The mechanism of hindering occupants’ evacuation from seismic responses of building

Natural Hazards - Pedestrian evacuation from buildings during an earthquake needs to consider human behavior and building shaking. This study sets up an indoor evacuation model based on the social...     

Torrential rainfall-triggered shallow landslide characteristics and susceptibility assessment using ensemble data-driven models in the Dongjiang Reservoir Watershed,China

Natural Hazards - This study investigated the characteristics of rainfall-triggered landslides during the Typhoon Bilis in the Dongjiang Reservoir Watershed, China. The comparative shallow...     

Energy transition,CO2 mitigation,and air pollutant emission reduction: scenario analysis from IPAC model

The salinization of freshwater-dependent coastal ecosystems precedes inundation by sea level rise. This type of saltwater intrusion places communities, ecosystems, and infrastructure at substantial risk. Risk perceptions of local residents are an indicator to gauge public support for climate change adaptation planning. Here, we document residential perspectives on the present and future threats posed by saltwater intrusion in a rural, low-lying region in coastal North Carolina, and we compare the spatial distribution of survey responses to physical landscape variables such as distance to coastline, artificial drainage density, elevation, saltwater intrusion vulnerability, and actual salinity measured during a synoptic field survey. We evaluate and discuss the degree of alignment or misalignment between risk perceptions and metrics of exposure to saltwater intrusion. Risk perceptions align well with the physical landscape characteristics, as residents with greater exposure to saltwater intrusion, including those living on low-lying land with high concentrations of artificial drainages, perceive greater risk than people living in low-exposure areas. Uncertainty about threats of saltwater intrusion is greatest among those living at higher elevations, whose properties and communities are less likely to be exposed to high salinity. As rising sea levels, drought, and coastal storms increase the likelihood of saltwater intrusion in coastal regions, integrated assessments of risk perceptions and physical exposure are critical for developing outreach activities and planning adaptation measures.

     

衡阳盆地南缘灯草坪花岗闪长斑岩地质特征及其与铜多金属矿成矿的关系

灯草坪岩体位于衡阳盆地西南缘,出露面积约0. 67km~2,为燕山晚期花岗闪长斑岩体。文章通过对灯草坪岩体进行主微量元素地球化学研究,讨论了其与周边铜铅锌矿床成矿的关系。分析显示灯草坪岩体具有高(过)铝、高硅、高K_2O/Na_2O和高Fe_2O_3/FeO比值,为镁质、高钾钙碱性岩系,W、Bi、Ag、As、Sb等元素丰度较高,ΣREE值总量中等,轻稀土较富集,δEu值接近1,为铕正常型,δCe值0. 84,具铈的弱的负异常。其岩石学、元素地球化学特征反映岩体形成于碰撞后环境,深部地壳或地幔物质参与了成岩-成矿作用,表明衡阳盆地中生代有色金属成矿活动一直持续至白垩纪。     

贵州开阳地区富磷矿成矿作用过程与找矿潜力

贵州开阳地区是我国富磷矿集中分布区。近年来,通过产学研协同创新、联合攻关,实现了磷矿理论创新,推动了该区磷矿找矿突破;厘清了开阳地区磷矿成矿受黔中古陆长期剥蚀夷平的平缓海岸型的无障壁海滩(缓坡浅滩)环境控制;建立了富磷矿"三阶段"动态磷矿成矿模式,阐明了"富"的成矿作用过程,即原始生物-化学、波浪波选(机械)暴露淋滤、磷质沉淀胶结成矿作用。建立新的磷矿区域成矿模式和地质找矿预测模型,开展找矿预测,通过工程验证,估算磷矿资源量(333+334?) 54892万吨,取得了富磷矿找矿新的重大突破。预测区内富磷矿还有8亿吨的找矿潜力。     

Jurassic granitoid dike in Luodian,Guizhou Province: discovery and geological significance

Acta Geochimica - In this paper, the Jurassic granitoid dike that intrudes into Permian diabase was reported in Luokun, Luodian County, south Guizhou. Zircon LA-ICP-MS U–Pb dating of the...     

