Accurate spatial models of tectonic plates and geological terrains are essential for analyzing and interpreting a wide variety of geoscientific data and developing compositional and physical models of the lithosphere. In a new study, scientists from the universities of Adelaide, Tasmania, Nevada-Reno and Geoscience Australia have created new models of tectonic plates that offer a fresh look at Earth’s history.
The models show how the continents are assembled. Compared to existing models, it improves the correlation between observed earthquakes and volcanic manifestations in deformation zones and microplates.
Dr Derrick Hasterok, a lecturer in the Department of Earth Sciences at the University of Adelaide who led the team that produced the new models, said:
“The continents were put together in several pieces at once, a bit like a puzzle, but each time the puzzle was completed, it was cut and reorganized to create a new picture. Our research helps to illuminate the various components so that geologists can collect previous images.
“We found that the boundary areas of the plates represent nearly 16 percent of the earth’s crust and an even higher share, 27 percent, of the continents.
“Our new tectonic plate model better explains the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes over the past two million years, while existing models capture only 65 percent of earthquakes.
Scientists have created three new geological models: a plate model, a province model and an orogeny model.
26 orogenesis (mountain building processes) have left their mark on the current architecture of the earth’s crust. Many, but not all, are related to the creation of supercontinents. This new work allows scientists to map tectonic plates and the formation of continents.
The Macquarie microplate, located south of Tasmania, and the Capricorn microplate, which separates the Indian and Australian plates, are among the additional microplates in the revised model of the plate. Other (precise) data have been added to further enrich the deformation zone boundary model: previous models have shown them as discrete areas rather than wide zones.
Dr Gasterok said: “The biggest changes in the slab pattern are in western North America, which often has a border with the Pacific Plate, drawn as the San Andreas and Queen Charlotte Faults. But the newly delineated border is much wider, approximately 1,500 km, than the pre-delineated narrow area.
“The other big change is in Central Asia. The new model now includes all deformation zones north of India as the slab makes its way with bulldogs in Eurasia.
“Our new tectonic plate model better explains the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes over the past two million years, while existing models capture only 65 percent of earthquakes.
“The sign model can be used to improve geohazard risk models; the orogeny model helps to understand geodynamic systems and better model the evolution of the Earth, and the provincial model can be used to improve mineral demand.
Journal reference:
- Derrick Hasterok et al. New maps of global geological provinces and tectonic plates. DOI: 10.1016 / j.earscirev.2022.104069
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