@inproceedings{c41b492fe802460c869057256c8caa08,
title = "The geology of a mafic dyke at Roerkulten, Sverdrupfjella, western Dronning Maud Land, Antarctica",
abstract = "The mafic dyke is metamorphosed to amphibolite-facies and is calc-alkaline with intermediate SiO 2 (∼56%) and high Al 2O 3 and TiO 2 and is transitional between basaltic to andesitic compositions. The dyke has high Sr, Zr and Ba contents. The steep chondrite-normalised REE profile has a small negative Eu anomaly. The dyke cross-cuts S1 planar fabrics but contains a S 2 planar fabric which is folded by F 3. A weak axial planar F 3 fabric is seen. U-Pb SHRIMP zircon data plot near concordantly at the lower intercept suggesting extensive recrystallisation at 523 ± 21 Ma and primary crystallisation at ∼900 Ma (upper intercept). Whole rock Rb-Sr data suggest a age of ∼748 ± 102 Ma. Whole rock Sm/Nd data only yield model ages of 1107Ma (TCHUR) and 1468Ma (TDM) with a mean ε Ndvalue of -2.9. Previously published Rb-Sr isotope data suggest mineral scale resetting at ∼460-500 Ma. The data suggest dyke intrusion at ∼900-1000 Ma and folding and metamorphism at ∼460-530 Ma. The asymmetry of the folds and the sense of shear on reverse faults elsewhere in Sverdrupfjella indicate tectonic vergence to the southeast. This vergence sense is consistent with ∼490 Ma age structures in northern Mozambique which was adjacent to Antarctica prior to Gondwana dispersal.",
author = "Grantham, {G. H.} and Armstrong, {R. A.} and Moyes, {A. B.}",
year = "2006",
language = "English",
isbn = "0415398991",
series = "Dyke Swarms - Time Markers of Crustal Evolution - Proceedings of the 5th International Conference, IDC-5",
pages = "213--224",
booktitle = "Dyke Swarms - Time Markers of Crustal Evolution - Proceedings of the 5th International Conference, IDC-5",
note = "5th International Dyke Conference: Dyke Swarms - Time Markers of Crustal Evolution, IDC-5 ; Conference date: 31-07-2005 Through 03-08-2005",
}