Much of the seafloor during the middle part of the third dive of the 2021 North Atlantic Stepping Stones expedition was dominated by these impressive pillow lavas with extensively developed botryoidal (or bubbly, grape-shaped) ferromanganese crust textures. These crusts precipitate slowly out of the water column over time at a rate of one millimeter per million years.
Pillow Lava
Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download larger version (jpg, 867 KB).

Much of the seafloor during the middle part of the third dive of the 2021 North Atlantic Stepping Stones expedition was dominated by these impressive pillow lavas with extensively developed botryoidal (or bubbly, grape-shaped) ferromanganese crust textures. These crusts precipitate slowly out of the water column over time at a rate of one millimeter per million years.

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