A geoscience expert to study why continents split where magma is lacking


D. Sarah Stamps. Credit: Mike Lee

The Earth’s surface keeps moving and changing shape, disintegrating and forming new land masses and oceans. In the billions of years of planet Earth’s history, there have been 10 supercontinents, the most famous and recent being Pangea which shattered around 175 million years ago.

Africa itself is slowly separating into several large and small tectonic blocks along the divergent East African Rift System, which includes Madagascar – the long island just off the coast of Southeast Africa – which itself will also divide into smaller islands. The culprit is the region’s rich and deep magma intrusions. Yet Africa is also experiencing continental rifts, separations, in areas where there is no evidence of magma intrusions. These types of continental rifts are known as low magma or “dry” rifts. In short, if it was a mystery, the identity of the culprit is unknown.

D. Sarah Stamps, associate professor in the Department of Geosciences, part of the Virginia Tech College of Science, wants to put her expertise in continental rifting to find the bad guy. Stamps recently received a $ 3 million grant from the National Science Foundation for the DRIAR project (short for Dry Rifting In the Albertine-Rhino Graben, Uganda) to help boost its efforts.

“You can think of the breakup of East Africa as the continuation of the breakup of Pangea,” said Stamps, head of the Geodesy and Tectonophysics Laboratory. “East Africa is actively disintegrating, and if this continues we will see new oceans forming. In northern parts of East Africa, such as Ethiopia and the Afar region, it has already spread to the point of forming baby ocean areas. the spread has already created a new oceanic crust. The land is sagging and the first stages of forming a new ocean basin are underway. “

Further south, in the East African Central Rift system, the continent’s break-up is less intense. This is where Stamps has spent much of his research career. For this effort, Stamps is leading a large team of experts. From the United States, his collaborators come from the Woods Hole Oceanographic Institute, the University of Kansas, Northwestern University, the University of California, Davis and Midwestern State University in Texas. In Uganda, the team works directly with the government’s Ministry of Energy and Mining Development and with Makerere University in Uganda.

“This team and I are very interested in understanding the physics of how a continent can shatter when there is no surface expression of magma in the form of volcanoes,” Stamps said.

The team will focus on the northwest branch of the East African Rift System located in Uganda, East Africa, where magma-poor rifting takes place. A wide range of geophysical, geological and geochemical observations will be collected and digital modeling of the region will be performed to understand how magma-poor rifts form and evolve.

Among the answers Stamps and coworkers seek to answer: In magma-rich faults, is deformation adapted by lithospheric weakening of melt? ; In poor magma rifts, is melt present below the surface weakening the lithosphere such that deformation is adapted during extension of the upper crust? ; And in magma-poor rifts, what if there is no deep melting and the deformation is lodged along fluid-filled faults or pre-existing structures such as lithospheric heterogeneities of inherited composition, structure and rheology?

“I hope there will definitely be impacts on our understanding of the physics of continental rifting,” Stamps said. “But we also have a lot of broader impacts in terms of capacity building in Uganda. So we will be organizing field schools in Uganda to teach people how to use the equipment and analyze the data.”

Three scientists, a Ph.D. work with Stamps. geoscience student from Uganda, Asenath Kwagalakwe, and two undergraduates from the Computer Modeling and Data Analysis program of the Academy of Data Sciences, third year student Esha Islam and Crystal Lee , third year student. The Academy of Data Science is also part of the College of Science.

“I’m working on the Albertine-Rhino Graben, which is the northernmost rift in the western branch of the East African rift system. My research interests focus on studying the physics of stress accommodation in the magma-poor eastern Albertine-Rhino Graben. African Rift System using geodynamic modeling and GNSS [Global Navigation Satellite System] geodesy, ”Kwagalakwe said.

Islam, on the other hand, took an elective geoscience course and greatly appreciated the presence of Stamps as a teacher in the classroom. Islam asked Stamps about research opportunities. “Data science is very flexible in what it can be applied to, and coding is used in most areas related to STEM. Therefore, even though I had no notable experience in geoscience, Dr Stamps was willing to offer me a place, ”she said. noted.

“Currently my job is to rerun test models from other graduate students to determine that we are all getting the same results. “

Lee added, “I was associated with the project through my friend, Esha Islam, who has worked with Dr Stamps for some time and is also a peer in my major. I was interested in joining the project when she told me about it because I wanted to expand my experience with data processing and modeling. ”Lee will analyze GNSS data collected in Uganda.

Among the benefits of the study, in addition to gaining a better understanding of the continental rift, Stamps highlights the improved estimates of carbon dioxide transfer to the atmosphere that occurs during the continental rift, advancing the rift models used to explore natural resources and create new information about the seismic risks associated with active fault.


East African rift system slowly disintegrates, with Madagascar splitting into pieces


Provided by Virginia Tech


Quote: A geoscience expert to study why continents separate where magma is lacking (2022, January 5) retrieved January 5, 2022 from https://phys.org/news/2022-01-geoscience-expert-continents-magma .html

This document is subject to copyright. Other than fair use for private study or research purposes, no part may be reproduced without written permission. The content is provided for information only.

About Lucille Thompson

Check Also

Small volcanoes play an important role in clarifying the structures of tectonic plates

Researchers from Tohoku University and the Chiba Institute of Technology have painted a clearer picture …