G2 



DATA OF GEOCHEMISTRY 



Gorham; Dr. Jun Kobayashi; Dr. D. S. Rawson; Dr. 

 Sirn6n Visser; the Laboratdrio de Analises Fisico- 

 quimicas e Micrograficas, Campanhia' das Aguas de 

 Lisboa; the Afghanistan Geological Survey; the Geo- 

 logical Survey of Pakistan; the Tehran Water Board; 

 the Hydro-Electric Commission, Hobart, Tasmania; 

 the South Australian Engineering and Water Supply 

 Department, Adelaide; the Government Chemical 

 Laboratories, Perth, Australia; the Ammistrazione 

 Fiduciaria Italiana della Somalia; Reparticao Tecnica 

 de Industria e Geologica, Provincia de Mocambique; 

 Reparticao Central dos Servicos de Geologia e Minas, 

 Provincia de Angola; the Chemistry Division, Ministry 

 of Health, Kaduna, Nigeria; the Federal Department 

 of Chemistry, Lagos, Nigeria; the Service Geologique, 

 French West Africa; the Service des Etudes Scien- 

 tifiques, Ministere de l'Algerie; the Direcion de Geol- 

 ogia, Ministerio de Minas e Hidrocarburos, Venezuela ; 

 Ministerio de Fomento y obras Publicas, Peru; and 

 my colleagues in the U.S. Geological Survey, particu- 

 larly Dr. W. H. Durum and the water chemists working 

 in California, Nevada, Oregon, and Washington. 



Very generous linguistic assistance was provided by 

 Dr. J. R. Bailey, Dr. Humio Osaki, and Dr. Athos 

 Ottolenghi. Miss Eveline Bowers, Miss Helen Oyler, 

 and Mr. Emerson Ford helped with bibliographic prob- 

 lems. Dr. F. B. Barker, Dr. Walter Durum, Dr. Eville 

 Gorham, and Dr. John D. Hem have read the manuscript 

 and made many helpful criticisms. Since beginning 

 this review 5 years ago I have had the unfailing sup- 

 port and encouragement of my wife, Bertha, who has 

 also helped to revise the manuscript and check the 

 tables. During the same time Dr. Michael Fleischer 

 has helped me in every way that an editor could — 

 finding obscure papers, preparing translations from 

 Russian, discussing general questions of geochemistry, 

 providing kind words of encouragement when the lit- 

 erature search seemed endless, and gently exercising 

 editorial restraint. 



ISOTOPIC COMPOSITION OF LAKE AND RIVER WATER 



In addition to the variation in the suspended and dis- 

 solved load of lake and river water, there is a consider- 

 able variation in the composition of the pure water sub- 

 stance itself. It has long been known that there are 

 variations in the density of pure water from natural 

 sources, and in the last few years a number of studies 

 of the isotopic composition of natural water samples 

 have been made. Mass spectrography has permitted 

 the determination of the stable isotopes, while low- 

 background counting methods have permitted the assay 

 of even the short-lived mass-three isotope of hydrogen. 



Oxygen-17 does not appear to have been measured 

 in natural waters. In air and commercial oxygen the 



18 /0 17 ratio is 4.9 ±0.2 (Murphey, 1941), so the natural 

 variations in oxygen-17 content of water are probably 

 barely measurable with present mass-spectrographic 

 methods. Oxygen- 18 has been measured by a number 

 of investigators, each referring the results to some arbi- 

 trary standard. The largest body of results referred to 

 a single standard appears to be that of Dansgaard (see 

 table 1), who used a Danish oxygen standard with 

 0.1950 atom-percent of oxygen-18. It appears from 

 the data, which are reproduced in table 1, that the 

 18 /0 16 ratio is higher in climates where there is a great 

 deal of post-precipitational evaporation, leading to a 

 loss of the lighter isotope. 



Table 1. — Oxygen-18 content of lakes and rivers 



[Analyses by Dansgaard (1954). The reference used was a Danish COa standard with 

 0.1950 atoms percent of Oi»] 



Locality 



Pasig River, Manila, Philippine Islands 



River water, Minglasulla, Cebu, Philippine Islands. 



Water fall, Maxwill, Taiping, Malaya 



Waterfall Gardens, Penang 



Me-Yome River, Prae, Siam 



River water, Bangkok 



Hoogly River, Ganges 



Ravi River, Madhopur, Pakistan 



Little Fugela, Winterton, Natal 



Seven Mile Stream, Hilton Road, Natal 



Ukamba Stream, Natal National Park 



Mulunguzi Stream, Zoniba Plateau, Nyasaland- 



Namadzi Stream, Nyondtwe 



Perana River, Posadas Misiones, Argentina 



River wate., San Nicolas, Buenos Aires 



Lugan River, Delta of Tigra _ _ 



San Juan River, Rosario, Santa Fe, N. Mex.. 

 Lake Nahuel, Huapsi, Neuguen, Argentina.. 

 Lake at West Vancouver, Canada 



Mosquito Creek, North Vancouver, Canada. 



River water, Salta, Argentina 



Do. _ 



Red River, Godhavn, Greenland 



Date 



Aug. 7, 1953 

 July 19,1953 

 Aug. 1, 1953 



June 29,1953 

 Sept. 30, 1953 

 Aug. 12,1953 

 July 8, 1953 



Jan. 14,1954 

 Jan. 31,1954 

 Jan. 14,1954 

 June 7, 1953 



June 14,1953 

 Oct. 0, 1953 

 Oct. 13,1953 

 Oct. 12,1953 



Sept. 11,1953 

 Sept. 8,1953 

 June 19,1953 



June 19,1953 

 Nov. 20, 1953 

 Nov. 20, 1953 

 NOV. 20, 1952 



0'» atoms/ 

 10W atoms 



19.82 

 19.73 

 19.74 

 19.77 



19.72 

 19.71 

 19.72 

 19.77 



19.81 

 19.82 

 19.82 

 19.79 



19.75 

 19.80 

 19.78 

 19.82 



19.92 

 19.70 

 19.68 



19.67 

 19.58 

 19.60 

 19.58 



A large number of analyses for deuterium given by 

 Friedman are reproduced in table 2. It is evident that 

 evaporational fractionation is involved here. In 

 another study, Clarke and others (1954) found that 

 the deuterium content of Thames water was near the 

 oceanic value. The slight evaporative enrichment in 

 the oceanic Thames basin appears to be sufficient to 

 equal the impoverishment during evaporation from the 

 ocean. 



Tritium, though much less abundant, can be measured 

 because it is a beta-emitter. Libby has summarized 

 his data on the tritium content of fresh waters of the 

 world, and they are presented in table 3. This isotope 

 has a half-life of 12 years and the time since leaving the 

 atmosphere, as well as the partition due to evaporation 

 or melting, determines its concentration in natural 

 waters. 



Some early measurements of water density are of 

 interest in connection with isotope concentration. For 

 example, it has been claimed that the water in the 



