Upper mantle rocks from basalts of the northern Hessian depression (NW Germany)     

J. Oehm  A. Schneider  K. H. Wedepohl 《Mineralogy and Petrology》1983,32(1):25-48

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Geochemistry of modern seawater and brines from salt pans: Main components and bromine distribution     

Albert Günter Herrmann  Doris Knake  Jürgen Schneider  Heide Peters 《Contributions to Mineralogy and Petrology》1973,40(1):1-24

Seawater at different stages of evaporation from the salt works of Seovlje near Portoro (Yugoslavia) was analyzed geochemically. The seawater there passes through 20 stages of concentration until the first halite crystallizes. All important parameters were determined at all stages: concentrations of Cl, SO₄, Na, K, Ca, Mg, and Br, temperature, pH, Eh, oxygen content and titration alkalinity. With increasing evaporation calcium carbonate crystallizes first followed by calcium sulphate as gypsum and after these halite. All three components crystallize from supersaturated solutions. The pH of the initial seawater is 8.32; it falls abruptly to 6.65 when the first calcium carbonate precipitates. Eh in the original seawater is +393 mv; negative values were found in the halite crystallization pans, which contain an anaerobic mud as a reducing agent. The oxygen content of the solution decreases parallel to the drop in Eh. In the pans in which NaCl crystallizes Eh is zero. Apparently the mud also adsorbs K, as can be inferred from a change in the Mg/K ratio.The bromine partition between crystallizing halite and the brine in the salt pans of Seovlje is discussed with regard to some genetic problems of marine salt deposits. In the conditions in the salt pans the bromine partition coefficient at the beginning of NaCl crystallization from seawater—expressed as b=wt.-% Br (mineral)/wt.-% Br (solution)—is 0.12 to 0.14 or—expressed as D=Br/Cl(mineral)/Br/Cl(solution)—0.030 to 0.034 at temperatures between 33° C and 42° C. The conclusion is that a Br content of about 60 to 75 ppm is to be expected for the first halite that crystallizes from evaporating seawater.  相似文献   

The theory of motion of the horizontal pendulum with a Zöllner suspension and some indications for the instrumental design     

Petr Vaníček  Geoffrey W. Lennon  Reviewer M. Schneider  Reviewer L. Skalský 《Studia Geophysica et Geodaetica》1972,16(1):30-50

Summary The aim of this paper is to examine the physical laws which govern the motion of a horizontal pendulum, mounted with the familiar Zöllner suspension geometry and to establish the equations of its motion. It is possible in this process to determine calibration parameters with greater precision and confidence and to demonstrate that procedures based upon period measurement can inherently claim a precision superior to some modern alternatives. Moreover in approaching the problem from a theoretical viewpoint it is possible to pinpoint those features of design which give rise to the troublesome aberrations. This facility makes it possible to comment upon design improvements so that a closer approach may be made to an ideal instrument.  相似文献   

