Structural Features and Composition of Amber from Placers on the East Coast of Sakhalin Island

2015 ◽  
pp. 97-107
Author(s):  
Valery V. Kononov ◽  
Olga P. Smyshlyaeva ◽  
Mihael E. Zelenski
Keyword(s):  
East Coast ◽  
Structural Features ◽  
Sakhalin Island

scholarly journals RECONSTRUCTION OF TECTONIC STRESSES ON THE SCHMIDT PENINSULA (SAKHALIN)

2021 ◽  
pp. 73-88
Author(s):  
А.V. Marinin ◽  
◽  
Yu.L. Rebetskiy ◽  
L.A. Sim ◽  
P.A. Kamenev ◽  
...  
Keyword(s):  
Stress State ◽  
East Coast ◽  
Sakhalin Island ◽  
Stress And Strain ◽  
Horizontal Shear ◽  
The West ◽  
Maximum Compression ◽  
Stable Orientation ◽  
Shear Type ◽  
Geodynamic Condition

The article presents data on the stress state of the Schmidt Peninsula of Sakhalin Island, obtained as a result of field tectonophysical studies in 2020. The importance of studying the northern part of Sakhalin is due to the prospects of this region for the minerals search. The performed studies allowed us to establish differences in the geodynamic condition between the western and eastern coasts of the peninsula. In general, the conditions of horizontal shear (shear type of deformation) prevail among the types of stress state in the studied territory. On the east coast, there are many situations of horizontal extension, which are usually confined to the axial parts of anticlinal structures. The west coast is characterized by the stable orientation of the axis of maximum compression in the NW direction and its subhorizontal position. For the east coast, the direction of the reconstructed orientations of maximum compression is characterized by greater variability. According to the data of the reconstruction, the stress-and-strain state pattern of the Schmidt Peninsula has significant differences from the main territory of Sakhalin Island.

GEOLOGIC IMPLICATIONS OF AEROMAGNETIC DATA FOR THE EASTERN CONTINENTAL MARGIN OF THE UNITED STATES

Geophysics ◽  
1968 ◽  
Vol 33 (5) ◽  
pp. 755-780 ◽  
Author(s):  
Patrick T. Taylor ◽  
Isidore Zietz ◽  
Leonard S. Dennis
Keyword(s):  
New England ◽  
Continental Slope ◽  
Magnetic Anomaly ◽  
East Coast ◽  
Gulf Of Maine ◽  
The United States ◽  
Structural Features ◽  
Magnetic Data ◽  
Aeromagnetic Survey ◽  
Line Spacing

An aeromagnetic survey extending from the Gulf of Maine to the tip of Florida was conducted by the U. S. Naval Oceanographic Office between 1964 and 1966. Flight traverses were flown in a northwesterly direction at right angles to the geologic grain. The flight lines were approximately 800 km long and had an 8‐km separation. The survey traversed part of the New England, Piedmont, and Coastal Plain provinces and extended some 320 km beyond the continental shelf into the Atlantic Ocean. Despite the wide flight‐line spacing, numerous geological and structural features became apparent from this survey. Interpretation of these features was aided by using the available gravity and seismic data in addition to the State and Provincial geologic maps. The residual aeromagnetic map shows a continuous magnetic high on or near the continental slope as far south as the 31st parallel. At about the 36th parallel, this east‐coast magnetic anomaly splits into two branches, and both of them parallel the 850‐fathom contour. At the 31st parallel, the outer branch of the anomaly swings westward and crosses the coastline near Brunswick, Georgia. This continuous magnetic anomaly may result from an igneous intrusive body that parallels the edge of the pre‐Paleozoic continental landmass. These magnetic data suggest that Florida and part of Georgia were added to the paleo‐continent in pre‐Paleozoic time. Landward from the east‐coast anomaly, the magnetic field is quite variable, whereas oceanward it has an extremely small gradient. The absence of magnetic anomalies east of the continental slope suggests that in this region layer 2 may be composed of metamorphosed basalt. The characteristic magnetic patterns observed over the Piedmont and New England provinces extend oceanward to the east‐coast anomaly.

Generation of a Tsunami from the Submarine Landslide Near the East Coast of Sakhalin Island

2018 ◽  
Vol 73 (2) ◽  
pp. 234-239
Author(s):  
A. A. Ivanova ◽  
E. A. Kulikov ◽  
I. V. Fine ◽  
B. V. Baranov
Keyword(s):  
East Coast ◽  
Submarine Landslide ◽  
Sakhalin Island

THE STATUS OF GEOPHYSICAL KNOWLEDGE IN THE EAST COAST AND EASTERN BASINS OF INDIA

1974 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
G. Ramakotaiah ◽  
D. N. Avasthi
Keyword(s):  
East Coast ◽  
Signal To Noise Ratio ◽  
Structural Features ◽  
Digital Data ◽  
Limited Area ◽  
Bengal Basin ◽  
Shelf Area ◽  
Technical Problems ◽  
Reflection Seismic ◽  
The Status

The major problem in geophysical exploration for hydrocarbons in the east coast basins of India (Mahandi, Krishna-Godavari, Palar and Cauvery Basins) is to obtain persistent and correlatable reflection seismic data from prospective zones at depth. From the geological and well data a considerable thickness of pre-Tertiary and Tertiary sediments is known to be present in these basins. As these areas are covered with a blanket of alluvium, the basin configuration and sub-surface structural features are to be inferred from geophysical data. Although gravity, magnetic and refraction surveys have broadly outlined the basin configuration, suitable seismic reflection techniques are yet to be evolved for detailed mapping of the structures. Experiments using offset spreads and geophone grouping parameters derived from noise studies have yielded encouraging results in a limited area of the Cauvery basin.The problems of the eastern basins (Assam, Tripura and Bengal) are varied in nature. The structures in the shelf area of Assam, have been successfully mapped using reflection seismograph, but the tectonic complexity of sub-thrust regions of the Naga Hills and the steeply folded belts of Tripura present formidable logistics and technical problems for delineating the sub-surface features. Some theoretical studies have been made for developing field techniques to improve the signal-to-noise ratio in these areas.The problem in the Bengal basin is the absence of continuous and correlatable reflection events from the prospective Mio-Pliocene section. The use of digital data acquisition and processing techniques has not substantially improved data quality from this section to date.

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

Sign in / Sign up

Export Citation Format

Share Document