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The Foelsche structure, Northern Territory, Australia: An impact crater of probable Neoproterozoic age

Citation

Haines, PW and Rawlings, DJ, The Foelsche structure, Northern Territory, Australia: An impact crater of probable Neoproterozoic age, Meteoritics and Planetary Science, 37, (2) pp. 269-280. ISSN 1086-9379 (2002) [Refereed Article]

DOI: doi:10.1111/j.1945-5100.2002.tb01109.x

Abstract

The Foelsche structure is situated in the McArthur Basin of northern Australia (16°40′S, 136°47′E). It comprises a roughly circular outcrop of flat-lying Neoproterozoic Bukalara Sandstone, overlying and partly rimmed by tangentially striking, discontinuous outcrops of dipping, fractured and brecciated Mesoproterozoic Limmen Sandstone. The outcrop expression coincides with a prominent circular aeromagnetic anomaly, which can be explained in terms of the local disruption and removal or displacement of a regional mafic igneous layer within a circular area at depth. Samples of red, lithic, pebbly sandstone from the stratigraphically lowest exposed levels of the Bukalara Sandstone within the Foelsche structure contain detrital quartz grains displaying mosaicism, planar fractures (PFs) and planar deformation features (PDFs). PFs and PDFs occur in multiple intersecting sets with orientations consistent with a shock metamorphic origin. The abundance and angular nature of the shocked grains indicates a nearby provenance. Surface expression and geophysical data are consistent with a partly buried complex impact crater of ∼6 km in diameter with an obscured central uplift ∼2 km in diameter. The deformed outcrops of Limmen Sandstone are interpreted as relics of the original crater rim, but the central region of the crater, from which the shocked grains were likely derived, remains buried. From the best available age constraints the Foelsche structure is most likely of Neoproterozoic age.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geology
Research Field:Structural Geology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Haines, PW (Dr Peter Haines)
ID Code:24729
Year Published:2002
Web of Science® Times Cited:11
Deposited By:Earth Sciences
Deposited On:2002-08-01
Last Modified:2003-02-27
Downloads:0

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