Analysis of stress and failure in rock specimens with closed and open flaws on the surface

Author(s):  
Amin Manouchehrian ◽  
Pinnaduwa H. S. W. Kulatilake
Keyword(s):  
Author(s):  
L. Montoto ◽  
M. Montoto ◽  
A. Bel-Lan

INTRODUCTION.- The physical properties of rock masses are greatly influenced by their internal discontinuities, like pores and fissures. So, these need to be measured as a basis for interpretation. To avoid the basic difficulties of measurement under optical microscopy and analogic image systems, the authors use S.E.M. and multiband digital image processing. In S.E.M., analog signal processing has been used to further image enhancement (1), but automatic information extraction can be achieved by simple digital processing of S.E.M. images (2). The use of multiband image would overcome difficulties such as artifacts introduced by the relative positions of sample and detector or the typicals encountered in optical microscopy.DIGITAL IMAGE PROCESSING.- The studied rock specimens were in the form of flat deformation-free surfaces observed under a Phillips SEM model 500. The SEM detector output signal was recorded in picture form in b&w negatives and digitized using a Perkin Elmer 1010 MP flat microdensitometer.


2013 ◽  
Vol 49 (5) ◽  
pp. 677-690 ◽  
Author(s):  
V. N. Oparin ◽  
O. M. Usol’tseva ◽  
V. N. Semenov ◽  
P. A. Tsoi

1916 ◽  
Vol 3 (10) ◽  
pp. 435-441 ◽  
Author(s):  
G. W. Tyrrell

The new material on which this paper is based has lately been received through Mr. D. Ferguson, who recently investigated the geology of the island, and collected the rocks described in an earlier paper. It consists of twenty-seven rock specimens from the south-eastern end of the island, between Cape Disappointment and Cooper Island, and nine specimens from Gold Harbour on the north-east coast between Cooper Island and Royal Bay. All these were collected by the staff of the South Georgia Co., Ltd., under the instructions of Mr. Th. E. Salvesen, managing director, of Leith.


2019 ◽  
Author(s):  
Yu. P. Stefanov ◽  
A. S. Romanov ◽  
R. A. Bakeev

1989 ◽  
Vol 26 (1) ◽  
pp. 88-105 ◽  
Author(s):  
Stavros I. Kalogeropoulos ◽  
Steven D. Scott

The Main Contact Tuff, in the vicinity of Millenbach mine, Noranda, Quebec, is an extensive, although discontinuous, ore-related volcanic exhalative metalliferous sediment, or "tuffaceous exhalite," of Archean age. It was formed by the variable contribution of two constituents: (1) exhalite (chemical) composed mainly of pyrite, quartz, sphalerite, pyrrhotite, and chalcopyrite and (2) tuff (clastic) composed of quartz, chlorite, and sericite.Tuffaceous exhalites such as the Main Contact Tuff and the similar tetsusekiei of the Japanese Kuroko deposits (Miocene age) indicate a fossil hydrothermal system that may or may not have produced economic concentrations of metallic sulfides. The Main Contact Tuff displays cryptic variations, which provide exploration guides at different scales: (1) the Fe/[Fe + Mg] ratios of chlorite decrease from 0.63 to 0.32 over a distance of 0.3 km approaching ore from the north, and from 0.72 to 0.32 over 1.5 km from the south; (2) the FeO/[FeO + MgO] (sulfide-free) ratios of whole-rock specimens decrease from about 0.8 to 0.3 approaching the ore; (3) ilmenite is replaced in the ore zone by rutile and (or) sphene; and (4) the most manganiferous ilmenite is found close to ore. On the other hand, trace elements of exhalative origin (e.g., Ag, Co) in the Main Contact Tuff appear not to provide useful vectors towards ore. They are concentrated relative to normal pelagic rocks, but their distributions with respect to ore are complicated by multiple input sources and postexhalative redistributions of elements.


Geophysics ◽  
1981 ◽  
Vol 46 (5) ◽  
pp. 806-808 ◽  
Author(s):  
N. C. Dutta

In the petroleum industry there is considerable current interest in understanding the causes of seismic energy loss. During the past few years, considerable progress has been made in the field of seismic wave attenuation as a result of both controlled laboratory studies of the static and the dynamic properties of rock specimens and theoretical modeling. During the 49th Annual International Meeting of the Society of Exploration Geophysicists in New Orleans, a research workshop on Seismic Loss Mechanisms was organized. The purpose of this workshop was to assess current understanding of the physical processes that cause attenuation of seismic energy. The workshop, organized by Kenneth Larner of Western Geophysical and the author, featured a multispeaker format involving invited papers from both industry and academia. The presentations were followed by discussions lasting approximately 90 minutes which included the speakers, the audience, and a panel of experts in the field of seismology.


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