黄山大气气溶胶微观特性的观测研究

根据2008年4—7月黄山大气气溶胶观测资料,研究了气溶胶粒子的数浓度、谱分布特征及其与气象因子的关系,探讨了雾天和非雾天气溶胶颗粒物时间和尺度分布特点。分析发现,黄山光明顶春、夏季大气气溶胶数浓度的平均值分别为3.14×103个/cm3和1.80×103个/cm3,其中超细粒子(粒径小于0.1μm的粒子)在春夏季分别约占总粒子数浓度的79%和68%;高数浓度值集中在粒径0.04～0.12μm;积聚模态气溶胶粒子(0.1～1.0μm)在体积浓度分布和表面积分布中占很大比例。结合气象资料比较了雾天与非雾天气溶胶分布的差异,发现细粒子浓度非雾天大于雾天,而气溶胶数浓度与温度呈正相关,与相对湿度成反相关。结果还发现,黄山在春季以西北风和偏南风为主,西北风时气溶胶数浓度较高,在夏季主要以偏南风,特别是西南风为主,但是气溶胶数浓度的高值多发生在偏东风的条件下。     

南京北郊冬季大气SO_2、NO_2和O_3的变化特征

利用差分吸收光谱仪DOAS(differential optical absorption spectroscopy),对2007年11月—2008年1月南京北郊大气SO2、NO2和O3进行了观测。结合Parsivel降水粒子谱仪和自动气象站的资料,对冬季大气污染气体的浓度变化规律及降水和风速风向对其的影响进行了分析。结果表明,南京北郊大气SO2浓度较高,呈明显双峰特征,分别在12时(北京时,下同)和00时达最大,受附近排放源的影响最大,东风及南风时比静风时SO2浓度更高。降水对SO2湿清除效果明显,清除系数平均为0.168 h-1。NO2气体呈明显单峰特征,在18时达最高值。南京北郊是NO2源区之一,主要受附近高速公路汽车尾气排放源的影响。静风时NO2浓度最高。O3浓度受NO2的影响较明显。O3日变化呈单峰特征,在15时达最大值,静风时O3浓度最低。降水对O3的间接影响较明显,在降水时,白天由于太阳辐射较弱,O3浓度降低;夜晚NO浓度较低,使得O3浓度升高。     

A lunar cryptomare dome near Mee H and Drebbel F

In this study, we examine the lunar mare dome Mee 1 situated near the craters Mee H and Drebbel F in a region showing evidence of ancient (pre-Orientale) mare volcanism and cryptomare deposits. Regional stratigraphic relations indicate that Mee 1 was formed prior to the Orientale impact at the beginning of the Imbrian period. Based on a combined photoclinometry and shape from shading technique applied to telescopic CCD images of the dome acquired under oblique illumination, we determined a diameter of Mee 1 of 25 km, a height of 250 m, a flank slope of 1.15^°, and a volume of . Based on rheologic modelling of the dome and a viscoelastic model of the feeder dike, we obtained a magma viscosity of , an effusion rate of , a duration of the effusion process of 1.6 years, a magma rise speed of , a width of the feeder dike of 32 m, and a horizontal dike length of 144 km. A comparison of Mee 1 with domes with similar morphometric properties, which are located near Milichius and inside the crater Petavius, reveals strong similarities with respect to the viscosity of the dome-forming magma and the feeder dike geometry, while the effusion rate and magma rise speed of Mee 1 are somewhat higher. The pronounced morphometric differences between Mee 1 and a smaller dome situated close to the crater Doppelmayer and characterised by a similar magma viscosity suggest that the growth of that dome was limited by exhaustion of the magma reservoir, while Mee 1 and the other larger domes display morphometric properties presumably coming closer to the cooling limit. The comparison of the ancient dome Mee 1 with the younger (Eratosthenian) edifices near Milichius and Doppelmayer suggests that the conditions in the upper mantle and the crust favoured high eruption volumes, effusion rates, and magma rise speeds, implying the occurrence of large magma reservoirs preventing the limitation of dome growth by magma exhaustion. On the other hand, we observe similar general morphometric, rheologic, and feeder dike characteristics and, thus, conclude that the formation conditions of lunar mare domes did not change fundamentally during the Imbrian period.     

