藏东玉龙铜矿带含矿斑岩及成岩系列

西藏东部新生代玉龙铜矿带含矿斑岩,包括玉龙、扎拉尕、莽总、多霞松多和马拉松多等,均为同期不同阶段侵入地质体构成的复式岩体。岩石类型有石英二长斑岩、二长花岗斑岩、正长花岗斑岩和碱长花岗斑岩。岩石化学成分均富碱（Ｎａ２Ｏ＋ｋ２Ｏ〉８％）、高钾和Ｋ２Ｏ／Ｎａ２Ｏ比值远大于１等,属于碱性钾质系列,即钾玄岩系列。     

Paleo-environmental and volcano-tectonic evolution of the southeastern flank of Mt. Etna during the last 225 ka inferred from the volcanic succession of the ‘Timpe’, Acireale, Sicily

The tectonic escarpments locally known as ‘Timpe’ cut a large sector of the eastern flank of Etna, and allow an ancient volcanic succession dating back to 225 ka to be exposed. Geological and volcanological investigations carried out on this succession have allowed us to recognize relevant angular unconformities and volcanic features which are the remnants of eruptive fissures, as well as important changes in the nature, composition and magmatic affinity of the exposed volcanics. In particular, the recognition in the lower part of the succession of important and unequivocal evidence of ancient eruptive fissures led us to propose a local origin for these volcanics and to revise previous interpretations which attributed their westward-dipping to the progressive tectonic tilting of strata. These elements led us to reinterpret the main features of the volcanic activity occurring since 250 ka BP and their relationship with tectonic structures active in the eastern flank of Etna. We propose a complex paleo-environmental and volcano-tectonic evolution of the southeastern flank of Mt. Etna, in which the Timpe fault system played the role of the crustal structure that allowed the rise and eruption of magmas in the above considered time span.     

2013-2018年天山北坡短时强降水中小尺度特征

利用常规观测、自动站逐时雨量、新一代多普勒天气雷达和ERA-interim再分析等资料， 对2013-2018年6-8月天山北坡73次短时强降水过程的中尺度影响系统、对流风暴特征进行分析研究。结果表明：天山北坡短时强降水过程主要中尺度系统为低空急流、低空切变线或辐合线及地面中尺度高压前的辐合线；雷达回波形态分为合并加强型（占33.9%）、列车效应型（占39.0%）及孤立对流型（占27.1%）3类，其垂直剖面有“低质心”和“高质心”2种结构，且前者占多数；径向速度图上有81%的过程有逆风区。以集合箱线图25%百分位作为最低阈值，天山北坡短时强降水阈值为最大反射率因子强度≥46.5 dBZ、强回波中心（40 dBZ）顶高≥4.0 km、回波顶高ET≥8.6 km及垂直累积液态水含量VIL≥7.0 kg?m-2，并以典型个例进行分析。     

天山两麓一次极端暴雪天气多尺度配置特征及机制分析

利用自动站小时监测资料、常规与加密观测资料、NCEP/NCAR再分析资料（0.25°×0.25°）、FY-2G卫星相当黑体亮温（TBB）资料，分析2017年2月19日至20日天山两麓的极端暴雪天气过程。结果表明: （1）此次过程发生在500 hPa南欧脊衰退、乌拉尔低槽与中亚偏南低槽先结合、后分段东移进入的环流背景下，天山北麓暴雪高低空系统呈典型后倾结构，天山南麓暴雪形势为典型“东西夹攻”型。（2）影响天山北麓暴雪的低空西北急流和影响天山南麓暴雪的低空偏东急流均为冷湿气流，西北急流风速的增大比雪强的增强提早12h左右，偏东急流比降雪提前6h出现。（3）主要水汽通道在850～400 hPa，水汽通量进入新疆后，850～700 hPa偏西水汽输送强于600～400 hPa西南水汽输送，水汽辐合主要在850～700 hPa。（4）乌鲁木齐降雪前位势不稳定性加强，沙雅降雪前有明显对流不稳定，两暴雪中心均有地形强迫强化产生并维持的中尺度垂直上升支和次级环流圈，而沙雅系统性动力作用小于乌鲁木齐的。（6）中尺度云团是造成天山两麓暴雪产生的最直接的影响系统。     

On some future tsunamis in the Pacific Ocean

Possible tsunamis in the Pacific Ocean, especially in its northeastern part, are discussed in relation to a predicted major earthquake in the Shumagin Seismic Gap (located in the eastern part of the Aleutian Island Chain) and to a major eruption of the St. Augustine volcano in Cook Inlet, Alaska. The deep-water propagation of the tsunami generated in the Shumagin Gap is simulated through the use of a spherical polar coordinate grid of the approximate size of 14km. The tsunami generated by the St. Augustine volcano is studied through the fine mesh grid confined to the Cook Inlet only. The numerical models were calibrated against historical tsunami data. The properties of the tsunami signal are described by the maximum amplitude which occurs in the tsunami record. This allows us to single out the direction along which a maximum tsunami is to be expected.Presented at the International Conference on Natural and Man-Made Hazards in Coastal Zones, held in Ensenada, Mexico, August 1988.     

