Anorthosite Belts, Continental Drift, and the Anorthosite Event

Science  23 May 1969:
Vol. 164, Issue 3882, pp. 944-947
DOI: 10.1126/science.164.3882.944


Most anorthosites lie in two principal belts when plotted on a predrift continental reconstruction. Anorthosite ages in the belts cluster around 1300 ± 200 million years and range from 1100 to 1700 million years. This suggests that anorthosites are the product of a unique cataclysmic event or a thermal event that was normal only during the earth's early history.