We started the day early along our nearby coastline learning of striations, which are the gouges and grooves on the surface of sedimentary rock. These gouges were created by ice-borne debris collected at the base of a glacier about 25,000 to 14,000 years ago. Apparently the glacier acted like a giant bulldozer tearing and scraping anything in its path.
Next we learned about Karst topography which is a landscape feature that is characteristic of highly soluble bedrocks like limestone and evaporite deposits like gypsum and anhydrite. We found that the ground, though rocky, is quite crumbly. Not a scientific description but it was pretty cool!
Then we went on to learn about ‘vertically tilted, Cambrian metasedimentary rocks’ (whew! what a mouthful!). The tilting likely occurred about 390 million years ago when two small plates of continental crust merged with each other. These rocks we visited were cut into to allow the creation of a highway. We passed them hundreds of times and until today they were just rocks!
Yesterday, as a pre-EarthCache Day find, we learned about drumlins, which are like long, sloping hills. These are believed to have been created when glacier ice became overloaded with sediment.
This has been a very interesting and educational weekend for us. EarthCaches are definitely one of our favorite types of cache and we look forward to our next one.
Btw – Everyday can be EarthCache Day – visit one today!
Keep on cachin’!