Lithosphere, mass

Lithosphere, mass of, 14-9 to 10 Logarithmic series, A-65 to 67 Log P, 16-41 to 45 Loss factor, glasses, 12-56 Loss tangent, 6-17... 

We know very much about the outermost portion of the lithosphere because it is available for direct study. In contrast, we know almost nothing about the inner lithosphere, though it constitutes over 99.5% of the mass of the earth. 

Williams RW, Collerson KD, Gill JB, Deniel C (1992) High Th/U ratios in subcontinental lithospheric mantle mass spectrometric measurement of Th isotopes in Gaussberg lamproites. Eartli Planet Sci Lett 111 257-268... 

The elements whose isotopes are routinely measured with gas inlet mass spectrometers are carbon (12C and 13C, but not 14C), oxygen (160, 170, l80), hydrogen ( H, 2H, but not 3H), nitrogen (14N and 1SN) and sulphur (32S, 33S, 34). Stable isotopes of H, C, N, O, and S occur naturally throughout atmosphere, hydrosphere, lithosphere, and biosphere. They are atoms of the same elements with a different mass. Each element has a dominant light isotope with the nominal atomic weight (I2C, 160,14N, 32S, and H) and one or two heavy isotopes (l3C, nO, 180, 15N, 33S, 34S, and, 2H) with a natural abundance of a few percent or less Table 1). 

Table 8.1 shows the general distribution of water masses in the hydrosphere. Although H2O occurs mainly in oceans, 19% of the earth s H2O mass is still trapped in lithospheric rocks. A nonnegligible H2O mass (about 1%) is also fixed in crystalline form as ice. 

Both diffusion and convection are modes of mass transfer. Typically, large-scale mass transfer is accomplished by convection, and small-scale mass transfer is accomplished by diffusion. Similarly, large-scale heat transfer in the Earth is through convection (mantle convection), and small-scale heat transfer is through heat conduction (e.g., through the lithosphere). To treat the complicated convection pattern and diffusion requires a large computational effort. Some simple problems can be treated analytically. 

Occurrence in Nature. About 99.6% of the earth s mass results from 32 of the chemical elements. The remaining 0.4% is apportioned among 64 elements, all of which are present as traces. Iodine is one of these 64. Estimates about abundance of the constituent elements of the lithosphere place iodine 46th on a restricted list of 59 elements (37 very rare elements are excluded) and 61st on a list in which 96 elements are included. Iodine is, indeed, one of the scarcest of the nonmetallic elements in the total composition of the earth (3). 

On a mass basis, oxygen constitutes 23% of the atmosphere (21% by volume), 46% of the lithosphere (the earth s crust), and more than 85% of the hydrosphere. In the atmosphere, oxygen is found primarily as 02, sometimes called dioxygen. The oxygen in the hydrosphere is in the form of H20, but enough dissolved 02 is present to maintain aquatic life. In the lithosphere, oxygen is combined with other... 

Buck R (1991) Modes of continental lithospheric extension. J Geophys Res 96(B12) 20,161-20,178 Carson MA (1976) Mass-wasting, slope development and climate. In Geomorphology and climate. Derbyshire E (ed) John Wiley and Sons, New York, p 101-136... 

From available, though approximate, estimates, about 1023 g of carbon-containing gases are concentrated in the rocks of the Earth s crust and mantle (lithosphere) (Korstenshtein, 1984 Sokolov, 1971). This mass of carbon exceeds by approximately 104 times the amount present today in the biosphere (over the Earth surface). Between the biosphere and lithosphere there is a constant, very intensive exchange of carbon that is self-regulatory. From the data of Barenbaum (2000, 2002), due to the Le Chatelier principle (Krapivin et al., 1982), the content of mobile carbon in the system tries to attain a stable relationship ... 

Li Y-H. (1972) Geochemical mass balance among lithosphere, hydrosphere and atmosphere. Amer. J. Sci. 272, 119-137. 

