A study published by researchers from Pennsylvania State University contradicts existing theories that suggest the rapid formation of tectonic plates earlier in Earth's history.
Previous research used single minerals to calculate the crustal growth rate, but according to the authors this method is prone to errors as mineral grains can recrystallize at a later time, adding"phantom time" to the supposed age of crystallization."We calculated how much reworking has happened by looking at the composition of igneous rocks in a new way," Reimink explains.
To do that, the researchers developed a unique method for determining how igneous rocks were reworked and reformed over time and experimentally demonstrating how the same rock could change in different ways over time. They used these calculations to calibrate the reworking documented in the rock records. Then, they calculated Earth's crustal growth curve using the new understanding of how the rocks were reformed. They compared the newly calculated curve to the rate of growth gleaned from mineral records by other experts.
The crustal growth curve based on the rocks fits a slow formation of continents better than a fast formation as suggested by the minerals alone. Reimink cautioned that the research improves on what researchers understand, but it's not the be-all and the end-all for crustal growth research. There are simply too few data points covering the first billion years of Earth's history to be absolutely sure.likely fueling the planets bio- and geodivesity