The Triassic Formations of Kueichou

正 Triassic fossils of Kueichou were made known nearly half a century ago~1. Subsequent investigators have from time to time brought back new materials, but they are in general more or less fragmentary in nature. Through successive trips     

On the Type Species of Chusenella

正 DIAGNOSIS: Test fusiform, slightly rounded at the ends; about 11.2 mm. long, 3.7 mm. wide, giving an axial ratio of about 1:3; whorl 9 to 10, the first three or four volutions closely coiled thence gradually evolute; spiral wall increases in thickness as the test grows, being 0.016 mm. in the firs     

Changes in Surface Energy Partitioning in China over the Past Three Decades

Surface energy balance and the partitioning of sensible heat flux(SHF) and latent heat flux(LHF) play key roles in land–atmosphere feedback. However,the lack of long-term observations of surface energy fluxes,not to mention spatially extensive ones,limits our understanding of how the surface energy distribution has responded to a warming climate over recent decades(1979–2009) at the national scale in China. Using four state-of-the-art reanalysis products with long-term surface energy outputs,we identified robust changes in surface energy partitioning,defined by the Bowen ratio(BR = SHF/LHF),over different climate regimes in China. Over the past three decades,the net radiation showed an increasing trend over almost the whole of China. The increase in available radiative energy flux,however,was balanced by differential partitioning of surface turbulent fluxes,determined by local hydrological conditions. In semi-arid areas,such as Northeast China,the radiative energy was transferred largely into SHF. A severe deficiency in near-surface and soil moistures led to a significant decreasing trend in LHF. The combined effect of increased SHF and decreased LHF resulted in significant upward trends in the BR and surface warming over Northeast China. In contrast,in the wet monsoon regions,such as southern China,increased downward net radiation favored a rise in LHF rather than in SHF,leading to a significant decreasing trend in the BR. Meanwhile,the increased LHF partly cancelled out the surface warming. The warming trend in southern China was smaller than that in Northeast China. In addition to impacts on heat-related events,the changes in the BR also reflected recent cases of extreme drought in China. Our results indicate that information regarding the BR may be valuable for drought monitoring,especially in regions prone to such conditions.     

Ion microprobe study of the Pomozdino and Peramiho eucrites

Abstract— Electron and ion microprobe measurements of major, minor, and trace element concentrations were made in individual grains of pyroxene, plagioclase, and Ca phosphates in Pomozdino and Peramiho, two eucrites previously classified as anomalous. Although Pomozdino pyroxene is highly magnesian, minor and trace element concentrations in both pyroxene and plagioclase of this meteorite are similar to those in other noncumulate eucrites. High incompatible element concentrations (similar to those in Stannern) coupled with mg# typical of cumulate eucrites confirm the anomalous character of this meteorite but do not allow us to distinguish unequivocally between different possible modes of origin. Peramiho has mg# and trace element concentrations similar to main group eucrites, indicating that this meteorite most probably belongs to this group. A previously reported low incompatible element concentration for Peramiho may be due to a sampling problem.     

Rupture process of the M_s 7.0 Lushan earthquake, 2013

On April 20, 2013 at 8:02 am, a magnitude 7.0 earthquake occurred in Lushan County, Sichuan Province, China, which induces massive landslides, causes great losses to life and property. Based on the locations of aftershocks provided by the China Earthquake Network Center and the characteristic of Longmenshan active faults system, combined with the current preliminary focal mechanism solution, the fault rupture direction is determined. With the finite fault inversion method, we invert the rupture process of the Lushan M s 7.0 earthquake by teleseismic waveforms data. The inversion results indicate that the main shock is dominated by thrust fault component and the rupture initiated at depth of 15 km, and most of slip ruptured around the hypocenter with the peak slip of about 1.5 m. Most of rupture slips released at the first 20 s and the main rupture occurred at the first 10 s after the onsets of the mainshock. Most of seismic energy released near the hypocenter with a length of 28 km, especially on both sides of the hypocenter with the range of 20 km, and the seismic energy released relatively smaller in other areas. There is a large area with weak slip between the main rupture and another two asperities on both sides of the hypocenter; it may imply that the accumulated strain on the rupture fault has not been completely released. Therefore, there is a significant possibility of having strong aftershocks in the areas where energy is not fully released. This is also the main reason why there are a lot of moderate to strong aftershocks in the Lushan aftershock sequence. In addition, there is an earthquake vacant zone with a length of about 50 km between the Wenchuan M w 7.9 earthquake and this event, which is of high earthquake risk and is deserved to be paid close attention to.     

