Von Damm states,
"Sodium is by far the most abundant cation in hydrothermal fluids, and as
such, its cycle is tightly tied to that of chloride. Sodium is not
conservative in water-rock reactions as is chloride, but has a major sink in
the albitization of basalt. The largest sodium deficits with respect to
chloride are found in high chlorinity fluids. In a few cases the Na/Cl ratio
is slightly greater than in seawater and the cause of this is not well
understood."(Von Damm, 1995, p. 238)
and
"Sodium, the most abundant cation, of necessity tracks chloride, but where it
does not (i.e., the Na/Cl ratio is lower than the seawater value) provides our
best evidence that albitization is an active process in hydrothermal vent
systems. "(Von Damm, 1995 p. 240)
The most important statement is the conservative nature of chlorine. If one
can count on the fact that the number of chlorine atoms in the hydrothermal
fluids are not changed by the trip through the hydrothermal system, and can
assume that the chlorine comes from the seawater, then the sodium/chlorine
ratio reflects the fate of sodium. Here is the data Von Damm gives for various
hydrothermal systems.
Chlorinity Sodium ratio
mmol/kg mmol/kg
North east Pacific
Escanaba Trough 668 560 .838
Juan de Fuca
s. cleft plume 1087 796 .7322
s. cleft vent 1 896 661 .7377
s. cleft vent 3 951 784 .8243
North Cleft Juan de fuca
Pipe organ 1245 924 .7421
Monolith 1990 908 695 .7654
1991 875 682 .7794
Table Brigadoon 880 681 .7738
Axial volcano juan de fuca
inferno 624 499 .7996
Hell 550 446 .8109
Mushroom 520 446 .8576
Hillock 482 391 .8112
Crack 258 209 .8100
Virgin Mound 176 148 .8409
Endeavour segmentJuan de
fuca
Hulk 505 391 .7742
Crypto 479 371 .7745
TP 448 350 .7812
Dante 457 358 .7833
Grotto 425 332 .7811
LOBO 428 336 .7850
Dudley 349 271 .7765
S&M 334 260 .7784
Peanut 253 216 .8537
North 477 378 .7924
Mid Atlantic Ridge
MARK 559 510 .9123
Tag Mid Atlantic Ridge 659 584 .8861
(Von Damm, 1995, p. 229-230)
Now, seawater contains 470 mmol/kg water sodium, and 550 mmol/kg water
chlorine. The normal sodim/chlorine molar ratio= .8545. Averaging the numbers
in Von Damm's paper, we find that .800 is the sodium/chlorine ratio of
hydrothermal output.The difference between the input ratio and output ratio is
.054. This means that .054*550 mmol/kg= 29.7 mmol/kg water sodium is removed
from the sea.
To convert this to grams of sodium we find, .0297 moles removed/kg water * 58
g/mole=1.72 g of sodium per kg water is removed by the hydrothermal process.
Since the annual flow rate of seawater through the hydrothermal systems is (2-
9) x 1014 kg/yr (Holland, 1978), this means (using the low point of this
range),
2 x 1014 kg/yr*1.72 g/kg water= 3.44 x 1014 g of sodium removed per year or
3.44 x 1011 kg per year
How does this compare to your value of sodium input? Both in Austin and
Humphreys (1990) and in your letter of June 24, 1996 you cite a maximum input
to the seas of 4.5 x 1011 kg of sodium input to the sea each year. In your
letter you revised the output to be 1.46 x 1011 kg/yr, but you have 0 for
albitization. Adding the albitization value to your June 24,1996 value we
have a total output of 4.9 x 1011 kg/year. Thus, considering the slop in the
numbers, we can conclude that the oceans are roughly in balance in regard to
sodium.
Your June 24, 1996 output list should be revised to show
Process 1010 kg/yr
Sea Spray 8.0 +/- 2.4
Low-T brine alteration(saponite) 0.44 +/- 0.37
High T Brine alteration (albite) 34.4
Burial of pore water 2.2 +/- 1.5
Halite deposition 0 *
Cation exchange 3.5 +/- .2
Zeolite formation 0.08 +/- 0.04
biogenic silica 0.046 +/- 0.023
biogenic carbonates 0.19 +/- 0.05
Total 49 x 1010 kg/yr
Evaporation should have a time-averaged value because of the geologically
episodic output.
Sincerely,
Glenn R. Morton
References
Austin, Steven A. and Russell Huphreys, 1990. "The Sea's Missing Salt: A
Dilemma for Evolutionists," 2nd Intl. Conf. on Creationism,(Pittsburgh, 1990),
pp 17-33
Heinrich D. Holland, 1978 The Chemistry of the Atmosphere and Oceans, (John
Wiley and Sons, 1978), p. 196)
Von Damm,K. L.,1995. "Controls on the Chemistry and Temporal Variability of
Seafloor Hydrothermal Fluids," in Humphris et al editors, Seafloor
Hydrothermal Systems: Physical, Chemical, Biological and Geological
Interactions, Geophysical Monograph 91, (Washington: American Geophysical
Union, 1995), pp222-247,
glenn
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm