贵州省1:500000地球化学块体图编制及应用

地球化学块体制作方法主要是运用地球化学块体的理论与方法技术,利用GeoMDIS2000软件系统制作地球化学块体图及统计与块体相关的参数。并通过对贵州区域化探资料剖析,划分出不同级次的地球化学块体,进行资源潜力评价和矿床规模预测。为矿产资源勘查及新一轮异常查证提供了战略靶区。

用新观念与新技术寻找巨型矿床

80年代以来,寻找巨型矿床(或称超大型矿床、特大型矿床、世界级矿床)已成为国际矿业界矿产勘查工作的焦点。这是因为全世界各种金属矿床,70～85％的储量都是集中在大约只占10％数量的巨型矿床之中。

Water Chemistry and Hydrometeorology in a Glacierized Catchment in the Polar Urals,Russia

This study aims to determine the relationships between local meteorological conditions,proglacial river discharge and biogeochemical processes operating in a periglacial basin located in the Polar Ural mountain range, Russia. Fieldwork was conducted in the catchment of Obruchev Glacier(13 km2) during the summer peak flow period in 2008. River discharge was dominated by snowmelt and changed from 3300 l s-1 to less than 1000 l s-1. The mean daily air temperatures of stations situated in the mountain tundra and near Obruchev Glacier from July 11 th to August 1st 2008 were 14.4°C and 10.3°C, respectively. The glacial river had low total dissolved solids varying from 4.5 to 9 mg l-1 and coefficients of correlation between Na+ and Cl-, K+ and Cl-, as well as NH4+ and Cl- were 0.94, 0.90 and 0.84, respectively. Rainfall events affected the snowmelt initiation and provided an essential part of the discharge during the intense snowmelt period, which occurred from July 11 th to July 18 th 2008. Data showed that Na+ and K+ in the surface water derived from snowmelt rather than chemical weathering of silicates. Also, it was obtained that NO3- derived from the melting snowpack, whereas ammonification occurring under the snowpacks was the primary source for NH4+.

Application of sequence stratigraphy to Triassic terrestrial strata in Tahe area of Tarim Basin

Based on a synthetic geological study of drilling,well logging and seismic data,core observations and geochemical analysis,it is recognized that Triassic sedimentary facies in the Tahe area of Tarim Basin include braided river deposits filling erosional valleys,and sublacustrine fan,canyon and delta facies.Braided river deposits filling erosional valleys are dominated by coarse-grained lithic quartz sandstone with oblique bedding,and represent the most important sedimentation type of sandstone in the study area.Sublacustrine fan and canyon facies are mainly distributed in the Middle Oil Member.Most delta sediments are deposited in highstand system tract(HST),Because of frequent changes in base level,delta sediments are commonly eroded and rarely preserved.Sedimentary cycles are clearly reflected by lithology,sedimentary structures and well logging data,and are closely related to the changes in lacustrine level.In accordance with the basic principle of sequence subdivision,seven type-I boundaries can be recognized in Triassic strata and six type-I sequences are subdivided correspondingly.In general,lowstand system tract(LST) is well developed within stratigraphic sequences and forms the main body of reservoir sandstone in this area;highstand system tract(HST) and transgressive system tract(TST) are often eroded by upper sequences or missed,Although various factors have different influences on terrestrial sequence stratigraphy,the classical sequence stratigraphy theory proposed by VAIL can be applied to terrestrial strata.

Geochemical characteristics of soil selenium and evaluation of Serich land resources in the central area of Guiyang City,China

