、平均相对误差(MRE)、均方根误差(RMSE)对模型反演的效果进行精度评价,选出最优的土壤水分反演模型并结合土壤水分限制系数,与研究区2019年林地、草地和耕地植被面积的空间数据、各站点生长季内的参考作物蒸散量,构建植被生态需水量模型,厘清研究区内土壤水分、植被需水量时空变化特征。结果表明:(1)2种数据源下的PDI、MPDI、VAPDI和实测数据之间均有着不同程度的线性负相关性,其中R^(2)分别为0.37、0.64和0.59,从评价指标的结果来看,MPDI的土壤水分回归模型的拟合决定系数最高,2种遥感数据反演的土壤水分空间分布格局具有一致性。(2)分辨率高的Sentinel-2L2A土壤水分反演更加精细,土壤水分整体呈波动增长趋势,多时段土壤水分的平均值为23.27%,呈现出降低再增加然后下降,总体增幅为74.07%。(3)兰州市南北两山4—10月植被需水量月均值也呈现先增加后下降的趋势,与土壤水分含量变化具有一致性,4—10月中7月植被需水量最大,为3.98×10^(7)m^(3),10月植被生态需水量最小,为0.97×10^(7)m^(3)。随着环境绿化工程的实施,兰州市南北两山从只能生长耐旱草本和低矮灌木的植物,逐步形成以多种类结合的群落结构。本研究可为兰州市南北两山土壤水资源合理利用及植被恢复提供参考。

南秦岭安康成矿带金矿地质特征与成矿条件研究

安康金成矿远景区位处南秦岭安康成矿带,区内赋矿层位为志留系下统斑鸠关组、梅子垭组,受北西西-南东东向展布的叶坪河复式向斜构造控制,成矿类型属沉积改造型。岩石地球化学分析表明,Au元素在各地层的平均质量分数值范围为1.19×10^(-9)-~6.68×10^(-9),而经后期变质改造的各地层中(含矿层片岩类),Au元素的质量分数值升高,各变质地层Au元素的质量分数值范围为255×10^(-9)~711×10^(-9),平均值的范围为23.06×10^(-9)~26.52×10^(-9),具找矿前景,是勘查区内主要的找矿目标。认为地层岩性、构造特征、围岩蚀变、化探异常可作为该区域金矿床找矿的标志。

南太行自然保护地空间分布格局及交叉重叠关系研究

以南太行地区5种类型99处国家级和省级自然保护地为研究对象,运用最邻近点指数、地理集中指数和核密度分析法并借助GIS的空间分析功能,对南太行自然保护地的空间分布特征以及交叉重叠情况进行定性和定量分析。结果表明,南太行自然保护地森林公园的数量最多,自然保护区面积最大,长治市内的保护地分布数量最多,整体呈集聚的空间分布类型;其保护地按照密度值可分为3档,大多为点状分布,高密度区主要呈带状和团块状分布在南太行东部地带及部分南部地区;99处保护地中存在27处交叉重叠,风景名胜区交地质公园是最多的重叠类型。

激电测深法在南秦岭苏岭沟金矿区的勘查应用

南秦岭夏家店金矿床由夏家店、苏岭沟和刘家峡3个矿区组成,是一处典型的具有重要经济价值的黑色岩系容矿的金矿床。在苏岭沟金矿区利用激电测深(IP)方法,探测了泥盆系地层覆盖地段Ⅰ号构造带和黑色含矿岩系在深部向西延伸及其倾向埋深展布情况。根据激电测深数据获得“低阻-高极化”特征的断面激电异常曲线图并结合地质资料,解译推测了深部含矿目标层及含矿构造空间赋存状况。经钻探验证,金矿化体位置与激电测深推断的极化率异常中心埋深基本吻合。同时,建立了矿区岩(矿)石电性参数的数据库。本次研究为本矿区及矿区外围开展激电测深法探寻同类型、同特征的矿床积累了数据支撑。

鲁中南山区侵蚀性降雨及典型作物对坡面产流产沙影响研究

为研究降雨量、降雨历时、降雨强度等降雨因素及典型作物对坡面产流产沙的影响,基于K-均值聚类分析法对山东省泰安市东周小流域2014-2020年77次侵蚀性降雨进行分类,并进一步分析不同降雨类型下不同作物产流产沙特征及对各降雨指标的响应.结果表明:①研究区侵蚀性降雨可以分为Ⅰ型(小雨量、短历时、大雨强)、Ⅱ型(大雨量、长历时、小雨强)、Ⅲ型(中雨量、中历时、小雨强)3类.各降雨频率为67.53%,3.9%,28.57%,占研究期内总降雨量的44.2%,14.02%,41.78%.②各径流小区产流和土壤流失量从大到小依次为大豆、裸地、地瓜、花生,花生和地瓜对径流和泥沙的削减效果相对较好.在Ⅱ型条件下,各小区产流产沙量最大,Ⅲ型次之,Ⅰ型最小;但当Ⅰ型和Ⅲ型雨频率较高时,产流产沙量也较大.③对坡面产流产沙影响最大的因素为降雨量,当作物种类不同时,影响次之的因素有所差别.径流对降雨因素的响应程度高于土壤流失量,控制产流发生可在一定程度上有效降低土壤流失量.

