1982年12月2日耀斑随时间变化的半经验模型

我们利用南京大学太阳塔中的多波段光谱仪,在H_α、H_β和CaⅡ H、K三个波段同时拍到了1982年12月2日日面S15W11处的一个SB级耀斑的光谱。本文给出其中七个时刻的谱线轮廓及有关参数的序列。在非局部热动平衡条件下计算了耀斑随时间变化的半经验模型,结果显示了色球耀斑的演化过程。利用模型得到了一些色球物质蒸发参数,结果同根据SMM的X射线观测所作的估计相一致。     

黑石-大山盆地赋煤特征初步探讨

通过收集整理物探、钻探资料,分析了黑石—大山盆地煤层赋存规律,认为在盆地的斜坡地带煤层赋存较好,总结出含煤岩系及煤层的变化规律,指出下一步找煤方向——在黑石东—塔拉站区域及官地镇—大山林场区域。     

煤岩构造变形与动力变质作用

煤岩是一种对温度、压力等地质环境因素十分敏感的有机岩,地质演化过程中的各种构造-热事件必然导致煤岩发生一系列物理与化学结构的变化,并形成不同类型的构造煤。在构造应力作用下,煤岩不仅发生脆性和韧性变形,而且还产生不同程度的动力变质作用。因而,关于煤岩构造变形与动力变质作用的研究不仅具有重要的科学意义,而且在煤层气资源评价以及煤与瓦斯突出危险性预测方面也具有重要的实际意义。文中在已有研究成果基础上,通过对构造煤系列Ro,max、XRD和NMR(CP/MAS+TOSS)等测试和实验方法的对比研究,深入分析了煤岩不同构造变形和动力变质特征,进一步探讨了构造应力下煤岩动力变质作用的机理。研究成果表明,在构造应力作用下,煤岩脆性变形主要是通过破裂面上快速机械摩擦转化为热能而引起煤岩化学结构与其成分的改变;而韧性变形煤主要是通过局部区域应变能的积累而引起煤岩化学结构的破坏,从而发生不同机制的动力变质作用。     

浅析宁波盆地膏盐地层的时代──兼对“宁波盆地北部的长河群”之时代质疑

宁波盆地地下揭示的一套包含暗色膏硝质泥岩、泥质白云岩在内的紫红、灰紫色泥岩、棕褐色砂砾岩、细砂岩和玻屑凝灰岩的地层，均称方岩组，内含膏盐并具油色显示。对其时代有早、晚白垩世和早第三纪之认识，笔者从70～90年代地质工作中所获化石分析认为，虽然宁波盆地这一层位含化石不丰，但从分布及数量上比较，相对占优势的应该是孢粉和植物化石，其时代意见也较为一致，指示为早白垩世。     

玛曲MS4.4地震震源机制解及其构造意义探讨

2021年5月22日青海省玛多县发生M_S7.4地震,数小时后在距离震中两百多公里的甘肃玛曲县发生了M_S4.4地震。利用甘肃、青海和四川区域测震台网记录的三分向宽频带数字波形资料,反演甘肃玛曲M_S4.4地震的震源机制解,结果显示此次地震活动面走向、倾角和滑动角分别为105.6°、74.1°和-38.7°。参考玛多M_S7.4地震的震源机制解,发现两次地震震源机制解具有较好的一致性,均呈现明显的左旋走滑特征。静态库伦破裂应力改变量分布计算结果表明,玛曲M_S4.4地震震中位置单位面积(m~2)受到来自玛多地震震中方向的拉应力约为0.02 MPa。综合两次地震的震中距、发震时刻和断层分布等情况,初步判断甘肃玛曲M_S4.4地震应为青海玛多M_S7.4强震的一次触发地震。     

