Impact origin for the Hummeln structure (Sweden) and its link to the Ordovician disruption of the L chondrite parent body
Research output: Contribution to journal › Article
Several studies of meteorites show that a large disruption of an asteroid occurred ca. 470 Ma in our solar system's asteroid belt. As a consequence, a large number of meteorite impacts occurred on Earth during the following few million years. The finding and characterization, for the first time, of planar deformation features in quartz grains from rocks collected at the Middle Ordovician Hummeln structure (Sweden) prove the hypervelocity impact origin of the structure. The unambiguous shock features allow us to close an similar to 200-yr-old discussion about its origin, and further the hypothesis of enhanced asteroid bombardment during the Middle Ordovician, adding an impact crater to the increasing number confirmed and properly dated from this period. Despite its relatively small size (similar to 1.2 km in diameter), similar to the young Meteor Crater (Arizona, USA), and its old age, the Hummeln structure is remarkably well preserved, contradicting the general assumption that small craters are not preserved on Earth for more than a few tens of thousands to a couple of million years.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Publication status||Published - 2015|
Related research output
Terrestrial consequences of hypervelocity impact – shock metamorphism, shock barometry, and newly discovered impact structuresSanna Alwmark, 2016, Lund: Lund University, Faculty of Science, Department of Geology, Lithosphere and Biosphere Science. 138 p.
Research output: Thesis › Doctoral Thesis (compilation)