Accurate spatial models of tectonic plates and geological terrain 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, created new models for tectonic plates that offer a fresh insight into Earth’s history.
The models show how the continents were assembled. Compared to existing models, it improves the correlation between an observed earthquake and the occurrence of volcanoes within deformation zones and microplates.
Dr. Derrick Hasterok, a professor in the Department of Earth Sciences at the University of Adelaide, who led the team that produced the new models, said: “We looked at current knowledge of the configuration of boundary zones. the plates and the past construction of the continental crust. ”
“The continents assembled a few pieces at once, a bit like a puzzle, but every time the puzzle was finished, it was cut and rearranged to produce a new image. Our study helps to illuminate the different components because geologists can gather the above images “.
“We found that plate boundary zones account for nearly 16 percent of the Earth’s crust and an even larger proportion, 27 percent, of the continents.”
“Our new tectonic plate model better explains the spatial distribution of 90% of earthquakes and 80% of volcanoes in the last two million years, while existing models only capture 65% of earthquakes.”
Scientists created three new geological models: a plate model, a province model, and an orogeny model.
26 orogenies (mountain building processes) have left their mark on the current architecture of the 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 in southern Tasmania, and the Capricorn microplate, which separates the Indian and Australian plates, are among the additional microplates in the revised plate model. Other (accurate) data were added to further enrich the model on the boundaries of the deformation zones: previous models showed them as discrete areas rather than wide zones.
Dr. Hasterok said: “The most significant changes in the plate model have occurred in western North America, which often has the boundary with the Pacific plate drawn as the San Andreas and Queen Charlotte faults. “But the newly demarcated boundary is much wider, about 1500 km, than the narrow area previously drawn.”
“The other big change is in Central Asia. The new model now includes all the deformation zones in northern India as the plate climbs toward Eurasia.”
“Our new tectonic plate model better explains the spatial distribution of 90% of earthquakes and 80% of volcanoes in the last two million years, while existing models only capture 65% of earthquakes.”
“The plate model can be used to improve georisk risk models; the orogeny model helps to understand geodynamic systems and better model the evolution of the Earth, and the province model can be used to improve mineral prospecting. “
Magazine reference:
- Derrick Hasterok et al. New maps of global geological provinces and tectonic plates. DOI: 10.1016 / j.earscirev.2022.104069