Lunar intrusive domes: Morphometric analysis and laccolith modelling

This study examines a set of lunar domes with very low flank slopes which differ in several respects from the frequently occurring lunar effusive domes. Some of these domes are exceptionally large, and most of them are associated with faults or linear rilles of presumably tensional origin. Accordingly, they might be interpreted as surface manifestations of laccolithic intrusions formed by flexure-induced vertical uplift of the lunar crust (or, alternatively, as low effusive edifices due to lava mantling of highland terrain, or kipukas, or structural features). All of them are situated near the borders of mare regions or in regions characterised by extensive effusive volcanic activity. Clementine multispectral UVVIS imagery indicates that they do not preferentially occur in specific types of mare basalt. Our determination of their morphometric properties, involving a combined photoclinometry and shape from shading technique applied to telescopic CCD images acquired at oblique illumination, reveals large dome diameters between 10 and more than 30 km, flank slopes below 0.9°, and volumes ranging from 0.5 to 50 km³. We establish three morphometric classes. The first class, In1, comprises large domes with diameters above 25 km and flank slopes of 0.2°-0.6°, class In2 is made up by smaller and slightly steeper domes with diameters of 10-15 km and flank slopes between 0.4° and 0.9°, and domes of class In3 have diameters of 13-20 km and flank slopes below 0.3°. While the morphometric properties of several candidate intrusive domes overlap with those of some classes of effusive domes, we show that a possible distinction criterion are the characteristic elongated outlines of the candidate intrusive domes. We examine how they differ from typical effusive domes of classes 5 and 6 defined by Head and Gifford [Head, J.W., Gifford, A., 1980. Lunar mare domes: classification and modes of origin. Moon Planets 22, 235-257], and show that they are likely no highland kipukas due to the absence of spectral contrast to their surrounding. These considerations serve as a motivation for an analysis of the candidate intrusive domes in terms of the laccolith model by Kerr and Pollard [Kerr, A.D., Pollard, D.D., 1998. Toward more realistic formulations for the analysis of laccoliths. J. Struct. Geol. 20(12), 1783-1793], to estimate the geophysical parameters, especially the intrusion depth and the magma pressure, which would result from the observed morphometric properties. Accordingly, domes of class In1 are characterised by intrusion depths of 2.3-3.5 km and magma pressures between 18 and 29 MPa. For the smaller and steeper domes of class In2 the magma intruded to shallow depths between 0.4 and 1.0 km while the inferred magma pressures range from 3 to 8 MPa. Class In3 domes are similar to those of class In1 with intrusion depths of 1.8-2.7 km and magma pressures of 15-23 MPa. As an extraordinary feature, we describe in some detail the concentric crater Archytas G associated with the intrusive dome Ar1 and discuss possible modes of origin. In comparison to the candidate intrusive domes, terrestrial laccoliths tend to be smaller, but it remains unclear if this observation is merely a selection effect due to the limited resolution of our telescopic CCD images. An elongated outline is common to many terrestrial laccoliths and the putative lunar laccoliths, while the thickness values measured for terrestrial laccoliths are typically higher than those inferred for lunar laccoliths, but the typical intrusion depths are comparable.     

西北地区东部冰雹云的卫星光谱特征和遥感监测模型

根据气象台站的冰雹观测记录,针对冰雹灾害多发的西北地区东部,选取2001—2004年间14次NOAA卫星过境的AVHRR资料,共88个样本数,对冰雹云和其他云的光谱特征进行对比分析。结果表明,雹云的热红外亮度温度的变化基本在245K以下,中红外波段反射率相对较低,基本变化在0.4及以下范围,可见光和近红外波段反射率>0.6。冰雹产生的两个重要条件是高的云光学厚度和大的云粒子有效半径共同发生的区域;西北地区冰雹发生的云顶高度基本在4.5～7km之间。根据雹云的光谱特征,确定雹暴指数及其模型阈值>0.35的冰雹监测方法,多普勒雷达回波和气象站观测结果说明,雹暴指数等多参数结合判别冰雹云效果显著。     

