Geology and mineralization of the Sanshandao supergiant gold deposit (1200 t) in the Jiaodong Peninsula,China: A review

The Jiaodong Peninsula in Shandong Province, China is the world’s third-largest gold metallogenic area, with cumulative proven gold resources exceeding 5000 t. Over the past few years, breakthroughs have been made in deep prospecting at a depth of 500–2000 m, particularly in the Sanshandao area where a huge deep gold orebody was identified. Based on previous studies and the latest prospecting progress achieved by the project team of this study, the following results are summarized. (1) 3D geological modeling results based on deep drilling core data reveal that the Sanshandao gold orefield, which was previously considered to consist of several independent deposits, is a supergiant deposit with gold resources of more than 1200 t (including 470 t under the sea area). The length of the major orebody is nearly 8 km, with a greatest depth of 2312 m below sea level and a maximum length of more than 3 km along their dip direction. (2) Thick gold orebodies in the Sanshandao gold deposit mainly occur in the specific sections of the ore-controlling fault where the fault plane changes from steeply to gently inclined, forming a stepped metallogenic model from shallow to deep level. The reason for this strong structural control on mineralization forms is that when ore-forming fluids migrated along faults, the pressure of fluids greatly fluctuated in fault sections where the fault dip angle changed. Since the solubility of gold in the ore-forming fluid is sensitive to fluid pressure, these sections along the fault plane serve as the target areas for deep prospecting. (3) Thermal uplifting-extensional structures provide thermodynamic conditions, migration pathways, and deposition spaces for gold mineralization. Meanwhile, the changes in mantle properties induced the transformation of the geochemical properties of the lower crust and magmatic rocks. This further led to the reactivation of ore-forming elements, which provided rich materials for gold mineralization. (4) It can be concluded from previous research results that the gold mineralization in the Jiaodong gold deposits occurred at about 120 Ma, which was superimposed by nonferrous metals mineralization at 118–111 Ma. The fluids were dominated by primary mantle water or magmatic water. Metamorphic water occurred in the early stage of the gold mineralization, while the fluid composition was dominated by meteoric water in the late stage. The S, Pb, and Sr isotopic compositions of the ores are similar to those of ore-hosting rocks, indicating that the ore-forming materials mainly derive from crustal materials, with the minor addition of mantle-derived materials. The gold deposits in the Jiaodong Peninsula were formed in an extensional tectonic environment during the transformation of the physical and chemical properties of the lithospheric mantle, which is different from typical orogenic gold deposits. Thus, it is proposed that they are named “Jiaodong-type” gold deposits.©2021 China Geology Editorial Office.     

China’s national carbon emissions trading scheme: lessons from the pilot emission trading schemes,academic literature,and known policy details

Upon completion, China’s national emissions trading scheme (C-ETS) will be the largest carbon market in the world. Recent research has evaluated China’s seven pilot ETSs launched from 2013 on, and academic literature on design aspects of the C-ETS abounds. Yet little is known about the specific details of the upcoming C-ETS. This article combines currently understood details of China’s national carbon market with lessons learned in the pilot schemes as well as from the academic literature. Our review follows the taxonomy of Emissions Trading in Practice: A Handbook on Design and Implementation (Partnership for Market Readiness & International Carbon Action Partnership. (2016). Retrieved from www.worldbank.org): The 10 categories are: scope, cap, distribution of allowances, use of offsets, temporal flexibility, price predictability, compliance and oversight, stakeholder engagement and capacity building, linking, implementation and improvements.

Key policy insights

• Accurate emissions data is paramount for both design and implementation, and its availability dictates the scope of the C-ETS.

• The stakeholder consultative process is critical for effective design, and China is able to build on its extensive experience through the pilot ETSs.

• Current policies and positions on intensity targets and Clean Development Mechanism (CDM) credits constrain the market design of the C-ETS.

• Most critical is the nature of the cap. The currently discussed rate-based cap with ex post adjustment is risky. Instead, an absolute, mass-based emissions cap coupled with the conditional use of permits would allow China to maintain flexibility in the carbon market while ensuring a limit on CO₂ emissions.

