Listric versus planar normal fault geometry: an example from the Eisenstadt-Sopron Basin (E Austria)

In a gravel pit at the eastern margin of the Eisenstadt-Sopron Basin, a satellite of Vienna Basin (Austria), Neogene sediments are exposed in the hanging wall of a major normal fault. The anticlinal structure and associated conjugated secondary normal faults were previously interpreted as a rollover anticline above a listric normal fault. The spatial orientation and distribution of sedimentary horizons and crosscutting faults were mapped in detail on a laser scan of the outcrop wall. Subsequently, in order to assess the 3D distribution and geometry of this fault system, a series of parallel ground penetrating radar (GPR) profiles were recorded behind the outcrop wall. Both outcrop and GPR data were compiled in a 3D structural model, providing the basis for a kinematic reconstruction of the fault plane using balanced cross-section techniques. However, the kinematic reconstruction results in a geologically meaningless normal fault cutting down- and up-section. Additionally, no evidence for a weak layer serving as ductile detachment horizon (i.e. salt or clay horizon) can be identified in stratigraphic profiles. Instead, the observed deflection of stratigraphic horizons may be caused by a displacement gradient along a planar master fault, with a maximum displacement in the fault centre, decreasing towards the fault tips. Accordingly, the observed deflection of markers in the hanging wall—and in a nearby location in the footwall of the normal fault—is interpreted as large-scale fault drag along a planar fault that records a displacement gradient, instead of a rollover anticline related to a listric fault.     

重力场定义的澄清

《朗曼现代英文词典》(LongmanModernEnglishDictionary)、《牛津高阶英汉双解词典》(OxfordAdvancedLearner’sEnglish ChineseDictionary)、《韦氏词典》(Merriam Webster’sNewCollegiateDictionary)、作为地球物理专业词汇定义源的《勘探地球物理百科词典》(EncyclopedicDictionaryofExplorationGeo physics)以及中国的一些重力教科书、专著及词典 ,把重力场定义为重力或重力作用存在的空间 ,重力效应可以测量的空间 ,即 :力或重力存在的空间。这个定义不同于国外英文地球物理教科书、专著及中、英、俄文场论教科书对重力场的定义 :空间中的重力。定义重力场为重力存在的空间 ,混淆了“场”本身及“场域”的概念 ,并不是一个标准的物理或地球物理定义 ,是一种误导。物理场是空间中存在的一种物理作用或效应 ,分布于引起它的场源体周围。两个物体之间存在着的相互作用力 ,通过每个物体引起的引力场给予另一个物体。重力场可以定义如下 :地球内部及其附近空间一点处存在的重力作用 ,或单位质量受到的重力。重力场是一种力或力场 ,存在于地球表面及其附近的空间。重力场不是空间 ,重力场的测量应当是在重力场存在的空间或场域中 ,而不是在重力场中进行。     

Review on Researches of Aragonite Saturation State in the Southern Ocean:A Key Parameter of Southern Ocean Acidification

The Southern Ocean is a strong sink for atmospheric CO₂, making it especially vulnerable to ocean acidification (OA). The aragonite saturation state (Ω_arg) of seawater has been used as an index for the estimation of OA, which plays a critical role in evaluating the living environment of marine calcified organisms. However, it is very difficult to perform the studies of OA and Ω_arg in the Southern Ocean due to its harsh climate. Therefore, in order to better understand the OA and its further influences, the advances of Ω_arg studies were summarized in the oceans surrounding the Antarctica. Significant spatial and temporal variations of surface seawater Ω_arg are demonstrated in the Southern Ocean. In general, the surface seawater Ω_arg shows a lower value in the off-shore areas than in the open oceans. And, Ω_arg also exhibits a strong seasonal cycle with a higher value in summer than in winter. The distributions of Ω_arg in vertical water column generally present a declining tendency from surface to bottom. In addition, the shoaling of Ω_arg horizon at high latitude could be attributed to the ventilation and upwelling of deep waters in the Southern Ocean. There are many factors that could impact the Ω_arg in the Southern Ocean, including sea ice melting, sea-air CO₂ exchange, biological activities and hydrological processes, etc. Finally, the future changes and key scientific problems of OA in the Southern Ocean are proposed.     

