About 1.1 Billion years ago, the mid-continental rift was trying
to break apart North America (See Pict 4). During this time, a
lot of things happened to North America, especially around Duluth
which is the focus of this report. Different types of rocks formed
from different minerals. Sand and mud was compacted to form Sedimentary
rocks. Some rocks were formed directly from cooling magma. These
are known as igneous rocks
Another key aspect in the formation of these rock formations was
Volcanism. Imagine what the earth was like about 1.1 billion years
ago. It was in a state of Volcanism. Volcanoes were erupting everywhere,
spitting out tons of lava and covering the earth with it. After
millions of years have passed, the lava eventually cooled and
formed different types of rocks. I will be explaining the different
types of rocks I looked at on my Geology field trip and why they
formed.
