黑龙江铁力鹿鸣斑岩型钼矿床埃达克岩的发现及其地质意义

鹿鸣钼矿是伊春-延寿成矿带内近年发现的大型斑岩钼矿,矿区主要出露含矿的二长花岗岩、花岗斑岩,不含矿的花岗闪长岩及似斑状花岗闪长岩四种岩性。二长花岗岩与花岗斑岩具有相似的低Sr高Y等地球化学特征,形成于194.8±0.7Ma~184Ma前后的早侏罗世,是斑岩型矿床的赋矿围岩。花岗闪长岩及似斑状花岗闪长岩含有暗色岩包体,主要为高钾钙碱性系列岩石,但以高Sr、低Y及富Na为特征,部分地球化学指标与中国东部埃达克岩极为相似,形成于176.2±2.1Ma并与辉钼矿Re-Os法获得的成矿年龄一致,被认定为斑岩型矿床的成矿母岩。高Sr和低Sr两类花岗岩形成于不同的构造背景,与中生代时期中国东部及其邻区几次重大地质事件密切相关。鹿鸣斑岩型钼矿床与中侏罗世太平洋板块俯冲在高氧逸度条件下熔融形成的埃达克质岩浆高侵位有关。鹿鸣矿区埃达克岩的发现表明中侏罗世太平洋板块已经发生了萎缩与消减,与之相关的岩浆作用及成矿应该具有广泛的区域性,扎实的岩石学工作可为区域更多斑岩型矿床的发现提供线索。     

基于孔压静力触探(CPTU)测试的连云港海相粘土前期固结压力确定方法研究

首先回顾了基于孔压静力触探(CPTU)测试确定前期固结压力的方法,通过连云港海相粘土场地进行的CPTU试验资料,以室内固结试验得到的前期固结压力作为参考值评估了经验方法预测前期固结压力的有效性。最简单的方法是直接建立前期固结压力和净锥尖阻力的关系,同时也是最有效的方法。     

喜马拉雅山东南地区地质灾害发育规律初步研究

利用遥感手段,结合MapGis,研究了喜马拉雅山东南地区地质灾害的发育情况,发现本区发育的主要地质灾害有滑坡、崩塌、泥石流、冰湖以及堰塞湖。其中崩塌、滑坡、泥石流斜坡地质灾害是本区最重要的地质灾害类型,占到总灾害数量的95.3%。在此基础上对喜马拉雅山东南地区地质灾害发育规律初步研究,发现本区地质灾害的发育在空间上的分布并非均匀,而是具有丛集性的特点。滑坡灾害主要发育在隆子和朗县。泥石流灾害比较严重的有米林、隆子和洛扎3县,而崩塌则主要集中在隆子县。研究发现,本区滑坡发育与地层、地形坡度以及土地类型关系密切,其中修康群、日当组和念青唐古拉群是本区的易滑地层。涅如组由于面积大,其中发育的滑坡较多,但是滑坡的发育率只略高于本区的平均水平。统计表明,16～30的坡度范围是滑坡最容易发生的。大于45以上的坡段很少发生滑坡。灌木林和天然草地这两种土地类型滑坡发育率最高。对于泥石流,研究表明,涅如组中泥石流发育面积最大,发育率也最高。泥石流发育的最适宜坡度也是16～30这样一个坡度范围。冰川和永久积雪区则最易发生泥石流。崩塌发育与地层类型、坡度的关系较为密切,崩塌主要发育在涅如组中,并且集中在坡度大于60以上的陡坡段中。这些初步成果的取得,是以后进行该区地质灾害空间预测的基础。     

中亚造山带西段俯冲起始时限及机制探讨

中亚造山带是世界上最大的显生宙增生型造山带,是研究增生造山过程和大陆地壳生长的绝佳场所,其形成记录了新元古代—早中生代古亚洲洋发展演化历程,主要由一系列微陆块、岛弧、海山/大洋高原、增生杂岩及蛇绿混杂岩构成.中亚造山带西段蛇绿混杂岩物质组成基本一致,除了典型的蛇绿岩组分外,大多发育典型的海山岩石组合,即枕状玄武岩、火山...     