新疆不同区域牧业雪灾损失时频变化特征

选用新疆1952-2013年75个县707条雪灾害资料, 采用灰色关联评估模型以县为单位将新疆分为特重雪灾区、 重雪灾区、 一般雪灾区、 小雪灾区. 用气候趋势系数与五阶函数分析各雪灾区牲畜死亡数额的长期变化趋势, 并用morlet小波分析其振荡周期. 结果表明: 全疆及各雪灾区牲畜死亡数额基本都存在23 a左右的长周期, 14～17 a中周期, 10 a左右的小周期, 另外, 还存在5～7 a的小波动, 各区周期振荡的强弱及时间范围不同. 全疆及特重雪灾区牲畜死亡数额长期以来有减少趋势; 而重雪灾区和一般雪灾区牲畜死亡数额长期以来有微弱的增加趋势. 特重雪灾区牲畜死亡数额长期变化趋势决定了新疆雪灾牲畜死亡数额的长期变化趋势, 全疆平均每年因雪灾牲畜死亡数额以0.4%的速率递减, 特重雪灾区每年按上一年度总额1.4%的速率递减. 由于20世纪80年代开始, 新疆有计划、 大规模推行牧民定居工程, 从而大大提高了新疆牧业抗御自然灾害的能力, 以及冬春气温升高的缘故, 使得全疆及各雪灾区牲畜死亡数额大大减少. 因为各牧业区实施牧民定居工程开始的时间不同, 使全疆各雪灾区牲畜死亡数额高值期(年代际与年际尺度振荡的活跃期)进入低值期(少发时期)的临界时间存在差异.     

Identification of an underfilled foreland basin system in the Upper Devonian of the Central Pyrenees: implications for the Hercynian orogeny

A foreland basin succession has been identified in the Frasnian of the Central Pyrenees. This succession comprises a carbonate-dominated transgressive system which recorded the cratonward migration of the foreland basin subsidence, and siliciclastic depocenters which recorded the progression of the thrust-fold deformation. The foreland basin system has always been maintained in deep-marine environments, i.e., at an underfilled depositional state. It was associated with a thrust wedge which descended toward a deep-marine hinterland, i.e., with a type of orogenic wedge usually related to subduction zones. The Frasnian foreland basin system differs from the one known in the Carboniferous which evolved to overfilled depositional state and was associated with a thrust wedge rising toward a mountainous hinterland. Consequently, the Hercynian orogeny in the Pyrenees seems to result first, from a Frasnian thrusting controlled by a subduction zone located north of the Pyrenees, and second, from a Carboniferous thrusting controlled by the surrection of a frontal thrust belt in the Pyrenees. The association of underfilled foreland basin systems and hinterland-dipping thrust wedges, as exemplified in the Frasnian of the Pyrenees, can be interpreted as illustrative of the initial stages of thrust-wedge growth in deep-marine settings.     

对造山带古地理学在盆地构造——古地理重建中的若干思考

造山带古地理学在盆地构造--古地理重建中的若干思考的核心，是以活动论的构造观指导盆地分析。本文强调以发展的、动态演化的思路来研究盆地。现存的一个盆地，可能只是地史期间大盆地的残余（或残留）部分；或是原来彼此分开和独立的几个盆地内的沉积记录组成的沉积物拼盘。一个盆地内现存的次级构造单元可能由年轻的造山运动形成；另一种可能性则是原来的次级单元已被后来的构造-热事件模糊或遮蔽了。在盆地的建造过程中，隆起（包括次级隆起）的时起时伏十分常见；相应地，盆地间的时分时合也十分常见。在泛大陆旋回与大盆地发育间有着内在联系，即：大盆地发育受邻侧的洋盆演化和造山过程制约，故“盆”“山”间的耦合分析是正确认识盆地动态演化的钥匙。体现在构造--古地理重建中，造山带古地理学倡导原地的古地理重建与非原地的古地理重建相结合且以后者为主。非原地的古地理重建可通过定量的（如基于古地磁资料的重建）和定性的两条途径实现。文章讨论了定性重建中的5个要点：1）时间上，要结合“反序”的研究，2）空间上，要结合“反转构造”的研究，3）强调构造复位在古地理重建中的意义，4）盆地建造阶段中的改造事件所起的承前启后作用，和5）盆地动力学与造山动力学的结合研究。     

An algorithm for the simulation of curvilinear plane-strain and axisymmetric hydraulic fractures with lag using the universal meshes

We present an algorithm to simulate curvilinear hydraulic fractures in plane strain and axisymmetry. We restrict our attention to sharp fractures propagating in an isotropic, linear elastic medium and driven by the injection of a laminar, Newtonian fluid governed by lubrication theory, and we require the existence of a finite lag region between the fluid front and the crack tip. The key novelty of our approach is in how we discretize the evolving crack and fluid domains: we utilize universal meshes (UMs), a technique to create conforming triangulations of a problem domain by only perturbing nodes of a universal background mesh in the vicinity of the boundary. In this way, we construct meshes, which conform to the crack and to the fluid front. This allows us to build standard piecewise linear finite element spaces and to monolithically solve the quasistatic hydraulic fracture problem for the displacement field in the rock and the pressure in the fluid. We demonstrate the performance of our algorithms through three examples: a convergence study in plane strain, a comparison with experiments in axisymmetry, and a novel case of a fracture in a narrow pay zone.     