Die Minas-Gruppe in Nordost-Bahia,Brasilien     

Dr. Heinz Jordan 《International Journal of Earth Sciences》1972,61(2):441-469

Zusammenfassung Die Quarzite und Phyllite der präkambrischen Serie Jacobina, deren geologische Beziehung zum umgebenden hochmetamorphen Kristallin bisher ungeklärt war, wurden in verschiedenen Teilgebieten kartiert und petrographisch untersucht. Im Gebiet von Juacema (Abb. 1) bildet die Serie Jacobina den Westflügel einer fast isoklinalen, schwach westvergenten Mulde. Sie wurde Jacobina-Synklinorium genannt und erstreckt sich vom Rio São Francisco im Norden rund 300 km weit nach Süden (s. Abb. 3 und 6). Auf dem Ostflügel der Mulde sind die Phyllite durch Kalifeldspatisation granitisiert worden (Reliktgefüge!); die eingeschalteten Quarzite sind denen der Serie Jacobina im sedimentären Mineralbestand, z. B. der Turmalin- und Hämatitführang, sehr ähnlich. Im Gebiet von Campo Formosa (Abb. 2) konnte nachgewiesen werden, daß die Serie Jacobina mit der Serie Lavras stratigraphisch identisch ist: Die Abfolge der Formationen Rio do Ouro — Cruz das Almas — Serra do Meio (der Serie Jacobina) entspricht der Abfolge Tombador — Caboclo — Morro do Chapéu in der Serie Lavras. Beide Serien müssen damit altersmäßig in die Minas-Gruppe eingestuft werden.Im nördlichsten Bahia wurde eine Quarzit-Paragneis-Gruppe vom älteren Kristallin abgegliedert und nach dem Ort Ibó benannt. Sie scheint im Westen—über einen Quarzitzug nordwestlich von Poço de Fora — mit dem Jacobina-Synklinorium Verbindung zu haben (s. Abb. 6). Auch gemeinsame Merkmale in der Lithologie und im tektonischen Bauplan deuten darauf hin, daß die Ibó-Gruppe ebenfalls ein Äquivalent der Minas-Gruppe ist. An dem über 200 km langen Quarzitzug von Orocó-Caldeirão läßt sich zeigen, daß die Minas-Paragneise nach Süden in hochkristalline Gneise und Migmatite übergehen: eine Trennung der Minas- und prä-Minas-Gneise ist hier kaum noch möglich. Diese und andere Beobachtungen beweisen, daß die als Caraiba-Gruppe bezeichneten alten Gneise Nordbahias bedeutende Anteile von hochmetamorphem Minas miteinschließen.Jedenfalls scheint die Minas-Gruppe im gesamten Raum Nordost-Bahias abgelagert worden zu sein. In den untersuchten Gebieten folgt meist auf eine quarzitreiche untere Subgruppe eine obere Subgruppe mit Metapelit und Metaarkose (s. Abb. 7); am Übergang treten hämatitreiche Gesteine auf. Der Metamorphosegrad der Minas-Schichten ist gebietsweise sehr unterschiedlich: Während im Westen, im Salitre-Becken, die Schichten fast unmetamorph sind, wurden die Pelite und Arkosen weiter östlich in Biotitgneis oder auch Migmatit und Diatexit (bis Granit) umgewandelt. Die Grenze der zwei Metamorphosebereiche wird durch die Phyllite und Grünschiefer der Serie Jacobina markiert.

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The quartzites and phyllites of the Precambrian Jacobina Series whose geological relations to the high-metamorphic rocks in the east were unknown until now, were mapped and petrographically examined in various areas. In the Juacema area (fig. 1) the Jacobina Series forms the western limb of an eastward dipping syncline. Almost isoclinal it stretches from Rio São Francisco in the north for about 300 km to the south (see fig. 3 and 6) and was called Jacobina Synclinorium. The phyllites on the eastern limb of the syncline are granitized by kalifeldspatization (visible by relic textures). The quartzites following the eastern limb, in mineral composition, as to the accessory content of turmaline and hematite, are very similar to those of the Jacobina Series.In the Campo Formosa area (fig. 2) the stratigraphic identity of the Jacobina and Lavras Series was proved. The division of the Jacobina Series into the formations Rio do Ouro — Cruz das Almas — Serra do Meio corresponds to that of the Lavras Series into Tombador — Caboclo — Morro do Chapéu. So both these series are seen as equivalents of the Minas Group.In the most northern part of Bahia a quartzite paragneiss group was divided from the crystalline basement and called after the village of Ibó. In the west this same group seems to join to the rocks of the Jacobina Synclinorium (see fig. 6); similar lithological and tectonical characteristics furthermore indicate the stratigraphic equivalence of the Ibó and the Minas Group. Along the Orocó-Caldeirão quartzite range was shown that the Minas paragneisses to the south are transformed into granitic gneisses and migmatites: Here the separation from pre-Minas gneisses is scarcely possible. This and further observations prove that the ancient gneisses of northern Bahia, subsumed under the name Caraiba Group, are including big parts of high-metamorphic Minas rocks.The Minas Group evidently has been deposited in whole north-eastern Bahia. In the examined areas the group mostly exists of a basic subgroup rich in quartzites and an upper one of metapelites and metaarkoses (fig. 7). Near the transition of the two subgroups rocks rich in hematite occur. The metamorphic grade of the rocks is greatly different from region to region. Whilst the Minas Group in the west, i.e. the Lavras Series in the Salitre Basin, is almost unmetamorphous, the pelites and arkoses farther to the east are transformed to biotite gneiss up to migmatite and granite. The limit between the two metamorphic zones is marked by the phyllites and greenschists of the Jacobina Series.

