中国砂质新成土的系统分类

以土壤的诊断层和诊断特性为依据,以土壤发生学作指导,阐述了我国砂质新成土的系统分类。砂质新成土是新成土纲中具有砂质沉积物岩性的土壤,相当于我国过去土壤分类中的"风砂土",是指风成砂性母质上发育的土壤,其形成过程可以划分为:流沙上的成土阶段、半固定沙上的成土阶段和固定沙上的成土阶段;具有细土累积、结皮形成和有机质聚集三个成土特点。砂质新成土的控制层段的深度标准规定为1~2m。砂质新成土亚纲可以划分为:寒冻砂质新成土、潮湿砂质新成土、干旱砂质新成土、干润砂质新成土和湿润砂质新成土等5个土类,在土类之下,又可主要根据是否偏离中心概念、是否具有附加过程的特征和是否具有母质残留的特征,进一步划分为永冻寒冻砂质新成土等22个亚类,并列有检索系统。最后,以砂质新成土的土类为单元,论述了其土壤分布、特征及其改造利用方向。     

A Remote Sensing Model to Estimate Sunshine Duration in the Ningxia Hui Autonomous Region, China

Sunshine duration (SD) is strongly correlated with solar radiation, and is most widely used to estimate the latter. This study builds a remote sensing model on a 100 m × 100 m spatial resolution to est...     

陕北靖边庙梁遗址动物遗存研究兼论中国牧业的形成

对庙梁遗址龙山早期出土的动物骨骼按照发掘单位逐一进行系统分类、测量、鉴定,总共鉴定出8种哺乳动物,分别为蒙古兔(Lepus tolai)、奥氏马(Equus ovodovi)、家猪(Sus domesticus)、梅花鹿(Cervus nippon)、马鹿(Cervus elaphus)、狍(Capreolus cap...     

京广沿线高铁站腹地的范围与结构研究

随着高铁网络建设全面展开,高铁这一新兴交通方式已在旅客运输中占据重要地位,极大地影响了人们对出行交通方式的选择.为研究高铁车站影响范围与结构,本文选取京广沿线14个高铁站为研究对象,引入“客流腹地”与“商务客流腹地”的概念,分别从总客流和商务客流的角度研究高铁站腹地的范围与结构,并结合相关理论深入探讨其影响因素.研究结果表明:京广沿线高铁站客流腹地的平均腹地半径约为151 km,大于其商务客流腹地(139 km);高铁站客流腹地范围大小与高铁站服务能力、乘客外部出行距离呈正相关,与乘客内部交通出行成本呈负相关;而高铁站商务客流腹地范围大小与高铁站服务能力、商务乘客外部出行距离呈正相关,与商务乘客内部交通出行成本呈负相关.高铁站客流腹地与商务客流腹地均具有明显的“核心—外围”结构,其中客流腹地的“核心—外围”结构与人口分布结构呈正相关,与乘客内部出行时间结构呈负相关,而商务客流腹地的“核心—外围”结构则与城市GDP结构呈正相关,与商务乘客内部出行时间结构呈负相关.     

移动测量系统及其在数字城市中的应用

移动测量系统作为一种全新的地理信息数据采集手段可以为数字城市提供多种数据,极大地丰富了数字城市的内容,也为数据的快速更新提供了重要的途径。介绍移动测量系统的特点和原理,分析其在数字城市中的重要作用。     

2006～2010年云南东部地区磁偏角变化特征

利用2006～2010年云南东部地区9期地磁三分量观测资料,经过日变改正、长期变化改正消除地磁场的日变化及长期变化影响,计算各期地磁内源场的曲面样条模型并剥离出地磁异常场分布,求解相邻两期地磁异常场差异获取地磁异常场的变化,并对磁异常场中磁偏角分布的变化进行了描述.     

广东韶关某地找矿的多种地球物理方法综合应用

综合地球物理方法可以发挥各种勘探方法的优势,补充单一方法的不足,并且对于单一方法无法解释的异常给出新的理论支持.依据地质资料,位于广东省韶关始兴良源矿区成矿母岩主要为黑云母花岗岩,以及黑云母花岗岩蚀变后形成的白云母花岗岩或云英岩化花岗岩.母岩在电性上均体现为高电阻率;另一方面,高电阻率的花岗岩一般具有低磁性的特征,而围...     

