The ocean monuments from the Release 1.8 Minecraft update introduce 4 new blocks (prismarine, prismarine bricks, dark prismarine, and sea lantern), 2 new mobs (guardians and elder guardians), and 2 new items (prismarine shards, prismarine crystals). You can use these items to craft 3 of the 4 new blocks.
What is a natural levee and how is it made? -Natural Levees are formed by the river in its process of flooding -A natural levee is formed by a deposit of sand or mud built up along, and sloping away from, either side of the flood plain of a river or stream.
Lava channels can develop in both pahoehoe and a'a basalt. Once established, lava channels will often develop lava levees along their lengths. In pahoehoe flows, natural levees will be constructed as the channel periodically overflows, thus allowing the lava to congeal and cool along the banks of the channel. In a'a flows, levee buildup can also occur by the bulldozing effect of the moving lava, which will push a'a blocks onto the lava banks. Although lava channels may initially be restricted to a topographic valley, as levees build up over time, they may eventually rise above the surrounding ground surface.