What does an unconformity in a sequence of rock layers reveal about geologic history? a. a rock layer must have turned upside down. b. a layer of rock might have eroded. c. the layers must cover hundreds of square miles. d. the layers must have been deposited very quickly.

What conclusion can be drawn about the location of the city of syracuse? it was built on the coastline due to easy access to the red sea. it was built on the coastline due to easy access to the mediterranean sea. it was built inland to protect it from invaders sailing in from the mediterranean sea. it was built inland to protect it from invaders sailing in from the red sea.