This layer of soil is called the A horizon.
1. The protection granted by a nation to someone who has left their native country as a political refugee.
2. An institution offering shelter and support to people who are mentally ill
Answer:
An eon
Explanation:
The first broad division of the geologic timescale is the eon. Others are Eras, Periods and Epoch.
Eons are the most broad and the largest of divisions of the timescale. There are two categories of the eons which are:
- Hadean eon
- Archean eon
- Proterozoic eon
- Phanerozoic eon
The Phanerozoic eon is the most recent. The Hadean eon is the is the oldest eon.