新疆北部石炭纪单体珊瑚新资料

文中描述的10属10个新种单体珊瑚,全部是小型角锥状、弯锥状,具中轴者居多.系发育边缘厚结带,鳞板不发育的类型.其中Rylstonia,Fasciculiamplexus,Homalophy-llites.and Tetralasma等在新疆属首次发现,不仅丰富了本区石炭纪珊瑚的属种,而且为相关地区石炭纪地层的对比提供了新的依据.同时也证明当时的北极海与我国的北方海槽及华南海是相互沟通的.     

STUDY ON DYNAMIC RESPONSE AND INSTABILITY OF SOIL-ROCK MIXTURE DEPOSIT WITH DIFFERENT STONE CONTENTS AND SLOPE GRADIENTS

Soil-rock mixture deposit is an extremely heterogeneous loose rock-soil deposit formed since Quaternary, which is composed of blocks, fine-grained soil and pore with a certain engineering scale and high strength and has a certain stone content. These soil-rock mixtures accumulated on slopes have been completely destroyed and their mechanical strength is very low. They are widely distributed in the mountainous areas of Southwest China, which poses a great threat to the engineering. Earthquakes occur frequently in Southwest China, and the instability of soil-rock mixture deposit under seismic load is one of the important factors causing the damage to this type of deposit. The dynamic response of soil-rock mixture deposit under seismic load is an important index to study its instability mechanism under seismic load. Based on indoor shaking table model test, the influence of rock content and slope gradient on dynamic response characteristics of soil-rock mixture deposit was studied. In model tests, rock content is 30%, 40% and 50%respectively, and slope gradient varies from 20°, 30° and 40°. Two different seismic loading frequencies and three different excitation strengths were given. The peak acceleration(PGA)amplification coefficients in horizontal and vertical directions of soil-rock mixture deposit were analyzed under the change of rock content and slope gradient. The permanent displacement and deformation law of the top and foot of the slope of soil-rock mixture deposit were analyzed by model test. The experimental results show that the dynamic acceleration response characteristics of the soil-rock mixture deposits at the top and foot of the slope are different under different slope gradients and rock content conditions, and the horizontal PGA amplification coefficients of the soil-rock mixture deposits are also different. With the same seismic frequency and excitation intensity, the horizontal PGA amplification coefficient increases with increased slope gradient, and the rate gets faster. With the increase of stone content, the magnification coefficient of horizontal PGA decreases, and the higher the stone content, the slower the decrease rate of horizontal PGA magnification coefficient. When the slope gradient of soil-rock mixture deposit increases, the corresponding horizontal and vertical PGA amplification coefficients increase with the same seismic frequency and excitation intensity. The amplification coefficients of PGA in the vertical direction are different, but the overall magnification is weaker than that in the horizontal direction. The vertical PGA amplification coefficients of the foot, middle and lower parts of the slope are larger, while the vertical PGA amplification coefficients of the upper and middle parts of the slope tend to decrease. The higher the frequency of seismic wave is, the smaller the vertical PGA amplification coefficient corresponding to the same elevation will be, which indicates that the vertical PGA amplification coefficient is negatively correlated with the elevation. The variation trend of PGA magnification coefficient of soil-rock mixed deposit in vertical direction is different with the change of stone content. Under the same excitation intensity, the larger the slope gradient is, the larger the permanent displacement at the top of the slope will be, and the larger the rock content, the smaller the corresponding displacement at the top of the slope. The permanent displacement of the top of the slope is obviously larger than that of the foot of the slope, which indicates that the magnification effect of the top of the slope is obvious. After the vibration process and sliding of the landslide, the large-sized particles in the soil-rock mixture deposit move downward faster and slip on the surface of the deposit body. There was a very obvious phenomenon of particle sorting in the pile-up at the foot of the landslide body. The results of this study are of practical significance for the analysis of the dynamic response law of soil-rock mixture deposit under seismic load due to the change of rock content and slope gradient.     

湘西地质公园红色碳酸盐岩石林发育特征与研究价值

红色碳酸盐岩石林是湘西地质公园最重要的地质遗迹之一。公园内的红色碳酸盐岩石林发育于奥陶系大湾组与牯牛潭组，集中分布于酉水－猛洞河两岸斜坡与峡谷地带，出露面积84 km2，是当前全球已知的面积最大的奥陶系红色碳酸盐岩石林地貌景观。红石林形态多样、成景效果好，发育了包括塔状、火焰状、墙状、剑状、柱状、锥状等十余种形态。红石林的形成经历了完整的地层沉积-构造抬升-风化剥蚀等阶段，适宜的古地理环境、有利的构造抬升运动和节理裂隙发育、温暖多雨的气候和丰富的地表地下水系是红石林发育的重要条件。因受成景地层的岩性组成复杂、地层偏薄、溶蚀作用差异等因素影响，红石林具有明显的垂直溶痕和水平溶痕叠加现象，具有独特的自然美，形态上与云南石林有较大不同，颜色上，红石林晴红雨黑、四季变幻，可能是石柱表面的藻类造成。除中国西南地区，其他国家或地区的奥陶系红色碳酸盐岩石林分布十分有限，仅泰国沙墩有报道，其稀有性非常突出，具有重要的科学意义和研究价值。但正由于其稀少，许多针对性的研究仍刚起步，值得未来各界学者进一步深入探讨。      