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Resumo Os metasedimentos da Série Jacobina foram mapeados e petrograficamente examinados en várias áreas escolhidas. Na área de Juacema (fig. 1) a Série Jacobina constitui o flanco occidental de um sinclinal quasi isoclinal, com vergência fraca para oeste. Foi denominada de Sinclinório de Jacobina e estende-se do Rio São Francisco no norte acerca de 300 km para o sul (veja fig. 3 e 6). No flanco oriental do sinclinório os filitos foram granitizados devido à felspatização potássica, como se verifica microscopicamente pelas estruturas internas conservadas. Os quartzitos intercalados nas rochas granitizadas, com respeito à composição primária sedimentar (conteudo accessórico de turmalina e hematita, etc.), são muito semelhantes aos quartzitos da Série Jacobina, e estratigraficamente correspondem a êstes.Na área de Campo Formoso (fig. 2) foi demonstrada a correlação estratigrafica das Séries Jacobina e Lavras; o perfil Formação Rio do Ouro — Cruz das Almas — Serra do Meio (da Série Jacobina) corresponde ao perfil Tombador — Caboclo — Morro do Chapéu na Série Lavras. As duas séries igualmente são equivalentes ao Grupo Minas.No extremo norte da Bahia foi mapeado um grupo quartzito-paragnaissico, denominado pelo nome da vilo Ibó. No oeste êste grupo parece ser ligado às rochas do Sinclinório de Jacobina, por uma faixa de quartzitos ao noroeste de Poço de Fora (veja fig. 6). O comportamento igual da litologia e tectônica confirma a correlação estratigráfica do Grupo Ibó e da Série Jacobina e Minas respectivamente. Ao longo de uma faixa de quartzitos, estendo-se de Orocó/Pe até Caldeirão/Ba, indicado pelas fig. 4 e 6, foi comprovado que, os paragnaisses do Grupo Minas se transformam para sul em gnaisses intensamente metamórficas e em migmatitos — petrograficamente idênticos às rochas cristalinas pre-Minenses. Esta e outras obvervações demonstram que, os gnaisses antigos reunidos sob o nome de Grupo Caraiba incluem grandes partes de rochas altamente metamórficas do Grupo Minas.O Grupo Minas evidentemente foi depositado em toda parte nordestina do Estado da Bahia. Nas áreas examinadas geralmente um subgrupo characterizado por quartzitos é sobrepôsto por um subgrupo de metapelitos e metaarcóseos (fig. 7). Perto da transição dos dois encontram-se rochas hematitíferas.O grau do metamorfísmo dos metasedimentos varía: Ao oeste, na Bacia de Salitre, o Grupo quasi não foi metamorfizado — a leste da Serra de Jacobina os pelitos e arcóseos foram transformados em gnaisses á biotita, migmatitos e até granitos. Os filitos e xistos verdes da Série Jacobina marcam o limite das duas zonas metamórficas.

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Jacobina, , . - Juacema (. 1) Jacobina - . Jacobina, Ri Sao Francisco 300 (. 3 6). ( ). , , Jacobina, . . . Campo Formoso (. 2) , Jacobina Lavras: Rio do Ouro — Cruz das Almas — Serra do Meiro ( Jacobina) Tombador — Caboclo — Morro do Chapeu Lavras. Minas. Bahia — Ibo'. , - de Fora — Jacobina (. 6). , Ibo'. Minas. Oroco-Cal deirao , 200 , Minas : Minas -Minas . , hi, raiba Minas. , , Minas. (. 7); . Minas : , Salitre , -, ( ). Jacobina.

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Ein Gerät zur Entnahme ungestörter Sediment-Grossproben in Seen     

Heinz Ambühl 《Aquatic Sciences - Research Across Boundaries》1969,31(1):132-140

Summary A new method is described for taking sediment sample cores of a diameter of 112 millimeters from deep lakes. The rather large core diameter requires a mechanism which closes the lower end of the core before retraction so that the core can be raised without loss of the sample. The apparatus is set on to a cutting table on which the core, still in the tube, is separated from the closing mechanism without disturbance by means of a blade. The bottom end of the tube is then secured and the corer can be re-used with a new core tube.   相似文献   

Frequency of dry and wet spells in san salvador     

Heinz Dieterichs 《Pure and Applied Geophysics》1956,33(1):267-272

Summary A study of the daily rainfall in San Salvador (El Salvador) has been made over a thirty year period 1918–47 in order to determine the dry and wet spells. It has been found that the extreme dry spells on the Pacific Coast of Central America last longer than in other climates, examined byHuttary. The occurrence of a dry spell in San Salvador lasting over half a year is being minutely examined, and the cause of its origin traced to orographic effects during northerly winds.

