Fabric at granodiorite-schist contact,Bear Island,Maryland

Summary The essential difference between the granodiorite and its wall rock fabric consists in the two well-defined deformation plans. The wall rock is a B-tectonite, the granodiorite an S-tectonite. Transport in the former was rotational and monoclinic, in the latter possibly by laminar flow parallel with the contact.The granite fabric could hardly be an in place fabric or replacement without differential movement. It would have retained the wall rock fabric, even if not the mineral composition. Transport in the granodiorite was presumably along the wall parallel S₄ and the contact. The present study is barely a beginning, but it is hoped that it can be continued in the near future and extended over a wider area.With 9 figures.     

Tropical cyclone-induced wave hazard assessment in Hainan Island,China

With the rapid expansion of the scale of deep sea net-cage use in the nearshore area of Hainan Island, tropical cyclone-induced wave hazard assessment is urgently needed. In this study, the wind-wave-current coupled ADCIRC?+?SWAN model, which considers the effects of tidal and storm surges, was used to simulate tropical cyclone events over the last 33 years. This model adopts an unstructured high-resolution grid with a nearshore resolution of up to 100 m. The compared simulated results and observations during typhoons JEBI (2013), HAIYAN (2013) and KALMAEGI (2014) were in agreement. This study statistically analyzed maximum significant wave heights on the basis of a large set of simulated storm wave level maps to derive the wave heights of different return periods. Then, the results of nearshore wave hazard classification were obtained by applying the affinity propagation (AP) clustering method to dozens of nearshore profiles. The results demonstrate that the risk at any point in the nearshore area of Hainan Island is dominated by the wave hazard type and water depth condition. The wave hazard assessment method developed for Hainan Island will be significant in assisting government decision-making in the rational planning of deep sea net-cage aquaculture.

     

Desertification and Re-Afforestation of the Coastal Land in Changjiang County,Hainan Island

Changjiang County is located to the northwest of the tailing range of the Wuzhi Mountains on Hainan Island,facing the sea and being against he Mountains.From southeast to northwest,it gradually descends in relief from mountain,hill,tableland,terrace to coastal plain.Its sandy coastal line is measued at 44.85km in length and its rocky coastal line at 7.15km along the county.The desertified coastal land covers and area of about 61.15km^2,extending from hundreds of meters to 3 km in width,of which the active sand land accounts for 5.333km^2 and the semi-active sand land,7.333km^2.The dunes are developed at the rate of 10-30m per year from the seashore toward the hinterland. The Forest Departments of Hainan Province and Changjiang County done a series of sand-control experiments.The chief technological measures are as follows:(1)to stabilize the drift sand first to create an adequate condition for afforestation;(2)to plant the big and strong saplings of Casuarin equisetifolia with nutrient bags in deep pits;and(3) to apply new techniques in “dry-season planting”to guarantee the quality of afforestation.The above experiments were successful.However,there still exist some problems such as quite seriously wilting shoot,lower survival rate of Pandanus tectorius in the vertical lines to the usual wind direction,monotonous the species in afforestation and subsequent poor management.Thus some suggestions are offered in this paper for future extension;(1)to apply REE fertilizers in the process of afforestation to increase the resistance of the plants;(2)to increase the vertical lines of Pandanus tectorius to the usual wind direcion to raise their survival rate in the network of sand stabilization;(3)to enlarge he area of liana planting to enhance the stability of sand;(4) to try to introduce new tree species from oter regions,which are of good performance in sand stabilization;(5) to interplant th adaptable economic crops;and (6)to make more investments and better management and conduct more extensive environmental education o ensure the early accomplishment of the protection forest belt around the island.     

