Metamorphic history and U-Pb Zircon (SHRIMP) geochronology of the Glenmore Granite: Implications for the tectonic evolution of the Natal Metamorphic Province

Crustal growth during island arc accretion and transcurrent deformation, Natal Metamorphic Province, South Africa: New isotopic constraints

“…5 and 6).. This is identical to the 434 SHRIMP U-Pb zircon age of 1091 ± 9 Ma reported in Mendonidis et al (2002). CL 435 imaging did reveal thin bright rims on the zircons from the Glenmore Granite, although 436 these rims were too thin to analyze (see Fig.…”

“…The granite is strongly foliated, peraluminous, with biotite, garnet and occasional 203 rapakivi feldspar textures (Grantham, 1983;Mendonidis, 1989;Mendonidis et al, 1991). 204…”

“…The Glenmore Granite has given a SHRIMP U-Pb zircon age of 1091 ± 9 Ma 208 . A sample of the granite was collected from the type locality 209 described by Mendonidis et al (1991). Poikilitic orthoclase is the dominant feldspar with 210 inclusions of quartz and plagioclase, with abundant myrmekite.…”

Geochronology of the Sikombe Granite, Transkei, Natal Metamorphic Province, South Africa

“…The date is also older than any yet obtained from the Margate terrane (e.g. Mendonidis et al, 2002), and it is considerably older than that reported from zircons of the "G2" augen gneiss of the Cape Meredith Complex (1067 ± 14 Ma: Jacobs et al, 1999), showing that this granite cannot be correlated with the Sikombe Granite. The Sikombe Granite is pre-to syntectonic with respect to the earliest (collision-related) metamorphic fabrics seen elsewhere within the belt.…”

“…This suggests that there may be no significant "younging" of tectonomagmatic events within the belt (c.f. Mendonidis et al, 2002), or that the Sikombe Granite belongs to a block that is older than the Margate terrane to its north.…”