An international team of researchers has found that some of the oldest terrain on Venus, known as Tessere, has layering that appears to correspond to volcanic activity. This discovery may provide insight into the geological history of the esoteric planet.
Tesserae are tectonically deformed regions on the surface of Venus that are often higher than the surrounding landscape. They comprise about 7% of the planet’s surface, and are always the oldest feature in their surroundings, about 750 million years old. In a new study displayed in Geology, Researchers point out that a significant portion of Tesseri have strikes corresponding to layering.
“There are usually two explanations for tesserae — either they are made of volcanic rocks, or they are equivalent to the continental crust of the Earth,” says Paul Burn, an associate professor of planetary science at North Carolina State University. “But the layering we find on some of the tessera is not consistent with the continental crust explanation.”
The team analyzed surface images of Venus from NASA’s 1989 Magellan mission, which used radar to image 98% of the planet through its dense atmosphere. While researchers have studied tesserae for decades, tesserae levels have not been widely recognized before this work. And according to Byron, this layering would not be possible if Tesseri were part of the continental crust.
“Continental crust is mainly made of granite, the formation of an igneous rock when tectonic plates move and water falls from the surface,” says Bern. “But granite does not form layers. If there is a continental crust on Venus, it is beneath the layered rocks we have seen.
“Apart from volcanic activity, another way to form layered rocks is through sedimentary deposits, such as sandstone or limestone. There is not a single place on Venus today where rocks of this type can form. The surface of Venus is just as hot . The self-cleaning oven and pressure is equivalent to being under 900 meters (about 985 yards) underwater. So the evidence that is present now points to parts of Tessera made of layered volcanic rock found on Earth. ”
Byron hopes that this work will help shed light on the complex geological history of Venus.
“While the data now point to the volcanic origins we have for Tesseri, if we were able to sample them one day and find that they are sedimentary rocks, they would have formed when the climate was very different – perhaps Earth “—Like,” Byron says.
“Venus is hellish today, but we don’t know if it has always been like this. Was it once Earth-like, but devastating volcanic eruptions ruined the planet? Tesseri would describe the possible origin of this rock. is. ”
The research team included scientists from the US, UK, Turkey, Canada and Russia. The images come from NASA’s planetary data system and Astrophysics data system.
Mercury’s volcanic activity — or lack thereof — may help astronomers discover other worlds like Earth
Paul K. Byron et al, Venus tesseri feature layers, folded and eroded rocks, Geology (2020). DOI: 10.1130 / G47940.1
Provided by North Carolina State University
Quotes: The ancient layered, twisted rocks of Venus point to the volcano (2020, 17 September) from https://phys.org/news/2020-09-venus-ancient-layered-volcanic.html again on 18 September 2020 get
This document is subject to copyright. No part may be reproduced without written permission, except for any impartial behavior intended for personal study or research. The content is provided for information purposes only.