Crustal and upper mantle structure and the deep seismogenic environment in the source regions of the Lushan earthquake and the Wenchuan earthquake

Following the M w 7.9 Wenchuan earthquake, the M w 6.6 Lushan earthquake is another devastating earthquake that struck the Longmenshan Fault Zone (LFZ) and caused severe damages. In this study, we collected continuous broadband ambient noise seismic data and earthquake event data from Chinese provincial digital seismic network, and then utilized ambient noise tomography method and receiver function method to obtain high resolution shear wave velocity structure, crustal thickness, and Poisson ratio in the earthquake source region and its surroundings. Based on the tomography images and the receiver function results, we further analyzed the deep seismogenic environment of the LFZ and its neighborhood. We reveal three main findings: (1) There is big contrast of the shear wave velocities across the LFZ. (2) Both the Lushan earthquake and the Wenchuan earthquake occurred in the regions where crustal shear wave velocity and crustal thickness change dramatically. The rupture faults and the aftershock zones are also concentrated in the areas where the lateral gradients of crustal seismic wave speed and crustal thickness change significantly, and the focal depths of the earthquakes are concentrated in the transitional depths where shear wave velocities change dramatically from laterally uniform to laterally non-uniform. (3) The Wenchuan earthquake and its aftershocks occurred in low Poisson ratio region, while the Lushan earthquake sequences are located in high Poisson ratio zone. We proposed that the effect of the dramatic lateral variation of shear wave velocity, and the gravity potential energy differences caused by the big contrast in the topography and the crustal thickness across the LFZ may constitute the seismogenic environment for the strong earthquakes in the LFZ, and the Poisson ratio difference between the rocks in the south and north segments of the Longmenshan Fault zone may explain the 5 years delay of the occurrence of the Lushan earthquake than the Wenchuan earthquake.     

Theoretical and Experimental Study of Breaking Wave on Sloping Bottoms

This paper studies the continuous evolution of breaking wave for the surface water waves propagating on a sloping beach. A Lagrangian asymptotic solution is derived. According to the solution coupled with the wave breaking criteria and the equations of water particles motion, the wave deformation and the continuous wave breaking processes for the progressive water waves propagating on a sloping bottom can be derived. A series of experiments are also conducted to compare with the theoretical solution. The results show that the present solution can reasonably describe the plunging or spilling wave breaking phenomenon.     

Refractory inclusions and aluminum‐rich chondrules in Sayh al Uhaymir 290 CH chondrite: Petrography and mineralogy

Abstract— Here we report the petrography, mineralogy, and bulk compositions of Ca,Al‐rich inclusions (CAIs), amoeboid olivine aggregate (AOA), and Al‐rich chondrules (ARCs) in Sayh al Uhaymir (SaU) 290 CH chondrite. Eighty‐two CAIs (0.1% of the section surface area) were found. They are hibonite‐rich (9%), grossite‐rich (18%), melilite ± spinel‐rich (48%), fassaite ± spinel‐rich (15%), and fassaite‐anorthite‐rich (10%) refractory inclusions. Most CAIs are rounded in shape and small in size (average = 40 μm). They are more refractory than those of other groups of chondrites. CAIs in SaU 290 might have experienced higher peak heating temperatures, which could be due to the formation region closer to the center of protoplanetary disk or have formed earlier than those of other groups of chondrites. In SaU 290, refractory inclusions with a layered texture could have formed by gas‐solid condensation from the solar nebula and those with an igneous texture could have crystallized from melt droplets or experienced subsequent melting of pre‐existing condensates from the solar nebula. One refractory inclusion represents an evaporation product of pre‐existing refractory solid on the basis of its layered texture and melting temperature of constituting minerals. Only one AOA is observed (75 μm across). It consists of olivine, Al‐diopside, anorthite, and minor spinel with a layered texture. CAIs and AOA show no significant low‐temperature aqueous alteration. ARCs in SaU 290 consist of diopside, forsterite, anorthite, Al‐enstatite, spinel, and mesostasis or glass. They can be divided into diopside‐rich, Al‐enstatite‐rich, glass‐rich, and anorthite‐rich chondrules. Bulk compositions of most ARCs are consistent with a mixture origin of CAIs and ferromagnesian chondrules. Anorthite and Al‐enstatite do not coexist in a given ARC, implying a kinetic effect on their formation.     

青藏地区大地水准面形态及其与构造动力学的关系

利用密合法求解青藏地区大地水准面模型，研究青藏地区大地水准面主要特征及其与该区内部构造和活动的相关性．表明青藏地区大地水准而异常与青藏高原隆起的形状极为相似，大地水准面整体负异常与下地幔相关，形状起伏与上地幔相对应，岩石层反映的大地水准而异常与青藏高原活动构造有较好的对应关系．     

应用地理信息系统辅助山坡地潜在崩山灾害评估模式之建立

山坡地开发具有潜在的自然危险因子,人工开挖也会触动这些因子,因此,要做好土地管理工作,需从分析潜在崩山灾害类型以及开发区位两方面考虑。地形分析在工程、灾害评估等方面广为应用,本研究以张石角(1987)提出的“简确工程地质灾害调查与评估法”为依据,以山坡地丙种建地作为评估对象,利用地理信息系统所提供的空间分析及数据库功能,完成台湾省中、北部地区大范围的山坡地潜在灾害评估工作,其成果也将为政府部门所采用.