Geochemical and Isotopic Techniques Constraints on the Origin, Evolution, and Residence Time of Low-enthalpy Geothermal Water in Western Wugongshan, SE China

Geothermal resources are increasingly gaining attention as a competitive, clean energy source to address the energy crisis and mitigate climate change. The Wugongshan area, situated in the southeast coast geothermal belt of China, is a typical geothermal anomaly and contains abundant medium- and low-temperature geothermal resources. This study employed hydrogeochemical and isotopic techniques to explore the cyclic evolution of geothermal water in the western Wugongshan region, encompassing the recharge origin, water–rock interaction mechanisms, and residence time. The results show that the geothermal water in the western region of Wugongshan is weakly alkaline, with low enthalpy and mineralization levels. The hydrochemistry of geothermal waters is dominated by Na-HCO3 and Na-SO4, while the hydrochemistry types of cold springs are all Na-HCO3. The hydrochemistry types of surface waters and rain waters are Na-HCO3 or Ca-HCO3. The δD and δ18O values reveal that the geothermal waters are recharged by atmospheric precipitation at an altitude between 550.0 and 1218.6 m. Molar ratios of major solutes and isotopic compositions of 87Sr/86Sr underscore the significant role of silicate weathering, dissolution, and cation exchange in controlling geothermal water chemistry. Additionally, geothermal waters experienced varying degrees of mixing with cold water during their ascent. The δ13C values suggest that the primary sources of carbon in the geothermal waters were biogenic and organic. The δ34S value suggests that the sulfates in geothermal water originate from sulfide minerals in the surrounding rock. Age dating using 3H and 14C isotopes suggests that geothermal waters have a residence time exceeding 1 kaBP and undergo a long-distance cycling process.     

黑河流域土地利用变化对土壤有机碳和全氮储量的影响——元分析（英文）

Land use and cover change(LUCC) is an important indicator of the human-earth system under climate/environmental change,which also serves as a key impact factor of carbon balance,and a major source/sink of soil carbon cycles.The Heihe River Basin(HRB) is known as a typical ecologically fragile area in the arid/semi-arid regions of northwestern China,which makes it more sensitive to the LUCC.However,its sensitivity varies in a broad range of controlling factors,such as soil layers,LUCCs and calculation methods(e.g.the fixed depth method,FD,and the equivalent mass method,ESM).In this study,we performed a meta-analysis to assess the response of soil organic carbon(SOC) and total nitrogen(TN) storage to the LUCC as well as method bias based on 383 sets of SOC data and 148 sets of TN data from the HRB.We first evaluated the calculation methods and found that based on the FD method,the LUCC caused SOC and TN storage to decrease by 17.39% and 14.27%,respectively;while the losses estimated using the ESM method were 19.31% and 18.52%,respectively.The deviations between two methods were mainly due to the fact that the FD method ignores the heterogeneity of soil bulk density(BD),which may underestimate the results subsequently.We then analyzed the response of SOC and TN storage to various types of the LUCC.In particular,when woodland and grassland were converted into cultivated land or other land types,SOC and TN suffered from heavy losses,while other LUCCs had minor influences.Finally,we showed that increasing the depth of the soil layers would reduce the losses of SOC and TN storage.In summary,we identified a series of controlling factors(e.g.soil layer,the LUCC and calculation method) to evaluate the impact of the LUCC on SOC and TN storage in the HRB,which should be considered in future research.     