Planform evolution of deltas with graded alluvial topsets: Insights from three‐dimensional tank experiments,geometric considerations and field applications

The profile of a river that conveys sediment without net deposition and net erosion is referred to as ‘graded’ with respect to vertical aggradation of the river segment. Three experimental series, designed in terms of the autostratigraphic view of alluvial grade, were conducted to clarify the diagnostic spatial behaviour of graded alluvial–deltaic rivers: an ‘R series’, which utilized a moving boundary setting with a stationary base level; an ‘F series’ in a fixed boundary setting with a stationary base level to produce ‘forced grade’; and an ‘M series’ in a moving boundary setting with constant base‐level fall to produce ‘autogenic grade.’ The results of the three experimental series, combined with geometrical modelling of the effects of basin water depth and other experimental data, suggest the following: (i) in a graded alluvial–deltaic system, lateral shifting and avulsing of active distributary channels are suppressed regardless of whether the downstream boundary of the deltaic system is fixed; (ii) in a delta with a downstream‐fixed boundary, the graded streams are stabilized within a valley that is incised in the axial part of the delta plain, whereby the alluvial plain outside the valley is abandoned and terraced; (iii) in moving boundary settings, the graded river simply extends basinward as a linearly elongated channel and lobe system without cutting a valley; and (iv) a modern forced‐graded alluvial river is most likely to be found in a valley incised into a fan delta in front of very deep water, and the stratigraphic signal of fossil autogenic‐graded rivers will be found in deltaic successions that accumulated in the outer to marginal areas of deltaic continental shelves during sea‐level falls. This renewed autostratigraphic view of alluvial grade suggests a thorough reconsideration of the conventional understanding that an alluvial river feeding a progradational delta is graded with a stationary base level.     

Dynamics of bubbles in supernovae and turbulent vortices

We consider the motion of a bubble in a central acceleration field created by gravity or a centrifugal force. In the former case, the bubble moves outwards from and, in the latter, towards the center. We have calculated the characteristic time needed for a bubble to leave or reach the center. The solution obtained provides insight into the processes of thermonuclear supernovae and combustion; in other words, into the interaction between a flame and a turbulent vortex. In the case of combustion, a light bubble of burnt material propagates towards the axis of a strong turbulent vortex faster than it drifts in the direction of rotation of the vortex. It is expected that the development of bubbles should prevent the formation of “pockets” at the flame front, similar to those predicted by a simplified model of turbulent combustion in a constant density flux. In the case of a thermonuclear supernova in a deflagration burning regime, it is shown that light products of burning rise from the center of the white dwarf substantially more rapidly than the thermonuclear flame front propagates. As a result, a flame cannot completely burn the central part of the star, and instead is pushed to the outer layers of the white dwarf. The effect of bubble motion (large-scale convection) makes spherically symmetric models for thermonuclear supernovae unrealistic, which is of prime importance for the supernova spectrum and energy. The motion of bubbles is even faster in the case of a rotating white dwarf; under certain conditions, the centrifugal force may dominate over the gravitational force. To test this theory, we have carried out numerical simulations of supernovae explosions for various sizes of the burned region in the core of the presupernova. We have derived a relation between the rate of large-scale convection and the size of the burned region, which is specified by the rate of the deflagration in the thermonuclear burning.     

The value of measurements of density in the study of dolerites

The value of density measurements in the study of differentiated dolerite sills is discussed. It is shown that density measurements correspond closely with the results of chemical and modal analyses. There is a considerable statistical fluctuation in measured values of the density from relatively close specimens, and a similar fluctuation is to be expected in the results of chemical or modal analyses. Because of their speed, it is possible to make a large number of density measurements and take mean values over fifty foot intervals to indicate trends.

The density in a moderately thick tholeiite sheet normally increases linearly from the lower contact to a maximum several hundred feet above it, and then decreases to a minimum at the most silicic region which usually occurs several hundred feet below the upper contact. For a sheet of uniform thickness, the variation of density with depth appears to be roughly the same at all points. The density remained constant in a horizontal tunnel at a constant height above the lower contact, but irregular changes in density, possibly associated with changes in level of the roof or flow can occur, and a remarkable case of a rapid horizontal variation in density is discussed in some detail.     