石油类污染建筑场地的环境调查与治理

污染造成的环境损害和土壤与地下水质量降低,直接影响生命健康与环境安全。污染企业搬迁后遗留场地的调查检测与修复治理,是土地资源开发利用与管理的重要环节。结合两个炼油厂污染地块在土地再开发期间所进行的土壤环境调查和治理修复案例,阐述了石油类污染地基土的环境调查方法、评价方式和治理修复措施,以期为污染土壤的调查与治理修复提供借鉴。     

湖北省巴东县新城区滑坡灾害空间预测

论文在综合分析巴东县新城区区域地质背景及滑坡基本特征的基础上,分析了影响滑坡灾害发生的各因素与滑坡发生之间的相关性,提出影响灾害发生的主要因素：地形坡度、斜坡形态、岩性、构造、水的作用、人类工程活动。利用GIS的空间分析功能将各因素图件栅格化为86216个不规则单元。基于逻辑回归的方法对滑坡灾害进行了定量的概率预测。同时,对研究区进行滑坡灾害空间预测分区,将预测结果与该地区历史滑坡灾害发生情况进行对比发现预测精度为85．71％。说明所建立的模型具有较高的预测精度,是可以用于预测分析的。     

西沙石岛生物礁的矿物组成及其环境指示意义

通过对西科1井岩心碳酸盐岩样品进行矿物组成分析, 来研究礁体的发育过程和古海洋环境的变化.初步研究结果表明: 西科1井岩心碳酸盐岩的矿物由低镁方解石、高镁方解石、文石和白云石组成.矿物组成特征表明, 井深35.4 m处为一重要的地层界面或环境变化界面.在岩心(井深0~748 m)中共识别出5个白云岩层, 其中上新统莺歌海组一层(井深: 289.3~312.3 m, 厚约23 m), 上中新统黄流组三层(分别位于井深: 373.3~412.7 m, 厚约39.4 m; 424.7~450.6 m, 厚约26.1 m; 469.70~564.96 m, 厚约95.2 m), 中中新统梅山组一层(井深: 615.20~636.96 m, 厚约21.7 m).各层的白云岩化程度不尽相同, 5层白云岩中白云石矿物含量的最大值在79.3%~100%之间.生物礁的发育主要受控于古海洋环境的变化, 与古气候变化有关的海平面升降间接地控制了岛礁碳酸盐岩的白云岩化作用.石岛西科1井中的5层白云岩应该是在较长时间稳定环境条件下发育而成, 主要应该是蒸发泻湖渗透回流作用下早期形成的方解石类碳酸岩白云岩化的结果, 但并不排除混合水白云岩化作用的可能性.      

陕西省蓝田县新街遗址全新世鸟类分类学记述

近2～3年来,陕西省考古研究院科研人员再次对蓝田县的新街遗址进行了抢救性发掘,经过清理整理,发现于新街遗址灰坑、探沟和探方中的全新世鸟类骨骼共70件.鸟类化石均为分散保存骨骼,但此次发现的鸟类骨骼保存不仅数量多,而且形态也较完好,是国内全新世鸟类化石发现记录所罕见的.本文记述了对这批鸟类化石开展形态解剖学的鉴定,并系统完成分类学研究的成果,新街遗址中总计鸟类所属8目、8科、8属,共9种,其中以水生鸟类居多.此外,根据鸟类的生存习性及鸟类骨骼上残存的人工痕迹,还针对新街遗址全新世时期的环境和古人类的生活行为进行了全方位多角度的分析和推理,为新街遗址在传统考古学研究的基础上提供了全新的科学信息和有益的补充.     

Hydraulic Fracturing In Situ Stress Estimations in a Potential Geothermal Site,Seokmo Island,South Korea

We conducted hydraulic fracturing (HF) in situ stress measurements in Seokmo Island, South Korea, to understand the stress state necessary to characterize a potential geothermal reservoir. The minimum horizontal principal stress was determined from shut-in pressures. In order to calculate the maximum horizontal principal stress (S _Hmax) using the classical Hubbert–Willis equation, we carried out hollow cylinder tensile strength tests and Brazilian tests in recovered cores at depths of HF tests. Both tests show a strong pressure rate dependency in tensile strengths, from which we derived a general empirical equation that can be used to convert laboratory determined tensile strength to that suitable for in situ. The determined stress regime (reverse-faulting) and S _Hmax direction (ENE–WSW) at depths below ~300 m agrees with the first order tectonic stress. However the stress direction above ~300 m (NE–SW) appears to be interfered by topography effect due to a nearby ridge. The state of stress in Seokmo Island is in frictional equilibrium constrained by optimally oriented natural fractures and faults. However, a severe fluctuation in determined S _Hmax values suggests that natural fractures with different frictional coefficients seem to control stress condition quite locally, such that S _Hmax is relatively low at depths where natural fractures with low frictional coefficients are abundant, while S _Hmax is relatively high at depths where natural fractures with low frictional coefficients are scarce.     

