The Holly Hill plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Mostly sunny
Mostly sunny; warmer
Mostly sunny
Mostly sunny
Mostly sunny
Mostly sunny
Mostly sunny
Holly Hill’s center stands about 120 ft above sea level. Within three miles the land runs from 80 ft to 160 ft, a difference of 80 ft: gently rolling country.
Under the town center the state geologic map shows Duplin Formation (sand, clay), from the Pliocene, 2.6 to 5.3 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sand, clay. Age: Pliocene, 2.6 to 5.3 million years old. About 9 mi of the line.
Sand, limestone. Age: Tertiary, 2.6 to 66 million years old. About 9 mi of the line.
Sand, gravel. Age: Quaternary, less than 2.6 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Holly Hill reaches the Atlantic Ocean by way of Home Branch, Four Hole Swamp, the Edisto and the North Edisto: about 90 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Holly Hill; river miles along the main stem, rounded.
