Which event occurred approximately 4.6 billion years ago?

When studying the calumet region of illinois and indiana alfred meyers noted four stages of development as new groups occupied this land in stage 2 farmers used the land primarily to grow food for their familes and their small communities

If the basis of an isosceles trapezoid have lengths of 11 and 26, what is the length of the median?

What happens when heat from inside earth is transferred to its surface? warmer material is pushed to the crust more dense material is pushed to the crust warmer material is pushed to the outer core less dense material is pushed to the outer core