Question

The dominant source of biogenic silica that makes up siliceous oozes in the deep ocean comes from?

1) Volcanic eruptions
2) Weathering of rocks
3) Marine organisms
4) Atmospheric deposition

Answer 1

The dominant source of biogenic silica in siliceous oozes is marine organisms, specifically diatoms and radiolarians, whose silica-based skeletons accumulate as sediment on the ocean floor.

Step-by-step explanation:

The dominant source of biogenic silica that makes up siliceous oozes in the deep ocean comes from marine organisms. These organisms, such as diatoms and radiolarians, have hard parts made of silica. When they die, their silica-rich skeletons accumulate on the ocean floor, forming siliceous oozes.

This process is part of a broader set of biogeochemical cycles that influence the global ecology, where diatoms alone account for over 40% of the ocean's production of oxygen and reduced carbon. Unlike volcanic eruptions, weathering of rocks, or atmospheric deposition, the contribution of marine organisms to the formation of biogenic silica in the deep ocean sediment is direct and a result of their life processes. These organisms extract dissolved silica from the water for their structural needs.