I am very confused about how styles work, and how you produce new ones without creating each new symbol within the depths of the Symbol Selector. However, I have located several style files associated with the FGDC Digital Cartographic Standard for Geologic Map Symbolization. The first link I used http://www.arcgis.com/home/item.html?id=bb02aa75305f40ff87fb6106aa297da9 gave me a lot of style files, but when I copied them over to the the Styles Folder under Program Files > ARCGIS > Desktop 10.4 > Styles, and then select them within the Symbol Selector, they do not show up in the viewing pane or show any symbols. There might be something about not having the correct version of ARCGIS, but if so I am not sure which version is required.
The second two I got from here: NGMDB | GeMS from the two ESRI style Implementations under Resources. Each one does open up within the Symbol Selector, but opens up as the wrong set of symbols (Which happens to be exactly the same between both files. This is obvious, because, there are no geology symbols, in a style suppose to be only made of those, and symbols such as smiley faces and clocks are labeled as small minor faults and lineations. What am I doing wrong that ArcMap is misreading my styles files?
With one of these last two files described above, the style file also came with a series of True Type font files and PDF files filled with what look like the correct geological symbols.