2. On the Laws of Structure of the more disturbed Zones of the Earth's Crust.

1857 ◽  
Vol 3 ◽  
pp. 378-390
Author(s):  
H. D. Rogers
Keyword(s):  
Earth’S Crust ◽  
General Proposition ◽  
The Subject ◽  
Earth's Crust

After adverting to previous publications on the subject by himself and Professor W. B. Rogers, the author of the paper began the enunciation of the laws of structure of disturbed tracts of strata, by stating the general proposition that in all districts where thestrata have been displaced from the original positions or levels in which they were deposited, they invariably have the form of one or many waves, even where, from a flatness of the undulations, they seemed to retain their original horizontality.

On a possible geological cause of changes in the position of the axis of the earth's crust

1867 ◽  
Vol 15 ◽  
pp. 46-54 ◽  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Earth’S Crust ◽  
The Subject ◽  
Earth's Crust ◽  
Geological Observation

At a time when the causes which have led to climatal changes in various parts of the globe are the subject of so much discussion, but little apology is needed for calling the attention of this Society to what possibly may have been one of these causes, though it has apparently hitherto escaped observation. That great changes of climate have taken place, at all events in the northern hemisphere of the globe, is one of the best established facts of geology, and that corresponding changes have not been noticed to the same extent in the southern hemisphere may possibly be considered as due, rather to a more limited amount of geological observation, than to an absence of the phenomena indicative of such alterations in climatal con­ditions having occurred.

scholarly journals On the agency of water in volcanic eruptions; with some observations on the thickness of the Earth's crust from a geological point of view; and on the primary cause of volcanic action

1887 ◽  
Vol 41 (246-250) ◽  
pp. 117-173 ◽  
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruptions ◽  
Point Of View ◽  
Earth’S Crust ◽  
Difference Of Opinion ◽  
Established Fact ◽  
The Subject ◽  
Earth's Crust

The important part played by water in volcanic eruptions is a well recognised and established fact, but there is great difference of opinion among geologists as to whether water should be considered the primary or secondary agent, and as to the mode, time, and place of its intervention. The prevailing opinion in this country is that water is the primary cause of volcanic activity. Whichever view may be adopted, the subject is one which is so largely concerned with the laws regulating the underground circulation of water, that the consideration of the two questions must proceed pari passu .

scholarly journals On the susceptibility of feebly magnetic bodies as affected by compression

1922 ◽  
Vol 101 (712) ◽  
pp. 445-452 ◽  
Keyword(s):  
Mechanical Stress ◽  
Compressive Stress ◽  
Cross Section ◽  
Complex Problem ◽  
Earth’S Crust ◽  
The Subject ◽  
Earth's Crust ◽  
Rock Specimens

This communication undertakes an investigation of the complex problem which is presented by the effects of mechanical stress upon the susceptibility, retentivity and other properties of magnetic substances. The present experiments are confined to compressive stress, and its effects upon the susceptibility of certain rock specimens. It was felt that an investigation into this part of the subject might possibly throw some light upon the susceptibility of the earth’s crust as affected by the enormous forces with which it has to contend, and their variations. It is unfortunate that, owing to the nature of rock specimens, the compressive stress has been limited to about 1200 kgrm. per square centimetre, but, nevertheless, some interesting results have been obtained, and these are recorded in the present paper. All the specimens are in the form of short bars about 4 cm. in length, whose cross-section is either square, being 1 cm. across each side, or 1 cm. in diameter; and, throughout the work, the compressive stress has been applied in the direction coinciding with the length of the bar. The susceptibility has been measured ( a ) in the direction of the stress and ( b ) at right angles thereto.

scholarly journals Hazardous geological processes in the conditions of technogenesis of the earth's crust: threats of disruption to the life of the population and deterioration of the environment

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Antonina Suzdaleva ◽  
Maria Kuchkina ◽  
Jargalsaihan Bolortuya
Keyword(s):  
Large Scale ◽  
Earth’S Crust ◽  
Geological Environment ◽  
Data Set ◽  
Geological Processes ◽  
Natural Rock ◽  
The Subject ◽  
Earth's Crust ◽  
Foreign Materials ◽  
Waste Accumulation

Technogenic transformation of the earth's crust leads to the formation of new geological bodies in it. They differ from natural rock mass by significantly lower stability and higher mobility. For this reason, the risk of dangerous phenomena increases sharply in the areas occupied by technogenic geological bodies. The study of the general patterns of development of the consequences of the lithosphere technogenesis was carried out on the basis of an analysis of an extensive data set. The subject of the study was simultaneously the processes of formation of new structures in the earth's crust and the dangerous consequences of their occurrence. The structure and dynamics of technogenic geological bodies are significantly different than those of elements of the natural geological environment. This necessitates the development of new methodological approaches to their study. There are two main categories of technogenic bodies: firstly, accumulations of various foreign materials located in the earth's crust or on its surface and, secondly, transformed rocks. In both cases, the emergence of technogenic geological bodies poses a threat to the population and the environment. As the analysis of the research results showed, the greatest danger was a decrease in the density of the transformed geological environment and the formation of karsts. Landslides, mudflows and collapses were also forming in places of large-scale waste accumulation. Even more catastrophic consequences were causing by earthquakes determined by the technogenic transformation of the geological environment.

