Calcareous ooze is a type of sediment found on the ocean floor, primarily composed of the remains of marine organisms that contain calcium carbonate. This includes the shells and skeletons of creatures like foraminifera and coccolithophores. When these organisms die, their hard parts accumulate and form a soft, chalky sediment. This ooze is typically found in deeper ocean areas, especially in regions where the water is warm and nutrient-rich. Over time, calcareous ooze can become compacted and lithified, contributing to the formation of sedimentary rocks like limestone.