信息化测绘实验平台建设实践

从信息化测绘实验教学存在的问题出发,结合测绘与地理信息实验教学示范中心建设,阐述了信息化测绘实验平台建设内容、方法与措施。实验平台建设过程中,不断探索创新实践育人机制,提升教师实验教学水平。     

贵州凉风洞洞穴系统锶同位素特征

对贵州茂兰自然保护区内凉风洞(LFD)洞穴系统中各组分(土壤水、洞穴滴水、土壤与基岩等)锶同位素组成(~(87)Sr/~(86)Sr)的系统分析结果表明,各个组分的~(87)Sr/~(86)Sr比值差异显著。不同剖面土壤水~(87)Sr/~(86)Sr比值明显不同,但均介于大气降水平均值和土壤之间;不同滴水点间~(87)Sr/~(86)Sr比值差异也很明显,大多落在洞穴上覆土壤水和基岩之间,受渗透水在洞穴顶板中发生的水-土作用和水-岩作用强度控制。此外,凉风洞上覆原生喀斯特森林生物量及其凋落物返还量较大,以植物落叶为主形成的凋落物层以及被微生物分解形成的表层有机土成为除洞穴上覆土壤和基岩外的另一个直接阳离子源,其释放的Sr随水体快速下渗对滴水~(87)Sr/~(86)Sr比值产生了明显影响。因此,利用本研究区洞穴滴水及其次生化学沉积物~(87)Sr/~(86)Sr指标表征洞穴上覆气候环境信息时,有必要事先识别不同物源~(87)Sr/~(86)Sr比值及其相对贡献、运移路径水文地质过程等限制性因素影响。     

南方喀斯特石漠化分区的名称商榷与环境特点

阐明了锥、塔峰等热带喀斯特地貌发育的适宜的气候和地质地貌条件,论述了我国南方喀斯特地区喀斯特地貌空间分布与气候和地质地貌条件的关系。针对现行《石漠化分区》命名存在的科学系统性问题,对石漠化分区的命名系统提出了修改意见:将我国南方喀斯特地区分为锥、塔峰喀斯特地貌区和非锥、塔峰喀斯特地貌区2个区。锥、塔峰喀斯特地貌区,根据喀斯特地貌类型分为浅碟型峰丛洼地,漏斗型峰丛洼地和峰林平原等3个亚区,分别对应原《石漠化分区》的岩溶高原区,峰丛洼地区和峰林平原区。非锥、塔峰喀斯特地貌区,根据区域地貌类型分为高原盆谷,高原峡谷,高原和中低山槽谷,中高山和中低山等5个亚区,分别对应原石漠化分区的岩溶断陷盆地区,岩溶峡谷区,岩溶槽谷区,中高山区和溶丘洼地(槽谷)区。鉴于热带喀斯特地貌区裸露性喀斯特坡地分布广,石漠化严重,特别是漏斗型峰丛洼地亚区裸露性喀斯特坡地面积比例高,是南方喀斯特地区石漠化最为严重的地区,也是集中连片的国家级贫困区,建议南方石漠化治理向黔桂滇接壤的漏斗型峰丛洼地亚区倾斜。     

矿物晶体的缺陷

晶体具有极其规则的原子结构.然而,大多数晶体物质不是完整的,原子排列的规则图像被晶体缺陷所破坏.本文列举不同类型的缺陷:点缺陷(空位、间隙离子、置换离子、反位缺陷、拓扑缺陷、Schottky缺陷和Frenkel缺陷)、线缺陷(位错)、面缺陷(颗粒边界、小角晶界、反相畴和堆垛层错)和体缺陷(空洞和析出物).     

The dynamics of organic matter in soil size and density fractions traced by stable carbon isotopes

1IntroductionSoilorganicmatter (SOM)isakeysourceofnutrientsforplantgrowth ,itisessentialforthemaintenanceofsoilstructureanditcontributestotheabilityofsoiltoretainnutrientsandwater.AnimprovedunderstandingofSOMdynamicsiscentraltothedevelopmentofmoreenvironmentallysoundandsustainablepracticesofagriculturalmanagement (Collinsetal.,2 0 0 0 ) .Avarietyofcon ceptualmethodshavebeenusedtodescribetheprocessesofSOMaccumulationandturnover (Jen kinsonandRayner,1 977;Duxburyetal.1 989;Partonetal.,1 99…     

