Question

the layering of eroded sediments is called- 1- limestone formation 2- mechanical weathering 3- deposition 4- the rock cycle

Answer 1

Deposition because we have layering 

Answer 2

The layering of sedimentary rocks is called 1/C DEPOSITION. Materials can be deposited by wind, water, ice etc. When these materials get compacted and cemented over time they firm sedimentary rocks.

Limestone is a sedimentary rock formed my the cementation and compaction of oceanic sediments rich in the calcium carbonate shells of marine organisms.
Mechanical weathering occurs when rocks or soil is broken down into smaller fragments. The chemical composition of the rocks does not change.
The rock cycle describes the process of formation and change of the three main types of rocks; igneous, sedimentary and metamorphic.