Birger Schmitz at Sea Floor Sediments (IMAGE) Lund University Caption An important method that led to the discovery was the measurements of extraterrestrial helium incorporated in the petrified sea floor sediments at Kinnekulle in southern Sweden. Credit Philip R. Heck Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.