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Old faults layer
The Old faults layer shows the faults that are part of the geological map.
These are mostly older, inactive faults.
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| Faults of Colorado |
Faults of the San Francisco region |
Details
Fault type
The type of the fault
Source
The source of the information about the fault, if known
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Options
Transparency
Determines how much the underlying layer(s) will show through this layer.
Color selection
- By type: the line color will depend on the type of fault
- One color: all faults will be of the same color
Color
If "one color" is selected, this determines the color of the lines used to represent the faults
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Origin
This data layer can be obtained from the U.S. Geological Survey.
Note that some states do not have a fault layer (e.g. Florida, Iowa).
Abstract
This open-file report presents the results of the USGS Mineral Resources Program activity to compile a national-scale geologic map database to support national and regional level projects, including mineral resource and geo- environmental assessments. The only comprehensive sources of regional- and national-scale geologic maps are state geologic maps with scales ranging from 1:100,000 to 1:1,000,000. Digital versions of these state maps form the core of what is presented here. Because no adequate geologic map exists for the state of Alaska, it is being compiled in regional blocks that also form part of this national database.
It is expected that this series will completed by approximately the end of 2007. These maps and databases are being released in blocks of states or, in the case of Alaska, as compiled blocks of 1:250,000-scale quadrangles as chapters in this series. For Alaska, formal maps as well as databases are being published here, whereas for the conterminous U.S. only state databases and preview graphics are presented, because published maps for most states already exist. For Alaska these regional compilations will form the base for compiling a new geologic map of the state. As documented in Chapter A, standards for the conterminous U.S. are somewhat different than those for Alaska and Hawaii.
Purpose
A primary goal of this work is to develop geologic map datasets with standardized structure and attribution. The database design and standards are documented in Chapter A of this series. The intent is that contiguous databases can be merged seamlessly and without any additional effort. In addition to a common database structure, the conterminous U.S. state databases (the contiguous 48 states) have been fitted to a set of standard state boundaries so that, when states are merged, they match without slivers or overlap. No attempt has been made to reconcile differences in mapping across state boundaries.
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