     

广西气象数据中心机房供电系统设计与保障

针对供配电系统容易发生的安全隐患,优化设计配电系统结构、采用一体化运维监控平台和采用高质量、高可靠性的设备,消除单点故障瓶颈,确保在停电、设备故障、维修维护等各种情况下提供不中断或快速恢复供电,避免停电对业务正常运行造成影响,确保机房供电安全。     

西太平洋暖池海温和山西盛夏降水关系研究

利用1961—2016年山西盛夏(7—8月)平均降水和同期NOAA重构海温资料,分析了山西盛夏降水分别与赤道中东太平洋海温和西太平洋暖池海温相关性的变化。结果表明:山西盛夏降水和赤道中东太平洋海温之间呈现稳定的显著负相关;和西太平洋暖池海温呈现正相关,并在20世纪70年代末到80年代初之后相关性加强,通过了0.05显著性检验。进一步分析表明,这种西太平洋暖池海温对20世纪80年代以来山西盛夏降水指示意义加强的事实,主要体现在赤道中东太平洋海温偏冷的背景下。西太平洋暖池海温异常通过影响与山西盛夏降水密切相关的大气环流、季风槽位置和东亚夏季风,导致山西盛夏降水异常。盛夏赤道中东太平洋海温偏冷时,西太平洋暖池海温偏暖(冷),通过遥相关引起中高纬度大气欧亚—太平洋型遥相关(EUP)和负太平洋—日本(PJ)波列,通过影响季风槽位置偏西偏北(偏东偏南),引起西太平洋副热带高压偏北(南)和季风指数偏小(大),导致山西盛夏降水偏多(少)。     

感热加热对华北及其周边对流活动的影响

利用2006～2017年风云气象卫星资料和气象再分析资料,对华北及周边5～8月对流活动和地面感热加热进行统计分析。分析表明,华北及周边白天平均感热加热和地形关系密切,内蒙古中部和东南部、华北北部和华北西部山区感热加热较强,最强感热加热出现在5月和6月,7月和8月明显减弱。和感热加热强度相对应,对流活动频率较高的月份同样出现在5月和6月,其中5月以弱对流为主,6月华北中北部强对流最活跃,另外,环渤海区域6～7月强对流相对频繁。5～8月日平均感热加热和对流频率趋势呈现一致的减弱对应关系。上午,感热加热引起河北西部和北部对流层低层出现辐合气流,700 hPa以下出现不同程度的增温,上升气流可达对流层中层,东侧的平原地区出现补偿下沉运动,升温和上升运动触发对流,在有利条件下发展东移。不同月份和区域对流频率日变化呈现明显差异,6月对流频率日变化显著,8月最弱,山区对流频率日变化显著,东部渤海及周边对流频率日变化较小。对流频率的月平均分布和日变化均表现出和地形相关的感热加热差异的特征。     

2000年后中国北方东部地区夏季极端降水减少及水汽输送特征

本文研究了1961～2016年中国北方东部地区夏季极端降水日数和极端降水贡献率的年代际变化特征,并进一步分析了该地区极端降水和普通降水的大气环流和水汽输送的差异。主要的研究结果表明:1961～2016年中国北方东部地区夏季极端降水日数和极端降水贡献率在2000年前后发生显著年代际变化,2000年后夏季极端降水天数和极端降水贡献率显著减少。与1984～1999年相比,2000～2016年在对流层高层从欧洲大陆、中亚到东北—蒙古地区,位势高度异常呈现出“正—负—正”的大气波列,从而造成北方东部地区上空为正压的位势高度正异常控制,伴随着下沉运动,大气层结趋于稳定,这些环流条件不利于极端降水发生。2000年后负位相的太平洋年代际振荡（PDO）和正位相的北大西洋多年代际振荡（AMO）共同加强了北方东部地区上空的正位势高度异常。进一步研究表明,极端降水与普通降水的水汽输送和收支以及关键的局地大气系统存在着显著差异,较普通降水而言,极端降水在南北向水汽输送和收支上更强;北方东部地区低空为较强的闭合低压控制,并不断受到高层高位涡空气下传的影响。     

青藏高原云团东传过程及其中中尺度对流系统的统计特征

利用逐小时风云卫星TBB资料、逐小时中国自动站与CMORPH降水产品融合数据以及国家级地面观测站24小时累积降水量,统计分析2010～2016年夏季,伴随下游地区（104°E以东）降水的青藏高原云团东传过程以及东传过程中镶嵌于云团中的中尺度对流系统（Mesoscale Convective System,简称MCS）特征。结果表明,共出现120次伴随下游降水的高原云团东传过程,6月出现最频繁,但持续时间较长的过程多出现在7月。云团向东传播的主要三条路径是平直东传、沿长江折向东传和复合东传。其中路径二——沿长江折向东传中的过程是高影响过程,因为过程次数较多（46次）,过程平均持续时间较长（62小时）,在下游地区引发的降水日数和暴雨日数最多。属于东传过程的MCS在7月形成最多,集中分布在青藏高原东坡、云贵高原东部、长江沿岸及其以南地区。高原MCS影响长江中下游地区降水主要是通过向东传播的形式实现,因为即使生命史更长的中α尺度对流系统（Meso-α Convective System,简称MαCS）也鲜少直接移动至110°E以东地区。不同区域的中α尺度持续性拉长形对流系统（Permanent Elongated Convective System,简称PECS）的日变化特征显示,东传过程MCS更容易在夜间从高原东坡向东传播至下游地区。在三条路径中,路径二中的东传过程MCS数量最多、在下游地区发展最旺盛并与降水日数和覆盖范围存在更好的对应关系。     

