岩浆驱动破裂的形态研究

轴地壳岩浆房是活动扩张中心海洋地壳结构的一个重要组成部分，轴地壳岩浆房通过深部岩浆源的补充，内部岩浆的同化熔融、结晶分异等岩浆房过程，其中的岩浆会破裂上覆的岩石层形成岩浆破裂，并沿岩浆破裂继续向上迁移。本文建立了岩浆迁移的层流模型，从理论上对岩浆迁移问题进行了探讨，并将遗传算法引入到该问题中来，用遗传算法求解了描述岩浆驱动破裂传播的积分方程。如果假设岩浆破裂在远离破裂末梢处的权限宽度为1M，则靠近末梢，破裂的宽度逐渐加大，在末梢处宽度为2m左右。并根据文献对岩浆流体的一些观测参数计算得出，岩浆破裂权限宽度不会很大，一般在1m左右的量级。     

新疆阿拉尔花岗岩MFC过程的微量元素综合效应

新疆阿拉尔花岗岩的微量元素比相关图显示了线性样点列与幂函数曲线形式的样点列相 复杂图型。该图型用简单混合或者单一结果分异模型都不能解释。本文建立了混合－结晶分异复合过程的微量元素综合效应模型。模型１：从初始混合线引起害虫函数曲线束形式的结晶分异线。特殊情况有结晶分异线简化为通过原点的直线束形式或者与初始混合线重合。     

Magnetic anisotropy produced by magma flow: theoretical model and experimental data from Ferrar dolerite sills (Antarctica)

Volcanic rocks forming sills, dykes or lava flows may display a magnetic anisotropy derived from the viscous flow during their emplacement. We model a sill as a steady-state flow of a Bingham fluid, driven by a pressure gradient in a horizontal conduit. The magma velocity as a function of depth is calculated from the motion and constitutive equations. Vorticity and strain rate are determined for a reference system moving with the fluid. The angular velocity and the orientation of an ellipsoidal magnetic grain immersed in the fluid are calculated as functions of time or strain. Magnetic susceptibility is then calculated for a large number of grains with a uniform distribution of initial orientations. It is shown that the magnetic lineation oscillates in the vertical plane through the magma flow direction, and that the magnetic foliation plane changes periodically from horizontal to vertical. The results are compared with the magnetic fabric of Ferrar dolerite sills (Victoria Land, East Antarctica) derived from low-field susceptibility measurements.     

席状岩浆房中的岩浆冷却及动力稳定性

关于岩浆房中岩浆的结晶分异方式一直存在着争议，其基本矛盾在于对岩浆冷却历史及热不稳定性可能引起的对流形式的理解各不相同。本文在充分考虑席状岩浆房的基本物理特征的基础上，建立了稳定岩浆体系的动态冷却模型，并以攀枝花层状岩体为例，计算了相应的温度场、密度场及粘度场。同时，提出了一种基于能量守恒的、对热不稳定性进行分析的新方法。计算了热不稳定性可能引起的对流强度、对流区域及对流时间，并深入讨论了在一定的热不稳定状态下，不同的岩浆屈服强度对对流特征参量的影响。结果表明，在该岩体的整个固化过程中，如果曾发生过自发对流，其对流也是极微弱而短暂的，不会影响中下部岩浆房中岩浆的固化和结晶。这一结论与对该岩体的实际观察相符。     

湘南中新生代玄武岩成因研究及构造环境分析

定量计算了湘南中新生代多种类型玄武岩的矿物－熔浆平衡条件和岩浆粘度、密度、上升速度等岩浆物理参数，识别出了三类原生玄武岩浆，橄榄拉斑武岩浆、白榴碧玄岩浆、碧玄岩浆、根据玄武岩的地质岩石学的地球化学特征，及岩浆起源条件，深部地质和地球物理等方面资料的综合分析，认为本区玄武岩是大陆岩石圈深部热扰动的产物。     

岩浆活动对油气藏形成条件的影响

结合众多实例，总结了国内外含油地中岩浆活动对油气藏形成的影响。一方面，岩浆活动所携带的高热流可以提高古地温，加速生油岩的演化，亦将使与岩浆岩毗邻的生油岩达到高成熟或过成熟，     

Crystal morphologies in pillow basalts: implications for mid-ocean ridge processes

We present the results of a detailed petrological study of a sparsely phyric basalt (MAPCO CH98-DR11) dredged along the Mid-Atlantic Ridge (30°41′N). The sample contains microphenocrysts of olivine that display four different rapid-growth morphologies. Comparison of these morphologies with those obtained in dynamic crystallization experiments allows us to constrain the thermal history of the sample. The dendritic morphology (swallowtail, chain and lattice olivine) is directly related to the final quenching during magma–seawater interaction. In contrast, the three other morphologies, namely the complex polyhedral crystal, the closed hopper and the complex swallowtail morphology result from several cycles of cooling–heating (corresponding to a maximum degree of undercooling of 20–25°C) during crystal growth. These thermal variations occurred before eruption and are interpreted to be the result of turbulent convection in a small magmatic body beneath the ridge. The results suggest that the Mid-Atlantic Ridge is underlain by a mush zone that releases batches of liquid during tectonic segregation. Aphyric basalts are emitted during eruptions controlled by the tectonic activity, whereas phyric basalts correspond to small fractions of magma from the mush zone mobilized by reinjections of primitive magmas.     

Evidence for high-Ca boninite magmatism from Paleogene primitive low-K tholeiite, Mukoojima, Hahajima Island group, southern Bonin (Ogasawara) forearc, Japan

Abstract   High-Ca boninitic inclusions are found in primitive low-K tholeiite from Mukoojima (Mukoo-Jima), an islet in the Hahajima Island group, Bonin (Ogasawara) forearc, Japan. While Chichijima Island group, 50 km north of Hahajima Island group, is well known as a type locality of boninite, there has been no report of boninitic rocks from the Hahajima Island group. The high-Ca boninitic inclusions are aphanitic and contain olivine, Ca-rich clinopyroxene, plagioclase, chromian spinel, opaque minerals and dark brown glass. The mode of occurrence of the inclusions and host tholeiite under the microscope indicates mingling of these two magmas, suggesting intimate association in space and time of the boninite and primitive tholeiite magmas around the Hahajima Island group in Paleogene time. Primitive compositions and slightly different Sr and Nd isotopic ratios suggest that these two magmas are derived from two distinct mantle sources. These two mantle sources were present at the same time around the Hahajima Island group, southern Bonin forearc. The source of the high-Ca boninite was higher in water content and/or shallower in depth compared to that of the primitive tholeiite.     

用混合和扩散云室对大气冰核浓度的观测分析

继1963年用混合云室对春季冰核浓度观测之后，1994～1996年，在同季节、同地点用混合和静力扩散云室又做了同步观测。对取得的资料进行整理分析，得出了凝华核浓度在不同天气背景下占总冰核浓度的百分比，两种云室测值的对应关系；分析了扩散云室的容积效应及冰核浓度随气压、能见度等气象因子的变化。