| |
| | The History of Granulite-Facies Metamorphism and Crustal Growth from Single Zircon U-Pb Geochronology: Namaqualand, ... (Site not responding. Last check: 2007-10-30) |
 | | In Namaqualand, for example, Waters, (1989,, 1990) argued that peak metamorphic conditions could be attained by magmatic accretion and that this might have been achieved by a thick basaltic underplate at least 10 km below the present level of erosion, accompanied by voluminous felsic intrusions into the mid-crust. |
 | | Little meaningful age information is available from this sample although the available data are consistent with it having been subjected to a similar history to the Brandewynsbank gneiss. |
 | | In western Namaqualand, north of the OCD, a pristine, relatively unmetamorphosed, remnant of this crust (the Richtersveld terrane) is preserved as the Vioolsdrif Suite and Orange River Sequence, which comprise a calc-alkaline composite batholith and associated extrusives perhaps akin to a magmatic arc adjacent to a convergent continental margin (Reid and Barton, 1983). |
| library.iem.ac.ru /j-petr/12-4099/html/egc082_gml.html (9048 words) |
|