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The synsedimentary faults and basin-marginal fans located in the central part of the deep-water area of the early Oligocene Qiongdongnan Basin have been investigated using seismic profiles, boreholes, and well-log data.Through the formations of the characterized paleogeomorphology, such as transverse anticlines, fault ditches,and step-fault belts, the synsedimentary faults are known to have controlled the development position,distribution direction, and extension scales of the basin-marginal fans. For example, at the pitching ends of two adjacent faults, transverse anticlines developed, which controlled the development positions and distributions of the fans. During the early Oligocene, the faults controlled the subsidence center, and fault ditches were formed at the roots of the faults. In the surrounding salient or low salient areas, which were exposed as provenance areas during early Oligocene, the fault ditches acted as the source channels and determined the flow paths of the clastics, where incised valley fills were obviously developed. The fault ditches which developed in the sedimentary basins were able to capture the drainage systems and influenced the distributions of the fans. The large boundary faults and the secondary faults generated two fault terraces and formed step-fault belts. The first fault terrace caused the clastics to be unloaded. As a result, fans were formed at the entrance to the basin. Then, the second fault terrace caused the fans to move forward, with the fans developing in a larger extension scale. The results obtained in this study will potentially be beneficial in the future prospecting activities for reservoirs and coalmeasure source rocks in the basins located in the deep-water areas of the South China Sea. 相似文献
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提出岩相古地理研究的优势相思路与方法,优势相划分由等时性界面限定的沉积持续时间和沉积厚度这条主线串联起来。优势相分析具有定性与定量兼有的特征,即以各种定性与定量的、反映某个时期或阶段沉积环境特点的关键因素或指标资料为基础,由点到线、由线到面,点、线、面结合,由二维到三维空间,确定该阶段或该时期占优势的主导沉积相或岩相。主导沉积相或岩相既要满足沉积持续时间的主导、又要满足沉积物质表现优势,还需满足盆地或区块总体背景和环境格局上的合理性与综合性。指出优势因素(或称优势参数)是优势相确定的基础和前提。提出了“广义岩相古地理”和“狭义岩相古地理”2个概念,在其研究内容、精度、理论深度、研究区域范围和应用等方面进行区别,但并不能由一两个指标就简单区分,需要综合对比和分析才可以界定。论文还论述了岩相古地理研究出现的7个新方向,这些新的研究方向可根据研究目的和解决的实际勘探目标,进行广义和狭义岩相古地理分析。运用优势相分析思路和方法,在柴达木盆地新生代等时性地层划分及建立了盆地等时地层格架基础上,进行了柴达木盆地关键时期岩相古地理恢复。 相似文献
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《New Astronomy》2016
We present an automatic algorithm to detect coronal mass ejections (CMEs) in Large Angle Spectrometric Coronagraph (LASCO) C2 running difference images. The algorithm includes 3 steps: (1) split the running difference images into blocks according to slice size and analyze the grayscale statistics of the blocks from a set of images with and without CMEs; (2) select the optimal parameters for slice size, gray threshold and fraction of the bright points and (3) use AdaBoost to combine the weak classifiers designed according to the optimal parameters. Experimental results show that our method is effective and has a high accuracy rate. 相似文献
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中国省际生态福利绩效测算及影响因素研究 总被引：2，自引：0，他引：2
采用非期望产出SBM模型对2001~2015年中国省际生态福利绩效进行测算研究,运用空间自相关方法和空间误差模型对中国省际生态福利绩效的空间分布特征及影响因素进行检验。结果表明:① 中国生态福利绩效总体水平较高,但呈现出下降态势;各省市之间差异性明显,仅有北京、上海等6个省市实现有效,其他省市均存在不同程度的无效率状态;区域之间也存在差异性,总体呈现出东部>西部>中部的分布格局。② 中国省际生态福利绩效呈现正向空间自相关性,存在明显的集聚状态。③ 中国省际生态福利绩效的主要影响因素有技术进步、绿化程度、社会性支出、医疗水平、城镇化、产业结构和环境规制。 相似文献
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Zhou Leisheng Huang Yubing Shao Zhuhai Ma Fenglin Zhang Peng Wang Yue 《Geotechnical and Geological Engineering》2021,39(7):5041-5061
Geotechnical and Geological Engineering - In order to solve the problem of surrounding rock rheological failure of large section chamber group in deep well, according to the engineering background... 相似文献
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我国北方典型岩溶地下水位对降水及气象指数的响应特征——以鲁中地区为例 总被引：2，自引：1，他引：1
我国北方岩溶水资源是其经济社会发展的重要资源基础,表征水资源赋存特征的岩溶地下水位动态及其影响因素分析能够为岩溶水资源管理及合理开发利用提供重要支撑。本文选取鲁中地区3个典型水文地质单元,基于2010-2017年月值降水、地下水位及NPI气象指数数据,采用小波分析方法对上述指标的周期性、响应特征及遥相关特征进行了分析。结果表明:（1）各岩溶地下水位动态、降水与NPI的主波动周期均为1 a,其显著周期与分布时段等的异同是受自然条件和人类活动共同作用的结果。（2）各水文地质单元岩溶水位对降水的响应时滞为95.81~146.64 d,其差异主要源于观测站所处的地下水流系统的位置的不同。（3）NPI与降水存在一定的遥相关,与受降水影响的岩溶水位动态也存在遥相关。各岩溶水位对NPI的遥相关时滞为111.75~169.77 d,相比水位对降水时滞有所增加。鲁中岩溶地区地下水位对降水与NPI存在规律性的响应时滞,此种特征可为我国北方岩溶地下水位的预警预报提供帮助。 相似文献
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对辽东北部地区中全新世聚落遗址的时空特征进行分析研究,结合辽东北部地区的自然环境背景,探讨自然环境变迁与聚落遗址时空分布的关系。结果表明：① 研究区全新世文化序列可分为新乐下层时期-后洼上层时期-偏堡时期-北沟时期,各时期遗址数量及在总数中的比重均呈现出先增后降再增的“N” 型变化趋势。② 各期遗址点高程大多分布在0~200 m地区且高程分布呈先增后降的倒“V” 型变化;从坡度和坡向来看,各期遗址主要分布于0°~6°间平缓地区,除后洼上层时期外均分布于阳坡半阳坡且各时期聚落均表现出逐河而居的特征。③ 新乐下层时期,古人类受气候影响选择居于平原区较高海拔处,以避开潮湿低洼地带;后洼上层时期,下辽河平原的古人类为躲避洪水侵袭而选择远离河流的更高海拔处,而辽东山地地区后洼上层文化居民向高处迁徙的同时仍倾向于近河流居住以利用良好的渔猎环境;偏堡时期,受降温事件打击,为寻求更为温暖且食物充足的驻地,古人类从山地进入平坦温暖的平原。北沟时期,气候寒冷干燥,海侵进入衰退期,古人类开始向相对温暖的沿海地带进发,在原先被海水淹没的地区定居。 相似文献