The Thermal and Alteration History of NWA 8114 Martian Regolith.

Authors: Jane Macarthur (University of Leicester) , John Bridges (University of Leicester) , Leon Hicks (University of Leicester) , Steve Gurman (University of Leicester)
Co-authored by industrial partner: No

Type: Conference Paper
Conference: 46th Lunar and Planetary Science Conference
Peer Reviewed: No

State: Published (Approved)
Published: February 2015
Diamond Proposal Number(s): 9418 , 10328

Open Access Open Access

Abstract: NWA 8114 (a pair of NWA 7034) is a polymict [1] martian basaltic breccia [2] with a bulkrock age of ~2.1 Ga [2] containing zircons dated at ~4.4 Ga [3]. It is the first sample of the martian regolith [3], with varied clasts bound in a fine grained matrix [4]. As the most hydrated martian meteorite identified to date [2], the majority of the water is thought to be hosted by hydrous Fe oxides, with a minor contribution from apatite [5]. The ferric phrases maghemite and goethite have been detected [6], making this potentially the most oxidized known martian meteorite [1,6]. The oxygen isotope ratio of water shows Δ17O values above the terrestrial fractionation line and the D/H isotope ratio analyses also support the martian origin of water in NWA 7034 [2]. The meteorite was likely formed as a result of an impact event [7] which may have led to hydrothermal systems causing further alteration to it [6,8]. Our work characterises the partial breakdown, and mantling by fine-grained material, of pyroxene clasts, in terms of their oxidation state and related textures. We combine this with mineral thermometry to reveal the thermal history of the impact regolith within which the parent rock of this meteorite formed.

Subject Areas: Earth Science, Materials, Physics

Instruments: I18-Microfocus Spectroscopy

Added On: 31/03/2015 18:13

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