YC #1. Cauden Giant Ring Structure (370km diameter) seen in the Yilgarn geological surficial data. An Archaean Superplume, Meteorite Impact Structure or….?
© Robert Bingley Watchorn 8th July 2017
This paper is the first in a series that will document research on Cauden giant ring structure (GRS) in the Yilgarn Craton as observed in the various geoscientific data. These papers are deliberately written in colloquial language for access to as many people as possible.
Location. The centre of the Cauden GRS is located at 31˚ 40’E and 119˚40’S about 60 km SSE of Southern Cross. The Cauden giant ring structure is clearly seen in the Yilgarn Craton raw geological surficial outcrop data. The western rim of the Cauden is seen in the raw data but the centre and eastern rim is clearer in the enhanced data. The method of enhancing data has been desk top tested and field tested around the SE and southern outer rings. The structures can be found on the ground. These field trips will be published in later papers.
Time of formation. The overprinting by the Cauden GRS of the gneisses of the Southern Cross terrane suggests, on first analysis, that it formed late in the gneiss formation period. My research suggests, on the contrary, that it formed early and was active through all other deformation events (by re-activation of the original ring structure as a palimpsest). This is the most likely scenario as on the outer western arc (1) the intrusives and mineralisation are older than 2.9Ga but in the outer eastern arc (2) they are younger than 2.7Ga. The Yilgarn Craton developed very early (Wyche et al, 2004) but the eastern arc structure of the Cauden GRS is intruded by the 2.65 Ga geology.
Question. The geographical continuity of Cauden GRS suggests that the whole Yilgarn Craton is underlain by greater than 3Ga lower crust? This has been partially confirmed by the discovery of zircons of 3.1Ga age in the eastern Fraser Orogen…………
The full paper and images are accessed by the following link …
| Mt Cauden GRS in Yilgarn geological outcrop 1 | 7.2 MB |