Composition of impact melt debris from the Eltanin impact strewn field, Bellingshausen Sea

• Published in: Deep-sea research. Part II, Topical studies in oceanography Topical studies in oceanography, 2002, Vol.49 (6), p.1029-1047
• Main Author: Kyte, Frank T.
• Format: Article
• Language: English
• Subjects: Geosciences (General); Marine
• ISSN: 0967-0645; 1879-0100
• DOI: 10.1016/S0967-0645(01)00140-0

The impact of the km-sized Eltanin asteroid into the Bellingshausen Sea produced mm- to cm-sized vesicular impact melt-rock particles found in sediment cores across a large area of the ocean floor. These particles are composed mainly of olivine and glass with minor chromite and traces of NiFe-sulfides. Some particles have inclusions of unmelted mineral and rock fragments from the precursor asteroid. Although all samples of melt rock examined have experienced significant alteration since their deposition in the late Pliocene, a significant portion of these particles have interiors that remain pristine and can be used to estimate the bulk composition of the impact melt. The bulk composition of the melt-rock particles is similar to the composition of basaltic meteorites such as howardites or mesosiderite silicates, with a contribution from seawater salts and a siderophile-rich component. There is no evidence that the Eltanin impact melt contains a significant terrestrial silicate component that might have been incorporated by mixing of the projectile with oceanic crust. If terrestrial silicates were incorporated into the melt, then their contribution must be much