Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The ancient rotation of the Iberian Peninsula left a magnetic trace

07.03.2016

The volcanic rock found in the south of Leon (Spain) experienced a rotation of almost 60º 300 million years ago, an example of what could have occurred across the entire Iberian Peninsula when, in that moment, it was still being formed. This fact is demonstrated by the magnetic signals of its minerals, currently being analysed by researchers from the universities of Salamanca and Utrecht (The Netherlands). This discovery improves our understanding of a now-disappeared mountain range that stood over what is now north-western Spain, France, and the southern United Kingdom.

The bathers that gather every summer on the banks of the rivers of the mountain ranges of La Cabrera and El Teleno in Leon (Spain) have little reason to suspect that the rocks that they can see near the water are of volcanic origin, over 460 million years old, when an emerging Iberian Peninsula was still on the coast of the continent of Gondwana, on the shore of the Rheic ocean.


This is an aerial photograph of the Truchillas river (Truchas, Leon), and detail of its volcanic rock.

Credit: J. Fernandez Lozano et al.

Around 350 million years ago, that ancient ocean closed during the formation of the Pangea supercontinent, and the sediments deposited in it became a large mountain range that later acquired a curved shape, becoming part of what is now the Iberian Peninsula around 300 million years ago.

Now scientists at University of Salamanca have collected, in the Leonese towns located between Truchas and Ponferrada, 320 samples of volcanic rock and limestone, a record of that turbulent, volcanic period of our planet's history.

... more about:
»Cantabrian »SINC »collision »magnetic field »volcanic

After having analysed the samples in one of the most important Palaeomagnetism laboratories in the world, located at Utrecht University (The Netherlands), they have been able to reconstruct the history of these ancient rocks based on the magnetic signal of their mineral content. The results have been published in the journal 'Tectonophysics'.

"These rocks were deposited on the ocean floor 440 million years ago near the south pole, and its components were oriented in the direction of the Earth's magnetic field at the time (N-S)," explains to SINC Javier Fernandez Lozano, a geologist at the University of Salamanca and co-author of the research.

About 120 million years later, the collision of two continents occurred, between what is now the North and South of Europe. The result of this collision was what is known as the Variscan orogeny, the raising of a mountain range along the North-South axis, which left the rocks with a secondary magnetic signal, adapted to the new magnetic field of the Earth.

The changes in the direction of that magnetic field were preserved in their minerals, and indicate that shortly after that process, the rocks of these mountains experienced a rotation of almost 60º, until they ended up in with their current orientation," notes Fernandez Lozano.

He points out that this magnetic signal can be associated with large-scale processes of mountain formation, and how these ranges can be curved until they create structures known as oroclines: "With a rock sample, we can analyse a process that has occurred on the tectonic plate level; and, specifically, offers new data that allows us to discover how this orogeny or large Variscan range and its curvature occurred. This information was preserved in the rocks of the British Isles, France, and North-West Spain, along more than 3,000 kilometres.

This study forms part of a long-debated geological problem: the Cantabrian orocline, an issue that a few years ago brought together specialists at an international congress held in Salamanca. An orocline is the curvature of a range or chain of mountains that was originally linear, and the Cantabrian orocline is recognizable 300 million years later in the geography of the Iberian Peninsula and surrounding areas.

Concretely, one can observe the arc formed by the Cantabrian range until it disappears into the continental shelf, and the curvature that continues onward towards the Iberian Range. Fernandez Lozano notes that the new research "goes beyond previous efforts, primarily focused on Asturias, in order to understand this orocline, and now we can find its traces further to the south, on the border between Leon and Zamora."

"Thanks to studies like this one, we can continue to provide information on the causes and processes that gave birth to curved mountain ranges after the collision between two continents," concludes the geologist.

###

References:

Fernandez-Lozano, J., Pastor-Galan, D., Gutierrez-Alonso, G. y Franco, P. "New kinematic constraints on the Cantabrian orocline: A paleomagnetic study from the Peñalba and Truchas synclines, NW Spain". Tectonophysics , 20 February 2016 (on line). Doi: doi:10.1016/j.tecto.2016.02.019

SINC | EurekAlert!

Further reports about: Cantabrian SINC collision magnetic field volcanic

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>