Large Meteorite Impacts and Planetary Evolution VI
This volume represents the proceedings of the homonymous international conference on all aspects of impact cratering and planetary science, which was held in October 2019 in Brasília, Brazil. The volume contains a sizable suite of contributions dealing with regional impact records (Australia, Sweden), impact craters and impactites, early Archean impacts and geophysical characteristics of impact structures, shock metamorphic investigations, post-impact hydrothermalism, and structural geology and morphometry of impact structures—on Earth and Mars. Many contributions report results from state-of-the-art investigations, for example, several that are based on electron backscatter diffraction studies, and deal with new potential chronometers and shock barometers (e.g., apatite). Established impact cratering workers and newcomers to the field will appreciate this multifaceted, multidisciplinary collection of impact cratering studies.
The Cleanskin impact structure, Northern Territory and Queensland, Australia: A reconnaissance study
†deceased
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Published:August 02, 2021
ABSTRACT
We report on the Cleanskin structure (18°10′00″S, 137°56′30″E), situated at the border between the Northern Territory and Queensland, Australia, and present results of preliminary geological fieldwork, microscopic analyses, and remote sensing. The Cleanskin structure is an eroded complex impact structure of ~15 km apparent diameter with a polygonal outline caused by two preexisting regional fault sets. The structure has a central uplift of ~6 km diameter surrounded by a rather shallow ring syncline. Based on stratigraphy, the uplift in the center may not exceed ~1000 m. The documentation of planar deformation features (PDFs), planar fractures (PFs), and feather features (FFs) in quartz grains from sandstone members of the Mesoproterozoic Constance Sandstone confirms the impact origin of the Cleanskin structure, as proposed earlier. The crater was most likely eroded before the Cambrian and later became buried beneath Cretaceous strata. We infer a late Mesoproterozoic to Neoproterozoic age of the impact event. In this chapter, the Cleanskin structure is compared with other midsized crater structures on Earth. Those with sandstone-dominated targets show structural similarities to the Cleanskin structure.
- Australasia
- Australia
- clastic rocks
- digital terrain models
- field studies
- fractures
- impact craters
- impact features
- Mesoproterozoic
- metamorphism
- Northern Territory Australia
- planar deformation features
- Precambrian
- Proterozoic
- Queensland Australia
- remote sensing
- sandstone
- sedimentary rocks
- shock metamorphism
- upper Precambrian
- Constance Sandstone
- Cleanskin impact structure