If one looks, for extent and origin of the Sand Hills, its border is essentially The Fall Line of the Piedmont, though there was some intrusion of the coastal plain up the north flank of the Congaree River to Columbia, SC it looks isolated from one mapping I found. The sand is windblown, not unlike the Great Sand Dunes out in Colorado
From Wiki
https://en.wikipedia.org/wiki/Geographical_Regions_of_South_CarolinaSandhills[edit]The Carolina [/color]Sandhills is a 10-35 mi wide physiographic region within the innermost part of the Atlantic Coastal Plain province.[/color][1] The northern extent of the Carolina Sandhills is located near Fayetteville in North Carolina, and the Carolina Sandhills extend south and southwestward into South Carolina and Georgia. The Sandhills is home to [/color]Sand Hills State Forest, part of the Congaree River, and the state capital of Columbia. The Carolina Sandhills are interpreted as eolian (wind-blown) sand sheets and dunes that were mobilized episodically from approximately 75,000 to 6,000 years ago. Most of the published luminescence ages from the sand are coincident with the last glaciation, a time when the southeastern United States was characterized by colder air temperatures and stronger winds.[/color][2][/color][/font][/size]
References[edit][/font]
^ Swezey, C.S., Fitzwater, B.A., Whittecar, G.R., Mahan, S.A., Garrity, C.P., Aleman Gonzalez, W.B., and Dobbs, K.M., 2016, "The Carolina Sandhills: Quaternary eolian sand sheets and dunes along the updip margin of the Atlantic Coastal Plain province, southeastern United States": Quaternary Research, v. 86, p. 271-286;
www.cambridge.org/core/journals/quaternary-research[/font]
- ^ Swezey, C.S., Fitzwater, B.A., Whittecar, G.R., Mahan, S.A., Garrity, C.P., Aleman Gonzalez, W.B., and Dobbs, K.M., 2016, "The Carolina Sandhills: Quaternary eolian sand sheets and dunes along the updip margin of the Atlantic Coastal Plain province, southeastern United States": Quaternary Research, v. 86, p. 271-286; www.cambridge.org/core/journals/quaternary-research