凤城市赛马镇风洞洞穴特征及发育基本条件

赛马镇风洞是我国东北规模较大的岩溶洞穴,洞长在2000m以上,已探测长度1265m.风洞具有纵坡降较小、支洞繁多、形态奇异及国内罕见的溶蚀景观“天锅”等特征.岩性、构造、水文地质特征等是控制洞穴发育的基本条件.风洞的发育约始于中更新世40万年前.     

北京房山世界地质公园岩溶景观特色

北京房山世界地质公园是以岩溶洞穴景观和峰丛地貌景观为主题的地质公园。大石河流域发育中奥陶统马家沟组石灰岩,自上而下,依次发育鸡毛洞、银狐洞、石花洞和孔水洞,由一条地下暗河将其连为一个洞系,其水源补给点在大石河上游,排泄点为孔水洞。周口店猿人遗址属于中奥陶统马家沟组岩溶洞穴。拒马河流域发育中元古界雾速山组白云岩,岩溶洞穴包括云水洞、仙栖洞、龙仙宫和三清洞,均属唐县期夷平面时期的产物。拒马河流域地层平缓的中元古界雾速山组峰丛地貌区东从张坊起,西至大沙地,南临笔架山,北抵石人峰,流域面积395km~2,其中碳酸盐岩岩石面积占360km~2,山体上部的岩石被溶解,形成峰丛地貌景观。     

南京汤山驼子洞洞穴堆积及其意义

通过对南京汤山驼子洞洞穴堆积观察描述和样品分析测试,结合前人研究成果和汤山地区地质地貌演化的历史,讨论了驼子洞堆积的时代、堆积过程和方式,并对其蕴含的构造、地貌、气候和生物进化等古环境信息进行了合理的挖掘。初步研究表明驼子洞堆积可能是跨早更新世与中更新世早期的地层,其上部含哺乳动物化石的堆积可能反映了偏暖的气候环境。     

滇中富民县宝石洞旅游地质特征与成景机制探讨

滇中富民县宝石洞岩溶地下河洞穴景观系统规模适中,洞内岩溶景观千姿百态,洞中有宝(玛瑙),洞外有优美的生态环境和多元民族宗教文化以及潜在的温泉资源,加上优越的交通区位,旅游要素集群度较高,具较高开发价值.文章根据宝石洞地区区域地质背景,分析了该地区区域地史演化特征,根据本次对宝石洞的实地探测成果,总结了宝石洞旅游地质特征...     

黄铁矿热电性在铜矿床深部找矿预测中的应用——以滇中和尚洞铜矿Ⅰ号矿体为例

黄铁矿热电性是矿床学及深部地质找矿的重要研究内容之一,该方法多应用于金矿床的地质勘探,而在铜矿床勘探中应用较少.滇中和尚洞铜矿床属于中高温热液矿床,矿体宏观地质条件差异小,深部找矿难度大,本文对该矿床Ⅰ号矿体开展了黄铁矿热电性特征及深部找矿预测研究.结果表明,该矿床黄铁矿热电系数分布呈现多峰组合,矿体铜矿化强度与黄铁矿...     

基于图像分割的成像测井资料目标拾取与计算

为了从FMI资料中提取定量信息,一个很重要的步骤就是要对FMI图像数据进行分割.即从实际FMI资料中分离出反映孔洞、裂缝的子图像,然后用相应的方法对分割后的子图像进行分析处理,提取相应参数.本文通过研究大量图像分割算法,认为奇异点多阈值分割算法、基于过度区的分割算法、Hopfield网络方法、基于图像间模糊散度的阈值化算法是FMI图像分割的有效方法,实现了从FMI图像中将地层中有用目标,从背景中分离出来.同时,为了得到孔洞及裂缝的形状参数,本文还研究了轮廓跟踪标识边缘的方法以及根据标识的边缘进行填充的算法.在此基础上,也研究了根据目标边缘坐标计算目标的长度、宽度、圆度、裂缝密度、孔洞密度等参数的方法.上述所有方法在SUN工作站GeoFrame平台上开发成功,通过对LX45等八口井的处理结果与岩心分析数据对比表明,效果较好.     

