The minerals calcite precipitates from seawater and coats sand grains

The minerals calcite precipitates from seawater and coats sand grains

Question
#1: Oolites are formed in tropical regions where evaporation is high. The minerals calcite precipitates from seawater and coats sand grains. These only form on beaches. Why do you think this might be? (5pts)

#2: Coquina is made of shell fragments. Given the condition of the shell fragments, do you think it formed in a low-energy environment (like the deep ocean) or a high energy environment (like a river, beach, or a storm bed)? Explain your answer. (5pts)

Thanks!