摘要
Geologists have long-debated about when plate tectonics started on the planet. One of the key indicators has been whether or not fragments of oceanic crust, generated at sea-floor spreading centers, are preserved in the planet’s oldest crust. New research integrating what has been learned about the variations in modern sea floor spreading environments with the geological record of the oldest preserved crust on
Geologists have long-debated about when plate tectonics started on the planet. One of the key indicators has been whether or not fragments of oceanic crust, generated at sea-floor spreading centers, are preserved in the planet＇s oldest crust. New research integrating what has been learned about the variations in modern sea floor spreading environments with the geological record of the oldest preserved crust on Earth shows that many belts in these ancient terrains have striking similarities to the different tectonic settings that oceanic crust is generated within the modem plate tectonic framework The new study shows that there is at least as much variation between ancient Precambrian （greater than 2.5 billion years） and modem oceanic spreading processes as there is in the modem oceans.
