Beachrocks are good indicators of sea-level stillstands on microtidal
coastlines and data for this sea-level curve is mainly based on dating
a series of Holocene beachrocks and planation episodes on the southea
st African coastline. Sea-level reached its present level along the so
uthern African coastline at ca. 6500 BP; sea-level then rose depositin
g a series of beachrocks at an elevation of + 2.75 m. This mid-Holocen
e sea-level highstand persisted for a period of 2500 years with a + 3.
5 m stillstand, dated at 4480 BP, being the highest sea-level reached
during the Holocene. In post-Holocene sea-level optimum times, a regre
ssion occurred lowering sea-level to its present level at 3880 BP and
down to -2 m at approximately 3000 BP. Subsequently; sea-level rose to
+ 1.5 m at 1610 BP and attained its present level at about 900 BP. Th
e mid-Holocene sea-level highstand appears to have resulted from a com
bination of isostatic emergence and the steric expansion of seawater r
elating to warmer ocean temperatures associated with the Holocene hyps
ithermal event on the eastern Agulhas Bank.