胶东新城金矿矿床地质特征及开采评价

位于焦家断裂带的新城金矿床矿体主要赋存于主裂面(断层泥)下盘的黄铁绢英岩化碎裂岩带和黄铁绢英岩化花岗闪长质碎裂岩带内。根据勘探资料和测试数据对矿床内Ⅰ号和Ⅴ号主要矿体的赋存特征进行分析, 并结合矿区水文和环境特点对矿床进行了开采评价。研究结果表明, 新城金矿区工程地质条件简单; 矿床开采形成的采空区对矿区岩体稳定性产生的影响较小, 研究区内的主矿体为地质环境条件良好型矿体。      

Progress of Long-Chain Alkyl Diols in Marine Environmental Reconstruction

Long-chain alkyl diols contain an alkyl chain with alcohol groups at C1 and at the middle position of carbon chain, which exist widely in seas, rivers and lakes. It has been proven that these compounds are relatively resistant to degradation and have an extended occurrence in the geological record. In addition, they are relatively easy to identify. Therefore, long-chain alkyl diols can be used as potential biomarkers to trace the past change in paleoenvironment and paleoclimate. Although the sources of long-chain alkyl diols are still uncertain, the studies indicate that 1, 13 and 1, 15-diols are mainly produced by eustigmatophytes, while 14-diols are mainly from diatom Proboscia. So far, some proxies based on long-chain alkyl diols have been established to indicate the change in diatom productivity, upwelling intensity, salinity, sea surface temperature, riverine organic matter input and surface seawater nutrient concentration, which are significant for paleoenvironmental reconstruction. Current research and application of long-chain alkyl diols proxies were summarized, which would be helpful for further studying the source of long-chain alkyl diols and the application of relevant proxies in China’s marginal sea.     

天然与风干状态下冷生亚黏土的崩解形态特征

土的崩解形态是描述土的崩解过程及探讨其崩解机理重要的必要条件之一,选取了一种高孔隙率、粉黏粒含量较高,且不具有湿陷性的原状冷生轻质亚黏土作为研究对象,对其天然含水量及风干含水量状态下的土样品进行崩解试验. 结果表明：天然状态的土样呈块状崩解,而风干状态下的呈鳞片状崩解,且鳞片状崩解的强度及平均速率都大于块状崩解;块状崩解的速率随时间变化较为缓和,而鳞片状崩解的速率随时间变化起伏较大. 崩解形态与崩解速率有着紧密的对应关系,与崩解形态相对比,发现崩解速率降低的过程是水侵入土样,且土样中空气压力增大的过程,而速率上升的过程则是土样崩解的过程.     

基于强度折减概念的滑坡稳定性三维分析方法(Ⅱ):加固安全系数计算

结合乌江洪家渡1#塌滑体加固设计工程,探讨了滑动面已知的条件下滑坡稳定性的三维分析方法。首先,模拟了塌滑体在天然状态下处于极限平衡状态时的滑动方向,并使用其应力成果计算了塌滑体的三维安全系数;其次,建议了基于强度折减概念的三维加固安全系数计算方法:最后,提出了加固设计的进一步优化方案。计算结果表明,塌滑体的滑动方向与局部地形等高线近于垂直。主滑方向变化较大,自后缘的NE15°方向逐步过渡到中部的NS向,最终过渡到前缘的NE30°方向,以致很难作出能表征主滑方向的地质剖面。基于应力计算成果的安全系数计算公式不能充分考虑滑坡体的抗滑潜能,也不能充分反映滑坡体的滑动方向,安全系数偏大。基于强度折减概念的三维加固安全系数计算方法具有有限元等方法的优点,较好地克服了上述局限性,可以合理地评价加固后的滑坡稳定性。     