scholarly journals II.—On Faults in Strata

1869 ◽  
Vol 6 (62) ◽  
pp. 341-347
Author(s):  
Henry B. Medlicott
Keyword(s):  
Structural Features ◽  
Earth’S Crust ◽  
Geological Survey ◽  
Rock Series ◽  
Experimental Field ◽  
History Of ◽  
The Subject ◽  
Earth's Crust

A Little time back there appeared in the Magazine, some short papers on the subject of faults, and on the nature of the conditions and the forces through which these important structural features may-have been produced. The points I would now bring to notice are more elementary; they refer to the evidence for faults; hence involving the principal data upon which the higher discussion of the phenomena must be based, and the same data very argely affect our attempted restoration and history of bygone phases of the earth's surface. Faults and flexures in stratified rocks are the leading features through which we interpret the disturbances that have affected the earth's crust; and any looseness in determining their existence, form and amount, must vitiate many of our inferences. No one but an experimental field geologist can appreciate the difficulty of such determinations, and understand how faults are particularly liable to elude observation. This circumstance accounts for, but does not justify, the arbitrary use of faults in interpreting sections. To call in question the evidence upon such a familiar subject implies, of course, dissatisfaction at the manner in which it is handled in practice. This I at once admit, and will proceed to explain. The criticism I have to make is no more than might oceur to one who had never left his study; but I would state that with me it has had a most practical origin: in the progress of the work of the Geological Survey of India, several great boundary faults have been proposed in connection with our main rock-series, and in some cases published descriptions have been already given; but both on the score of the in-sufficiency of the evidence brought forward, and after personal examination in the field, I am unable to admit that some of the features in question can, without very implicit qualifications, be brought within the received definitions of a fault.

III.—Hot Springs

1904 ◽  
Vol 1 (6) ◽  
pp. 252-260 ◽  
Author(s):  
Ernest H. L. Schwarz
Keyword(s):  
Surface Waters ◽  
Full Text ◽  
Hot Springs ◽  
Earth’S Crust ◽  
The Public ◽  
The Earth ◽  
Long Time ◽  
The Subject ◽  
Earth's Crust

Through the great kindness of Professor Suess I have received the full text of his paper on Hot Springs, read before the Congress of Naturforscher und Aerzte held last year in Karlsbad, in which he adduces very strong arguments in favour of their being due to vapours given off from the molten interior of the earth as it gradually cools. I have for a long time been observing the hot springs that occur in the Cape Colony, and had come to the conclusion that they were surface-waters that had sunk deep into the earth's crust, and were returned heated in consequence of their having been in the neighbourhood of potential fusion of the rocks. This latter view I alluded to in a recent paper, and I do not like to have to give up a long-cherished idea before submitting to the public a statement of the reasons that led me to my view of the subject.

III.—The Relationship of Isostasy, Earthquakes, and Vulcanicity to the Earth's Infra-Plutonic Shell

1914 ◽  
Vol 1 (2) ◽  
pp. 65-67 ◽  
Author(s):  
L. Leigh Fermor
Keyword(s):  
High Pressures ◽  
Earth’S Crust ◽  
Dominant Factor ◽  
Sufficient Degree ◽  
The Subject ◽  
Earth's Crust ◽  
Mineral Transformations ◽  
Relationship Of ◽  
The Relationship ◽  
The Himalaya

The recent discussion on the origin of the Himalaya, initiated by Colonel S. G. Burrard in his paper “On the Origin of the Himalaya Mountains”, has centred in the theories of isostasy and mountain compensation advocated by the Rev. O. Fisher and Mr. J. F. Hayford.In his latest contribution to the subject Colonel Burrard states very clearly the problem of isostasy now requiring solution—“Continents and mountains have been found to be compensated by underlying deficiencies of density; how has this condition resembling hydrostatic equilibrium arisen upon a solid globe of rock?”In a recent paper I have advanced reasons for believing in the existence in the earth's crust at a certain depth, at present unknown, of a highly garnetiferous shell of rock, for which the name infra-plutonic zone or shell is suggested. This zone is situated at such a depth that pressure becomes a dominant factor in mineral transformations, the accompanying high temperature ensuring a sufficient degree of molecular mobility. It is suggested that under the influence of these high pressures (and temperatures) reactions will ensue between the various ferromagnesian silicates—micas, amphiboles, pyroxenes, olivines—and anorthite felspar, with the formation of garnet as a characteristic mineral: the reason assigned is that a reduction of volume accompanied by an absorption of heat is thereby effected, it being accepted that the garnet-forming reactions are endothermic.If one can accept the philosophical necessity for the existence of this infra-plutonic shell, then some theory of isostasy seems logically to follow, with the garnetiferous plastic-solid shell as the cushion upon which the isostatic adjustments of the earth's crust have their foundation.

Tides in the Earth's Crust

1915 ◽  
Vol 79 (2058supp) ◽  
pp. 382-383
Author(s):  
Alphonse Berget
Keyword(s):  
Earth’S Crust ◽  
Earth's Crust
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