Spectral P-wave magnitudes, Aki's ω-square model and source parameters of earthquakes

The earthquake magnitude is a quantity sampling the spectrum of the far-field radiation.With a suit of properly defined magnitudes in a sufficiently broad range of frequencies, the radiated spectrum can be restored and analyzed.A method is proposed for the extraction of stress drop, fault length and seismic moment from magnitudes on a routine basis. Thereby, the theoretical spectrum as predicted by the ω-square model of Aki is utilized.In applying the method to earthquakes which occurred in several parts of Asia over a time-span of 3 years, it is shown that in most cases earthquakes in a given region are characterized by the same stress drop, varying however from region to region. In one region a change of the stress drop with time is found, eventually indicating a change in the state of stress in the particular region during the time interval investigated.     

The influence of man on climate

The economic activity of man has lately been exerting a considerable influence on global climate. This influence ranges from the growth of carbon dioxide concentration to an increase in aerosol chemicals in the atmosphere. The first results in a rise in air temperature at the surface of the earth, while the second provides for a fall in temperature. The overall influence of various man-made factors results in a fall in some tenths of degree in average temperature. Because of a rapid growth of the carbon dioxide concentrations and a growth of energy consumption with an extra heating of the atmosphere, it may be expected that a fall in temperature caused by economic activity will give place to a temperature rise in the near future. According to some calculations an average temperature at the surface of the earth may rise in 0.5⁰ by the end of the present century. It may be followed by a considerable reduction in the area of the Arctic ice, by changes in the atmospheric circulation and by the diminution of precipitation in a number of regions.     

简单斜坡油气富集规律——以松辽盆地西部斜坡北段为例

斜坡是断陷和凹陷型盆地的重要构造单元，按其断裂发育程度和沉积厚度分为复杂斜坡和简单斜坡。松辽盆地西部斜坡为断裂不发育、平缓的简单斜坡，简单斜坡油气成藏有特殊性，表现在三个方面：一是简单斜坡的原油主要来自临近的凹陷，油气沿砂体以优势路径方式侧向运移，油气呈“线状”分布；二是简单斜坡大规模构造圈闭不发育，圈闭类型以地层、岩性和构造-岩性圈闭为主，其分布受构造带控制，超覆带发育岩性上倾尖灭圈闭，受规模较大的断层控制形成的鼻状构造带上发育断层遮挡和构造-岩性圈闭，不受断层控制的鼻状构造带主要发育构造-岩性圈闭。三是简单斜坡普遍受大气水的淋滤作用，由于游离氧的进入使原油遭受氧化降解作用而稠化，造成简单斜坡稠油分布普遍。这种成藏的特殊性决定了油气富集规律：只有位于油气运移路径上的圈闭才有成藏的可能。简单斜坡油气勘探方向是，在油气运移路径上寻找低幅度构造背景下的岩性油气藏（小规模）、规模较大断层附近寻找断层遮挡油气藏（中等规模）和地层超覆带上寻找岩性上倾尖灭油气藏（大规模）。     

Thoughts on the Measurement and Calculation of Geogenetic Depth

The method of determining the depth of geological events is based on the geobarometer method. According to this method, a depth to a certain position is obtained in such a way that the pressure at that position is divided by the specific weight(density) of the overlying rock formations, called the "W/SW" method in this paper. This method follows the principle of hydrostatics, assuming that rocks in this case are in a static fluid state(standard state) rather than a solid state. If so, only pressure could be measured from the rocks because the latter does not exist in a hydrostatic     

地下水中苯并[a]芘来源探讨

采用色谱质谱法对2000~2002年地下水中苯并[a]芘含量进行了分析,在分析苯并[a]芘在地下水环境中迁移特征的基础上,初步探讨了地下水中苯并[a]芘的来源。结果表明,苯并[a]芘在潜水含水层、200m的承压含水层以及500m的煤系地层和1000m以上的岩溶水中都有检出,含量低,为数个ng/L;由于苯并[a]芘的辛醇-水分配系数kow很大,为106个数量级,具有很强的憎水性,会强烈地被吸附在土壤颗粒物的有机碳上,因此苯并[a]芘很难从表层土壤中迁移进入地下水,土壤和沉积物是其主要的环境归宿;从理论上看,地下水中的苯并[a]芘是天然来源。     

Correlation of reefal Oxfordian episodes and climatic implications in the eastern Paris Basin (France)

