534 OLR (1988) 35 (6)

C. CHEMICAL OCEANOGRAPHY

CI0. Apparatus and methods

88:3345 Harrison, R.M., 1987. Physico-chemical speciation

and chemical transformations of toxic metals in the environment. Spec. Publ. Br. ecol. Soc., 6:239-248.

The commoner experimental techniques for speci- ation of trace metals such as Pb, Cd, Cu and Zn in environmental media are described. The shortcom- ings inherent in the various methodologies are discussed and selected results of speciation inves- tigations are reviewed. Where precise chemical speciation information is available, it is possible to infer chemical transformation reactions occurring within the environment, and some such reactions are proposed. Dept. of Chem., Univ. of Essex, Col- chester CO4 3SQ, UK.

88:3346 Heydorn, K., T. Braun, E. Bujdoso (editors) and

V.P. Guinn (reviewer), 1987. Modern trends in activation analysis. Proceedings of the 7th In- ternational Conference, Copenhagen, June 23- 27, 1986. Part 6. J. radioanalyt, nucl. Chem., 114(2): 207-421; 24 papers.

This sixth collection of reports from the 1986 MTAA conference consists of a methodology section (seven papers on the counting system) and three appli- cations sections: forensic science, archaeology, and geochemistry. The latter includes descriptions of activation analysis techniques for the determination of U in natural waters and of trace elements in sediments. (gsb)

88:3347 Iida, Yasuo, 1987. Repetitive spectral subtraction

method for the spectropbotometric determination of rare earth elements. Z. analyt. Chem., 328(7): 547-552. Govt. Industrial Res. Inst., Nagoya 1-1, Hirate-machi, Kita-ku, Nagoya 462, Japan.

88:3348 Kutsch, Horst, 1987. The thermo-optical analysis of

humic subslances---a new method with dimethyl sulfoxide as reagent. Z. analyt. Chem., 328(7): 572-576. FB III, Univ. Trier, D-5500 Trier, FRG.

88:3349 Madaro, M. and A. Moauro, 1987. Trace element

determination in rocks and sediments by neutron

activation analysis. J. radioanalyt, nucl. Chem., 114(2):337-343. E.N.E.A., Chem. Div., C.R.E. Casaccia, Via Anguillarese 301, P.O. Box 2400, 00100 Rome, Italy.

C40. Area studies, surveys

88:3350 Peng, T.-H., Taro Takahashi, W.S. Broeeker and Jon

Olafsson, 1987. Seasonal variability of carbon dioxide, nutrients and oxygen in the northern North Atlantic surface water: observations and a model. Tellus, 39B(5):439-458.

The seasonal variation of various surface water properties was monitored at a station ~120 miles south of the Iceland-Greenland sill. In summer, pCO 2 and concentrations of CO 2 and nutrients were lowest, while the 02 concentration was highest; this situation was reversed in winter. To account for the seasonal variation, a vertically l-D, two-box ocean model was constructed; results show the spring bloom effect can be simulated by short-term reduc- tion of the phosphate residence time and gas exchange rate. Environ. Sci. Div., Oak Ridge Natl. Lab., Oak Ridge, TN 37831, USA.

C50. Seawater composition

88:3351 Goldstein, S.J. and S.B. Jacobsen, 1987. The Nd and

Sr isotopic systematies of river-water dissolved material: implications for the sources of Nd and Sr in seawater. Chem. Geol., 66(3-4):245-272.

Data on the isotopic composition and concentration of Nd and Sr in the dissolved load of rivers from North America, Australia, Japan, the Philippines and Venezuela, are used to characterize Nd and Sr behavior during weathering and transport; estimate their concentration and isotopic composition in runoff to the oceans; and construct an isotopic mass balance for Nd and Sr in seawater. New Sr data lower the estimated mean S7Sr/S6Sr of river runoff and reduce the calculated seawater-basalt Sr ex- change near mid-ocean ridges. This yields a hydro- thermal water flux of (2.9_2.5)× 10 ~6 g yr -~. River inputs are the dominant factor in determining the Nd and Sr isotopic signature of modern seawater. Dept. of Earth and Planetary Sci., Harvard Univ., Cambridge, MA 02138, USA.