Penecontemporary tectonic forms in basement areas: evidence derived from quarry exposures on northwestern Eyre Peninsula, South Australia

Abstract

Monitoring of quarry exposures on northwestern Eyre Peninsula, South Australia has shown that the granite domes of that region are structurally complex features, commonly with several structural domes within each topographic form. The rock masses are in horizontal compression so that few steeply inclined fractures have been penetrated by water and hence are not weathered, though sheet fractures, which are tectonic features, are arched, dilated, and thus readily infiltrated by water. Neotectonic forms, such as fault scarps, A-tents, or pop-ups, and disturbed blocks are still developing. These observations provide further evidence of neotectonism, even in cratonic lands.

Keywords:

• Neotectonism
• Granite
• Quarry exposure
• A-tent
• pop-up
• Imbrication
• Eyre Peninsula