Geologic maps are products of complex analyses and interpretations, and as such, contain a certain amount of uncertainty. Unfortunately, it is difficult to estimate the uncertainty within a geologic map. Much of this difficulty is due to the lack of a clear framework for describing the sources of uncertainty within the map and poor awareness, within the mapping community, of methods capable of ...

Reconnaissance geologic mapping of south-central Oregon is being done by the U. S. Geological Survey, in cooperation with the State of Oregon Department of Geology and Mineral Industries, as part of a larger program to prepare a geologic map of the eastern half of the state. Current work in south-central Oregon is limited geographically to the eastern half

To illustrate the spatial resolution of measurements of Mercury’s surface elemental composition by the Gamma-Ray Spectrometer on the MESSENGER spacecraft after one year of orbital observations, we have simulated a global coverage map of the 846-keV iron gamma-ray count rate. The simulated map suggests that distinct geologic units larger than 800 km in horizontal dimension will be discernable wh...

Introduction Magnetic property data Geologic Setting Comparison of aeromagnetic map data with geologic data Relations between mapped rock units and magnetic anomalies Trends in the magnetic survey data and their relation to geologic features Inferences from textural measures of the aeromagnetic data Textural measures of potential field data Moving window processing Results for one line of an ae...

Geologic field data collection, analysis, and map compilation are undergoing a revolution in methods, largely precipitated by global positioning system (GPS) and geographic information system (GIS) equipped mobile computers paired with virtual globe visualizations. Modern, ruggedized personal digital assistants (PDAs) and tablet PCs can record a wide spectrum of geologic data and facilitate ite...

For database limitations, see following page ii DATABASE LIMITATIONS Content This database is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. This database, identified ...

INTRODUCTION This paper was prepared for the National Association of Geoscience Teachers Far Western Section Fall Conference, High Sierra Institute, Baker Station, Sierra Nevada September 7 9, 2012. The maps and map interpretations in this document (Figures 1, 2, 3, 4, 5) form about a fourth of a much larger map and manuscript that have been peer reviewed by David John of the U.S. Geological Su...

Many state and national geological surveys produce map products from surficial and bedrock geologic maps as a value-added deliverable for a variety of stakeholders. Improvements in powerful geostatistical exploratory tools and robust three-dimensional capabilities within geographic information systems (GIS) can facilitate the production of derivative products. In addition to providing access to...

Population statistics for As concentrations in rocks, sediments and ground water differ by geology and land use features in the New England region, USA. Significant sources of As in the surficial environment include both natural weathering of rocks and anthropogenic sources such as arsenical pesticides that were commonly applied to apple, blueberry and potato crops during the first half of the ...