Geochemical evidence for non-marine depositional environment of foraminiferal fossils from the Nihewan Basin, China

From the first finding in 1970s, the findings of foraminiferal fossil assemblages in inland basins have been reported from time to time, especially in recent years. The debates on the depositional environment of foraminiferal fossils have become the hot spot of researches again in China. Based on the researches of trace element geochemistry and electron scanning microscope of shells of Quaternary foraminiferal fossils from the Xiaodukou section in the inland Nihewan basin, the original ⁸⁷Sr/⁸⁶Sr and other geochemical information of shells were believed to be preserved well and could be used to rebuild the geochemistry of contemporary waters where foraminifera deposited, although there existed some effects of burial diagenesis on the geochemistry of shells to a certain extent. The ⁸⁷Sr/⁸⁶Sr ratios of well-preserved Xiaodukou foraminiferal shells were measured, giving a range of 0.711190±25–0.712018±14, apparently higher than the value of contemporary seawater (0.709087–0.709147) and similar to that of the Sanggan River, proving that it represented the value of the ancient lacustrine water. The hyperbolic mixing models of ⁸⁷Sr/⁸⁶Sr-palaeosalinity and ⁸⁷Sr/⁸⁶Sr-Sr/Ca indicated that the contemporary waters where Xiaodukou foraminifera inhabited was an inland lake and there was no seawater input to the depositional environment.     

Comparative study on CO2 sources in soil developed on carbonate rock and non-carbonate rock in Central Guizhou

In this paper, by using concentration and carbon stable isotope the CO2 sources of soil profiles developed on limestone, dolostone and claystone basements in Central Guizhou, China are comparatively studied. The results show that CO2 concentration of soil profiles developed on different basements is different, having the following sequence: limestone>dolostone>claystone. Below the soil depth of 20 cm from the surface the ? 13C value of CO2 in soil profile developed on limestone ranges from -12.811‰ - -13.492‰(PDB), that in soil profile developed on dolostone varys from -13.212‰ - -14.271‰(PDB) and that in soil profile developed on claystone is about -20.234‰ - -21.485‰(PDB). Taking the carbon isotope of soil organic matter and carbonate rock as two isotopic endmembers, the proportion of soil CO2 generated by dissolution of carbonate rock is calculated, about 21%-25% for soil profile developed on limestone basement, 19%-21% for soil profile developed on dolostone basement. There is almost no influx of CO2 generated by the dissolution of carbonate rock in soil profile developed on claystone basement.     

碳酸盐岩酸不溶物作为贵州岩溶区红色风化壳主要物质来源的证据

贵州岩溶区红色风化壳是中国南方红色负化壳的重要组成部分，本文根据部分红色风化壳剖面野外特征、矿物学、地球化学及土壤物理学等的研究结果，对其物源及成因进行了探讨。各剖面，尤其邻近剖面显著的矿物学、地球化学差异排除了远程风成沉积物、火山灰、上覆或者高处碎屑岩层作为统一且重要物源的可能。极低的石英含量表明贵州常见的长石石英砂岩不是其主要物源，具有中稀土（MREE）富集的特征也排除了粘土岩、页岩作为主要物源的可能。风化壳剖面间的差异性均可从基岩酸不溶物的差异性得到很好解释，表明它们是下伏碳酸盐岩风化、酸不溶物（准）原地堆积的结果。部分剖面甚至显示了典型风化壳剖面的一些特征，具有正常风化序列的剖面结构特征。     

早震旦世大塘坡期锰矿成因新认识

中国南方早震旦世大塘坡期锰矿的形成一直存在热水成因、生物成因或化学成因的争议。通过对贵州松桃早震旦世大塘坡期锰矿的碳、硫同位素和藻类化石的研究，认为早震旦世大塘坡期锰矿是在700－695Ma全球性Sturtian冰期后形成，由于大气中含有很高的CO2与海洋中的Ca^2 、Mn^2 反应，造成大量CaCO3和MnCO3快速沉淀，形成“碳酸盐岩帽”（碳酸锰）所致。对大塘坡组藻类化石研究还表明，在含锰矿的层次，藻类化石很少，而锰矿层上下，微体藻类化石都很丰富，这说明锰矿成矿与藻类关系并不那么密切。