Geologic Time

Geologic Time. Western North Carolina's rich geologic history is as dramatic as its topography. Tectonic events beginning over 1 billion years ago influenced the type and structure of rock that formed, guiding where mountains, valleys, streams, and rivers developed. Take a look at the first rock in our garden, which was mined right here in Buncombe County; it's not every day you can touch something that's a billion years old! , Western North Carolina's mountains consist mostly of igneous rock (cooled, molten material) such as granite, sedimentary rock (formed in bodies of water) such as sandstone, and metamorphic rock (formed under heat and pressure) such as gneiss. , Approximately 270 million years ago, North America and Africa collided, pushing up the Blue Ridge Mountains that surround us. At that time our mountains were among the highest in the world - as high as the Rockies are now - over 12,000 feet in elevation. , Today, due to hundreds of millions of years of erosion, the highest peak east of the Mississippi River, Mount Mitchell, is "just” 6,684 feet high. Mount Mitchell is located 10 miles to the north.