2. Descibe the sequenc of events in the formation of an evaporite.?

Answer 1

erosin forms silt
water mets on the suface
silt dris
Voila! Evaprite.

Answer 2

1. Start with a lake with no outlet or make a barrier across a marine basin. The water in lakes and oceans have dissolved "salts" in them that have washed in from rivers.
2. Dry up the lake or the marine basin (arid environment). You will get a left-over residue of salts (evaporites) on the old floor of the lake, sea, or lagoon.
The most common evaporite mineral is halite (NaCl--salt). But, depending on the original composition of the water, the evaporation process produces other halides, sulfates, nitrates, and borates.
If you want to know more--
wiki--http://en.wikipedia.org/wiki/Evaporite
http://seis.natsci.csulb.edu/bperry/Sedimentary%20Rocks%20Tour/evaporites.htm