Late Quaternary Slip Rate of the Xiugou Segment,Eastern Kunlun Fault Zone

The Eastern Kunlun fault zone (EKLF) is a large left-lateral strike-slip fault, whose slip rate is meaningful to seismic hazard assessment and geodynamics of the Tibetan Plateau. Previous studies suggested that the late Quaternary average slip rate was stable and uniform (10~13 mm/a) in the central and western segment of the EKLF. But there were a few researches of accurate slip rate in the central segment on the EKLF. Therefore, we focused on an offset and well preserved alluvial fan from Xiugou basin, located in the east of Xidatan-Dongdatan, to make it clear. Moreover, we used high-resolution satellite images and digital elevation model extracted from SPOT7 stereo image pairs to restore the offset alluvial fan, and combined terrestrial cosmogenic nuclides method, including 13 quartz-rich samples from this fan surface, 1 quartz-rich sample from the main active channel bed and 1 ¹⁰Be depth profile from this fan edge to eliminate the ¹⁰Be concentration of inheritance accurately, with 1 optically stimulated luminescence sample to obtain the reliable age of this alluvial fan together. Referring to field observations, this alluvial fan was offset left-laterally by (1 862±103) m, and its age is (76.55±3.20)~(106.37±3.38) ka which can be determined through the actual geologic setting and improving chi-square test. Thus, we used the Monte Carlo method to obtain a left-lateral slip rate of (20.3+3.5/-2.3) mm/a with 68% confidence envelopes since the late Pleistocene in the Xiugou basin. As a result, combining with the results of previous studies, the left-lateral slip rate indicated that the obviously decreasing activity transferred from late Pleistocene to Holocene on the central segment of the EKLF.     

地质雷达电磁干扰分析及在隧洞岩溶探测中的应用

将地质雷达用于千岛湖配水工程某隧洞岩溶探测,分析了倾斜状电磁干扰异常与溶洞雷达异常差异,通过雷达剖面及疑似异常区单道时间-频率谱的分析,推断了隧底岩溶的性质及空间分布特征,含水溶洞在雷达剖面反映为同相轴错断,强振幅及能量高衰减的特性,高频干扰波振幅幅值较异常区小且能量不满足随时间推移逐渐衰减的规律,雷达成果为隧洞安全施工提供了准确的参考。      

河北阳原东目连第四纪湖相叠层石

河北省阳原县东目连村泥河湾组中发现的第四纪湖相叠层石,形态有柱状、包心菜状和皱纹状。叠层石中的微生物主要为蓝藻门中的纤细席藻（Phormidiumtenue（Menegh）Gomont）湖泊鞘丝藻（LyhgbyalimneticaLemmermann）,色球藻科（Chroocoocaceae）,念球藻科（Nostocaceae）     

甘肃北山野马泉岩体同位素地球化学特征

Nd、Sr、Pb同位素研究结果揭示：甘肃北山野马泉岩体第Ⅰ、Ⅱ侵入阶段花岗岩类具有Ⅰ-型花岗岩的特征，(87Sr/86Sr)i=0.708~0.710，εNd=-2.229~-5.866，在207 Pb/204Pb-206Pb/204Pb构造模式图上其投影点落在造山带演化线附近，在εNd-εSr图解中，其投影点落人Ⅰ-型花岗岩类范围内，其成岩物质为壳幔混合来源。第Ⅲ侵人阶段的岩石成因类型为S-型，其(87Sr/86Sr)i=0.7149~0.7358, εNd＝-7.3750~-8.9556。该岩体形成的地球动力学环境是北山陆内碰撞造山带。     

河北宣化赵川地区矿渣碎屑流工程特性及其启动机制

张家口宣化地区存在大量具有潜在危险的松散矿渣堆积体,文章以该地区具有代表性的响水沟松散矿渣堆积体为研究对象,对矿渣的颗粒组成、矿物成分、力学性质等进行详细的室内试验研究,结果表明:矿渣堆积体属砾质砂土,粘粒含量少,且级配不良,松散易流动。同一干密度下,随含水率增加,矿渣抗剪强度先增大后减小,当含水率为15%时,其粘聚力最低,表明响水沟矿渣堆积体失稳启动下滑的界限含水率可能在15%左右。综合以上分析结果,拟合得到粘聚力与含水率关系公式,初步预测矿渣碎屑流启动下滑的临界含水率。这一认识对该区矿渣堆积体的稳定性评价及碎屑流灾害预警有重要意义。