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1.
P. Soler 《Mineralium Deposita》1987,22(2):135-143
About 1,500 samples of Pb and Zn concentrates and ores from 89 ore deposits of the polymetallic province of the Andes of central Peru have been analyzed. The distributions of Cd, In, Ge, Ga, Ag, Bi, Se, Hg, and Sn in these ore deposits can be reported on the basis of the typology of ore deposits, i.e., some types of ore deposits (syndiagenetic without associated volcanism and volcano-sedimentary of Triassic-Lias, exhalative sedimentary of Upper Jurassic) show very characteristic minor and trace element patterns; the temperature of ore formation that controls the abundance of Bi and Hg, in general, and of Ag, Se, and Sn in the Tertiary hydrothermal deposits; the age and nature of the country rock, e.g., an In, Ga, and Sn positive anomaly and Cd negative anomaly appears in the deposits with Paleozoic country rock; the geographic position of ore deposits, e.g., in the northern part of the province an In, Ga, Ge, and Cd positive anomaly appears. 相似文献
2.
Principe is one of the volcanic centres comprising the Cameroun line in West Africa. The volcanic rocks can be divided into two stratigraphic units:
- Younger lava series — basanite and nephelinite overlying.
- Older lava series — transitional to mildly alkaline basalt and hawaiite.
- Phonolites which evolved by low pressure crystal fractionation of the younger lava series basanitic magma, and
- Tristanite — trachyte — trachyphonolite suite which may have evolved by high pressure crystal fractionation of the older lava series magma.
3.
Dr. Barbara Theilen-Willige 《International Journal of Earth Sciences》1982,71(1):318-327
The following facts have supported the origin of the Araguainha circular structure in Central Brazil by a meteoritic impact:
- the almost circular contour
- the impact-morphologic sequence including a central uplift, ring walls and a basin rim of escarpments
- outcrops of suevites and mixed breccias
- the evidence of shock metamorphism
- the presence of shatter cones, and
- negative anomalies of the total intensity of the magnetic field at the center of the ring structure.
4.
Alexander A. Godovikov George C. Kennedy 《Contributions to Mineralogy and Petrology》1968,19(2):169-176
Prior experimental work has shown that in the laboratory the mineralogy of eclogites is sensitive to the ratio of CaO ∶ MgO ∶ FeO and that the reaction pyroxene + kyanite?garnet + quartz proceeds to the right at high pressures in rocks rich in magnesium and to the left in rocks rich in calcium and iron. Typical basalts crystallized at high pressure never contain kyanite. The chemistry and mineralogy of a large number of naturally occurring eclogites show they belong to three classes.
- Kyanite-free magmatic eclogites, rich in magnesium, from:
- kimberlites
- dunites and serpentinites.
- Kyanite-bearing eclogites and grosspydites rich in CaO and low in FeO with intermediate MgO from:
- kimberlites
- gneisses.
- Kyanite-free eclogites of metamorphic origin rich in iron with low magnesium and intermediate amounts of calcium from:
- glaucophane schists
- gneisses.
5.
Pasquale Iannello 《International Journal of Earth Sciences》1971,60(2):630-655
The detailed investigation of the Bushveld granites, around the Rooiberg area, has revealed the existence, in the field, of at least three main types:
- Granophyric rocks, which form a belt (transition-zone) between the country rocks (sediments and felsite) and the Main granite.
- Main granite, which is the most common type of granite.
- Younger granites, which are responsible for the tin mineralization.
6.
According to their material sources, China’s pegmatities can be divided into two broad types: (1) the crust-source pegmatites derived mainly from the upper continental crust, which can be subdivided into metamorphic differentiated, mixed metasomatic and anatectic magmadifferentiated pegmatites, and (2) the mantle-source pegmatites generated from the mantle, including those related to late differentiates and carbonatites. In space, carbonatites are usually accompanied with alkaii syenite. The criteria of discriminating the two-source pegmatites of China are listed as follows:
- Rock-forming minerals (micas and feldspars);
- REE distribution patterns;
- Zr/Hf ratios in zircons; and
- Species of apatite and REE contents.
7.
