EarthCache: Geology for everyday people

My family wants to be able to pick up a rock on a hiking trail and understand why it looks the way it does. How it was created. How the geological process works. But the reality is, we don't know a darn thing about geology. Short of taking a semester-long course on the subject, which would take more time and effort than I have right now, I wasn't sure how to tackle my family's desire to learn more about geology. Then I ran across the Geological Society of America's (GSA) EarthCache website. The GSA has a listing of EarthCaches, locations found with a GPS unit, that teach visitors about a unique feature or aspect of the earth. The listings not only provide the coordinates to the EartCache, they also provide educational information to help people learn why that particular site is important to scientists who study our planet. Learning about geology by spending time outdoors to explore and experience it sounded perfect for my active family. After downloading several EarthCache coordinates to my hand-held GPS unit, I printed out the corresponding information page to bring along on the trail. I wanted to make sure we understood what geological feature we were looking for and could answer the questions required to log our visit for GSA's EarthCache Masters program. The Masters program, an optional bit of fun for the goal-oriented family, requires participants to answer a few questions about the EarthCache (proving you've actually learned something) and take a digital photo of yourself at the location. Participants of the program earn a special pin from the GSA and everyone in my family decided they had to have one. We set off for Rye, New Hampshire, first to discover the Dikes of Odiorne Point and learn about the large basalt dikes there. It was cold and windy the day we visited but that didn't stop us from skipping rocks, picking up sea shells and examining several broken lobster traps on the beach. It was my 10-year-old who spotted the "black rock veins" first. An apt description for the dark molten volcanic material (basalt) cutting through the rocky shore. We answered the EarthCache questions necessary to log our visit and found the site to be fascinating. Scientists believe the Rye Formation, where the dikes are located, to be 460,000,000 years old. "How do they know it's that old? How did they figure that out?" OK, so we can't learn everything about geology at an EarthCache site but we can take the time to be awed by nature and the scientists who study it. We were eager to find another EarthCache and decided to explore a second coastal feature, this time at Old Orchard Beach. We parked near the pier and set off for our walk on the beach to get as close to the EarthCache coordinates we could during high tide (the coordinates we were given were taken at a low spring tide). To log this EarthCache, we had to figure out whether our visit coincided with a spring or neap tide. This is determined by the moon phase and since it was the first day of a the new moon, our visit was during the spring tide. This might sound complicated but the EarthCache information page was written in an easy-to-read format, complete with an animated graphic, that my 10-year-old had no trouble figuring out. After logging these two EarthCache finds, the kids chose our next location a few days later, the Madison Boulder in New Hampshire. The inland trail through the woods is home to the largest known glacial erratic in New England. Basically it's a big piece of bedrock that traveled a substatial distance from it's original location by a glacier thousands of years ago. The kids were fascinated by the enormous, seemingly out of place boulder and we spent an hour discussing it and taking photos. This included some 'trick' photography with my 10-year-old pretending to hold the boulder in her hand and then both girls appearing to have jumped off the large erratic. When you're 10- and 12-years old, this is the kind of geology lesson that tends to stick with you. After logging our third find and realizing we had already accomplished the Bronze Earthcache Master level (we visited and logged three EarthCaches in two states), we decided to set our goals higher. We're going for the Silver and estimate it will take us until mid-summer to complete. This level requires logging six EarthCaches in three states and developing an Earthcache of our own. The real challenge with the Silver level will be in developing our own Earthcache. But we've got some ideas in the works and everyone is excited to start working on it. Visiting an EarthCache is a great way to learn and appreciate the wonders of our earth and will provide your family with a hands-on geology lesson everyone will enjoy. To learn more about EarthCache sites, go to www.earthcache.org This column was published in Raising Maine magazine, May 2008.