Based on the results of multipurpose regional geochemical surveys of the Guizhou Province, geochemical characteristics of soil Se and Se-rich land resources in the central area of Guiyang City were studied and evaluated.Major conclusions are as follows:(1) the Se content in surface soil of the central area of Guiyang City was 0.17–2.89 mg kg^(-1), and the average was 0.78 mg kg^(-1), which were respectively 2.6 and 3.9 times of the national background value of soil and the world background value of soil.The Se content in deep soil was 0.11–1.48 mg kg^(-1), and the average was 0.44 mg kg^(-1), which were respectively 1.5 and2.2 times of the national background value of soil and the world background value of soil. The soil Se content decreased with the increase in the soil depth on the vertical profile, and the surface soil had a higher Se content.(2)Distribution of Se content was mainly affected by parent material, physicochemical properties of soil and other components, soil type, and land use type. Parent material played a key role, as the soil Se content was mainly originated from parent rock and increased with the background value of Se in parent rock, physicochemical properties of soil and other components had certain influences upon the Se content. Se was shown to have a significant linear positive correlation with S and organic carbon but no significant correlation with p H value. Se content varied with different types of soil as follows: skeleton soil > yellow soil > paddy soil > limestone soil > purple soil. Land use type also hadcertain influences upon the soil Se content as follows: dry land > construction land > garden plot > grassland =garden plot > forest land.(3) Taking 0.4 mg kg^(-1)B x(Se) <3.0 mg kg^(-1) as the standard for Se-rich soil, Se-rich soil of the study area covered an area of 2224 km^2 and 92.5% of the total area; the remaining is general soil. The study area had no Se-excess soil. Therefore, the central area of Guiyang City has a high proportion of Se-rich land, a large area of Serich land resources, and a moderate selenium enrichment strength, which have been rarely seen anywhere and provide advantageous resources for the development of Se-rich featured agriculture.

Relocation of the Yellow River Estuary in 1855 AD Recorded in the Sediment Core from the Northern Yellow Sea

Relocation of the Yellow River estuary has significant impacts on not only terrestrial environment and human activities, but also sedimentary and ecological environments in coastal seas. The responses of regional geochemical characteristics to the relocation event, however, have not been well studied. In the present study, we performed detailed geochemical elemental analyses of a sediment core from the northern Yellow Sea and studied their geochemical responses to the 1855AD relocation of the Yellow River estuary. The results show that TOC/TN, Co/A1203, Cr/A1203, Ni/A1203 and Se/A1203 ratios all decreased abruptly after 1855 AD, and similar decreases are observed in the sediments of the mud area southwest off the Cheju Island. These abrupt changes are very likely caused by the changes in source materials due to the relocation of the Yellow River estuary from the southern Yellow Sea to the Bohai Sea, which the corresponding decreasing trends caused by the changes in main source materials from those transported by the Liaohe River, the Haihe River and the Luanhe River to those by the Yellow River. Because the events have precise ages recorded in historical archives, these obvious changes in elemental geochemistry of sediments can be used to calibrate age models of related coastal sea sediments.

Spatial Differentiation of Elements in Soils on Red-Earthy Hill Landscape of Central China

Samples of 21 soil profiles and 165 top soils from an area of approximate 1.5km^2 on red-earthy hill landscape were collected and analysed.The content of Ca,Mg,K,P,Fe,Mn,Zn and Cu in soils relate with the kind of parent material and the position of topography,however,there is great variation due to the local difference of the form of soil utilization.From the difference in spatial distribution of elements content,it is believed that eight kinds of elements are lost by chemical leaching and physical translocation,meanwhile some are added (such as Ca,P,K,Mg) and some mobilized (such as Fe,Mn,Zn,Cu and P) through cultivation,fertilization and irrigation in the soils on the landscape investigated.The sectional differentiation in abundance or deficiency of elements in top soils on the landscape investigated is distinct,which is important for carrying out agricultural management and reasonable fertilization according to local conditions.

Physico-chemical and Bacteriological Specification Groundwater of Tangier

The drinking water for all the inhabitants of Tangier is still an aim far from being achieved. Therefore, all rural areas and some urban areas feed water wells and springs whose composition and safety are unknown. In the absence of data on water and ignorance of consumers towards the risk of poisoning and waterborne diseases transmitted by these waters, the authors conducted a study to determine the composition, physico-chemical quality and bacteriological these waters. This study is to provide a basic physico-chemical and bacteriological data from these waters in some urban areas of old or missing infrastructure in some sites in the province of Tangier. Such as Ziatine sites, Gzenaya, Rmilate, Malabata ＋ Mnar, Mghoura ＋ Aouama and Downtown. Analyzes are performed according to AFNOR methods （AFNOR： French Standards Association）. The results indicate that these waters are generally mild and are experiencing significant geochemical imbalance. Moreover, these waters also have a significant organic and bacteriological pollution. It is concluded that the waters of these sites are of poor quality, unfit for human consumption.