小兴安岭阔叶红松林次生演替不同阶段空间结构特征研究

选取小兴安岭凉水自然保护区内阔叶红松林次生演替序列中的天然枫桦次生林、次生阔叶林、次生针阔混交林以及原始阔叶红松林为研究对象,采用空间结构参数(角尺度、大小比数、混交度)的一元和二元分布,分析林木的空间结构特征。结果表明:一元二元分布中,林分角尺度均呈现相对正态分布,在W=0.5时频率最高,4个阶段的平均角尺度分别为0.577、0.557、0.634、0.589,均以轻度聚集分布为主;并随着演替进行,聚集趋势上升,到原始阔叶红松林后聚集程度又下降;4个演替阶段林木之间呈现混交状态为极强混交,强度和极强度混交的比例依次为69.94%、70.08%、65.56%、63.64%,混交林木的比例随着演替序列呈现先上升后下降的趋势。从不同演替阶段的优势种空间分布来看,前5位优势树种呈集聚分布,树种混交程度都较高,但阳性先锋树种和耐阴树种林木的大小分化差异较大。可见,阔叶红松林4个演替阶段的变化说明演替前期林木的角尺度和混交度较大,后期尤其是原始阔叶红松林中聚集程度降低,随机分布比例上升,有利于群落长久稳定发展。

华南多雨山地果树避雨技术效果与成本分析

[目的]针对华南高海拔山地地区春、夏两季雨水过多造成沤花、裂果致落果而严重影响产量、品质问题,设计不同的避雨技术试验,对比避雨效果、投入与产出。[方法]以常规露地栽培作为对照组,设置周年避雨(钢架棚、竹木棚)及开花期遮阳网棚(树盘沥水、树盘沥水+覆膜、平垄覆膜、高垄覆膜)共6个避雨栽培处理,观察各处理新植树的成活率和生长量,结果树产量、裂果率、落果率和商品果率,以及分析各避雨栽培的投入与产出比。[结果]避雨处理新植果苗的成活率和生长量均显著高于对照;钢架棚、竹木棚全株避雨处理产量高、无裂果,落果少,沥水+地膜、高垄地膜土壤避雨处理产量较高、裂果较少;钢架棚初始投入最大、年投入最小、产出最大、利润最高,竹木棚初始投入较小、年投入最大、产出大、利润高,沥水+地膜初始投入、年投入均小、产出较大、利润较高。[结论]投资能力强的,推荐搭建钢架避雨棚;竹木资源充足的,推荐搭建竹木棚。投资能力较欠缺的,可搭建遮阳网临时避雨棚,结合沥水+地膜。新植果树苗,可采取沥水、树盘覆膜或沥水+覆膜措施,以提高定植成活率。

基于最小数据集的祁连山南坡不同土地利用方式土壤质量评价

为了评估高寒地区不同土地利用方式下的土壤质量状况,明确不同土地利用方式下的土壤质量的关键影响因子,在祁连山南坡采集了林地、灌丛、草地及耕地4种主要土地利用类型的土壤样品174份,通过主成分分析(Principal component analysis,PCA)建立最小数据集(Minimum data set,MDS),综合评估研究区不同土地利用方式下的土壤质量。结果表明:林地、灌丛、草地和耕地土壤质量指数值分别为0.535,0.519,0.466和0.544,表现为耕地>林地>灌丛>草地,对土壤质量分级为Ⅰ~Ⅵ级,对应指数分别为≤0.3,(0.3~0.4],(0.4~0.5],(0.5~0.6],(0.6,0.7]和>0.7,草地等级为Ⅲ级,处于“中等”水平;耕地、林地和灌丛土壤质量等级为Ⅳ级,处于“中等偏上”水平。土壤质量关键指标间存在互相影响,因此,建议研究区域土地要实施分类科学管理。此外,合理开发和应用绿色高效的新型生物技术是应对影响研究区土壤质量的微生物指标的有效措施。

从黑色雅典娜到绿色中国:全球南方视野中的中国式现代化及其跨文化传播

什么是人与自然和谐共生的现代化 2023年8月,来自全球且肤色、学科背景、年龄都不同的学者走进生态富集的浙江缙云,在这个中国南方山区小县初步找到了答案。这一次,他们不再将“那座白色大理石雕塑的雅典娜”作为背景板的一部分,不再将环境问题作为推行霸权政治的工具,而是通过人与人、人与田野,以及田野与田野间的跨文化对话,将中国式现代化置于全球南方背景下予以审视,同时识别西式现代化想象的局限性,在历史、政治与文化等多重视野的叠加下敞开第三世界国家可持续的现代化发展之路的无限可能性。这一识别与敞开的过程同时蕴含着传播学的未来,为国际传播这一曾经在文明等级论话语框架中爬行的学术领域提供了全新的理论视野与实践支撑。

Re-Os Geochronology of Porphyry Molybdenum Deposit in South Segment of Da Hinggan Mountains,Northeast China

The ages for porphyry Mo deposits in south segment of Da Hinggan Mountains, Northeast China, are not well known. Five molyhdenite samples from the Aolunhua （奥伦花） porphyry Mo deposit, five molybdenite samples from the Yangchang （羊场） porphyry-quartz vein Mo deposit and two molybdenite samples from the Banlashan （半拉山） porphyry Mo deposit were selected for Re-Os dating. Three deposits are spatial-temporally associated with the granite porphyry stock. Re-Os isochron age of 131.2±1.9 Ma was obtained for the Aolunhua porphyry Mo deposit. The Yangchang Mo deposit provides isochron age of 138.5±4.5 Ma for two groups of molybdenite （within porphyry ore and within quartz vein）. The Banlashan porphyry Mo deposit provides model ages of 140.5±2.4 and 143±2.2 Ma. All of these Re-Os ages are consistent presumed Yanshanian ages for granite intrusions, formed in crust thinning setting in Cretaceous in North China.