Since 1980, many of the state governments in India have introduced programmes to integrate traditional medical systems (TM) into official health care institutions and services at different administrative levels. One of these schemes is at Primary Health Centres (phcs) in various districts. However, little research has been undertaken to date on relative demand and utilization, or on the extent to which TM is seen or used as a complement, alternative or supplement to biomedical services, in the same phc setting. The consumer assumes an important role in an integrated approach, where illness behaviour is understood to be a decision-making process. From the structuralist aspect also, the needs and decisions (in a given situation) as perceived by the administration are not necessarily the same as subjectively felt needs, wants, or even expressed needs of individuals. It is hoped research into the degree of usage and levels of clinical utilization of the two coexisting services will be useful in planning norms and services, estimation of recurrent expenditures and allocation of resources for effective functioning of the phcs. This paper presents the findings of a questionnaire based on a quota sample of users of phcs. eighty patients in each of the Allopathy and Siddha medicine wings were interviewed in three phcs in Tamil Nadu, a total of 480 respondents. The main issues considered in this paper are:
- Socio-economic characteristics of the users.
- Treatment patterns: differential preferences for treatment methods for various disease conditions; multiple-usage — interchangeable or concurrently for the same ailment; degree of medical pluralism; spatial patterns of movement.
- The reasons for participating in the present treatment.
- Behaviour, satisfaction, attitudes, opinions, preferences, experiences.
- Conclusions and implications of the study for research and service planning.
8.
B. Lammerer I. Fruth D. D. Klemm E. Prosser K. Weber-Diefenbach 《International Journal of Earth Sciences》1976,65(1):436-459
Geologic, petrological and geochemical investigations have been carried out in the western part of the “Zillertaler Alpen”. Important results are:
- The premetamorphic material of the Greiner series consists of conglomerates, breccias, arcosic-sandstones or greywackes, bituminous shales, volcanic lavas and tuffs.
- The southern part of the “Zentralgneis” shows a differentiation trend from alkaline granite to quarzdiorite with predomination of granodiorite.
- Chemical relationships of granodiorite to its restitic inclusions allow the supposition of a palingenetic origin of the granitic rocks.
- At least two stages of metamorphism can be differentiated.
- Parts of the Greiner series, covered by triassic metasediments, are supposed to be of Permian age. A lower age boundary can not yet be given.
- Some vertical, northeast striking faults with throws of more than 1 or 2 kilometers produced southward verging drag folds.
- Geodynamic aspects, revealed from regional metamorphism and tectonics, are discussed.
9.
H. Kenneweg 《GeoJournal》1994,32(1):47-53
The development of inventory activities in the field of forest damage assessment and monitoring during the last decade in Germany and the present state are recorded as far as remote sensing has been involved. Any forest inventory is influenced by external factors, and the resulting difficulties for an introduction of new technologies are described. The following tasks and/or methods are discussed: -global approaches to deforestation monitoring -working experience from local and regional case studies -vegetation and vegetation-damage monitoring in ”urban forestry” -sampling approaches for large areas -the contribution of spectral signatures and satellite remote sensing to damage assessment 相似文献
10.
W. E. G. Taylor 《International Journal of Earth Sciences》1968,58(2):564-587
The paper presents novel information on the Caledonian orogeny in Ireland. A series of Dalradian (Upper Precambrian-Lower Cambrian) metasedimentary rocks occur as an envelope to a granitic igneous complex at Slieve Gamph, Western Ireland. These metasedimentary rocks have been deformed at several distinct times and evidence is shown for the following sequence of events:
- formation of major nappe structures and a tectonic slide. The axial-plane traces of the folds probably trended N. E.-S. W.
- formation of upright, gently plunging folds with axial-plane traces of the folds trending N. E.-S. W. Emplacement of the components of the Slieve Gamph igneous complex.
- formation of a conjugate set of folds:
- Open folds with N. N. E.-S. S. W. trending axial-planes which dip to the east,
- Open folds with E.W. trending axial-planes which dip to the north.
- formation of kink-bands, open and conjugate folds with an axialplane trace trending N. W.-S. E.
11.
