Cave of the Mounds the Interior and the National Park Service. To be considered a NNL, "a site must be one of the best examples of a natural region's characteristic biotic or geologic features." Cave of the Mounds is home to many varieties of speleothems. As with most caves, stalactites and stalagmites are common. Formations found inside the cave include: These formations come in many different brilliant colors such as reds, browns, blues, and grays. The reds and browns are caused by the presence of iron oxide in the formation. Similarly, blues and grays are caused by manganese oxide. Some speleothems are even partially
Anthodite of a cactus or thistle plant. In its composite stalagmite form, frostwork may possess spiny limbs like a miniature fir tree. The term was first used by cave guides at Wind Cave in South Dakota, USA, during the 1890s to describe speleothems which looked like ice “frostwork”. Anthodite Anthodites (Greek ἄνθος "ánthos", “flower”, "-ode", adjectival combining form, "-ite" adjectival suffix) are speleothems (cave formations) composed of long needle-like crystals situated in clusters which radiate outward from a common base. The "needles" may be quill-like or feathery. Most anthodites are made of the mineral aragonite (a variety of calcium carbonate, CaCO),