广西南宁盆地早第三纪沉积相特征

本文论述了南宁盆地的地质构造背景和第三纪地层、沉积相、古地理演化特征,其中侧重对沉积相剖析认为:南宁盆地在中生代以来形成的NE、NW向两组断裂的“X”型构造背景条件下,受NEE、NNE向各两条断裂控制呈菱形状的第三纪陆相断陷盆地;沉积相以湖相为主,河流相、洪积相次之。前者可分为滨湖、浅湖、半深湖等3个亚相,尤以浅湖相发育,后二者仅在古新世至始新世早、中期发育并分布在湖盆边缘;盆地演化过程中始新世时曾一度上升遭受剥蚀,致使瓦窑村组与上覆地层呈不整合接触,由古新世→始新世末盆地中心由SW→NE迁移,盆地范围增大趋势。还指出南湖组与凤凰山组、古亭组是同期(始新世早、中期)异相产物,盆地内产褐煤、粘土与石英砂等矿产。     

广西岩石可钻性分级研究初探

岩石可钻性的合理分级,是正确选择钻进方法、技术参数、钻头类型和制定合理的生产与物化定额、专核钻探生产技术与经济指标的科学依据。利用与岩石可钻性密切相关的物理力学性质—压入、摆球硬度、研磨性、塑性系统与声学特性为自变量,以微钻钻速为因变量,在计算机上进行一元和多元回归分析,建立其数学模型,以此将不同岩石划分为12级。这种方法具有较强的模拟性、代表性和较大的适用范围。     

广西河池市地下水总硬度逐年升高机理分析

近几年来,河池市地下水总硬度出现逐年升高趋势。本文采用地下水化学成分随机抽样回归分析法分析其形成机理。认为该市地下水总硬度的组成是以重碳酸盐和硫酸盐为主,而硬度的升高是以组成暂时的重碳酸盐的增大表现出来的。并对防止地下水硬度升高提出具体意见。     

桂北地区剪切带型金矿成矿机理研究

桂北地区金矿划分为石英脉型、石英细脉带型和构造蚀变岩型金矿.不同级别剪切带构造控制矿化集中区、矿床、矿体分布以及矿脉形态、产状和矿化类型,具有上部石英脉型、中部石英细脉带型、下部构造蚀变岩型金矿的矿化分带模式.金质矿源主要来源于上地壳围岩,硫源主要来自深部,金矿成矿溶液主要来源于大气降水,热源来自变质和构造运动,成矿时代主要为燕山期.矿床成因属是产于前寒武纪浅变质碎屑岩系的与脆一韧性剪切带有关的中低温热液脉状金矿.     

Discovery of six high-redshift quasars with the Lijiang 2.4 m telescope and the Multiple Mirror Telescope

Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and redshifts between 2.4 and 4.6 from spectroscopy with the Yunnan Faint Object Spectrograph and Camera (YFOSC) at the Lijiang 2.4 m telescope in February, 2012. These quasars are in the list of z > 3.6 quasar candidates selected by using our proposed J K/i Y criterion and the photometric redshift estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine candidates were observed by YFOSC, and five among six new quasars were identified as z > 3.6 quasars. One of the other three objects was identified as a star and the other two were unidentified due to the lower signal-to-noise ratio of their spectra. This is the first time that z > 4 quasars have been discovered using a telescope in China. Thanks to the Chinese Telescope Access Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and emission line properties of these six quasars, as well as their central black hole masses and Eddington ratios, were obtained.     

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。