高原涡和西南涡影响的两次四川暴雨过程的对比分析

为了进一步研究高原涡、西南涡对西南地区暴雨的影响,本文用中国气象局自动站与CMORPH降水数据融合的逐时降水资料、国家卫星气象中心的逐时FY-2E卫星的云顶亮温（TBB）资料、欧洲气象资料中心（ERA-interim）的再分析资料,通过天气学诊断分析方法以及拉格朗日轨迹模式HYSPLITv4.9,对发生在四川盆地的有高原涡东移影响西南涡发展引发暴雨的两次过程进行对比分析,发现:（1）两次暴雨过程的降水强度和分布有明显区别,并且TBB活动特征显示在过程一中有MCC（Mesoscale Convective Complex）的产生和发展,过程二则没有。（2）对于过程一,500 hPa上,高原涡逐渐减弱为高原槽并伸展到四川盆地上空,850 hPa上,在鞍型场附近有MCC的产生和发展,200 hPa上,高原涡在南亚高压北部偏西风急流下方的强辐散区内,位于南亚高压东南侧急流区下方稳定少动,偏东风急流北部有辐散中心,有利于西南涡的加强。对于过程二,500 hPa高原涡东移在四川盆地上空与西南涡耦合,形成一个稳定且深厚的系统,这也是过程二的暴雨强度比过程一强的最主要原因。200 hPa上,四川盆地始终位于南亚高压东侧的西北气流中,“抽吸作用”明显。（3）在过程一中,位涡逐渐东传且位涡增加的地方对应强降水区与MCC发展区,反映了暴雨和位涡的发展基本一致。在过程二中,中层位涡高值区从高原上东移并下传至盆地上空,两涡耦合使得上下层打通,位涡值比耦合之前单独的两涡强度更强。 MCC产生的必要条件是中层大气要有强正涡度、强辐合和强上升运动,在未产生MCC前,过程一与过程二在盆地上空的动力条件甚至是相反的;从热力条件看,过程一中有明显的干冷空气入侵,增强不稳定条件,有利于MCC的产生并引发强降水;另一方面,本文也应证了二阶位涡的水平分布与暴雨落区有较好的对应关系。（4）通过拉格朗日方法的水汽轨迹追踪模式和聚类分析方法分析可得两次暴雨过程的水汽输送源地和通道也有明显区别,过程一主要有两条水汽通道,通道一来自阿拉伯海和孟加拉湾洋面的底层,通道二来自四川南部750 m以下高度;而过程二的主要水汽输送通道有三条,通道一来自西方地中海、黑海和里海上空1500～2500 m高度附近,通道二来自阿拉伯海和印度洋的底层,通道三的水汽从孟加拉湾低层绕过云贵高原直接输送到四川盆地。     

华北雨季开始早晚与大气环流和海表温度异常的关系

本文利用国家气候中心的1961~2016年华北雨季监测资料、美国国家环境预报中心/大气研究中心（NCEP/NCAR）的大气再分析资料、NOAA海表温度资料,分析了华北雨季开始早晚的气候特征,然后利用合成分析、回归分析等方法,研究了华北雨季开始早晚与大气环流系统和关键区域海表温度的关系。结果表明,56 a来华北雨季开始最早在7月6日,最晚在8月10日,1961~2016年华北雨季开始平均日期是7月18日。华北雨季开始时间具有显著的年际变化,但雨季发生早晚的长期变化趋势不太明显。华北雨季开始早晚与西太平洋副热带高压（简称副高）、东亚副热带西风急流、东亚夏季风等环流系统的活动关系密切,当对流层高层副热带西风急流建立偏早偏强,中层西太平洋副高第二次北跳偏早,低层东亚夏季风北进提前时,华北雨季开始偏早,反之华北雨季开始偏晚。华北雨季开始早晚与春、夏季热带印度洋、赤道中东太平洋海表温度关系显著且稳定,当Ni?o3.4指数和热带印度洋全区海表温度一致模态（IOBW）为正值时,贝加尔湖大陆高压偏强,副高偏强偏南,东亚夏季风偏弱,导致华北雨季开始偏晚;当海表温度指数为负值时,则华北雨季开始偏早。     

中国东部夏季降水与气温的联合EOF分析

采用JEOF等方法分析中国东部夏季降水和气温的协同变化时空分布特征,结果表明:当时间系数为正时,第1典型场降水型态从北向南(下同)呈"++-"分布,气温表现为冷异常,500 hPa回归场在中纬度地区呈显著低压异常,SST回归场表现为太平洋海域呈西北-东南的分布;第2典型场降水呈"+-"分布,气温则呈"-+"分布;第3典型场降水分布呈中间型,气温场呈"-+"分布。