Marblehead Lighthouse


The pictures below show a type of igneous rock called rhyolite. You've probably learned that one way to tell igneous rocks apart from sedimentary or metamorphic rocks is that igneous rocks don't show layering... but these do! Can you explain how an igneous rock could form such distinct layers?

Now, to challenge your thinking even further, if you look closely at the rocks you will notice that the layers are vertical! How is this possible?


Note that the pictures below were taken from above. This means that the layers you see are vertical!