Are you a spelunker? Spelunkers are individuals who enjoy exploring caves. Buried beneath the Earth’s surface in many parts of the United States are vast networks of caverns—many of which are bigger than your school! Imagine walking down into a cave and shining your headlamp on the beautiful walls all around you. As you look up, you see what appear to be huge icicles reaching almost to the floor. In other areas you see huge cones coming up from the floor. These beautiful rock formations are called stalagmites and stalactites.
Stalactites “drop” from the ceiling, while stalagmites rise up from the floor of the cavern. Many times these rock formations will grow together forming beautiful pillars, veils, “soda straws,” or even what appear to be waterfalls. These amazing rocks are formed from minerals carried in groundwater. As the groundwater trickles through the cracks in the ground, it finally becomes exposed to the air in the cavern. As the water dries, a dissolved mineral—calcium bicarbonate—is precipitated out, leaving a ring of calcite. Calcite is the primary mineral that is found in underground caverns, and it can display a variety of colors and shapes. This process of water seeping out, drying, and leaving behind calcite goes on over and over, causing the stalagmite or stalactite to get bigger. The beautiful colors that are often seen in stalagmites and stalactites are caused by iron or other impurities that are in the groundwater.
Many people suggest that it takes millions of years to form these amazing rock formations. However, we know today that it does not require millions of years. In truth, stalactites can be found on modern structures, such as the Lincoln Memorial or man-made tunnels from West Virginia to San Francisco! In fact, at Mother Shipton’s Cave in England this process happens so quickly that visitors can watch as teddy bears and dinosaur figurines become covered in rock (see picture to the left). While many would point to stalagmites and stalactites as proof for evolution, the truth is, these beautiful rock formations can form rapidly and they stand as just one more beautiful example of the handiwork of God.