a) A sample of continental crust with radiogenic concentrations listed below Ele
ID: 288057 • Letter: A
Question
a) A sample of continental crust with radiogenic concentrations listed below Element Concentration 1.42 parts per million 5.60 parts per million Th b) Asample of mantle-derived peridotite with radiogenic concentration listed blow: Element Concentration (kg/kg) 1 parts per billion Th4 parts per billion 30 parts per million c) A sample of chondritic meteorite with radiogenic concentrations listed below: Element Concentration (kg/kg) Th 29 parts per billion 560 parts per million 2) From the concentrations listed above, what can you say about the partitioning (ie. dividing up) of radiogenic elements between the crust and mantle, and what are the implications for internal heat production in the earth today? Note that chondritic meteorites are considered to have concentrations similar to the primordial earth.Explanation / Answer
From the above mentioned data we're seeing that the concentration of Uranium, Thorium and Potassium produced by radioactivity that is present in the crust is more than that is present in the mantle (see the concentration values and difference in the unit hundreds, million and billions). This means that there is a lot of radioactive reactions that is going on inside the mantle and the heat produced by these reactions are used to keep the asthenosphere in its form so that it can flow plastically and hence by this convection current of asthenosphere the listhospheric plates can move which is the cause of plate tectonic. Therefore the heat of the radioactive reactions is used to keep our earth surface in a dynamic form.
If we'll compare the products of radioactive elements that is present in the mantle with chondritic meteorites we'll see the concentration of products of radioactive elements is more in mantle which states for the reason that from the time of the formation of the earth these radioactive reactions are happening inside the surface of earth and hence we have more products as compared to chondritic meteorites.
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