Patterns of total strain in the crestal region of immature diapirs

1978 ◽  
Vol 15 (9) ◽  
pp. 1437-1447 ◽  
Author(s):  
W. M. Schwerdtner ◽  
R. H. Sutcliffe ◽  
Björn Tröeng
Keyword(s):  
Structural Analysis ◽  
New Brunswick ◽  
Total Strain ◽  
Gneiss Dome ◽  
Independent Evidence ◽  
Model Experiments ◽  
Quantitative Models ◽  
Strain Pattern ◽  
Northwestern Ontario

Conformable domes can result from diapirism as well as cross buckling and other types of cross folding. The total-strain pattern of natural structures offers a means of discriminating between diapiric domes and nondiapiric domes. Similarly, one may distinguish between diapiric ridges and other types of antiforms.Immature diapirs in metamorphic terrains and appropriate quantitative models are characterized by crestal zones of horizontal extension. Similar zones occur in the convex-hinge regions of very competent buckles and the adjacent incompetent matrix of fold models. But these model experiments are rarely applicable to natural buckle folds in metamorphic terrains, which typically involve low competency contrasts. Where upright buckle folds can be identified by means of independent evidence, their hinge zones are generally devoid of stratiform foliation and other features due to horizontal extension. An Archean gneiss dome of the northwestern Ontario is subjected to structural analysis, and interpreted as an immature diapir on the basis of widespread subhorizontal foliation about the dome's centre. The strain pattern of the gneiss dome corresponds to that of salt diapirs in New Brunswick.

La zonation structurale des dômes gneissiques. Un exemple : le massif de Saint-Malo (Massif armoricain, France)

1977 ◽  
Vol 14 (8) ◽  
pp. 1697-1707 ◽  
Author(s):  
Jean-Pierre Brun
Keyword(s):  
Structural Analysis ◽  
Dynamic Model ◽  
Experimental Models ◽  
Gneiss Dome ◽  
Gneiss Domes

The Saint-Malo massif provides an example of a gneiss dome with a migmatitic core. The results of a structural analysis are used to describe a structural zonation around the migmatitic core, and a dynamic model of the massif is proposed. A comparison of these results with experimental models of gneiss domes shows that this zonation is the product of diapirism.

THE EUROPEAN SKIPPER, THYMELICUS LINEOLA (LEPIDOPTERA: HESPERIIDAE), IN MANITOBA AND NORTHWESTERN ONTARIO

1981 ◽  
Vol 113 (12) ◽  
pp. 1123-1124 ◽  
Author(s):  
W. B. Preston ◽  
A. R. Westwood
Keyword(s):  
United States ◽  
British Columbia ◽  
Nova Scotia ◽  
North America ◽  
New Brunswick ◽  
Present Note ◽  
North Central ◽  
The North ◽  
Northwestern Ontario ◽  
Central United States

The spread of Thymelicus lineola (Ochsenheimer) in North America has been extensively documented (Rawson 1931; Clench 1956; Pengelly 1961; Arthur 1966; Burns 1966; McNeil et al. 1975; McNeil and Duchesne 1977). In Canada, T. lineola has been recorded from British Columbia, Ontario, Quebec, New Brunswick, Nova Scotia, Newfoundland, and now Manitoba (Gregory 1975; Jackson 1978). In the north central United States T. lineola has been recorded from St. Louis Co. and International Falls, Minnesota (Brewer 1977; Lundeen 1980). Pengelly (pers. comm.) observed T. lineola at Dryden, Ontario in 1972. McCabe and Post (1977) did not include this species in their list for North Dakota. The purpose of the present note is to report on the presence and collections of T. lineola in Manitoba and in northwestern Ontario.

Magnetization of the Perry Formation of New Brunswick, and the rotation of Newfoundland

1968 ◽  
Vol 5 (5) ◽  
pp. 1175-1181 ◽  
Author(s):  
W. A. Robertson ◽  
J. L. Roy ◽  
J. K. Park
Keyword(s):  
New Brunswick ◽  
Remanent Magnetization ◽  
Upper Devonian ◽  
Late Devonian ◽  
Independent Evidence ◽  
Best Estimate ◽  
Before And After ◽  
The Stability

The remanent magnetization of the Upper Devonian Perry Formation of New Brunswick consists of two components B and A acquired before and after folding (pre-Westphalian D) respectively. The stability spectra of these components overlap and it is therefore difficult to define them accurately and calculate their errors. The best estimate of the older (B) component (with respect to bedding) is 175,+23 (pole 32° N, 118° E), but this may be in error by 15° or more: its age is considered to be Late Devonian or Mississippian. The best estimate of the younger (A) component (with respect to present horizontal) is also 175, +23 and its age is considered to be early Pennsylvanian or older. The uncertainty in estimating these directions, however, means that the paleomagnetic observations, although they do not preclude the possibility that Newfoundland has rotated, also do not provide independent evidence that this has occurred, as has been suggested.

Notes on the Biology of Synetaeris tenuifemur Walley (Hymenoptera: Ichneumonidae)

1963 ◽  
Vol 95 (1) ◽  
pp. 24-28 ◽  
Author(s):  
C. A. Miller ◽  
T. R. Renault
Keyword(s):  
British Columbia ◽  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Green River ◽  
Low Level ◽  
Northwestern Ontario ◽  
North Western

The species discussed below was first recorded under the name Synetaeris n. sp. as a parasite of the spruce budworm, Choristoneura fumiferana Clem., in Ontario by McGugan and Blais (1959), although they point out that it may have been collected from budworm in British Columbia during the 1940's but incorrectly identified at that time. These authors collected S. tenuifemur during the declining years of a budworm outbreak in the Lake Nipigon region of northwestern Ontario, and it was during the declining years of a severe outbreak that the parasite was first reared from budworm in the Green River area of north-western New Brunswick (Morris, 1963, in press). These data suggest that S. tenuifemur is associated with endemic budworm populations, an assumption advanced by McGugan and Blais (1959). However, it was not found in the Green River area from 1945 to 1947 when budworm density was at a low level prior to the 1949-1959 outbreak.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Interpreting HVEM of muscle-cell impulse networks

1992 ◽  
Vol 50 (1) ◽  
pp. 126-127
Author(s):  
Paul DeCosta ◽  
Kyugon Cho ◽  
Stephen Shemlon ◽  
Heesung Jun ◽  
Stanley M. Dunn
Keyword(s):  
Structural Analysis ◽  
Muscle Cell ◽  
Electron Micrographs ◽  
Relative Size ◽  
Automatic Classification ◽  
Nerve Fibers ◽  
Analysis Algorithm ◽  
Structural Networks

Introduction: The analysis and interpretation of electron micrographs of cells and tissues, often requires the accurate extraction of structural networks, which either provide immediate 2D or 3D information, or from which the desired information can be inferred. The images of these structures contain lines and/or curves whose orientation, lengths, and intersections characterize the overall network.Some examples exist of studies that have been done in the analysis of networks of natural structures. In, Sebok and Roemer determine the complexity of nerve structures in an EM formed slide. Here the number of nodes that exist in the image describes how dense nerve fibers are in a particular region of the skin. Hildith proposes a network structural analysis algorithm for the automatic classification of chromosome spreads (type, relative size and orientation).

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