 The Elephant Rocks, for which Elephant Rocks State Park is named, is a pile of residual boulders of weathered Graniteville Granite.It is a medium- to coarse-grained, muscovite-biotite alkali granite that, on the average, consists of 55 percent alkali feldspar, 40 percent quartz, and less than 5 percent mafic minerals.The Graniteville Granite is a pluton formed 1.4 billion years ago in the Proterozoic by the cooling of magma that intruded into the volcanic strata and country rock associated with a collapsed caldera.