岩浆成矿体系的热演化和剥露史的数字模拟

通过对岩浆冷却过程的数字模拟研究,揭示出岩浆在冷却成矿过程中的温度分布和变化规律及影响因素．在此基础上,进一步应用高精度的温龄计组合来限定岩浆成矿体系的热演化和剥露历史,精确地计算出岩浆的初始侵位时间和深度、矿物结晶时间、冷却速率、冷却和暴露地表时间,以及剥露和剥蚀速率等重要参数,并将模拟结果应用于斑岩铜矿床的成矿研究中．研究表明,将精确的年龄测试手段与计算机模拟技术相结合,可为定量研究岩浆矿床的热演化和剥露史、深入了解矿床的成因机制提供一种有效方法．     

Giant Mineral Deposits and Their Geodynamic Setting in the Lanping Basin, Yunnan, China

There are giant mineral deposits, including the Jinding Zn-Pb and Baiyangping Ag-Co-Cu, and otherimportant mineral deposits (e.g., Baiyangchang Ag-Cu, Jinman Cu deposits, etc.) in the Lanping Mesozoic-Cenozoic Basin, Yunnan Province, China. The tabular ore-bodies and some veins hosted in terrestrial clastic rocks of the Mesozoic-Cenozoic age and no outcropping of igneous rocks in the giant deposits lead to the proposal of syngenetic origin, but the giant mineral deposits are not stratabound (e.g. MVT, sandstone- and Sedex-type). They formed in a continental red basin with intense crust movement. The mineralization is controlled by structures and lithology and occurs in different strata, and no sedimentary nature and no exhalative sediments are identified in the deposits. The deposits show some relations with organic matter (now asphalt and petroleum) and evaporates (gypsum). The middle-low-temperature (mainly 110℃ to 280℃) mineralization took place at a depth of about 0.9 km to 3.1 km during the early     

Ore-Bearing Formations of the Precambrian in South China and Their Prospects

In the Precambrian System of the Yangtze and Cathaysian plates six ore-bearing formations can be identified: the Cu-Pb-Zn-bearing formations in volcanic rocks of marine facies of the Neoarchean-Paleoproterozoic, Cu-Au-bearing formations and Pb-Zn-bearing formations in volcanic rocks of marine facies of the Mesoproterozoic, Pb-Zn-bearing formations in volcaniclastic rock and carbonate rock of the Neoproterozoic, Fe-Mn-bearing formations in the volcaniclastic rock of the Neoproterozoic, and Ni-Cr-serpentine-bearing formations in ophiolite and ultrabasic rock of the Meso- and Neoproterozoic. They were mostly formed in the marginal rift valleys of the Yangtze and Cathaysian plates, where occur stratabound and stratiform ore deposits, thermal deposits and porphyry polymetallic deposits. The six regions with ore-bearing formations have good prospects for ore deposits.     

广西百色盆地东部古近系那读组湖相灰岩

百色盆地东部田东坳陷那坤地区古近系那读组三段下部发育一套数米至数十米厚的湖相灰岩,岩石以浅灰色-灰色、含大量的螺蚌化石和具核形石结构为特征,间夹有薄层的泥岩、钙质泥质粉砂岩。本文在实测地表剖面和详细观察岩心的基础上,仔细研究了此套灰岩的岩石学特征。依据丰富的原生沉积构造、古生物化石标志以及沉积地球化学、测井相特征将湖相灰岩的沉积相划分为滨湖、颗粒滩、浅湖三个亚相以及灰泥坪、沼泽、颗粒坪、滩缘、滩核、滩间水道、灰泥浅湖、泥质浅湖等八个微相,并详细地研究了各微相的沉积特征。结合该灰岩的区域分布和沉积相的平面展布格局指出沉积相主体属于浅湖的颗粒滩,并提出了相应的沉积相模式。     

滇西兰坪盆地五茂林剖面下白垩统景星组沉积相

实测了云南西部兰坪盆地东部下白垩统下部景星组的五茂林剖面,建立了曲流河、三角洲和湖泊3种沉积序列,其中三角洲序列在云南下白垩统中属首次建立。分析了粗碎屑岩的组成,将该剖面上出露的砾岩分成4类。早白垩世时兰坪盆地属丹那沙林-高黎贡弧的弧后盆地,景星组自下而上为曲流河沉积、三角洲沉积和湖泊沉积,且随湖侵发生,湖泊向西扩大。