chemical composition of primitive mantle. The primitive mantle has K = 152 ppm, U = 0.020 ppm, Th = 0.078 ppm, K/U = 7724, and Rb/Sr = 0.025. However, there are elements like nickel and iron which are enclosed in the mantle. Mantle composition Several approaches have been used to try to determine the bulk composition of the Earth, or more specifically, the composition of its crust, mantle, and core. The composition of the whole mantle is estimated by requiring chondritic ratios of the major elements as well. implies cooler lower-mantle temperatures and more efficient heat-extraction during the thermal evolution of the Earth. By and large, the portions of the crust that poke above the sea to form land consist of 'continental crust'. Chemical composition - 'crust' and 'mantle' The surface of the Earth is the top of the 'crust' - whether one is under the sea or on land!
Tsuyoshi Komiya, Material circulation model including chemical differentiation within the mantle and secular variation of temperature and composition of the mantle, Physics of the Earth and Planetary Interiors, 10.1016/j.pepi.2003.03.001, 146, 1-2, (333-367), (2004). Although the pyrolite model is widely accepted as providing the chemical composition of the Earth’s fertile upper mantle, it is still not clear whether it is also representative of the lower mantle. The ratios are significantly less than previous estimates. 1. The composition of primitive mantle (54 elements) is estimated by a mass balance approach that does not make a priori assignments of basalt:peridotite ratios or LIL contents of these components.

It is concluded by now that the composition of the mantle is 46% silicon oxide, 38% magnesium oxide, 8% iron oxide and other compounds like “garnet”.
They correspond crudely to: a) looking at (the In this way one can estimate the volatile and siderophile content of the mantle. This approach based on terrestrial samples is more satisfac- The main composition of the earth's mantle is a huge rocky body. ‘‘Primitive man-tle’’ (PM) and ‘‘bulk silicate Earth’’ (BSE) are synonymous referring to the chemical composition of mantle after core segregation but before the extraction of continental crust. The exact composition of the mantle is not known with certainty, but is determined or inferred by the material coming from volcanic eruptions coming from up to 300 km depth.