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  2. Obsidian - Wikipedia

    en.wikipedia.org/wiki/Obsidian

    Pig carved in snowflake obsidian, 10 centimeters (4 in) long. The markings are spherulites. Obsidian is also used for ornamental purposes and as a gemstone. [67] It presents a different appearance depending on how it is cut: in one direction it is jet black, while in another it is glistening gray.

  3. Cementation (geology) - Wikipedia

    en.wikipedia.org/wiki/Cementation_(geology)

    Pendant cements form on the bottom of grains where water droplets are held. Hardgrounds are hard crusts of carbonate material that form on the bottom of the ocean floor, below the lowest tide level. Isopachous (which means equal thickness) cement forms in subaqueous conditions where the grains are completely surrounded by water (Boggs, 2006).

  4. Obsidian hydration dating - Wikipedia

    en.wikipedia.org/wiki/Obsidian_hydration_dating

    Obsidian hydration dating (OHD) is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian.. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping, or breaking off pieces in a controlled manner, such as ...

  5. Marine sediment - Wikipedia

    en.wikipedia.org/wiki/Marine_sediment

    Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor.These particles either have their origins in soil and rocks and have been transported from the land to the sea, mainly by rivers but also by dust carried by wind and by the flow of glaciers into the sea, or they are biogenic deposits from marine organisms or from ...

  6. Weathering - Wikipedia

    en.wikipedia.org/wiki/Weathering

    Weathering is a crucial part of the rock cycle; sedimentary rock, the product of weathered rock, covers 66% of the Earth's continents and much of the ocean floor. [ 4 ] Physical

  7. Marine geology - Wikipedia

    en.wikipedia.org/wiki/Marine_geology

    Marine geology or geological oceanography is the study of the history and structure of the ocean floor. It involves geophysical, geochemical, sedimentological and paleontological investigations of the ocean floor and coastal zone. Marine geology has strong ties to geophysics and to physical oceanography.

  8. A geologist has found part of a lost ocean that existed long ...

    www.aol.com/article/2016/08/15/geologist-found...

    NASA/Goddard Space Flight Center The roughly 60,000-square-mile piece of crust has been hiding below the eastern Mediterranean Sea for about 340 million years (give or take 30 million years).

  9. Seabed - Wikipedia

    en.wikipedia.org/wiki/Seabed

    The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of the ocean is very deep, where the seabed is known as the abyssal plain. Seafloor spreading creates ...