The first fossil meteorite from the mid-Ordovician of the Gullhögen quarry, Billingen, southern Sweden

Abstract

A fossil meteorite, c. 1 cm in diameter, has been found in a loose limestone block in the Gullhögen quarry at Billingen, southern Sweden. The meteorite, named Gullhögen 001, is almost completely pseudomorphosed by clay minerals and calcite, but contains abundant relict chromite grains and high platinum group element concentrations. Chromite element chemistry indicates that Gullhögen 001 most likely belongs to the L chondrite group, like most or all of the c. fifty mid-Ordovician fossil meteorites previously found in the Thorsberg quarry at Kinnekulle, 35 km to the northwest. Conodont studies show that the limestone surrounding Gullhögen 001 belongs to the Yangtzeplacognathus crassus Zone, i.e. the meteorite fell at the same time as those in the middle to upper part of the meteorite-yielding section in the Thorsberg quarry. The find of Gullhögen 001 supports the idea that the meteorite flux to Earth was strongly enhanced during a part of the mid-Ordovician, directly following a major asteroid disruption event in the asteroid belt.

Key Words:

• fossil meteorites
• chromite
• L chondrite
• middle Ordovician
• meteorite flux