ILLINOIS UNIVERSITY IN URBAN-CHAMPAIGN, BUREAU NEWS
CREDIT: JIASHUN HUE GRAPHIC COURSE
CHAMPAIGN, Illustration – The Andes Mountains are much taller than plate tectonic theories predict them, a fact that has puzzled geologists for decades. Models of mountain construction tend to focus on the deep-floor compressive forces that occur when tectonic plates collide and send rock up into the sky. A new study demonstrates how modern top-down models that account for climate-related factors combined with traditional bottom-up tectonic models can help uncover the puzzling history of Andes Mountains.
Research by University of Illinois Urbana-Champaign alumni Jiashun Hu, Illinois Geology professor Lijun Liu and professor at the California Institute of Technology Michael Gurnis, published in the journal Essential communication.
“The Andes Mountains are unique for their tectonic setting,” says Liu. “The center of the band is unusually high for a part formed by relatively low compressive stresses and weak inter-plate coupling that we think occurs when thin, dense oceanic crust sinks – or slide down – the continental crust is thick.”
Geochemical and chronological data show that the most recent period of Andean Mountain building began 40 million years ago, and the most significant shortening of the crust – mountain formation – began in the central to north of the present-day Andes and gradually extended southward.
There is preserved geological evidence along the Andean coast that the southern Andean expansion continues today, but causes migration and layer deformation, Liu said. This substantial shell remains unclear.
Many studies show higher rates of erosion in the southern Andes, due to a warmer and wetter climate in the north, which corresponds chronologically with evidence of increased sedimentation into the Andean Trench. This sediment, deposited along the bottom of the trench along the Nazca plate next to the transducer, may have acted as a lubricant on top of the sub-plate by reducing compression and leading to low mountains, the researchers say. than.
Liu’s team took this tectonic-climate relationship one step further, discovering the influence of a curious east-west trend feature known as the Juan Fernandez Ridge – a chain of mountain hotspots. Flooded fire still exists to this day.
“Today, where the Juan Fernandez Ridge meets the Chilean coast, it acts as a barrier to northward migrating sediments,” said Hu, lead author of the study. “We hypothesize that this ridge has been around for millions of years, slowly migrating south with the subducting Nazca Plate, starving northern Andean Trench deposits that strengthen plate connectivity and shape become a mountain behind the migratory mountainside”.
The team’s new model explains the impact of the Juan Fernandez Ridge on sediment transport over time.
“When we used our model to reverse time and reconstruct the subduction history of the Nazca Array in 3D, the effects of including Juan Fernandez Ridge corresponded distinctly to the features of the Nazca Plate. geology that we see in the Andes today,” said Hu.
The model has yet to be tested with a range of hypotheses that exist about the formation of the Andes Mountains – some of which include extremely complex plate subduction geometries, the study’s report says.
“This study is an important step towards potentially quantitatively linking climate and tectonics – something that has not been clearly demonstrated by previous studies,” said Liu.
The National Science Foundation, the National Natural Science Foundation of China, and the Center for Computational Science and Engineering at Southern University of Science and Technology supported this research.
Editor’s Note:
To contact Jiashun Ju, send an email [email protected].
To contact Lijun Liu, call 217-300-0378; email [email protected].
Available article “Southern expansion of plate coupling due to variation in sedimentation as the cause of Andean development” is available. Online and from U. of I. Department of News. DOI: 10.1038 / s41467-021-27518-8.
JOURNEYS
Nature Communications
DOI
RESEARCH METHODS
Simulation / computational modeling
RESEARCH SUBJECTS
Do not apply
ARTICLE TITLE
Southward expansion of plate alignment due to variation in sedimentation is responsible for Andean development.
ARTICLE PUBLICATION DATE
December 14, 2021
REPORT REPORT
Many authors state that they have no interest in competing.
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