内蒙古西乌旗地区早二叠世皱纹珊瑚化石组合及其地质意义

基于生物地层学的研究，详细描述了内蒙古西乌旗地区早二叠世的皱纹珊瑚，建立了7个新种，划分了2个珊瑚组合：Lytvolasma-Cyathocarinia组合和Lytvolasma-Caninophyllum-Pseudopolythecalis组合。前一组合主要为小型单体，无鳞板，隔壁加厚，外壁厚，一些分子具典型中柱的珊瑚类型；后一珊瑚化石组合表现为群体珊瑚和单体珊瑚混生融合。本区珊瑚动物群在早二叠世阿木山期混生类型为超覆型，在早二叠世包特格期混生类型为混合型。这种混生现象与石炭纪末一二叠纪初全球气候变冷事件相吻合，并反映了古气候暖-冷-暖的变化。同时也佐证了古亚洲洋洋壳的性质在稍早的时期已经发生了本质变化。此时海盆性状应该是岛弧浅海，而不是大洋。     

天津蓟县盘山花岗岩麦饭石矿床及麦饭石研究

天津蓟县麦饭石矿床产于石英二长花岗岩的风化壳中 ,试验证明其主要功能是改善水质和药用     

La plate-forme carbonatée oxfordienne de Lorraine : arguments pour une ouverture vers la mer Germanique

The study of sedimentary facies in the quarry of Dompcevrin (Middle Oxfordian) located northwestward of St-Mihiel (Meuse department) provides evidences of high-energy depositional conditions. The occurrence of beaches associated with hurricane coral breccias containing megaclasts is characteristic of platform edge environments. The open sea was located northeastward, in the direction of Germany, as it is indicated by the direction of progradation of beaches. It is concluded that the Oxfordian carbonate platform of Lorraine was opened to the northeast toward the Germanic Sea during the Middle Oxfordian. To cite this article: C. Carpentier et al., C. R. Geoscience 336 (2004).     

大同云岗石窟文物渗水病害防治方案探讨

大同云岗石窟是国家级重点文物保护单位。多年来其水害严重，造成了文物的损坏，对其治理已经列入文物保护部门的日程。本文分析了大同云岗石窟石质文物渗水病害的类型与成因，并提出了新的渗水病害防治方法，为我国石质文物的保护提供参考。     

Deep-sea coral geochemistry: Implication for the vital effect

Deep-sea corals hold a great potential as a key to important aspects of paleoceanography for at least two reasons, 1) they offer temporal high resolution records of deep-sea environment, because they have growth banding structures, 2) and they are well suited for studying vital effects, because the deep-sea environment does not change over short time scales. However, the relationship between the chemical composition of deep-sea coral skeletons and environmental factors is not well understood. In this study, the chemical composition of deep-sea corals was measured in bulk individuals and along skeletal micro-structures. Among the bulk individuals, δ¹⁸O value and Sr / Ca ratio show a negative but weak correlation with ambient temperature. On the other hand, the Mg / Ca ratio has a positive, weak correlation with the temperature. Large variations were found among samples collected from similar temperature. The variation is up to 3.8‰ for δ¹⁸O, 0.9 mmol/mol for Sr / Ca ratios, and 0.78 mmol/mol for Mg / Ca ratios among samples with ambient average temperature within 1 °C. This variation may be due to a large vital effect. The centers of calcification (COCs), which were formed at high calcification rate, have lower Sr / Ca, U / Ca and higher Mg / Ca ratios than surrounding fasciculi. This chemical distribution supports the model that elemental incorporation depends on calcification rate. This suggests that calcification rate is a very important factor for the chemical composition in deep-sea corals and is one of the most significant mechanisms of the vital effect. Because of this large vital effect, further investigations are essential to use the deep-sea coral as a temperature proxy.     

四川乐山大佛风化的初步探讨

四川乐山大佛石刻是我国重要的“世界文化与自然遗产”之一,石刻表面毁损非常严重。本文通过（1）检测石刻所在地区粉砂岩的样品成分（XRFS）获悉,SiO₂含量高达84%;（2）安装微侵蚀测量装置（MEM）直接测得粉砂岩的表面侵蚀速率大约为0.216～0.305mm/a;结合（3）粉砂岩表面的相对硬度测试比较等途径,对石刻毁损的表面过程机制进行了初步的综合分析。结果表明,由于粉砂岩结构松散,经水浸后表面硬度急剧下降,而且当地的水、气等条件适宜于生物繁衍等特点,石刻风化毁损的原因主要在于水、生物等环境因素对粉砂岩胶结物有强烈的破坏作用。     

Unique recovery stage of reef communities after F/F event in a huge coral reef of Carboniferous, Southern Guizhou,China

Carboniferous is a global recession period of reef-building. There were fewer reefs at that times due to massive extinction and the great glacial catastrophe in the southern hemisphere in Frasnian/Famennian[1]. So far, however, most of the researches concerning Carboniferous reefs have been limited, which leads to insufficient knowledge regarding the composition, structure, ecological characteristics of reef-building communities, the reef growth models, etc. Interna-tional studies conducted o…