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Resumen Se estudiaron las observaciones diaras de la precipitación en San Salvador (El Salvador), realizadas en los aňos 1918–47. Resulta que en la costa Pacifica Centroamericana los períodos secos duran más que los períodos más largos en los climas estudiados porHuttary. Un período seco que duró más de medio aňo en San Salvador se analiza detenidamente, se supone que éste se habría originado en influencias orográficas efectivos cuando hay viento del norte.

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Dr.Heinz Dieterichs, Jefe meteorólogo en el Servicio Meteorológico Nacional de El Salvador,San Salvador (El Salvador, Central America).  相似文献   

Organic compounds in the early atmosphere formed abiotically from atomic carbon     

Prof. Dr. Friedemann Freund  Dipl. Min. Rolf Knobel  Dr. Heinz Wengeler  Dipl. Min. Hendrik Kathrein  Dipl. Min. Gert Oberheuser  Dr. Rainer G. Schaefer 《International Journal of Earth Sciences》1982,71(1):1-21

The recent discovery that atomic carbon occurs plentiful in olivines from mantle-derived rocks opens new aspects for the chemical evolution of the early atmosphere and the origin of life. It has been shown conclusively that atomic carbon which is dissolved in the model oxide MgO is capable of reacting in an O₂-free atmosphere with the lattice oxygen to give CO₂ and with the lattice hydrogen, derived from OH^–, to give a profuse variety of hydrocarbons.The diffusional processes and low temperature gas/solid interface reactions involved in these processes are expected to introduce, purely abiotically, isotope fractionation resulting in a¹³C enrichment of the CO₂ fraction and in a¹³C depletion of the hydrocarbon fraction which may be confused with the¹²C/¹³C isotope fractionation along biological pathways.Atomic carbon dissolved in olivines and in basalts shows a similar behaviour and yields similar quantities as C in MgO: 1–2 mg/g CO₂ and 25–100g/g hydrocarbons degassing between 400 and 1000 °C. On a geological scale this means that each cubic kilometer of basaltic magma degassing in an O₂-free atmosphere has the capacity of sending off about 3–6·10⁹ kg (2·10⁹ m³) of CO₂ and about 1–3·10⁸ kg (2·10⁸ m³) of hydrocarbons. The presence of water modifies the composition to give, among others, alcohols and organic acids.On the basis of these results we are led to the conclusion that the early atmosphere of the earth may have contained a very high concentration of abiotically formed organic compounds of great chemical complexity.

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Zusammenfassung Die Entdeckung des atomar gelösten Kohlenstoffs in Olivinen aus Mantelgesteinen führt zu neuen Vorstellungen über die Zusammensetzung der Uratmosphäre und Entwicklungsbedingungen des Lebens. Atomarer Kohlenstoff im MgO ist in der Lage, in einer O₂-freien Atmosphäre mit dem Gittersauerstoff zu CO₂ zu reagieren und mit dem aus OH^– stammenden Gitterwasserstoff eine große Vielfalt von organischen Verbindungen zu bilden.Diffusionsprozesse und Gas-Festkörper-Austauschreaktionen, die an diesen Reaktionen beteiligt sind, führen nach ersten Untersuchungen zu einer¹³C-Anreicherung im CO₂ und einer¹³C-Abreicherung bei den Kohlenwasserstoffen. Diese¹²C/¹³C-Fraktionierung ist gleichsinnig mit der biologischen¹²C/¹³C-Fraktionierung.Atomarer Kohlenstoff in Olivinen und Basalten zeigt ein sehr ähnliches Reaktionsverhalten wie im MgO und führt zu ähnlichen Reaktionsprodukten: 1–2 mg/g CO₂ und 25–100g/g Kohlenwasserstoffe zwischen 400–1000 °C. Übertragen auf geologische Verhältnisse bedeutet dies, daß jeder km³ eines entgasenden basaltischen Magmas 3–6·10⁹ kg (2·10⁹ m³) CO₂ und 1–3·10⁸ kg (2·10⁸ m³) abwüschen Kohlenwasserstoff abgeben kann. Die Anwesenheit von Wasser führt zur Bildung von Alkoholen und organischen Säuren. Diese Ergebnisse deuten darauf hin, daß die Uratmosphäre und die Ursuppe viel reicher waren als bisher angenommen an komplexen organischen Verbindungen, die rein thermisch entstanden sind.