Reverse-Time Migration of Converted S-Waves of Varying Densities

Ocean-Bottom Node(OBN) acquisitions provide both non-converted and converted reflection energy. There is a clear advantage to independently imaging both P-and S-waves, as they provide more information collectively than either does alone. In many conventional converted-wave pre-stack migration algorithms, density is treated as a constant, which is not the real-life case on earth. S-wave velocity and density information is crucial for hydrocarbon detection because it helps in the identification of porefilling fluids. In this paper, we focused on the effect of density on imaging, and developed a method of reverse-time migration(RTM) on converted s-waves of varying densities(VD-RTMCS). Phase correction was required prior to pre-stack migration to avoid constructive interference between data from adjacent sources. Synthetic data examples showed that when density variations were included, image profiles showed advantages in signal-to-noise ratio, vertical resolution and imaging of complex structures.     

Three Decades of Sea-Ice Variability in Jiaozhou Bay Revealed by Landsat Observations

In this study, we used Landsat images and meteorological data to examine the spatiotemporal distribution and variability of sea ice in Jiaozhou Bay(JZB) between 1986 and 2016. The results show that JZB is not always covered by sea ice in winter, but in some extreme cases, sea ice has covered more than one-third of the sea area of the bay. Sea ice in JZB has generally formed between January 1 and February 5, primarily along the coast, and gradually expanding to the central area of the bay. Both meteorological and artificial factors have played important roles in modulating the sea ice distribution. We found sea ice coverage to have been strongly correlated with the accumulated freezing-degree days nine days before the occurrence of sea ice(R2 = 0.767). North-northwest surface winds have dominated the freezing period of sea water in the JZB, and wind speed has exerted a more significant influence on the formation of sea ice when the sea ice coverage has been generally small. Additionally, artificial factors began to affect the expansion of sea ice in JZB since 2007. The construction of the Jiao-Zhou-Bay Bridge(JZBB) is believed to have retarded water flow and reduced the tidal prism, thereby leading to the formation of an ice bridge along the JZBB, which effectively prevents the southward expansion of sea ice.     

300 BC-1900 AD无定河流域城镇时空格局演变

通过分析和整理从战国中晚期（约300 BC）至清末（约1900 AD）无定河流域历代县级及以上城址的位置、兴废年代数据,结合行政区划沿革、经济社会发展、政权更迭等资料,分析流域城镇格局的时空演变过程。研究表明：① 受气候周期性波动影响,无定河流域城镇的兴起与衰废具有明显的周期性特征,城镇几何中心的移动轨迹具有明显的“西北—东南”向潮汐性运动特征;② 城址存续年限普遍较短,具有明显的阶段性特征,流域内曾存在过4个阶段性中心城镇,中心城镇移动的方向和过程与城镇几何中心的潮汐性移动过程趋势一致;③ 流域城镇空间格局可分为3种类型,即秦汉与隋唐时期的沿河流谷地分布,宋、明两代的沿边境线与长城分布,以及元、清两代集中于流域下游分布。流域城镇未来的发展布局应重视气候变化对城镇分布的长期影响,关注区域环境的脆弱性,合理安排城镇体系发展规模与布局。     

山东省产业生态化时空分异特征与影响因素——基于17地市时空面板数据

本文综合构建了产业生态化评价指标体系,并利用熵值法、耦合协调分析、探索性空间数据分析方法、空间计量等多种计量方法对2005—2016年山东省17地级市产业生态化水平时空分异特征与影响因素进行了综合研究,结果表明：① 产业生态化依赖于产业化物质消耗型规模增长,但不以结构优化为基础的产业化势必忽视经济要素的横向转移反馈作用与集群效应,导致资源配置的低效现象;② 产业生态化水平逐年递增反映出产业系统与生态环境系统由拮抗向良性共轭方向发展,但其增长率较低说明了产业轻型化与清型化进程滞缓,其质量提升之路漫长而艰巨;③ 产业生态化呈现东中西递减的空间梯度分异特征,东部沿海地区始终是热点区,西部地区尤其是鲁西南地区始终是冷点区;④ 产业生态化水平空间相关性较为显著,经济发展水平、产业结构、外商投资等因素负向溢出效应比较明显,而政府调控以及环境规制强度等因素正向溢出效应突出。