广西填海项目海籍调查结果与存在问题探析

海籍调查资料是海域管理的重要资料,本文遵照海域、测绘等规范,结合围填海现状调查,对广西壮族自治区海岸带确权填海项目海籍调查资料进行分析,发现项目填海位置与海域批复的位置存在偏移,为优化海域管理,针对海籍调查中宗海图绘制过程所涉及的海岸线、坐标系统、控制点等要素进行研究,得出应严格按照现行海域管理要求,使用统一的坐标系统及法定岸线,以确保准确可靠的海籍调查资料,发挥其在海域使用及自然资源规划管理方面中的作用。     

一次致灾超级单体雹暴过程数值模拟和发展机制分析

利用高分辨率中尺度数值模式WRF,模拟了2019年3月21日发生在浙江省的一次大范围致灾超级单体雹暴过程,结合多普勒雷达探测产品,分析了风暴的雷达回波结构、流场结构、各类水成物等特征及其演变,并探究冰雹形成的物理机制.结果表明:此次雹暴过程是在高空急流轴右侧和低层切变线相重叠的区域发生和发展的,强垂直风切变有利于雹暴的...     

Variability of organic δC and C/N in the Mersey Estuary, U.K. and its implications for sea-level reconstruction studies

Microfossil analysis (e.g. diatoms, foraminifera and pollen) represents the cornerstone of Holocene relative sea-level (RSL) reconstruction because their distribution in the contemporary inter-tidal zone is principally controlled by ground elevation within the tidal frame. A combination of poor microfossil preservation and a limited range in the sediment record may severely restrict the accuracy of resulting RSL reconstructions. Organic δ¹³C and C/N analysis of inter-tidal sediments have shown some potential as coastal palaeoenvironmental proxies. Here we assess their viability for reconstructing RSL change by examining patterns of organic δ¹³C and C/N values in a modern estuarine environment. δ¹³C and C/N analysis of bulk organic inter-tidal sediments and vegetation, as well as suspended and bedload organic sediments of the Mersey Estuary, U.K., demonstrate that the two main sources of organic carbon to surface saltmarsh sediments (terrestrial vegetation and tidal-derived particulate organic matter) have distinctive δ¹³C and C/N signatures. The resulting relationship between ground elevation within the tidal frame and surface sediment δ¹³C and C/N is unaffected by decompositional changes. The potential of this technique for RSL reconstruction is demonstrated by the analysis of part of an early Holocene sediment core from the Mersey Estuary. Organic δ¹³C and C/N analysis is less time consuming than microfossil analysis and is likely to provide continuous records of RSL change.     

辽东铀成矿带连山关地区韧性剪切带与铀成矿作用

连山关地区位于华北克拉通北缘铀成矿省辽东铀成矿带,已知铀矿床（点）均发育在韧性剪切带附近。为了解韧性剪切带运动学、几何学构造变形机制及与铀矿的关系,本文以连山关岩体周缘韧性剪切带为研究对象,通过野外宏观调查和室内微观研究相结合的研究方法,探讨构造变形期次、韧性剪切带形成机理及其对铀成矿的控制作用。研究表明：连山关岩体周缘发育的韧性剪切带与近南北向挤压构造变形有关,其右行韧性剪切带应变类型为压扁应变,属于一般压缩-平面应变范围,Flinn指数K值在0.19~0.69之间,岩石类型属于S/SL型构造岩。研究区内铀矿体均为隐伏盲矿体,主要赋存于沿着连山关岩体和辽河群接触带右行剪切作用形成的背斜褶皱核部,和北东东向断裂关系密切。综合分析认为,连山关岩体南缘北西向韧性剪切带为一级控矿构造,是区内铀矿热液运移的通道,而剪切带边部的晚期北东东向断裂则是铀矿储存空间;铀源可能来自于太古宙古风化壳,并在大型韧性剪切活动（提供热液运移通道）和基性脉岩侵入（提供热源和还原剂）等综合因素作用下运移、富集成矿。     

黄海及其沿岸历史地震初步研究

黄海及其边缘，经历史地震资料整理，地震参数估定与编目，截至1949年8月，共有M≥3级地震2187次，其中M≥43/4级地震259次，资料显示大致有三个相对集中活跃区，16世纪曾有过历史地震活动高潮。     

珠江口盆地白云凹陷新生代构造演化动力学

白云凹陷构造演化史的研究对在白云凹陷开展油气勘探和深水沉积研究具有重要的意义。通过对断裂与沉积结构平面和剖面特点的分析,结合岩浆活动特点,文中提出白云凹陷是一个复式地堑,推测这种结构特点与凹陷下地壳的强烈韧性减薄和颈缩变形有关,表现为热岩石圈的伸展。其发育机制推测与白云凹陷位于构造转换带上有关,特殊的构造位置使白云凹陷成为强烈构造变形区,岩石圈地壳强烈减薄,伴随伸展过程和地幔上涌,脆性地壳或上地幔中部分熔融物质的出现导致岩石圈强度的急剧降低,在区域伸展应力场下以韧性流变方式减薄。岩浆在构造转换带下聚集并发育主岩浆房,由于白云凹陷南北边缘没有发育正断裂系统,岩浆主要沿垂直伸展的方向运移,因此在珠琼运动一幕和二幕南南东向伸展应力作用下,岩浆向白云凹陷的东部和西部运移至北西向基底深大断裂处,那里由于北西向断裂表现为左行张剪性质而成为压力较低的地区,从而成为岩浆上涌和侵位的地方。在岩浆聚集的地区,活动岩浆体附近的脆性变形被分散的韧性变形所取代,因此在凹陷的东北和西南两个角上,发育了张性和张剪性小断裂群,由于热岩石圈弹性较差,白云凹陷长期持续沉降。白云凹陷的断裂活动和沉积演化史还受到南海海盆扩张活动的影响。     