In computing the average of the whole crust the relative proportions estimated by one of us2 some years ago were adopted. The latest estimates of the masses and compositions of the hydrosphere and atmosphere have been used. These relative masses are as follows Lithosphere 93% hydrosphere 7% atmosphere 0.03%. 

Despite the popular expression, you can t carry the world on your shoulders Scientists estimate that the lithosphere, or solid Earth, has a mass of 6.0 x 1024 kg. The hydrosphere, or the portion of Earth covered by water, has an estimated mass of 1.4 x 1021 kg. 

Horizontal and vertical mass transfer in the atmosphere, hydrosphere, and lithosphere, follow-... 

As introduced above, the interaction between the hydrosphere and the lithosphere frequently results in mass exchange. In this way rocks get dissolved, sediments build-up, stalactites and stalagmites form, materials get transported, and so on. The pH of water and of sediments determines the mobility and solubility of different elements, which may in turn modify the redox potential of the aqueous medium. For example, aluminum, calcium, magnesium, iron, manganese, and other metals become more soluble at low pH if pH increases, their solubility decreases and precipitation occurs. 

If the scheme of a steady-state ocean is adopted, in which volatile components (mainly HCl and CO2) occurred from the beginning in the same proportions in which they are now found in the lithosphere and hydrosphere, then the original solution would have been hydrochloric acid saturated with CO2 at high pressure. On the basis of calculations of mass made by Garrels... 

In 1980 a mass of about 355 Tg of sulfur has been removed from somewhere in the lithosphere-pedosphere. Of this mass 195 Tg has been deposited in the ocean water, 35 Tg in intracontinental water sheds and 125 Tg in oceanic sediments. 

The accepted mean density of Mars, based on its measured volume and determination of its mass from spacecraft orbits, is 3.9335 0.0004 g cm (Lodders and Fegley, 1998). The density of the elastic lithosphere (approximately equivalent to the crust), estimated from models of the relationship between gravity and topography from Mars Global Surveyor data, is 2.95-2.99 g cm (McKenzie et al., 2002), which is similar to the density of basalt. The planet s dimensionless moment of inertia (0.3662 0.0017), calculated from Mars Pathfinder measurement of the rate at which its spin pole precesses (Folkner et al., 1997), constrains the core radius to —1,300-1,500 km, depending on core composition. 

Oxidation of sulfur-bearing gases in the atmosphere can lead to non-mass-dependent isotopic fractionation, manifested as excesses or deficiencies in Farquhar et al. (2000) found small deficits in a nakhlite, and proposed that this was an isotopic signature of martian atmospheric chemistry. This subtle non-mass-dependent signal was not seen in other martian samples, but it bolsters the idea that outgassed volatiles are fractionated in the atmosphere and then returned to the lithosphere. 

The mantle comprises 68% by mass of Earth, and an accurate estimate for its composition is the very basis for unraveling the origin and differentiation of our planet. The bulk chemical analysis of xenoliths has been central to understanding the composition of the Earth s mantle, the genesis of basalt and the physical properties in the lithosphere that bear on its stability in the rigid part of the mantle system. 

Calculated bulk rock trace-element systematics of eclogites have wider implications for mantle recycling models and bulk silicate earth mass balance. The subchondritic Nb/Ta, Nb/La, and Ti/Zr of both continental cmst and depleted mantle require the existence of an additional reservoir with superchondritic ratios to complete the terrestrial mass balance. Rudnick et al. (2000) have shown that rutile-bearing eclogites from cratonic mantle have suitably superchondritic Nb/Ta, Nb/La, and Ti/Zr such that if this component formed 1 -6% by weight of the bulk silicate earth, this would resolve the mass imbalance. This mass fraction far exceeds the likely mass of eclogite in the continental lithosphere and so the material is proposed to reside in the lower mantle, possibly at the core-mantle boundary. 

---