胶东三山岛金矿床黄铁矿原位微区微量元素特征及对矿床成因的指示

胶东地区是我国最大金成矿聚集区,其金矿床的成因长期以来一直存在很大争议,三山岛金矿床是胶东地区最大的金矿床,通过采用LA-ICP-MS分析不同阶段黄铁矿中微量元素组成,可以探讨成矿流体演化及成矿物质来源。根据野外地质特征及岩相学观察,结合SEM结构分析将三山岛金矿床的黄铁矿分为3个阶段,6个亚类,即黄铁绢英岩化带(Py1)中包裹大量绢云母和石英的Py1-a和表面光滑的Py1-b,石英—黄铁矿±菱铁矿脉(Py2)中富含矿物包裹体的Py2-a和与菱铁矿共生且表面光滑的Py2-b,石英—多金属硫化物脉(Py3)中有很多细粒多金属硫化物包裹体的Py3-a和表面光滑的Py3-b。3个阶段黄铁矿晶格中金含量均很低,大部分小于1×10^-6,金主要以可见金形式存在。从早阶段到晚阶段黄铁矿中Au与Ag,Cu,Pb,Sb有较好的正相关性,且含量有逐渐增加的趋势。最早阶段黄铁矿中Co+Ni的含量很高(最高为9268×10^-6),反映了早期黄铁矿可能来源于岩浆岩源区,后期Co/Ni值逐渐降低,暗示了成矿流体温度逐渐降低。结合地质特征和黄铁矿微量元素研究,表明三山岛金矿床成矿物质可能来源于深部岩浆热液储库,通过地震泵机制沿断裂构造多次侵位成矿。     

青藏高原北部冰前湖沉积记录的中晚全新世冰川活动

青藏高原的冰川为亚洲地区大多数人口提供了重要的水资源,研究青藏高原的冰川活动历史有助于预估未来气候变化条件下的冰川响应。本文通过对羌塘腹地布若错沉积物岩芯的粒度、元素以及总有机碳等指标进行分析,重建了该流域中晚全新世以来的冰川活动历史。结果表明,布若错流域在5.2~4.0 cal.ka B.P.期间,冰川退缩,气候相对温暖;然而,4.0 cal.ka B.P.以来环境逐渐变干,印度季风持续减弱;随着3.2 cal.ka B.P.左右大规模的冰川前进,布若错流域进入新冰期,并受到较强西风的影响,气候寒冷干旱;1.3 cal.ka B.P.以来,流域内冰川仍然维持着较大规模,然而湖面却略有升高,可能反映了西风带来了一定的降水。此外,该流域存在4次显著的冰川前进事件,它们分别发生在3.6~3.4 cal.ka B.P.、3.2~2.3 cal.ka B.P.、1.9~1.7 cal.ka B.P.和0.4~0.1 cal.ka B.P.。这4次冷期与青藏高原其他古气候记录对应较好,这种频繁发生的冷事件可能与太阳辐射的长期衰减以及太阳活动的周期性变化有关,热带辐合带的持续南退是季风持续减弱的重要原因;此外,中晚全新世北大西洋的气候变化通过增强的西风环流对该流域产生影响。     

小冰期结束以来贡嘎山海螺沟冰川退缩区土壤化学风化与发育过程

选择海螺沟冰川退缩区,对冰川退缩年龄分别为0年、30年、40年、52年、80年、120年的样点按土壤发生层分层采集样品,通过分析样品的化学风化速率及理化性质变化,探讨小冰期结束以来土壤发育过程及影响因素,并评估不同阶段土壤质量。结果表明,退缩区前40年样点中主要以碳酸盐风化为主,80年后硅酸盐风化作用增强。土壤长期风化速率随土壤年龄呈现升高-降低-升高的趋势,52年样点长期风化速率最低,为48.06cmol/(m^2·a),矿物组成和气候是影响土壤风化速率的重要原因。土壤的粒度组成以砂粒为主,多数样点占比约为80%~90%。随着土壤年龄增加,容重值和pH减小,pH从8.54减小到5左右;土层厚度、土壤有机质(SOC)及总氮(TN)含量增加,这些土壤理化指标的快速变化表明冰川退缩区土壤发育迅速。适宜的温度、充足的降水以及快速的植被演替可能是退缩区土壤快速发育的原因。模糊数学法计算土壤质量的结果显示,除了0年样点,其余样点土壤质量指数(SQI)均大于0.4,说明退缩区土壤质量状况整体属于中等水平,土壤肥力状况较好。研究结果有助于揭示土壤矿物风化过程和土壤发育的影响因素,理解土壤发育机制。