Skip to main content
    • Aa
    • Aa
  • Get access
    Check if you have access via personal or institutional login
  • Cited by 4
  • Cited by
    This article has been cited by the following publications. This list is generated based on data provided by CrossRef.

    Kraus, S. Poblete, F. and Arriagada, C. 2010. Dike systems and their volcanic host rocks on King George Island, Antarctica: Implications on the geodynamic history based on a multidisciplinary approach. Tectonophysics, Vol. 495, Issue. 3-4, p. 269.

    LEVER, H. and FANNING, C. M. 2004. Alunite alteration of tuffaceous layers and zircon dating, Upper Permian Kennedy Group, Carnarvon Basin, Western Australia. Australian Journal of Earth Sciences, Vol. 51, Issue. 2, p. 189.

    Yeo, Jeong Pil Lee, Jong Ik Hur, Soon Do and Choi, Byeon-Gak 2004. Geochemistry of volcanic rocks in Barton and Weaver peninsulas, King George Island, Antarctica: Implications for arc maturity and correlation with fossilized volcanic centers. Geosciences Journal, Vol. 8, Issue. 1, p. 11.

    2004. Abstracts. Applied Earth Science, Vol. 113, Issue. 2, p. 125.


Successive geothermal, volcanic-hydrothermal and contact-metasomatic events in Cenozoic volcanic-arc basalts, South Shetland Islands, Antarctica

  • ROBERT C. R. WILLAN (a1) and DEBBIE C. ARMSTRONG (a1) (a2)
  • DOI:
  • Published online: 01 July 2002

Hydrothermal alteration in volcanic arcs occurs in many settings and may involve magmatic, marine, lacustrine or groundwaters, driven by magmatic, tectonic or thermal events. King George Island, part of the South Shetland Island Cenozoic volcanic arc, contains an 80 km long zone of propylitized volcanic rocks, with numerous occurrences of quartz veining, silicic, sericitic, argillic and advanced-argillic alteration. On Barton Peninsula, a basaltic lava sequence (49–44 Ma) intruded by a small, high-level granodiorite pluton (∼42 Ma), contains these alteration types, previously interpreted as a single porphyry-copper system. In this study, we report three, possibly four, distinct fossil hydrothermal episodes. (1) Banded chalcedonic quartz, quartz-sericite and propylitic alteration occurs along ESE faults and as reworked clasts in nearby tuffs. Drusy quartz + calcite veins with silicic/sericitic, argillic and propylitic wallrocks may represent feeders to the near-surface silicification. These characteristics, and anomalous Ag + Pb + Sb + Au plus Te + Se + Zn + As, suggest a neutral-pH geothermal system that was active during volcanism. (2) The lavas and banded-quartz rocks were brecciated, veined and replaced by alunite+native sulphur+pyrite, and pyrophyllite + quartz + pyrite + zunyite + diaspore assemblages with anomalous Hg + Se + As + Bi + Au + Tl + Sb + Cu. Such advanced-argillic alteration is diagnostic of degassing of a felsic magma into shallow (<500 m) meteoric groundwaters. Rhyolite tuffs, previously not reported on King George Island, may represent leakage of this magma to the surface. (3) Subsequent burial to ∼3 km was followed by emplacement of a granodiorite pluton and formation of a silicic contact-metasomatic aureole containing muscovite, biotite, actinolite, magnetite, K-feldspar and tourmaline. Disseminated andalusite + corundum also formed in areas previously affected by the advanced-argillic alteration. Iron/copper-sulphide veinlets are locally abundant, but a porphyry-style geochemical signature is not present. Early Cretaceous Ar–Ar ages near the intrusive contact indicate flow of an excess Ar-bearing hydrothermal plume up the contact. Finally, isolated areas of propylitic alteration in the lavas nearby may be related either to quartz veins of episode 1 at depth or to (4) continued circulation of heated groundwaters around the cooling pluton.

Corresponding author
Author for correspondence:
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Geological Magazine
  • ISSN: 0016-7568
  • EISSN: 1469-5081
  • URL: /core/journals/geological-magazine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *