Follow ALL these instructions to successfully install and run inkscape 0.91 on MacOS version 10.7-10.10. Skip instructions if you don’t want it to work properly. More up to date (but less detailed) install instructions are found on this page:
I’ve just put a new section on this website with Illustration/Graphics resources. In this section is a page with a USGS AI pack instructions and a download link. The pack contains patterns for geological mapping such as schist, limestone and other things. The instructions make it really easy to use.
I will be adding a USGS Inkscape pack soon with instructions. I will also be adding more Illustration/Graphics resources as time permits.