Prof. Dr. G. Haase Dr. L. Händel Dr. Chr. Nagel Dr. Chr. Opp Dr. R. Zierath 《GeoJournal》1990,22(2):153-165
Problems of landscape and resource protection resulting from the intensification of land-use can be mastered only by intersectoral planning and a land management considering (landscape-)ecological principles right from the beginning. In the district of Leipzig ecological studies in the '80ies have focussed on:
- Determination of the regional pattern of atmospheric immissions;
- Registration of heavy metals in soil and vegetation;
- Soil compaction, soil erosion;
- Study of stress indicators in the aeration zone and in the top-most aquifer in order to examine barrier effects in the percolation process.
12.
Dr. Elmar Sabelberg 《GeoJournal》1986,13(1):59-66
The “South-Italian city” is characterized at four different levels as an independent cultural-genetic city-type:
- The characteristics arrangement of the functional areas and the residential areas of different social groups is represented in a model.
- From the model, developments and changes in the arrangement of the functional areas can be identified which clearly deviate from those which are derived from the universal city model.
- Some of the structural individuality can be directly explained by the peculiar features of the respective social and economic history.
- Some of the special features must, however, be traced back to a wider historico-cultural background. Through this run processes which flow through the universal city development in similar forms, to the deviating structure of the “South-Italian city”.
13.
Systematic natural hazard mapping in Japan was started after WW II using aerial photographs. Analysing the interaction between disaster occurrence and land conditions is the most useful method for establishing the disaster prediction system for three types of disaster, flood disaster, mass-movement disaster, and earthquake disaster, which are strongly related to land conditions. A series of maps on natural hazards were established based on the results analysed. In our opinion, the following problems of natural hazard mappings remain so far unsolved:
- No clear distinction is made between natural hazard mapping and land classification.
- Organization of information for natural hazard prevention is not yet established.
- There is no established earthquake disaster prevention map.
- Utilization of new machines and tools is inadequate.
- Effect of human activity is not estimated.
14.
Concordant granite sheets from the granulite facies Scourian Complex, N.W. Scotland exhibit the following features:
- a common planar fabric with their host pyroxene granulites;
- the presence of an exsolved ternary feldspar phase;
- a low-pressure, water-saturated minimum composition;
- K/Rb ratios (450–1,350) distinctly higher than most upper crustal granites but similar to the surrounding granulites;
- low absolute concentrations of the rare earth elements (REEs), light REE enrichment, and large positive Eu anomalies.
15.
According to Sakai-Ohmoto's theory regarding the evolution of sulfur isotopes in hydrothermal systems, in conjunction of new data on chemical resaction equilibrium constants and equilibrium isotopic fractionation factors as well as on individual ion activity coefficients of aqueous sulfur species, the following lgfo2.-pH diagrams are constructed:
- mole fractions of aqueous sulfur species (X i ),
- stability fields of some minerals in the Fe-S-O system,
- diagram depicting the oxidation-reduction-state ratio for aqueous sulfur species (R′)
- isotopic compositions of sulfur compounds ( \(\delta S_1 ^{34} \) ).
16.
Massive sulfide deposits located on Hercynian islets of northwestern Morocco exhibit four main characteristics: They are strata-bound massive pyrrhotite deposits mined for sulfur and/or base metals occasionally occurring as sulfides of workable grade. Volcanic rocks with which these massive sulfide orebodies are associated are scarce, although always present as acid flows of submarine emissions of either rhyolitic or more often quartz-keratophyric nature. Later on, basic plutonics intruded the pelitic country rocks. Stockworks underlying the massive sulfide orebodies are common, but not systematic. When present, they occur in siltite ± phyllite ± carbonate rocks at the wall of massive sulfide lenses. They consist of fissural disseminations transformed by epimetamorphic recrystallization and by one schistosity generally concordant with s0. Associated alterites and exhalites belong to three types, i.e., sericitite (or biotite-rich rock), chloritite, and/or chert (jasper). Generally well located in a back-arc basin environment characterized by a two-phase geological history, i.e., “extension and volcanism, compression and metamorphism”, these volcano-sedimentary deposits exhibit distal features with regard to the volcanism coeval with their sedimentation. They are mostly linked with strongly reducing environmental properties entailing pyrrhotite and/or magnetite syngenetic deposition, whatever the iron activity. 相似文献
17.