Impact of Changing Climate in the Kairouan Hydrological Basin （Central Tunisia）

The Merguellil catchment （central Tunisia） has undergone rapid hydrological changes over the last decades. The most visible signs are a marked decrease in surface runoff in the upstream catchment and a complete change in the recharge processes of the Kairouan aquifer downstream. Fluctuations in rainfall have had a real but limited hydrological impact. Much more important are the consequences of human activities such as soil and water conservation works, small and large dams, pumping for irrigation. Several independent approaches were implemented： hydrodynamics, thermal surveys, geochemistry including isotopes. They helped to identify the different terms of the regional water balance and to characterize their changes over time.

Geochemical tracing and modeling of surface and deep water–rock interactions in elementary granitic watersheds(Strengbach and Ringelbach CZOs, France)

From the study of the Strengbach and Ringelbach watersheds we propose to illustrate the interest of combining the geochemical tracing and geochemical modeling approaches on surface and deep borehole waters,to decipher the diversity of the water flow and the associated water–rock interactions in such elementary mountainous catchments. The results point to a clear geochemical typology of waters depending on the water circulations(deep vs. hypodermic) within the substratum.

Evaluation of Gold Geochemical Anomalies in the Liaodong Paleorift

89 Au geochemical anomalies are delineated by using 1/200000 regional geochemical exploration data. By researching regional geochemical characteristics and the relationship with the geological background, the author points out that： the main factors causing high background of Au geochemical anomalies are Gaixian and Dashiqiao formation of Liaohe group, intrusions of Mesozoic intermediate-acid intrusive rocks. The elements combination types of typical anomalies are determined by using factorial analysis,cluster analysis and other mathematical methods with the combination of elements association in typical anomalies：the composite anomaly of Baiyun gold deposits is Au-As-Sb, Maoling gold deposit is Au-As- Bi-Mo, Wulong gold deposits is Au-As-Bi-W, Xiaotongjiapuzi gold deposit is Au-As-Bi-Mo-Sb. By using multivariate statistical analysis method,62 ore-caused anomaly are preferred in 89 Au geochemical anomalies delineated. On this basis, the 62 anomalies are divided into 4 kinds of anomaly types reference to elements combination types of typical anomalies,the classification results of ore-caused anomalies are： 4 geochemical anomalies of Baiyun type,36 geochemical anomalies of Maoling type,11 geochemical anomalies of Wulong type, 11 geochemical anomalies of Xiaotongjapuzi type. According to the results, the prospecting direction is provided for the futme of gold exploration.

The spatial distribution of archaeal lipids in a mesoscale subtropical watershed, Southeast China

Archaea play an important role in global carbon and nitrogen cycles. Archaeal lipids, such as isoprenoid glycerol diakyl glycerol tetraethers(i GDGTs), are important biomarkers tracing change in archaeal community structure and biogeochemical processes in the natural environments. In this research, the spatial distributions of archaeal lipids in the surface sediments of the Jiulong River(JR) and the Jiulong River estuary(JRE) were examined. GDGT-0(containing zero cyclopentyl ring) and crenarchaeol were the most abundant i GDGTs in the JR and JRE. From the rivers to the estuary, the total i GDGTs, GDGT-0, crenarchaeol and archaeol concentrations showed significant spatial variation; in particular, GDGT-0 and archaeol in the river may be predominantly derived in situ from methanogens, whereas crenarchaeol in the estuary mainly derived in situ from Thaumarchaeota. We inferred that archaeal community was dominated by methanogens in the Jiulong River and by Thaumarchaeota in the Jiulong River estuary, which are consistent with change in archaeal community structure observed in other estuarine environments.