Sweden on EARTH Magazine

Meteorites did not spark Ordovician biodiversification

Mon, 15 May 2017 15:08:48 -0400

Zircon crystals contain trace amounts of uranium and thorium, making them useful for radiometric dating. These highly magnified crystals are about the size of a grain of sand. Credit: Anders Lindskog.

During the Ordovician Period, roughly 470 million years ago, an asteroid the size of a small moon collided with another rocky object in the belt between Mars and Jupiter, shattering the asteroid into billions of pieces. Fragments from the epic collision still occasionally fall to Earth today, making up a large share of the meteorites recovered. But in the immediate wake of the Ordovician event, many pieces rained down on the planet, settling on the surface and in layers of rock forming at the time. In a new study, researchers studying some of these meteorite-rich layers have refined the timescale for the collision. The results bring into question a proposed link between the meteorite bombardment and an evolutionary uptick known as the Great Ordovician Biodiversification Event (GOBE).

New type of meteorite found in Sweden

Mon, 17 Oct 2016 09:10:03 -0400

An 8-centimeter-wide meteorite, recently found embedded in pink limestone in a quarry in Sweden, is chemically distinct from all other known types of meteorites. Credit: Qing-zhu Yin, University of California, Davis.

Meteorites offer a glimpse into the workings and origins of our solar system. Now, a meteorite found in a Swedish quarry, reported in a new study in Nature Communications, is opening a whole new window: The find has been classified as a new type of meteorite, never before seen on Earth.

Travels in Geology: Gotland getaway: Sweden's 'tropical' escape in the Baltic

Wed, 16 Mar 2016 19:46:07 -0400

The iconic sea stacks, called raukarna, of Langhammars Nature Reserve on Fårö Island are the remnants of Silurian coral reefs. Credit: Naomi Lubick.

White sand beaches and thatched-roof houses probably are not part of most people’s conception of Sweden, yet they are characteristic of this northern European nation’s very own coral reef island getaway. This is no tropical island, mind you: 3,100-plus-square-kilometer Gotland sits squarely in the Baltic Sea, off the southeastern shore of Sweden just a short trip from the capital, Stockholm. My husband and I had heard about Gotland since we moved to Sweden several years ago. Swedes extol their country’s largest island as a place with good food, great beaches and lovely summers.