Multistage dolomitization and distribution of dolomitized bodies in Early Jurassic carbonate platforms (Southern Alps,Italy)

The Early Jurassic dolomitized carbonates are a hydrocarbon exploration target in Northern Italy. Of these carbonates, the Liassic Albenza Formation platform and the overlying Sedrina Formation shelf were studied to define a pervasive dolomitization model and to shed light on dolomite distribution in the sub‐surface. Field work, as well as analyses of well cores, stable isotopes, trace elements and fluid inclusions, was carried out on the outcropping thrust belt and sub‐surface deformed foreland of the Southern Alps. Petrographic analyses showed a first, pervasive, replacement dolomitization phase (D1) followed by volumetrically less important dolomite cement precipitation phases (D2, D3 and D4). The δ¹⁸O values fall between ?8·2‰ and 0·1‰ Vienna‐Pee Dee Belemnite with the more depleted samples belonging to dolomite cement‐rich dolostones; the δ¹³C ranges from 2·6‰ to 3·7‰ Vienna‐Pee Dee Belemnite. Analysis of trace elements showed different Fe and Mn contents in the sub‐surface and outcropping dolostones, and a higher Fe in the younger dolomite cements. An increase in the precipitation temperature (up to 130 °C from fluid inclusion data) and a decrease in diagenetic fluid salinity (from sea water to brackish) are observed from the first pervasive replacement dolomite to the dolomite cement phases. Field observations indicate that, in the Albenza Formation, dolomitization was limited to palaeohighs or faulted platform margins in the Early Jurassic carbonates. The pervasive replacement phase is interpreted based on a ‘compaction model’; the formation fluids expelled from compacting basinal carbonates could have funnelled along faults into permeable palaeohighs. The high homogenization temperature of the dolomite cements and decreased salinities indicate precipitation at great depth with an influx of meteoric water. These data, along with the thermal history, suggest that the dolomite cements precipitated according to the ‘tectonic squeegee’ dolomitization model. The dolomite precipitation temperature was set against the thermal history of the carbonate platform to interpret the timing of dolomite precipitation. The dolomite precipitation temperatures (90 to 100 °C) were reached in the studied formations first in the thrust fold belt (Early Tertiary, 60 Ma), and then in the foreland succession during the Late Tertiary (10 Ma). This observation suggests that the dolomite precipitation fronts moved southwards over time, recording a ‘diagenetic wave’ linked to the migration of the orogenic system. Observations suggest that the porosity increased during the first phase of replacement dolomitization while the dolomite cementation phases partially occluded the pores. The distribution of porous dolomitized bodies is therefore linked to the ‘compaction dolomitization’ model.     

江西靖安东周墓出土玉器的玉质特征研究

为配合江西省文物考古研究所的出土文物研究,运用宝玉石学、岩石学和物理谱学的理论与资料,采用肉眼观察、宝石显微镜、红外吸收光谱（反射法）、激光拉曼光谱（散射法）、X射线衍射法和环境扫描电子显微镜等无损测试方法对江西靖安李洲坳东周墓的13件出土玉器样品进行了玉质特征鉴定。结果显示,有11件出土玉器样品为透闪石质软玉,2件出土玉器样品为粉砂岩类岩石。同时,还揭示了11件透闪石质软玉玉器的外观特征差异与其玉石成分和质地结构的关系。     

武夷山西南缘构造应力场演化及其与成矿的关系

武夷山西南缘及邻区地处华南特提斯与环太平洋构造域交接地带,自元古宙以来历经了多期次的构造演化,形成了相应的构造应力场。通过对主要古构造运动应力值大小的测定和3个主要构造演化阶段构造应力场数值模拟,得出古应力值自早到晚总体上有增大的趋势,到中生代古应力值强度大且持续时间较长。重要的成矿阶段主要对应区域拉张构造应力场。不同阶段构造应力场模拟结果表明,自前泥盆纪至燕山期,该区主构造线方向从EW—NEE向NE—NNE向转变,与主构造应力场的变化相对应。同时不同时代构造应力的分布为多金属矿产的形成创造了良好的成矿地质条件。