Lot 82
Lake Murray
The Robert Elliott Meteorite Collection
Auction: 18 August 2009 at 15:00 BST
Description
Etched part slice
Dimensions
3.9kg, 38.5 x 16.8cm
Footnote
Lake Murray (Carter County, Oklahoma, USA) IIB (iron) - found 1933
A single mass of iron was found in a gully in 1933 and recognised as a meteorite in 1952. The Lake Murray meteorite was recovered from undisturbed Antler Sandstone dating from the Lower Cretaceous period, indicating that Lake Murray landed in a near-shore shallow sea while these beds were being deposited about 110 million years ago. This is the oldest true meteorite known to science.
With such a long Earth-age, the exterior was heavily corroded and a 6-inch thick skin of rusty shale surrounded the iron. However, the inner nickel-iron core was relatively unweathered, unaltered and wonderfully preserved, probably due to the thick oxide layer giving a high degree of protection to the inner core.
Lake Murray is a coarsest octahedrite and the etched face reveals large kamacite & taenite bands measuring up to 115mm across. Several of these large bands contain central 'rosettes' of swirling schreibersite inclusions.