Curtin researchers have developed a new technique by studying the age of ancient grains of sand from beaches, rivers and rocks from around the world to reveal previously hidden details of the Earth\u2019s distant geological past.<\/p>\n
Lead researcher Dr Milo Barham, from the Timescales of Mineral Systems Group within Curtin\u2019s School of Earth and Planetary Sciences, said the team devised a metric, which determines the \u2018age distribution fingerprint\u2019 of minerals known as zircon within sand, shedding new light on the evolution of the Earth\u2019s surface over the last few billion years.<\/p>\n
\u201cWhile much of the original geological record is lost to erosion, durable minerals like zircon form sediments that effectively gather information from these lost worlds to paint a vivid picture of the planet\u2019s history, including changing environments, the development of a habitable biosphere, the evolution of continents, and the accumulation of mineral resources at ancient plate boundaries,\u201d Dr Barham said.<\/p>\n
\u201cThis new approach allows a greater understanding of the nature of ancient geology in order to reconstruct the arrangement and movement of tectonic plates on Earth through time.<\/p>\n
\u201cThe world\u2019s beaches faithfully record a detailed history of our planet\u2019s geological past, with billions of years of Earth\u2019s history imprinted in the geology of each grain of sand and our technique helps unlock this information.\u201d<\/p>\n
Co-author Professor Chris Kirkland, also from the Timescales of Mineral Systems Group within Curtin\u2019s School of Earth and Planetary Sciences, said the new method can be used to trace the Earth\u2019s history with greater detail than previously achievable.<\/p>\n
\u201cZircons contain chemical elements that allow us to date and reconstruct the conditions of mineral formation. Much like human population demographics trace the evolution of countries, this technique allows us to chart the evolution of continents by identifying the particular age population demographics of zircon grains in a sediment,\u201d Professor Kirkland said.<\/p>\n
\u201cThe way the Earth recycles itself through erosion is tracked in the pattern of ages of zircon grains in different geological settings. For example, the sediment on the west and east coasts of South America are completely different because there are many young grains on the west side that were created from crust plunging beneath the continent, driving earthquakes and volcanoes in the Andes. Whereas, on the east coast, all is relatively calm geologically and there is a mix of old and young grains picked up from a diversity of rocks across the Amazon basin.\u201d<\/p>\n
Dr Barham and Professor Kirkland are affiliated with The Institute for Geoscience Research (TIGeR), Curtin\u2019s flagship Earth Sciences research institute and the research was funded by the Minerals Research Institute of Western Australia.<\/p>\n