Where did all that sand on the Lowcountry’s beaches come from?

When you stroll the beach, you are walking on the ancient remains of mountains. The sands of the Coastal Plain are the erosional deposit of ancient river systems that once carried, bit by bit, Upstate mountains to the sea over the eons. That mountain-to sea transport system is largely no longer in place due to the damming of rivers, which is a contributing factor to present-day beach erosion. Our beaches are no longer replenished by natural forces. While granite quartz from the Appalachian mountains is by volume the greatest constituent of local beach sand, the pulverized shells of marine mollusks and organic detritus, or dead stuff, are also in the mix.