Oxfordian reefal episodes of Lorraine and Burgundy have a long time been considered as contemporaneous. Biostratigraphic data and sequential evolutions peculiar to each region indicate their structural autonomy during Oxfordian times. A north‐south‐oriented well‐logging transect shows that, during the Middle Oxfordian, a shallow reefal platform developed in Lorraine while thin deeper deposits occurred in Burgundy. In spite of their different ages, reefal episodes of Middle Oxfordian in Lorraine and Upper Oxfordian in Burgundy exhibit a broadly similar vertical evolution of coral communities. During the Late Oxfordian, the contemporaneous occurrence of a diversified assemblage in the Burgundy region, a colder coral assemblage characterized by eurytopic genera and the decrease in seawater isotopic temperatures in Lorraine can be explained by a shift in trophic conditions, a climatic change related to structural rearrangements in this strategic place and a modification of oceanic circulations between the arctic and the Tethyan regions.     

生物礁的群落相

本文提出了生物瞧群落相的概念。群落相是指保存在生物礁中一组能够反映适应它们生长和繁衍环境条件的古生物群团的特征和面貌。群落相是研究生物礁的发展演化规律、空间分布规律及与油气储集分布规律的关系的一个重要途径。     

Scattering of cyclotron radiation in a moving plasma

We consider the scattering of cyclotron radiation in a plasma moving along a homogeneous magnetic field. The equation of radiation transfer in a co-moving frame is derived and two limiting cases are pointed out. In the first case of a “small” velocity gradient, the total Doppler frequency shift due to variations in the plasma velocity over the flow is much smaller than the width of the line. The second, opposite, case of a “large” velocity gradient is analogous to the Sobolev approximation in the theory of moving stellar envelopes. The solution of the transfer equation for a wind-type flow illuminated by radiation of a given intensity is obtained in the latter case, when the influence of the plasma motion on cyclotron scattering is most important. It is shown that cyclotron scattering in a moving plasma differs from the known (and qualitatively similar) problems of resonance scattering in moving stellar envelopes and cyclotron scattering in a motionless plasma permeated by an inhomogeneous magnetic field. In particular, a symmetric absorption band with residual intensity proportional to the velocity gradient appears in the spectrum of the outgoing radiation, while in these two other problems, the depth of the corresponding spectral features cannot exceed half the continuum level. Detailed qualitative analysis reveals that this difference is due to the particular form of the frequency redistribution for cyclotron scattering.     

近50 a塔里木河流域生长季大风日数变化特征及对特色林果业的影响

大风是塔里木河流域特色林果业的主要气象灾害. 在对塔里木河流域44个气象站大风资料进行质量控制基础上, 统计分析了1960-2011年作物生长季节(3-10月)月大风日数. 结果表明: 近50 a来塔里木河流域生长季节内各月大风日数的长期变化具有显著的递减趋势, 递减速度为0.8~2.6 d·(10a)^-1, 趋势系数为-0.37~-0.8, 通过了95％的秩检验; 但二次和三次系数为正, 反映出生长季节大风日数近期呈现回升的趋势. 周期分析发现, 生长季节大风日数存在11~15 a左右的中期振荡, 5~8 a的短周期振荡, 以及5 a以下的小扰动. 虽然从更高的20 a频域尺度看, 20世纪80年代中期之后是大风的少发时期, 但从15~16 a周期上看, 生长季节大风日数亦开始有回升的趋势. 尤其是在春末及夏秋(4-9月)塔里木河流域特色林果业的关键生长时期, 大风日数占整个生长期(3-10月)的89%. 虽然, 近10 a平均每年大风日数只有20世纪60年代的一半, 但每年平均也有7 d之多, 并没有脱离大风的威胁, 而且近期大风日数还有回升的趋势. 因此, 春末及夏秋(4-9月)是塔里木河流域特色林果业的重点防风时期. 从空间分布上看, 南疆东部平均每年大风日数1~2 d, 是塔里木河流域生长季节防风重点地区.     

The blazar 0059+581: Successful prognosis of activity

Our earlier joint analysis of light curves for the blazar 0059+581 at 4.8, 8, 14.5, 22, and 37 GHz with high-resolution VLBI images led us to suggest that the activity in this source develops in cycles, or periods, with a duration of about four years, with a “typical scenario” for the development of the source’s activity taking place over a cycle. Based on this analysis, we predicted in 2002 that a new superluminal component would be ejected from the core of this source in a structural position angle ～170° no later than by the end of 2003. A 43-GHz VLBI image obtained on September 14, 2003, as part of a program to monitor the structure of reference sources used for a radio astronomical coordinate system, convincingly confirms the correctness of this prediction. This is the first time in the history of radio astronomy that a new superluminal component has been detected at a predicted time and in a predicted structural position angle.