Laihunite Research Group 《中国地球化学学报》1982,1(1):105-114
Laihuite reported in the present paper is a new iron silicate mineral found in China with the following characteristics:
- This mineral occurs in a metamorphic iron deposit, associated with fayalite, hypersthene, quartz, magnetitc, etc.
- The mineral is opaque, black in colour, thickly tabular in shape with luster metallic to sub-metallic, two perfect cleavages and specific gravity of 3.92.
- Its main chemical components are Fe and Si with Fe3+>Fe2+. The analysis gave the formula of Fe Fe 1.00 3+ ·Fe 0.58 2+ ·Mg 0.03 2+ ·Si0.96O4.
- Its DTA curve shows an exothermic peak at 713°C.
- The mineral has its own infrared spectrum distinctive from that of other minerals.
- This mineral is of orthorhombic system; space group:C 2h /5 ?P21/c; unit cell:α=5.813ű0.005,b=4.812ű0.005,c=10.211ű0.005,β=90.87°.
- The Mössbauer spectrum of this mineral is given, too.
18.
Following a tentative evaluation of palynological information from Ladinian and, more particularly, Karnian successions, there seems to be every indication that qualitative and quantitative compositional differences of palynological assemblages could well be applied in testing concepts of Triassic phytogeography and palaeoclimatology. The following implications are emphasized:
- There is sufficient palynological evidence that the Mediterranean region includes a domain of mixed northern (Laurasian) and southern (Gondwana) types of floras.
- The concept of an essentially arid nature of a wide equatorial climatic belt during Triassic times finds palynological support.
- Palynological evidence does not contradict a concept of pronounced decrease in precipitation towards the western part of the Mediterranean region.
- In Europe, occurrences of hygrophytic palynofloras and coals within an arid climatic zone can be explained by the water-supply of extensive river-systems.
19.
Geological and geochemical characteristics of REE iron formation (REEIF), a term proposed by Prof. Tu Kuang-chih to specify a special type of Precambrian iron formations rich in REE, are discussed in this paper with special reference to its REE contents, REE distribution patterns, the formation mechanism, the relationship between its development and the multi-stage evolution of the continental crust in China, and the implications of REE as an indicator of oxidation state for ancient atmosphere. Major conclusions are outlined as follows:
- REEIFs are characterized by high REE concentrations against the very low REE levels in normal Precambrian iron formations.
- REEIFs are formed by marine sedimentary-diagenetic processes in miogeosynclines or transition zones during Proterozoic times To some extent, volcanic activity may play an important role in the deposition of ore-forming materials. In a broader sense, REEIFs belong to Fe-bearing dolomite formations. Most REEIFs in China may be superimposed by late geological processes such as hydrothermal-metasomatism, migmatization and metamorphism. Generally, REEIFs have much in common with stratabound ore deposits in respect to their characteristic features.
- Similar to Precambrian iron formations, REE are enriched in LREE. But, the degree of LREE enrichment is noticed to increase of total REE content. Most REEIFs are characterized by high ratios of σ Ce/σY, (Mg+Fe)/Ca, Na/K, Nb/Ta, Zr/Hf, Th/U, Ba/Sr, etc.
- The extensive occurrence of REEIFs indicates higher REE abundance in the continental crust of China, thus lending further support to the multi-stage theory regarding the evolution of chemical elements and the differentiation in the continental crust of China.
- Preliminary data seem to support the time-dependence of REE distribution patterns and relative Eu contents of REEIFs in China.
20.
In Hungary loess has long been used for soil reclamation. The main steps of the method are: horizon A and B are removed from a suitable area and their material is stockpiled at the margins of the resulting pit. The loess (horizon C), this way exposed, is excavated and spread over the salt affected soils to be improved then mixed with their upper layer. The pit is named in Hungarian digó (pit). The name of the reclamation process is the digo method or spreading of yellow earth. Digó method is mainly used for the amelioration of salt affected soils with an acid A horizon and its benefits are as follows:
- The acidity of the horizon A is eliminated
- The soil structure is improved
- The amount of calcium (a plant nutrient) is increased
- Soil fertility is improved continuously
- The soil depth is extended which adds to the relative volume of the ground water table.