河南省嵩县地质灾害风险评价

基于ArcGIS环境下,通过选取河南省嵩县区域高程、地貌、工程岩组、植被覆盖度、距构造距离、距水系距离、坡度、坡向等 8个因子建立危险性评价模型,易损性选取建筑物、人员和交通等 3 个承灾因子,分别采用信息量模型和层次分析法对河南省嵩县区域进行地质灾害易发性、危险性和易损性评价。研究结果表明,嵩县区域划分为低风险区面积为965.34 km2,占嵩县区域面积32%;中风险区面积为1114.65 km2,占嵩县区域面积的37%;高风险区面积为826.23 km2,占嵩县区域面积的27%;极高风险区面积为102.68 km2,占嵩县区域面积的3%。研究成果可应用于嵩县防灾减灾及地质灾害风险管控等方面。     

Ore-forming Material Sources of Liaotun Gold Deposit in Bama County,Northwestern Guangxi

Please refer to the attachment(s) for more details     

陕西陇县李家下滑坡风险评价

在野外勘查及室内实验的基础上,应用滑坡风险评价方法,对李家下滑坡进行了较为完整的风险评价,包括滑坡失稳概率计算、承灾体承灾概率计算、承灾体易损性计算和承灾体价值核算,最后得出滑坡总风险值,并将风险值用价值的形式量化表示。     

基于GIS技术的巴东新城区滑坡灾害危险性区划

基于ArcGIS8软件平台开发了三峡库区巴东县新城区滑坡灾害信息系统,通过全面分析巴东新城区滑坡灾害的地形条件,工程地质岩组、构造与斜坡结构类型、人类工程活动、水的作用等影响因素,建立了相应的滑坡灾害危险性评价指标体系。采用基于GIS技术的信息量模型和敏感性评价方法,实现了巴东县新城区滑坡灾害危险性区划,其中,高危险区面积3.30km^2,占7.196;中危险区面积5.77km^2,占12.4％;低危险区面积16.40km^2,占35.3％;基本安全面积21.05km^2,占45.2％,可以作为巴东新城区城镇建设规划和减灾防灾的参考依据。     

Spatial analysis of land use and shallow groundwater vulnerability in the watershed adjacent to Assateague Island National Seashore,Maryland and Virginia,USA

Spatial relations between land use and groundwater quality in the watershed adjacent to Assateague Island National Seashore, Maryland and Virginia, USA were analyzed by the use of two spatial models. One model used a logit analysis and the other was based on geostatistics. The models were developed and compared on the basis of existing concentrations of nitrate as nitrogen in samples from 529 domestic wells. The models were applied to produce spatial probability maps that show areas in the watershed where concentrations of nitrate in groundwater are likely to exceed a predetermined management threshold value. Maps of the watershed generated by logistic regression and probability kriging analysis showing where the probability of nitrate concentrations would exceed 3 mg/L (>0.50) compared favorably. Logistic regression was less dependent on the spatial distribution of sampled wells, and identified an additional high probability area within the watershed that was missed by probability kriging. The spatial probability maps could be used to determine the natural or anthropogenic factors that best explain the occurrence and distribution of elevated concentrations of nitrate (or other constituents) in shallow groundwater. This information can be used by local land-use planners, ecologists, and managers to protect water supplies and identify land-use planning solutions and monitoring programs in vulnerable areas.     