Eruptive activity at Mount St Helens,Washington, USA, 1984–1988: a gas geochemistry perspective

The results from two different types of gas measurement, telemetered in situ monitoring of reducing gases on the dome and airborne measurements of sulfur dioxide emission rates in the plume by correlation spectrometry, suggest that the combination of these two methods is particularly effective in detecting periods of enhanced degassing that intermittently punctuate the normal background leakage of gaseous effluent from Mount St Helens to the atmosphere. Gas events were recorded before lava extrusion for each of the four dome-building episodes at Mount St Helens since mid-1984. For two of the episodes, precursory reducing gas peaks were detected, whereas during three of the episodes, COSPEC measurements recorded precursory degassing of sulfur dioxide. During one episode (October 1986), both reducing gas monitoring and SO₂ emission rate measurements simultaneously detected a large gas release several hours before lava extrusion. Had both types of gas measurements been operational during each of the dome-building episodes, it is thought that both would have recorded precursory signals for all four episodes. Evidence from the data presented herein suggests that increased degassing at Mount St Helens becomes detectable when fresh upward-moving magma is between 2 km and a few hundred meters below the base of the dome and between about 60 and 12 hours before the surface extrusion of lava.     

Decadal‐scale change of infiltration characteristics of a tephra‐mantled hillslope at Mount St Helens,Washington

The cataclysmic 1980 eruption of Mount St Helens radically reduced the infiltration characteristics of ∼60 000 ha of rugged terrain and dramatically altered landscape hydrology. Two decades of erosional, biogenic, cryogenic, and anthropogenic activity have modified the infiltration characteristics of much of that devastated landscape and modulated the hydrological impact of the eruption. We assessed infiltration and runoff characteristics of a segment of hillslope thickly mantled with tephra, but now revegetated primarily with grasses and other plants, to evaluate hydrological modifications due to erosion and natural turbation. Eruptive disturbance reduced infiltration capacity of the hillslope by as much as 50‐fold. Between 1980 and 2000, apparent infiltration capacities of plots on the hillslope increased as much as ten fold, but remain approximately three to five times less than the probable pre‐eruption capacities. Common regional rainfall intensities and snowmelt rates presently produce little surface runoff; however, high‐magnitude, low‐frequency storms and unusually rapid snowmelt can still induce broad infiltration‐excess overland flow. After 20 years, erosion and natural mechanical turbation have modulated, but not effaced, the hydrological perturbation caused by the cataclysmic eruption. Copyright © 2005 John Wiley & Sons, Ltd.     

Palynology of Archean microfossils (c. 3.0 Ga) from the Mount Grant area, Pilbara Craton, Western Australia: Further evidence of biogenicity

Palynological techniques have only rarely been applied to Archean rocks, mainly because of concerns about contamination. However, where microstructures are abundant and well documented, palynology can add considerably to interpretations based on thin-section examination. A modified palynological preparation method, which avoids vigorous physical or chemical methods that might cause the fragmentation of fragile specimens, was applied to black chert from the c. 3.0 Ga Farrel Quartzite of the Mount Grant area, Pilbara Craton, Western Australia, known to contain abundant microstructures of putative biogenic origin.Four main morphological types have been reported from chert thin sections: threads, films, hollow spheres and spindles. These microstructures exhibit morphological and chemical signatures consistent with a biological origin as well as showing features indicative of taphonomic degradation. Nevertheless, the possibility remains that they are artefacts. Similar structures have been attributed to physical processes, such as the accretion of fine particulate matter that has subsequently been redistributed as a result of crystal growth.By extracting structures palynologically, we have increased the probability of a biogenic origin. Firstly, examination of the morphology free of the encompassing matrix demonstrates that they are indeed three-dimensional structures with complex morphology; secondly, the extraction of entire specimens militates against them being particulate matter aggregations, which would simply disintegrate during preparation and thirdly, the chemicals used remove silicates and most other minerals, confirming the organic composition of the structures. To date, we have extracted films, hollow spheres and a few poorly preserved spindles, but preparation continues. The fact that the specimens retain their morphological integrity during palynological extraction argues strongly in favour of a biogenic origin for the microstructures.     

Typology of Natural Hazards and Assessment of Associated Risks in the Mount Bambouto Caldera (Cameroon Line,West Cameroon)

Abstract: Mount Bambouto is a polygenic stratovolcano of the Cameroon Volcanic Line, built between 21?Ma and 4.5?Ma. It is situated approximately 200?km NE of Mount Cameroon, between 09°55′ and 10°15′ longitude east and, 05°25′ and 05°50′ latitude north. The volcano covers an area of 500?km2 and culminates at 2740?m at Mélétan dome and bears a collapsed caldera at the summit (13?×?8?km). Mount Bambouto is characterized by several natural hazards of different origins: meteorological, such as landslides and rock falls; anthropogenic, such as bushfires, tribal wars and deforestation; and volcanological, such as volcanic eruption. The thematic map shows that 55–60% of the caldera has high probability of occurrence of mass movement. The caldera has a high population density (3000 inhabitants), which increases the level of risk, evaluated at approximately $US3.8 million for patrimony, 3000 civilian deaths and destruction of biodiversity.     

滇东北宣威一带铌矿床地质特征

随着贵州威宁玉龙、黑石头等地铌矿床（点）的发现,结合该区域同类型铌矿床研究成果,以及本次在宣威倘塘一带所开展的矿产地质调查工作中发现的铌矿体（点）,总结了滇东北宣威一带铌矿床地质特征,认为主要赋矿层位为峨眉山玄武岩顶部的铁质凝灰岩地层,受峨眉山玄武岩喷发后期剥蚀沉积成矿。含矿层具有明显的高铌低钽,并伴(共)生稀土及钪、钛等元素之特征。成矿类型初步定为玄武岩喷发后期剥蚀沉积型铌矿床。