Geologic maps and cross sections of mine levels at the Pea Ridge iron mine, Washington County, Missouri

2001 ◽  
Keyword(s):  
Cross Sections ◽  
Washington County ◽  
Iron Mine ◽  
Geologic Maps

scholarly journals GMDE: Extracting quantitative information from geologic maps

Geosphere ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 1495-1507
Author(s):  
Richard W. Allmendinger
Keyword(s):  
Cross Sections ◽  
Error Propagation ◽  
Satellite Images ◽  
Structural Information ◽  
Quantitative Information ◽  
Testing Error ◽  
Geologic Maps ◽  
Microsoft Windows ◽  
Cylindrical Folds

Abstract GMDE is a program, available on the desktop for Apple Macintosh, Microsoft Windows, and Linux platforms and in a mobile version for iOS, that enables geologists to extract quantitative structural information from geologic maps and satellite images. The program facilitates the digitizing of strikes and dips or calculating them from three-point problems, calculation of stratigraphic map thickness, determination of piercing points on faults, and the construction of down-plunge projections and vertical cross sections with projected apparent dips, contacts, and cylindrical folds. The program also enables the automatic plotting of planar contacts across topography based on orientation calculated from three clicked points, which can be carried out in the field for immediate hypothesis testing. Error propagation is built into many of the calculations. Maps and satellite images require no projection or datum information, just four points with known latitude and longitude information. Alternatively, the user can enter the map or image in MBTiles format. Users can easily extract X-Y-Z data for any clicked or calculated point or polygon, enabling them to make their own calculations.

Geology of southeastern Barbados

2021 ◽  
Author(s):  
Robert C. Speed ◽  
Hai Cheng
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Marine Terraces ◽  
Long Duration ◽  
Stratigraphic Division ◽  
Geologic Maps ◽  
Event Histories ◽  
Structural Configurations ◽  
Thickness Variations ◽  
Radioisotopic Dating

ABSTRACT This chapter presents geological documentation of Quaternary (and perhaps older) event histories of southeastern Barbados. The Barbados Limestone is herein formally defined. A time-stratigraphic division of the Barbados Limestone in southeastern Barbados and the properties of the stratigraphic units are presented. A major finding of this study is that the marine terraces originated wholly by marine erosion, not by reef construction, and evolved in stages over a long duration. The hydrology and thickness data of the Barbados Limestone are discussed, and hypotheses on causes of thickness variations are given. The study domain is divided into seven areas that contain a continuous flight of nine marine terraces preserved in various partial sequences. Discussions of these key seven areas in southeastern Barbados are supported by geologic maps at large scale and cross sections. Sections with VE > 1 display limestone stratigraphy and facies over relatively large lengths. Sections with VE = 1 show true structural configurations over short lengths. Detailed observations and radioisotopic dating of the limestone units permit differentiation and correlation among them.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

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