福建平和县西环路滑坡防治工程勘察实践与稳定性分析

滑坡是重大地质灾害之一,严重危害着人类的生命和财产安全。滑坡防治工程勘察是滑坡防治设计的重要基础工作。本文针对福建省平和县西环路滑坡防治工程开展了滑坡区工程地质测绘与调查,结合工程地质钻探成果,分析了滑坡的成因、滑坡稳定性计算及评价,提出了合理的防治措施。推测滑动面位置,确定岩土设计参数,选择合适的安全系数,对滑坡防治工程的综合治理至关重要。     

四川青川县碾子崩塌风险性评价

2008年5月12日四川省发生8级地震,地震对青川县造成了巨大破坏,同时引发了大量的次生地质灾害。本文以碾子村五社崩塌灾害点为研究评价对象,在工程地质条件、危岩体分布特征、变形破坏模式的研究基础之上,计算了研究区典型危岩体的稳定性及破坏概率。在野外滚石实验的基础上,运用专业软件模拟了失稳块石的运动轨迹,得到了落石运动过程中的速度、跳高及动能,并进一步确定了崩塌的影响范围。在野外调查和收集当地社会经济资料的基础上,对崩塌的易损性及风险性进行了评价,并根据灾害特点及评价结果提出了相应的防灾减灾措施。     

皖南石台大山富硒区人居放射性环境评价

安徽石台大山地区分布着较为广泛的下寒武统荷塘组石煤层,而石煤出露地区即是富硒区也是放射性水平含量较高区.根据本次调查在下寒武统荷塘组含煤岩系分布区的地方,其天然γ射线水平较高,不适宜人类在此居住.而调查区内的居民村庄大多远离含煤岩系分布区的地方,对当地的居民接收天然γ辐射照射人均年有效剂量估算,该地区居民居住的村庄和学校的人年均天然贯穿辐射有效剂量当量为0.32~0.43 mSv.因此,可以确定认为该地区居民居住γ射线辐射水平对人居环境影响不大,天然γ射线辐射环境对当地居民健康是安全的.     

藏北高原班戈县地质灾害综合风险评价

区域地质灾害风险评价虽然开展多年, 但是由于地质灾害危险性难以评价和量化, 承灾体数据难以调查和获取, 区域风险评价的质量和精度一直不高, 研究进展缓慢; 更兼藏北高原自然条件恶劣、高寒缺氧、山峰多为冰川所覆盖, 大部分地区人迹罕至, 研究程度极低, 基础地质资料及地质灾害研究成果相对匮乏, 区域地质灾害风险评价接近空白, 难以满足地方政府减灾防灾和应急管理的需求。本文以西藏自治区那曲市班戈县为研究区域, 利用2020年、2021年的高分一号、高分二号遥感影像数据及GIS空间分析技术, 基本查明了班戈县2.8×104 km2范围内地质灾害的数量、类型、规模、发育特征及分布规律, 并采用"信息量法"较为系统地进行了全县地质灾害1:50 000的风险评价, 对全县地质灾害的易发性、危险性、易损性及风险性进行了综合性的评价。研究表明, 班戈县由于位于青藏高原台面, 地广人稀, 地质灾害风险程度总体不高, 承灾体主要分布在城镇周边, 因此98%的地区为低风险区, 中、高风险区主要集中分布在城镇周边; 此评价结果为班戈县的地质灾害减灾防灾、风险管控等提供科学依据。     

Chert provenance analysis at the Mack Canyon Site,Sherman County,Oregon: An evaluative study

Chert is the most frequent lithic raw material in the Columbia Plateau, but archaeologists have made few attempts to link chert artifacts to their quarries in this area. The Mack Canyon Site in north-central Oregon is near a chert source, providing an opportunity to compare provenance analysis techniques. Macroscopic and microscopic visual attributes and element concentrations were determined for 26 samples from six sources in the Columbia Plateau. Additional concentration data from two other sources were included for comparison. Four artifacts were selected from the Mack Canyon Site for comparison to the nearby outcrop. Although all of the artifacts were macroscopically indistinguishable from the local material, microscopic attributes and element concentrations indicate that only one of the artifacts came from the outcrop. Linking chert artifacts and quarries through statistical analysis of element concentrations holds promise for the Columbia Plateau. © 1996 John Wiley & Sons, Inc.     

桐梓县矿山主要环境地质问题及防治对策

桐梓县矿业开发引起的矿山环境地质问题种类较多,主要为矿山地质灾害对土地、植被及地貌景观的占用与破坏,对地下水均衡的破坏,及矿山废水、固体废弃物排放对水环境的污染等几种。通过对矿区矿山地质环境的现状评估分区及其保护、治理分区,提出了矿山地质环境保护与治理的防治措施。