The Stratigraphy and Age of the Precambrian Rocks of Surinam
To verify the Precambrian stratigraphic succession in Surinam, four samples of the two main granite emplacements were analyzed by Priem and others (1965). The ages determined ranged from 1825 ± 80 m.y. to 2060 ± 100 m.y., with an average age of 1950 m.y., which agrees with data from Guiana 1 and French Guiana. These data indicate that a major event occurred about 1950 m.y. ago. However, a biotite in one of the granite samples gave Rb-Sr and K-Ar ages of near 1300 m.y., suggesting a younger event. The study was based on samples from only four granite bodies and therefore does not provide sufficient evidence for a correlation of Surinam with the other Guianas. More work must be done before the stratigraphical relationship of the Guiana Shield is fully understood.