Geomorphic constraints on the active tectonics of southern Taiwan

Taiwan is a region of rapid active tectonics, yet the study of the tectonic processes that shape the interior of the island is difficult due to the high rates of erosion and dense vegetation. We use digital topography to look for indications of active deformation preserved in the local geomorphology. In particular, anomalies in the regional pattern of drainage are used to infer zones of enhanced tectonic activity. The apparent anticlockwise rotation of major river systems in plan view indicates the presence of a diffuse zone of left-lateral shear running down the southeastern side of Taiwan. Asymmetries in the catchments of individual drainage basins show the influence of varying rates of uplift across southern Taiwan, with the most rapid uplift close to Taitung at the indentation point of the Luzon arc with the Chinese continental margin. Our interpretations, though based predominantly on remote-sensing observations, are consistent with the available field evidence. This study demonstrates the usefulness of drainage basins as tectonic markers in the quantification of regional strain and uplift, which may have wider applicability in other deforming parts of the world.     

Statistical properties of seismicity of fault zones at different evolutionary stages

We perform a systematic parameter space study of the seismic response of a large fault with different levels of heterogeneity, using a 3-D elastic framework within the continuum limit. The fault is governed by rate-and-state friction and simulations are performed for model realizations with frictional and large scale properties characterized by different ranges of size scales. We use a number of seismicity and stress functions to characterize different types of seismic responses and test the correlation between hypocenter locations and the employed distributions of model parameters. The simulated hypocenters are found to correlate significantly with small L values of the rate-and-state friction. The final sizes of earthquakes are correlated with physical properties at their nucleation sites. The obtained stacked scaling relations are overall self-similar and have good correspondence with properties of natural earthquakes.     

Comprehensive Multi-Level Exploration of Buried Active Faults： an Example of the Yinchuan Buried Active Fault

The paper introduces the steps and methods of multi-approach,multi-level exploration of buried faults in thick Quaternary sediment regions by taking the test exploration of the Yinchuan active fault as example.Based on the comprehensive analyses of previous data,we choose the Xinqushao Village of Xingqing District of Yinchuan City as the test site for the comprehensive exploration.Firstly,we adopted shallow seismic investigation with group intervals of 10m,5m and 1m to gradually trace layer by layer the master fault of the Yinchuan buried fault from a deep depth to a shallow depth where drilling could be used.Then,with composite geological profile drilling,we determined the precise location and dip angle of the fault.The drilling show the buried depth of the upper offset point is 8.3m.Finally,large-scale trenching revealed that the actual buried depth of the upper offset point of the fault is 1.5m from the ground surface and there are paleoearthquake events of 5 stages.Combined with the preliminary result of corresponding sample age,we conclude the Yinchuan buried fault is a mid to late Holocene active fault.     

高分辨率浅层人工地震勘探探测隐伏断裂实例

利用高分辨率浅层地震勘探反射波法探测了福建某火电厂场址内的隐伏断裂。结果表明断裂显示清楚,为一走向NE40~55°,上断点埋深为11 m和31 m,断距2~4 m的正断层,为工程避让提供较可靠的依据。     

Sr isotope diversity of hot spring and volcanic lake waters from Zao volcano,Japan

The ratio of ⁸⁷Sr/⁸⁶Sr was measured from different water samples of thermal/mineral (hot spring as well as crater lake) and meteoric origins, in order to specify the location and to verify the detailed model of a volcano-hydrothermal system beneath Zao volcano. The ratio showed a trimodal distribution for the case of thermal/mineral water: 0.7052–0.7053 (Type A, Zao hot spring), 0.7039–0.7043 (Type B, Okama crater lake and Shin-funkiko hot spring), and 0.7070–0.7073 (Type C, Gaga, Aone, and Togatta hot springs), respectively. However, in comparison, the ratio was found to be higher for meteoric waters (0.7077–0.7079). The water from the central volcanic edifice (Type B) was found to be similar to that of nearby volcanic rocks in their Sr isotopic ratio. This indicates that the Sr in water was derived from shallow volcanic rocks. The ⁸⁷Sr/⁸⁶Sr ratio for water from the Zao hot spring (Type A) was intermediate between those of the pre-Tertiary granitic and the Quaternary volcanic rocks, thus suggesting that the water had reacted with both volcanic and granitic rocks. The location of the vapor–liquid separation was determined as the boundary of the pre-Tertiary granitic and the Quaternary volcanic rocks by comparing the results of this strontium isotopic study with those of Kiyosu and Kurahashi [Kiyosu, Y., Kurahashi, M., 1984. Isotopic geochemistry of acid thermal waters and volcanic gases from Zao volcano in Japan. J. Volcanol. Geotherm. Res. 21, 313–331.].     

GPS测时在电力系统中的应用

介绍了利用GPS测时及时间传递的几种方式，详细地讨论了GPS用在电压相角测量，输电线路故障定位以及线路网损和电能结算系统几个方面的应用原理，设计出应用的方案，并得到部分结果。     

海底电场传感器原理及研制技术

因海底电场信号微弱，海下自然环境复杂以及海水导电介质以氯离子为主等原因，用于海下电场测量的电场传感器在材料和结构上有其特殊性。研制海底电场传感器成为开展海洋大地电磁探测的重要技术内容之一。研制过程遇到的主要技术问题有；海底电极材料的选择；电极的制作工艺；承压与密封技术；海水运动对测量产生不利影响的克服办法；水下弱信号传输的抗干扰问题，等等，阐述了对上述问题的解决办法。提出了海底电场传感器的全套研制方案。并列举了相关的室内模拟实验和海洋试验的结果。     

福建省物探找矿若干实例分析

物探作为一种地质勘察技术方法在国民经济各个领域，得到广泛的应用，物探方法和其它地质学科一样都存在着不足为奇的解释多解性。通过对福建省金，多金属，煤等矿产的地球物理勘察实例分析。认为要取得物探找矿效果应注意以下几点；（1）分析矿产的地质规律和特点；（2）掌握矿体与围岩之间物性差异的特征，直接找矿与间接找矿并举；（3）选择适合的物探方法，发挥各种方法的长处，（4）建立和利用矿床的地质-地球物理模型。圈出矿床（体）赋存的部位。     

关于金矿构造化探问题的探讨

构造控矿是找矿地质学和矿床地质学非常重要的问题，分别从主成矿阶段矿物组合，基底控矿，盖层，岩体，重磁线性构造，矿床密集区及系统论工程的角度探讨了金矿构造化探问题。