With few exceptions, surface dislocations within the earth's crust or ‘earthquake-faults,’ have been described in connection with all earthquakes of large proportions. The Charleston earthquake of August 31st, 1886, stands out in some contrast with most others in this particular, and it is further in contrast with some other earthquakes for the reason that the phenomena recorded in connection with it have not as yet been brought into any relation with the structural geology of the district. A partial explanation of this may perhaps be found in the fact that the area most disturbed—the so-called ‘epicentral tract’—is entirely included within the coastal plain of the South-Eastern United States. Upon this plain the basement of rock is covered to very considerable depths by unconsolidated material, and it would perhaps be too much to expect that displacements upon fracture planes in the rock would be revealed in full measure at the surface.