Hello and welcome to Science Thursday! Today, we are going to start learning about one of the three different kinds of rocks we introduced last week – sedimentary, metamorphic, and igneous. Last week, we learned that rocks are made from one or more minerals and are grouped together and given names based on how they are formed. This week, we will learn about sedimentary rocks.
Sedimentary rocks form when dirt, pieces of other rocks, and the remains of dead organisms (seashells or coral, for example) pile up on top of each other and become cemented together. Geologists call this material (the dirt, pieces of rocks, and remains of dead organisms) “sediment”. This material is what gives sedimentary rocks their name.
In last week’s post, we showed you a picture of a kind of sedimentary rock called brownstone. Brownstone is a type of sedimentary rock that was once heavily quarried (mined) in central Connecticut. Many buildings in cities up and down the east coast were made from brownstone quarried in or near Portland, Connecticut. The last brownstone quarry in Portland closed in 2012. One former quarry is now the location of a water park!
For this week’s baking project, Miss Christa is going to show us how to bake Sedimentary Rock Magic Bar Cookies. The baking process involves laying down layers of “sediment” (graham crackers, chocolate chips, butterscotch chips, chopped nuts, coconut flakes) and using the heat of our ovens to cement those layers together. Follow the directions in the photographs below to create your own batch of delicious sedimentary bar cookies!