Agricultural land use in the coastal area of the Alexander von Humboldt National Park, Cuba and its implication for conservation and sustainability

In the Alexander von Humboldt National Park in eastern Cuba many endemic animals and plants are found in various different natural habitats, which are considered to be the most important ones for in-situ conservation in the entire Insular Caribbean. In some areas of the National Park agriculture is practised. Thus, the objective of this study was to document and analyse the different land use activities and their consequences for local resource management and conservation of biodiversity in two village areas. A particular question was: what has changed since the foundation of the National Park in 1996? As time series data for land use and aerial photographs were not available for this part of Cuba, a qualitative evaluation was carried out. For this, six different land use units were mapped in 2001 and additional information gathered for areas with special interest related to sustainable land use and resource conservation. Although most parts of the study area are influenced to various degrees by human impact, the different types of land use seem presently not to have a crucial or detrimental impact on the land resources of the Alexander von Humboldt National Park. However, exploitation of the natural resources in certain areas could be improved with different management options to reach sustainability as well as to meet the conservation objectives of the National Park. This includes reduced or abandoned agricultural use of steep slopes to reduce erosion risk as well as a facilitated regeneration of natural vegetation in many parts of the study area to be able to conserve the high valuable biodiversity of the Park. Environmental education seems to have played an important and successful role since the foundation of the Park in 1996. Since then, cropping on steep slopes as well as illegal logging and poaching could be reduced.     

在"数字国土工程"中我区地学数据库建设的现状及发展趋势

近年来,在国土资源部的高度重视下,我区相继建立了一系列地学数据库。这些地学数据库的建立不仅为地矿行业提供了基础性数据,也加速了"数字国土工程"和国土资源信息化建设的步伐。随着信息技术的高速发展,利用地理信息系统(GIS)将各类地学数据有机地结合起来,形成地学数据应用与管理系统,最终通过网络服务于社会,必将是各类地学数据发展的必然趋势。     

The Port Mouton Shear Zone: intersection of a regional fault with a crystallizing granitoid pluton

The peraluminous tonalite–monzogranite Port Mouton Pluton is a petrological, geochemical, structural, and geochronological anomaly among the many Late Devonian granitoid intrusions of the Meguma Lithotectonic Zone of southern Nova Scotia. The most remarkable structural feature of this pluton is a 4-km-wide zone of strongly foliated (040/subvertical) monzogranites culminating in a narrow (10–30 m), straight, zone of compositionally banded rocks that extends for at least 3 km along strike. The banded monzogranites consist of alternating melanocratic and leucocratic compositions that are complementary to the overall composition of that part of the pluton, suggesting an origin by mineral–melt and mineral–mineral sorting. Biotite and feldspar are strongly foliated in the plane of the compositional bands. These compositional variations and foliations originated by a process of segregation flow during shearing of the main magma with a crystallinity of 55–75%. Subsequent minor brittle fracturing of feldspars, twinning of microcline, development of blocky sub-grains in quartz, and kinking of micas demonstrate overprinting by a high-temperature deformation straddling the monzogranite solidus. Small folds and late sigmoidal dykes indicate dextral movement on the shear zone. This Port Mouton Shear Zone (PMSZ) is approximately co-linear with the only outcrops of Late Devonian mafic intrusions in the area, two of which are syn-plutonic with well-developed mingling textures in the marginal tonalite of the Port Mouton Pluton. Also closely co-linear with the mafic intrusions are a granitoid dyke that extends well beyond the outer contact of the Port Mouton Pluton, a swarm of large aligned angular xenolithic slabs, a zone of thin wispy schlieren banding, a large Be-bearing pegmatite, and a breccia pipe with abundant garnetiferous metapelitic xenoliths. In various ways, the shear zone may control all of these features. The Port Mouton Shear Zone is parallel to many other NE-trending faults and shear zones in the northern Appalachians, probably related to the docking of the Meguma Zone along the Cobequid–Chedabucto Fault system.     

Momentum transport of wave zero during March: A possible predictor for the Indian summer monsoon

Analysis of monthly momentum transport of zonal waves at 850 hPa for the period 1979 to 1993, between ‡S and ‡N for January to April, using zonal (u) and meridional (v) components of wind taken from the ECMWF reanalysis field, shows a positive correlation (.1% level of significance) between the Indian summer monsoon rainfall (June through September) and the momentum transport of wave zero TM(0) over latitudinal belt between 25‡S and 5‡N (LB) during March. Northward (Southward) TM(0) observed in March over LB subsequently leads to a good (drought) monsoon season over India which is found to be true even when the year is marked with the El-Nino event. Similarly a strong westerly zone in the Indian Ocean during March, indicates a good monsoon season for the country, even if the year is marked with El-Nino. The study thus suggests two predictors, TM(0) over LB and the strength of westerly zone in the Indian Ocean during March.     