Epikarst hydrology and implications for stalagmite capture of climate changes at Grotta di Ernesto (NE Italy): results from long‐term monitoring

Grotta di Ernesto is a cave site well suited for palaeoclimate studies because it contains annually laminated stalagmites and was monitored from 1995 to the end of 2008 for microclimate, hydrology and hydrochemistry. Long‐term monitoring highlighted that cave drips show three different hydrological responses to rainfall and infiltration: (1) fast seasonal drips in the upper part of the cave, which are mostly fed by fractures, (2) slow seasonal drips, located at mid‐depth in the cave characterized by mixed feeding and (3) slow drips, mostly located in the deeper gallery, which are fed by seepage flow from bulk porosity with a minor fracture‐fed component. The slow drips display daily cycles during spring thaw. Monitoring also indicated that drip waters are only slightly modified by degassing within the soil zone and aquifer and by prior calcite precipitation. Hydrochemical studies show a clear seasonality in calcite saturation index, which results in most cave calcite precipitation occurring during late autumn and winter with similar amounts of precipitated calcite on most stalagmites, regardless of drip rate (discharge) differences. Drip rate, and drip rate variability, therefore, has a minor role in modulating the amount of annual calcite formation. In contrast, drip rate, when associated with moderate reduction in calcite saturation index, clearly influences stalagmite morphology. Increasing drip rate yields a passage from candle‐, to cone‐ to dome‐shaped stalagmites. Very high drip rates feed speleothems with flowstone morphology. In summary, monitoring provides information about the karst aquifer and how hydrology influences those physical and chemical characteristics of speleothems which are commonly used as climate proxies. Copyright © 2010 John Wiley & Sons, Ltd.     

周口店新发现距今11～1.9万年的洞穴堆积层的成因及年代学研究

本文对周口店新发现距今11～1.9万年的东岭子洞穴堆积物进行了成因研究,认为该套堆积物并非全属岩溶堆积物,其中也有风成黄土沉积。应用古地磁、热发光及铀系法等年代学方法测定,认为这套堆积为距今11～1.9万年间沉积,弥补了周口店地区近5万年的晚更新世洞穴地层空缺,是一个含有丰富地质事件的晚更新世洞穴地层剖面。     

瞬变电磁法在工程地质勘察中的应用

用瞬变电磁法在黄石市某矿主竖井建设地段查明了地表到地下100m的岩洞、构造破碎带、断裂带,并利用这些资料讨论了洞的成因及其与断裂破碎带的关系.圆满地完成了矿方提出的地质任务.     

Mass movements in cave sediments: investigation of a ∼40,000-year-old guano mudflow inside the entrance of the Great Cave of Niah, Sarawak, Borneo

The West Mouth of the Great Cave at Niah in Sarawak, northwest Borneo and the North Passage that leads to the West Mouth contain large deposits of guano. The main deposit, several metres thick in places, forms the sloping floor of the entire North Passage. A mass movement deposit identified in the West Mouth, having a volume of 600 m³, originated as a guano mudflow up the North Passage in the order of 40,000 years ago. This failure of the guano slope was investigated to determine whether particular conditions or events could be identified as the most likely causes. The physical, hydrological and geotechnical properties of samples of the material were determined so that the stability of the slope could be assessed. Stability analyses showed that shearing failure of the slope would require inputs of water to the slope in quantities for which no feasible explanation can be suggested. However, the properties of the guano are similar to those of loess, indicating a high susceptibility to ‘hydrocollapse’. Very shallow failure of the slope, possibly as several smaller mudflows, could therefore have occurred due to additional water in quantities that could realistically be supplied as rainwater spray, possibly with a seismic trigger. The climate must therefore have been wetter than it is at present. These findings have implications for the interpretation of sediment deposits in other relict caves.