572 



Table 719 

 GEOCHEMICAL DATA 



Eighty-three chemical elements (86 including Po, Ac and UrX 2 ) are found on the earth. Besides the eight occur- 

 ring uncombined as gases, 23 may be found native, Sb, As, Bi, C, Cu, An, Ir, Fe, Pb?, Hg, Ni, Us, Pd, Pt, Kh, Ru, 

 £s, Ag, S, Ta ?, Te, Sn ?, Zn ?. Combined the elements form about 1000 known mineral species. Rocks are in general 

 aggregates of these species. Some few (e. g., quartzite, limestone, etc.) consist of one specie. We have some knowl- 

 edge of the earth to a depth of 10 miles. This portion may be divided into three parts : the innermost of crystalline or 

 plutonic rocks, the middle, of sedimentary or fragmentary rocks, the outer of clays, gravels, etc. 93% of it is solid mat- 

 ter, 7% liquid, and the atmosphere amounts by weight to 0.03% of it. Besides the 9 major constituents of igneous rock 

 (see 7th col. of table) 3 are notable by their almost universal occurrence, TiO», P 2 O s , and MnO. Bo, Gl,and Sc are also 

 widelv distributed. 



The density of the earth as a whole is 5.52 (Burgess) ; continental surface, 2.67 and outer 10 miles of crust, 2.4c 

 (Harkness). Computed Irom average chemical composition: outer ten miles as a whole, 2.77; northern continents 

 2.73 ; southern, 2.76 ; Atlantic basin, 2. S3 ; Pacific basin, 2. 88. 



Data of Geochemistry, Clarke, Kul. 616, U. S. Geological Survey, 1916; Washington, J. Franklin. Inst. 190, 

 p. 757, 1920. 



Average Composition of Known Terrestrial Matter. 



Atomic 

 number 



and 

 element. 



8 O 



14 Si 

 13 Al 

 26 Fe 

 30 Ca 

 12 Mg 

 11 Na 

 19 K 



1 H 

 22 Ti 



6 C 

 17 CI 

 35 Br 



15 P 



16 S 

 56 Ba 

 25 Mn 

 38 Sr 



7 N 



9 Fl 

 etc. 



Average composition. 



Litho- 



sphere, 



Q3% 



47-33 



27-74 



7-85 



4-5° 



3-47 



2. 24 



2.46 



2.46 



o. 22 



0.46 



.19 



.06 



Hydro- 

 sphere, 

 7% 



8579 



0.05 

 o. 14 

 1. 14 

 0.04 

 10.67 



2.07 

 0.008 



Average 

 includ- 

 ing 

 atmos- 

 phere. 



63 



°9 



85 



60 



127 



629 



.027 



055 



•3° 

 .052 

 .048 

 .096 

 .018 



.077 

 .111 



Igneous 

 rocks. 



47.29 

 28.02 

 7.96 

 4 56 

 3-47 

 2. 29 

 2.50 

 2.47 

 o. 16 

 .46 



• 13 

 .063 



• 13 



• 103 

 .092 



.078 



• 033 



. 10 

 .091 



Average composition of lithosphere. 



Compound. 



SiO:. 

 AI2O3 

 Fe2C>3 

 FeO. 

 MgO. 

 CaO. 

 Na 2 

 K2O. 

 H2O. 

 TiC-2. 

 ZrO:. 

 CO2.. 

 P2O5. 

 S.... 

 SO3. . 

 CI... 

 F.... 

 BaO. 

 SrO. . 

 MnO 

 NiO. 

 Cr 2 3 

 V2O3. 

 Li20. 



a... 



Igneous 

 rocks, 

 95% 



59.09 

 '5-35 

 3-oS 

 3- 80 

 3-49 

 5.08 

 3.84 

 3»3 

 1. 14 

 1.05 

 0.039 

 .102 

 .30 

 •OS3 



.056 

 .078 

 •OSS 

 .022 

 •125 

 .025 

 .056 

 .032 

 .007 



Shale, 

 4% 



58.10 

 15 -4° 

 4.02 

 2-45 

 2.44 

 3-II 

 1-3° 

 3-24 

 5.00 

 _6 5 



2.63 



.64 



Sand- 

 stone, 



°-75% 



78.33 

 4-77 

 1.07 



• 30 

 1. 16 

 5-50 



•45 

 1. 31 

 163 



• 25 



Lime- 

 stone, 



0.25% 



5-19 

 0.81 



Weighted 

 average. 



• 09 



.025 



Average Composition of Meteorites: The following figures give in succession the element, atomic number 

 (bracketed), and the percentage amount in stony meteorites (Merrill, Mem. Nat. Acad. Sc. 14, p. 28, 1916). The 

 "iron" meteorites contain a much larger percentage of iron and nickel, but there is a tendency to believe that with 

 such meteorites the composition is altered by the volatilization or burning up of the other material in passing through 

 the air. Note the greater abundance of elements of even atomic number (97.2 per cent). 



Smithsonian Tables. 