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Résumé La découverte du carbone atomique dans les olivines du manteau entraîne de nouvelles idées sur la composition de l'atmosphère originelle et sur les conditions du développement de la vie. Comme l'est le cas pour le MgO, le carbone atomique dans les olivines est capable de réagir, dans une atmosphère exempte de O₂, avec l'oxygène du réseau cristallin en formant du CO₂, et avec l'hydrogène provenant des groupements OH^– du réseau, pour former une grande variété de composés organiques.Les processus de diffusion et d'échange gas-solide liés à ces réactions provoquent, d'après les premiers résultats, un enrichissement en¹³C dans le CO₂ et un appauvrissement en¹³C dans les hydrocarbures formés. Ceci ressemble au fractionnement dû à des réactions biologiques.Le comportement du carbone atomique et sa réactivité se retrouvent dans les basaltes et les olivines. La gamme des produits de réaction et leur quantité ressemble à celle du MgO: 1–2 mg/g CO₂ et 25–100g/g composés organiques. A l'échelle géologique ceci implique que chaque km³ de magma basaltique dégazé en contact avec une atmosphère exempte d'oxygène pouvait émettre 3–6·10⁹ kg, soit 2·10⁹ m³ de CO₂ et 1–3·10⁸ kg, soit 2·10⁸ m³ d'hydrocarbures abiotiques. La présence d'eau entraîne la formation d'alcools et d'acides organiques.La conclusion tirée de ce travail indique que l'atmosphère originelle et la»soupe primordiale» étaient plus riches qu'on ne l'a admis jusqu'à présent en composés organiques dûs à des processus purement thermiques, et donc abiotiques.

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. MgO , COg, -, , . , , — — ¹³ ₂ . ¹²/¹³ , . , , - : 1–2 / O₂ 25–100 / , 400–1000 . , 3–6·109 (2·10^{9 3}) ₂ 1– 3·10⁸ (2·10^{8 3}) . . , , , , .

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Presented in part at the meeting Precambrian Problems, Copenhagen, March 1981.  相似文献   

Drought,demography, and destitution: Crisis in the Norte Chico   总被引：1，自引：0，他引：1  

Hans J. Schneider Dr. 《GeoJournal》1982,6(2):111-119

Growing population pressure, limited natural resources, and recurring droughts are thought to be the chief reasons for the socio-economic backwardness in the Norte Chico region of Chile (29 to 33^o S).Droughts occur with rather high statistical frequency; in recent decades they appear to have become even more frequent. Depletion of the already scant forest resources of the area occured during the nineteenth century, when most of the wooden species were used as firewood, charcoal or fuel for settlements, mines ans smelters. Also during that century, forests and shrubs were cut down in order to make room for wheat cultivatio. At the same time as agricultural exploitaion and mining intensified, increasing sheep and goat herding contributed further to the deterioration of the environment.Disputable is the assumption that the cause of the socio-economic depression in the Norte Chico is the population pressure on limited natural resources. Census figures reveal that the region has not been growing as fast as other regions in the country and that outmigration has constituted a constant demographic drain from the area. The cause for this migration has been not so much the environmental deterioration but the perpetuation of land tenure patterns that stress latifundia and minifundia without allowing for the development of independent mid-size agricultural establishments.To a large degree the backwardness of the Norte Chico is to be blamed not so much on the unwise exploitation of the resources but on the persisting patterns of economic exploitation and social structures.  相似文献   

The seismotectonic character of the September 3, 1978, swabian jura earthquake series     

J. Turnovsky  G. Schneider 《Tectonophysics》1982,83(3-4)

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Book reviews     

Lettau  Heinz H.  Munn  R. E.  Pack  Donald H.  Galloway  J. N. 《Boundary-Layer Meteorology》1983,26(1):99-102

Boundary-Layer Meteorology -  相似文献