Depositional architecture and sequence stratigraphy of the Karoo basin floor to shelf edge succession, Laingsburg depocentre, South Africa

The Laingsburg depocentre of the SW Karoo Basin, South Africa preserves a well-exposed 1200 m thick succession of upper Permian strata that record the early filling of a basin during an icehouse climate. Uniformly fine-grained sandstones were derived from far-field granitic sources, possibly in Patagonia, although the coeval staging and delivery systems are not preserved. Early condensed shallow marine deposits are overlain by distal basin plain siltstone-prone turbidites and volcanic ashes. An order of magnitude increase in siliciclastic input to the basin plain is represented by up to 270 m of siltstone with thin sandstone turbidites (Vischkuil Formation). The upper Vischkuil Formation comprises three depositional sequences, each bounded by a regionally developed zone of soft sediment deformation and associated 20-45 m thick debrite that represent the initiation of a major sand delivery system. The overlying 300 m thick sandy basin-floor fan system (Unit A) is divisible into three composite sequences arranged in a progradational-aggradational-retrogradational stacking pattern, followed by up to 40 m of basin-wide hemipelagic claystone. This claystone contains Interfan A/B, a distributive lobe system that lies 10 m beneath Unit B, a sandstone-dominated succession that averages 150 m thickness and is interpreted to represent a toe of slope channelized lobe system. Unit B and the A/B interfan together comprise 4 depositional sequences in a composite sequence with an overall basinward-stepping stacking pattern, overlain by 30 m of hemipelagic claystone. The overlying 400 m thick submarine slope succession (Fort Brown Formation) is characterized by 10-120 m thick sand-prone to heterolithic packages separated by 30-70 m thick claystone units. On the largest scale the slope stratigraphy is defined by two major cycles interpreted as composite sequence sets. The lower cycle comprises lithostratigraphic Units B/C, C and D while the upper cycle includes lithostratigraphic Units D/E, E and F. In each case a sandy basal composite sequence is represented by an intraslope lobe (Units B/C and D/E respectively). The second composite sequence in each cycle (Units C and E respectively) is characterized by slope channel-levee systems with distributive lobes 20-30 km down dip. The uppermost composite sequence in each cycle (Units D and F respectively) are characterised by deeply entrenched slope valley systems. Most composite sequences comprise three sequences separated by thin (<5 m thick) claystones. Architectural style is similar at individual sequence scale for comparable positions within each composite sequence set and each composite sequence. The main control on stratigraphic development is interpreted as late icehouse glacio-eustasy but along-strike changes associated with changing shelf edge delivery systems and variable bathymetry due to differential substrate compaction complicate the resultant stratigraphy.     

淮河源区中更新世黄土堆积的元素地球化学特征及其古气候意义

利用地球化学元素分析方法,对淮河源区中更新世黄土、古土壤剖面含有的化学元素及多种化学元素指标进行了分析。研究表明:区内中更新世以来的气候变化,主要以湿热气候为主,淋溶及氧化作用较强;表现在气温上HT-1~HT-3的气温较低,HT-4~HT-7的气温高,HT-8的气温又相对较低,其变化趋势表现为中更新世经历了从早期寒冷转湿热转温干,中期凉干转暖湿到晚期温湿转暖湿。     

一种夏季强雷雨预报因子的选取方法

为了提高对武汉天河机场夏季强雷雨天气预报准确率,利用极值剔除法选取了5个预报因子;这些因子分别与中低层大气和地面的温度、湿度等要素有关。将预报结论与天气实况进行对比后发现:极值剔除法所得的预报因子可以有效地减少夏季强雷雨的漏报率。     

高速公路交通事故与气象条件的关系研究

选取2013—2017年河北高速公路逐日发生的一般等级以上交通事故起数、伤亡人数、经济损失及同期气象要素资料,基于序关系分析法将事故量及等级量化为事故指数,分析了对高速通行高影响的雾天、雨天和雪天事故的年际、月际及日变化特征,并构建日均交通事故指数与气象要素的非线性回归模型。研究表明：（1）交通事故发生时不利天气条件下交通事故总起数、死亡事故起数及人数、经济损失为雾天>雨天>雪天,而伤人事故及人数为雨天>雾天>雪天。（2）雨天、雪天交通事故峰值与当年雨雪极端天气事件有关,雾天单起交通事故的直接经济损失呈上升趋势;事故月、日分布有显著性差异,表现为雾天事故高发月份在9月至翌年2月、雨天事故多发于在5—10月、雪天事故多发于1—2月、12月;05—08时和00时为事故高发时段。（3）分别针对不同等级日雨量和能见度与日均交通事故指数建立了一般等级以上交通事故模型,非线性回归效果显著。