Which can be use to determine if two rock layers were deposited at the same time

Index Fossils can be used to determine if two rock layers were deposited at the same time.

Hope this helps. :)

the proximity of water was an advantage to western europe and its culture was able to flourish as a result. trade and travel by sea were easier and safer in historical times.

1. there are no mountains to protect it from the sea

2. and its has wet cool summers and wet, mild winters.