Clicking on the following geologic unit identifiers will open summaries, in a paragraph below, including the names and brief descriptions of each of the units.

The above description is taken directly from the 1963 Chester R. Longwell map and report. Because the mapping was reconnaissance in nature, the geologic units are quite general. Some of the units are named to indicate tentative petrogenetic relationships with units outside of the area covered by this map but present on the more extensive original. Later mapping, described in the following section, is more detailed and descriptive and has not continued the use of some of these naming conventions. Because of the date that the work was performed the 1963 work has a more overriding outlook, attempting to find a regional system of units and geologic history, or story, with which all mapped units are in accordance. The southern portion of this map was major gold production region at one time. The discussion of the siliceous plutonic and volcanic rocks is quite confusing and the author notes that differentiation of those rocks which predated and postdated the major volcanic sequences had not been made at that time.

Clicking on the following geologic unit identifiers will open, in a paragraph below, summaries including the names and brief descriptions of each of the units.

The above description is taken, almost verbatim, from the 2014 Tracey J. Felger et al map with consultation of the 2007 L.S. Beard et al report. There is not a high level of coherency with regard to unit definition and names between the two projects so cross referencing by unit names and identifiers is not clear cut. It is possible to find and correlate rock type descriptions in both. Also, as noted in the summary of the reconnaissance map unit descriptions above, some of the units described in these maps and reports are named differently than those in the reconnaissance work. The groups of mapped units in the 2014 work appear to be similar to the larger units mapped in the earlier work. Each of the unit groups can contain several units. Color coordination of the units within the groups has been made in this effort to show the distribution of both the units and the larger groupings of units. This allows for a greater ability to compare the reconnaissance mapping and the later detailed mapping. Because of the dates the later work was performed the nature of the work was less to establish an overriding thesis of the history of the rocks but more so a descriptive context where less of an importance is placed on locating spacially extensive units. In general the following correlations between the reconnaissance work and the recent work can be made: the oldest rocks, the Precambrian of the reconnaissance work, are categorized as both the Paleozoic sediments and Pre-Paleozic rocks in recent mapping. The Patsy Mine Volcanics are correlative. The Golden Door Volcanics of the early work are divided into the River Mountain Volcanics and lower Mount Davis Volcanics of the later work. The Mount Davis Volcanics of the older work are correlative with the upper and middle Mount Davis volcanics of the later. The Muddy Creek sedimentary and volcanic rocks of the older are generally correlative with both the Cenozoic sedimentary rocks and the older and younger basalts of the later, although there is overlap with the Mount Davis Volcanics. Siliceous plutonic and volcanic rocks on the older map are divided into older and younger groups separated by the major volcanic sequences. However the author notes that this differentiation is difficult and the resulting attempt is very confusing. This is also the case in the later mapping as well. Even though some of these rocks have been dated, because they are similar in both lithology and chemistry and their distribution is not clearly defined, attribution remains confusing. In the later mapping the older siliceous plutonic rocks are included with the Pre-Paleozic rocks.