The Formation Continent - A new way to calculate the age of the Earth's crust has been developed by researchers from the University of Bristol and University of St. Andrews.
A new way to calculate the age of the Earth's crust has been developed by researchers from the University of Bristol and University of St. Andrews.
Continental crust is the main recording conditions on Earth for 4.4 billion years. Its formation changed the composition of mantle and the atmosphere, it supports life, and remain as washers carbon dioxide through the weather and erosion. Therefore, continental crust has a major role in the evolution of the Earth, and yet the timing of derivatives remains a topic of heated debate.
It was widely believed that the young continental crust has grown from the depleted upper mantle. One common way to find out when new crust is formed is to determine the radiogenic isotope composition of sample crust, and compared the characteristics of isotopes with a coat that has been thinned. In other words, radiogenic isotopes can be used to calculate 'model age' crust formation, which represent the time because the crust samples separated from the source of his coat.
The concept of 'model age' has been widely used in the study of crustal evolution during the last three decades. But increasingly clear that using the isotope composition of the depleted mantle as a reference age calculation models of continental crust derivatives could lead to incomplete interpretations.
In a paper published yesterday in the journal Science, Dr. Bruno Dhuime of Bristol School of Earth Sciences and colleagues describe a new methodology for the calculation model of age, based on the isotope composition of the average new continental crust.
Dr. Dhuime said: "Age is calculated this way are significantly younger than the model ages calculated from the isotope composition of the depleted mantle. The new age is obtained more consistent with the geological record, which opens new perspectives in crustal evolution studies based on radiogenic isotopes." Similarly, as quoted from Physorg (13/01/11).