Sm-Nd ISOTOPIC AGE OF LAMPROPHYRES IN THE GEZHEN GOLD-BEARING SHEAR ZONE ON HAINAN ISLAND AND ITS GEOLOGICAL IMPLICATIONS

Sm-Nd isotopic compositions of eight lamprophyre samples, which come from the Gezhen gold-bearing shear zone on western Hainan Island, are measured. The Sm-Nd isochron age is 495.98±13.14 Ma, (143Nd/144Nd) 0=0.512094, εNd(t) ranges from +1.80 to +2.00 and TDM from 982 Ma to 1196 Ma (average: 1060 Ma). The authors point out that the whole-rock Sm-Nd isochron age (495.98 ± 13.14 Ma) really represents the petrogenetic age of lamprophyre and the time of magmatism during subsequent subduction.     

华北陆块北缘西段中元古代与裂谷作用有关的铁、稀土、多金属矿床特征及成因

华北陆块北缘西段狼山—白云鄂博裂谷系中元古代形成的大型多金属矿床 ,是我国重要的铁、稀土、铜、铅、锌矿产地。矿床为产于沉积岩中热水沉积型多金属矿床。其形成受地层、构造控制 ,与裂谷作用有着密切的关系。裂谷系内外分支的地质环境及矿床矿种不同 ,导致矿床特征及成因具有一定差异。白云鄂博铁、稀土矿床为钾、钠、磷等含量较高的热水沉积型 ,霍各乞铜、铅、锌多金属矿床为与中基性火山岩有关的过渡热水沉积型 ,东升庙和甲生盘等铅、锌多金属矿床为热水沉积型。文中将对上述矿床分别进行论述。     

Cretaceous and Tertiary terrane accretion in the Cordillera Occidental of the Andes of Ecuador

New field, geochronological, geochemical and biostratigraphical data indicate that the central and northern parts of the Cordillera Occidental of the Andes of Ecuador comprise two terranes. The older (Pallatanga) terrane consists of an early to late (?) Cretaceous oceanic plateau suite, late Cretaceous marine turbidites derived from an unknown basaltic to andesitic volcanic source, and a tectonic mélange of probable late Cretaceous age. The younger (Macuchi) terrane consists of a volcanosedimentary island arc sequence, derived from a basaltic to andesitic source. A previously unidentified, regionally important dextral shear zone named the Chimbo-Toachi shear zone separates the two terranes. Regional evidence suggests that the Pallatanga terrane was accreted to the continental margin (the already accreted Cordillera Real) in Campanian times, producing a tectonic mélange in the suture zone. The Macuchi terrane was accreted to the Pallatanga terrane along the Chimbo-Toachi shear zone during the late Eocene, probably in a dextral shear regime. The correlation of Cretaceous rocks and accretionary events in the Cordillera Occidental of Ecuador and Colombia remains problematical, but the late Eocene event is recognised along the northern Andean margin.     

加强科学管理是“九五”重点项目顺利实施的重要保障

本文对辽宁省防震减灾“九五”重点项目实施过程中采取的管理体制及管理措施进行了介绍。在管理体制上 ,建立了较为完善的组织机制构 ,按照全省地震系统一盘棋的指导思想 ,把市地震局作为一级管理机构 ,由市地震局负责本地区项目的实施与组织管理工作 ;在项目管理中 ,采取了跟踪检查、抓样板示范、抓项目施工质量、抓创新、抓技术培训等行之有效的措施 ,为“九五”重点项目的顺利完成并取得较好成绩提供了保证     

2-D viscoelastic FEM simulation on stress state in the deep part of a subducted slab

Introduction It is found that there are some relationships between the thermal structures of subduction zones and the deep seismicity, while the mechanism relates the thermal structure and the deep seismicity is still unsure (Helffrich, Brodholt, 1991; Furukawa, 1994; Kirby, et al, 1996). From 1980s, geoscientists have constituted a series of numerical simulations on the stress states of subduction slabs. Based on the kinetic computation of Sung and Burns (1976a, b), Goto, et al (1983, 1987…     

Analysis and comparison of the tidal gravity observations obtained with LCR-ET20 spring gravimeter

Introduction The tidal variation signals of the solid Earth recorded with the modern measuring techniques can be used to provide effectively the means to cognize the Earths motion, deformation and structure character, especially to monitor the material motion in the Earths interior. In the recent 20 years, the distribution character of the global gravity field has made great progress since the continuous and deep theoretical studies in geophysics and geodesy domains. The successful manufactur…