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.

On the origin of Early Proterozoic gneiss domes and metamorphic nodes, northern Michigan

1996 ◽  
Vol 33 (7) ◽  
pp. 1053-1053 ◽  
Author(s):  
David Schneider ◽  
Daniel Holm ◽  
Daniel Lux
Keyword(s):  
Gravity Anomaly ◽  
Gneiss Dome ◽  
Near Surface ◽  
Dome Formation ◽  
Crustal Shortening ◽  
Gneiss Domes ◽  
History Of ◽  
The Republic ◽  
Different Origins ◽  
Northern Michigan

Biotite 40αr/39αr cooling ages from medium-pressure (500–600 MPa) rocks in the Watersmeet district, northern Michigan, suggest significant cooling–uplift and concomitant deformation during gneiss dome formation at~1755 Ma, well after the close of the 1870–1830 Ma Penokean orogeny. However, an 1822 Ma hornblende plateau date indicates that the isograds surrounding the dome are Penokean in age. We attribute gneiss dome formation and doming of Penokean-aged isograds to an episode of orogenic collapse superimposed on an earlier history of crustal shortening. This contrasts with the compressional origin for gneiss domes preserved in the low-pressure (200–300 MPa) Republic district. The different origins may reflect the fact that collapse was localized along the overthickened region of the orogenic belt. In contrast to the Watersmeet area, hornblende and biotite 40Ar/39Ar ages obtained from the Republic area are 1720–1680 Ma. Given the relatively shallow depth of this region, it is unlikely that temperatures remained above 500 °C for over 100 Ma following collision. We interpret these ages to reflect a major thermal event that may have been responsible for formation of the Republic metamorphic node. This interpretation is supported by the recent identification of an ~1730 Ma pluton that is likely the cause of a large, near-surface, negative gravity anomaly coincident with the node, and by the fact that the metamorphic node crosscuts Penokean structures.

scholarly journals Structural analysis for dynamic model of time‐varying switch in bond graph – a case study of single phase switch converters

2017 ◽  
Vol 10 (7) ◽  
pp. 756-766
Author(s):  
Kuo‐Hsiung Tseng ◽  
Tuo‐Wen Chang ◽  
Ming‐Fu Hung ◽  
Kuan‐Wen Chen
Keyword(s):  
Structural Analysis ◽  
Dynamic Model ◽  
Single Phase ◽  
Bond Graph ◽  
Time Varying

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.

Structural tests of diapir hypotheses in Archean crust of Ontario

1990 ◽  
Vol 27 (3) ◽  
pp. 387-402 ◽  
Author(s):  
W. M. Schwerdtner
Keyword(s):  
Solid State ◽  
Horizontal Displacement ◽  
Gneiss Dome ◽  
Gneiss Domes ◽  
Archean Crust ◽  
Structural Tests ◽  
Greenstone Belts ◽  
Ductile Shear

Detailed structural maps of two granitoid complexes in the Wabigoon Subprovince are used to test three diapir hypotheses advanced in earlier papers. The gneiss masses of, and individual domes within, the complexes fail the test for solid-state diapirism. The gneiss domes also fail the test for tensile bending caused by hypothetical magmatic diapirs in the subsurface. An oval pluton located near the best-exposed gneiss dome proves to be a synformal sheet rather than a funnel-shaped magmatic diapir. This pluton could be a syenite–diorite phacolith emplaced into a concordant zone of dilation during the late upright folding of the gneiss mass about horizontal axes. Earlier tight folds were probably recumbent and south verging and, like the gneissosity, generated in a ductile shear regime with subhorizontal glide planes. These observations have important implications for Archean tectonics, especially the relative horizontal displacement of large greenstone masses (potentially allochthonous greenstone belts).

Analytical Modeling in Electronic Packaging Structures: Its Merits, Shortcomings and Interaction With Experimental and Numerical Techniques

1989 ◽  
Vol 111 (2) ◽  
pp. 157-161 ◽  
Author(s):  
E. Suhir
Keyword(s):  
Theoretical Model ◽  
Structural Analysis ◽  
Electronic Packaging ◽  
Analytical Modeling ◽  
Experimental Models ◽  
Theoretical Modeling ◽  
Numerical Techniques ◽  
Numerical Computer ◽  
Computer Aided

We discuss the role of theoretical and, in particular, analytical modeling in mechanical problems for electronic packaging, including requirements for a feasible theoretical model, how such a model is developed, the role of mathematics, what can be gained by using theoretical modeling, as well as the interaction of analytical, numerical (computer-aided) and experimental models. Peculiarities of theoretical modeling in Structural Analysis are also briefly discussed.

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.

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