Isomorphic sodium admixture in garnets formed at high pressures

Na₂O contents were determined by electron microprobe analysis in 124 garnets from diamonds, xenoliths of peridotites, eclogites from kimberlitic pipes and metamorphic complexes. Na₂O content ranges between 0.01 and 0.22% with the limit of detection at about 0.01%. In the garnets of diamond-bearing eclogites and orange garnets from diamonds a regular increase in the Na₂O content has been established, varying from 0.09 to 0.22, as compared to garnets from eclogites of metamorphic complexes (range 0.01 to 0.06). It is assumed that the increased Na₂O content in the garnets of eclogites is mainly connected with higher pressure, whereas isomorphism of sodium is connected with the initial stages of the transition from Si⁴ to Si⁶ in the garnet structure: CaAlNaSi.The study of the sodium content of garnets has shown that all the orange-coloured garnets from diamonds so far studied are related to eclogite assemblage. Determination of the Na₂O content of individual inclusions of chrome pyropes from diamonds permits a conclusion on the type of assemblage (with or without clinopyroxene). Proceeding from these data, the importance of garnet-olivine paragenesis within the stability field of diamond has been revealed.Some clear distinctions in the sodium content of the garnets from xenoliths of the kyanite eclogites from the Zagadochnaya pipe in Yakutia and the Roberts Victor mine in South Africa confirm the relation of these eclogites to different subfacies.A conclusion is drawn as to the possibility of utilizing the Na/Na+Ca distribution in the garnets and pyroxenes of eclogites of especially deep-seated origin as a pressure indicator and to the necessity for experimental testing of the dependence of the distribution of these elements in garnets and pyroxenes on pressure, presumably in the range of 30–100 kbars.     

Deformation Mechanism and Stability of a Rocky Slope

A high slope is located on the side of the spillway at a hydropower station in Southwest China, which has some weak inter-layers inclining outwards. Parts of the slope show heavy weathering and unloading. There appeared deformation and tensile crack either on the surface or on the afteredge of the slope during excavation, and under a platform （elev. 488 m）, two levels of slopes collapsed on the downriver side. Based on the investigation in situ and the analysis of the geological structure, the conceptual model of deformation and failure mechanism was erected for this slope. Furthermore, the deformation characteristics were studied with FLAC^3D numerical simulation. Comprehensive analysis shows that the whole deformation of the slope is unloading rebound in certain depth scope and the whole body does not slide along any weak interlayer. In addition, two parts with prominent local deformation in the shallow layer of the slope show the models of ＂creep sfiding-tensile cracking＂ and ＂slidlng-tensile cracking＂, respectively. Based on the above analysis, the corresponding project of support and reinforcement is proposed to make the slope more stable.     

山西西山煤田7号煤层成因类型研究

煤的成因类型通过煤的有机显微组成、矿物成分等来体现。从微观研究的角度出发，以各子样的显微煤岩组分统计值、镜惰比（V/I）、骨基比（F／M）、矿物质含量为依据，对西山煤田屯兰煤矿7号煤进行成因类型划分，分为4类6型，即Ⅰ-①、Ⅲ-①、Ⅲ-②、Ⅳ-①、Ⅳ-②、Ⅴ-①。自下而上对煤层划分了23个成因分层。7煤层以Ⅳ类成因类型为主，沉积了覆水森林沼泽环境。     

层滑构造煤岩体微观特征及其应力应变分析

层滑构造在煤层及其顶、底板间普遍发育,它对地质勘探、煤矿生产、矿井工程灾害防治以及煤层气的开发等方面都有着重要影响。本文以淮北煤田海孜煤矿为例,在研究宏观层滑构造带组合特征的基础上,探讨了层滑构造的微观特征和形成机理。构造煤是层滑引起的煤层流变最显著的特征之一。通过对构造煤与构造岩的微观特征测试,发现层滑运动除了产生脆性变形外,还产生较强烈的塑性变形。利用煤镜质组光率体各向异性和构造岩组构,结合层滑构造的实测数据进行了煤岩体应力、有限应变分析。结果表明:层滑构造以顺层剪切为主,煤层受力的主要方向为NW-SE向。     

京张地区区域地壳稳定性评价

在野外调查和广泛收集资料的基础上,分析了控制和影响京张地区区域地壳稳定性的主要因素及内外动力地质的耦合作用。选取活动断裂、地震活动性和深部地球物理等因素,同时选取工程岩组、地形地貌与地表地质灾害等11个因素作为评价因子,并对评价因子进行了分类赋值。采用多因素加权叠加分析方法,建立了区域地壳稳定性评价模型,基于GIS平台对京张地区的区域地壳稳定性进行了定量化评价,将研究区划分为稳定区、次稳定区、次不稳定区和不稳定区4个等级。依据区域地壳稳定性评价结果,为京张高速铁路、云顶滑雪场、石京龙滑雪场的建设和运营提出相关建议,为京张地区国土规划提供了基础依据。