Science: bubbles of molten rock rising to the surface in the earth’s mantle, a dinosaur with another fossil in its stomach, the age of our planet’s solid inner core, water on the Earth

Photo: This map shows both volcanic chains (top: Tristan-Gough, below: Shona). The arrows mark the hotspot traces, also recognizable through the age of the volcanos in the boxes. Source: Stephan Homrighausen, created with GeoMapApp

Recent discoveries about our planet, its rocks and other “stone” topics

Volcanic chains can form, when bubbles of molten rock rise to the surface in the earth’s mantle, resembling a lava lamp. A research team led by GEOMAR Helmholtz Centre for Ocean Research Kiel has studied this so-called hotspot volcanism in the Atlantic and was able to learn more about the composition of earth’s lower mantle by analyzing the deposited rock layers. The study was recently published in the journal Science Advances.
 

The image shows the ichthyosaur's teeth, with the broken white line indicating the approximate gum line of the upper jaw. Source: Jiang et al./ ScienceWhen paleontologists digging in a quarry in southwestern China uncovered the nearly complete skeleton of a giant, dolphin-like marine reptile known as an ichthyosaur, they didn’t expect to find another fossil in its stomach. This second skeleton belonged to a four-meter-long, lizard-like aquatic reptile known as a thalattosaur and is one of the longest fossils ever found in the stomach of a prehistoric marine reptile.
 

A computer simulation of the Earth's magnetic field, which is generated by heat transfer in the Earth's core. Source: NASA/ Gary A.GlatzmaierBy creating conditions akin to the center of the Earth inside a laboratory chamber, researchers have improved the estimate of the age of our planet’s solid inner core, putting it at 1 billion to 1.3 billion years old, according to research by the University of Texas at Austin’s Jackson School of Geosciences. The results place the core at the younger end of an age spectrum that usually runs from about 1.3 billion to 4.5 billion years, but they also make it a good bit older than a recent estimate of only 565 million years.
 

An approximately 10-centimetre long piece of the Sahara 97096 meteorite, one of the enstatite chondrites studied. Water concentrations of around 0.5% by mass were measured in it, and part of the hydrogen was found to be located in the chondrules (the white spheres visible in the photograph). Sample belonging to the French National Museum of Natural History (Paris). Source: Christine Fieni / Laurette PianiThe Earth is the only planet known to have liquid water on its surface, a fundamental characteristic when it comes to explaining the emergence of life. However, was this water always present in the rocks that made up our planet? Alternatively, was it delivered later by asteroids and comets that bombarded the Earth? Or did the Earth’s water originate from a combination of both sources? Scientists from the Centre de Recherches Pétrographiques et Géochimiques in Nancy (CNRS/Université de Lorraine) contribute to this debate by showing that most of the water present on the Earth today has probably been there right from the very beginning.

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(05.09.2020, USA: 09.05.2020)