Geologic Map of the northwestern part of the Greenback Creek 7 1/2' Quadrangle, Gila County, Arizona v.2.0
Dates
Publication Date
1999-06-01
Start Date
2022-08-10
End Date
2022-08-10
Citation
Spencer, J.E., Richard, S.M., Ferguson, C.A., and W.G. Gilbert (2022). Geologic Map of the northwestern part of the Greenback Creek 7 1/2' Quadrangle, Gila County, Arizona v.2.0
Summary
The Greenback Creek 7 ½’ Quadrangle is located on the west flank of the Sierra Ancha and directly northeast of Theodore Roosevelt Lake (Figure 1). The geology is dominated by sedimentary rocks of the middle Proterozoic Apache Group and the middle Proterozoic diabase that commonly intrudes it (e.g. Bergquist et al., 1981; Wrucke, 1989). Early to middle Proterozoic granitic rocks are exposed beneath the Apache Group, primarily along the southwestern edge of the bedrock exposures in the map area. Tertiary conglomerate and local sandstone are deposited on the bedrock and in the flanking Tonto Basin, and have been subjected to only minor faulting and tilting. Upper Cenozoic sedimentary units and geomorphic surfaces were not mapped for this [...]
Summary
The Greenback Creek 7 ½’ Quadrangle is located on the west flank of the Sierra Ancha and directly northeast of Theodore Roosevelt Lake (Figure 1). The geology is dominated by sedimentary rocks of the middle Proterozoic Apache Group and the middle Proterozoic diabase that commonly intrudes it (e.g. Bergquist et al., 1981; Wrucke, 1989). Early to middle Proterozoic granitic rocks are exposed beneath the Apache Group, primarily along the southwestern edge of the bedrock exposures in the map area. Tertiary conglomerate and local sandstone are deposited on the bedrock and in the flanking Tonto Basin, and have been subjected to only minor faulting and tilting. Upper Cenozoic sedimentary units and geomorphic surfaces were not mapped for this study because they have been mapped previously (Anderson et al., 1987), and the bedrock was not mapped in the southern and eastern parts of the quadrangle because this area also had been mapped previously (Berquist et al., 1981). This map was prepared so that fairly good geologic-map coverage would be available for the entire Greenback Creek 7 ½’ Quadrangle.
This is a new version of the OFR-99-10 map. Principal changes include the addition of GIS data in the USGS GeMS format and may also include corrections to metadata, map units, age information, and other geologic interpretations. This work was funded by the USGS National Geological and Geophysical Data Preservation Program under grant G21AP10428.
