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d) Keep the EarthCache to one topic.
An EarthCache usual usually works best when it covers one topic, not several. Some related topics can be described, but then there must should be a strong connection. For example, land rising and shingle beach can work, but not land rising and grain size in minerals/rocks.
Try to keep the EarthCache to one topic, in description and logging task.
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The focus of the questions has of course to follow the cache description and be about the local geology. The answers should make sure the visitors have been at the cache, and therefore should not be found on the Internet. It’s the answers to the question that shows that the person really did find the correct location.
The recommendation is to put the strongest question first question in the logging task should always be the strongest, the visitor should find the answer at the cache location and not on the Internet. The question should also make the visitor "think" a little, this means that the answers cannot be an easy measurement tasks or just "readable" from an information sign, you can use an information sign as information to the cache but just not to read the answer from.
Remember: The visit to the cache location combined with the cache description should make it possible to complete the logging task.
Visitors should reflect about what they see and read, and learn something about geology by completing the logging task.
A question like "describe what you see" is not good enough, visitors will see different things and there is no right answer. The question must should be more specific.
4) Questionable/difficult topics, see link.
Waterfalls. A waterfall is by itself is not enough geology as a feature for an EarthCache, but with a description how the waterfall affects the local geology or how it has been created, the cache can work. Remember that the described geological feature must be visible at the site, and be able to build the logging task on.
Museums, or indoors in general. Earthcaches must involve, just like any other cache, GPS usage, so you cannot create an Earthcache that is completely indoors. However, if there is an outdoor stage/waypoint on the cache that involves GPS usage and it is possible to connect with something that you see indoors, the cache can work. The logging task must also include outdoor/GPS usage.
Statues, sculptures or other building stones. These kind of EarthCaches must describe the stone structure, minerals or fossils. Descriptions about rock types, formation or general description of the rocks origin is not good enough. The logging task must also be linked to the stone in place and its geological properties describe above.
5) Helpful links for further Reading.
Geocaching Help Center about EarthCaches, link to Geocaching HQ
EarthCache Submittal Guidelines, available in many languages, link to Geological Society of America
The Geological Society of America, EarthCache FAQ, link to Geological Society of America
The Geological Society of America, homepage of EarthCaches, link to Geological Society of America
