An Impact Crater in Palm Valley, Central Australia?

TL;DR

This study investigates a circular depression in Palm Valley, Australia, considering impact origin over erosion, but definitive evidence is lacking, highlighting the need for further research and criteria for impact crater identification.

Contribution

The paper presents a detailed analysis of a potential impact crater in Palm Valley, emphasizing the importance of developing diagnostic criteria for small, ancient impact craters.

Findings

No evidence of volcanism in the region.

The depression is unlikely formed by erosion.

Impact origin remains a plausible hypothesis.

Abstract

We explore the origin of a ~280 m wide, heavily eroded circular depression in Palm Valley, Northern Territory, Australia using gravity, morphological, and mineralogical data collected from a field survey in September 2009. From the analysis of the survey, we debate probable formation processes, namely erosion and impact, as no evidence of volcanism is found in the region or reported in the literature. We argue that the depression was not formed by erosion and consider an impact origin, although we acknowledge that diagnostics required to identify it as such (e.g. meteorite fragments, shatter cones, shocked quartz) are lacking, leaving the formation process uncertain. We encourage further discussion of the depression's origin and stress a need to develop recognition criteria that can help identify small, ancient impact craters. We also encourage systematic searches for impact craters in Central Australia as it is probable that many more remain to be discovered.