How does chalk form?
A) evaporation of water in a lake or sea
B) accumulation of microscopic organisms composed of calcium carbonate
C) precipitation from seawater early in Earth's history
D) accumulation of silica-rich organisms or mixing of seawater and groundwater

Question

Quizplus · Accepted Answer

Chalk forms through the accumulation of microscopic organisms composed of calcium carbonate, primarily the remains of planktonic algae and foraminifera that settle to the sea or lake floor over millions of years.

How Does Chalk Form