OLR (1987) 34 (9) D. Submarine Geology and Geophysics 757

87:5039 McCave, I.N., 1987. Fine sediment sources and sinks

around the East Anglian coast (UK). J. geol. Soc., Lond., 144(1): 149-152. Dept. of Earth Sci., Univ. of Cambridge, Cambridge CB2 3EQ, UK.

87:5040 Murray, J.W., 1987. Biogenic indicators of suspended

sediment transport in marginal marine environ- ments: quantitative examples from SW Britain. J. geol. Soc., Lond., 144(1):127-133.

Suspended sediment samples taken from the water column in the English Channel contain size-sorted benthic foraminiferal tests, <200 ~m in diameter, derived from shelf sediments. Similar associations of small tests are found in estuaries where the indig- enous living assemblages are totally different. Net transport from the shelf to the estuaries is therefore inferred to have taken place. Tests <200/~m in size are probably equivalent to quartz spheres of silt size and they indicate the net transport path for this size grade. An attempt has been made to quantify the transport budget. Dept. of Geol., The Univ., North Park Rd., Exeter EX4 4QE, UK.

87:5041 O'Connor, B.A., 1987. Short and long term changes

in estuary capacity. J. geol. Soc., Lond., 144(1): 187-195.

Capacity changes over the last 100 yr show that the four estuaries considered have suffered large scale siltation. In the Lune, Ribble and Mersey estuaries, engineering works have been responsible for large permanent changes in capacity; in the Humber, siltation is probably a result of natural infilling from past glacial over-deepening and fluvial action. A detailed study of the Mersey suggests that the estuary was also over-deepened and over-widened and has only been tidal for the last ~9000 yr. Calculations suggest that a new equilibrium will be achieved in ~250 yr and the estuary may then be in a state of dynamic equilibrium. The much smaller Lune Estuary may already have achieved this state. Civil Engng Dept., Liverpool Univ., Brownlow St., P.O. Box 147, Liverpool L69 3BX, UK.

87:5042 Qin, Yinshan and Fan Li, 1986. Study of the

influence of sediment loads discharged from Huanghe River on sedimentation in the Bohal and Yellow seas. Stud. mar. sin., 27:125-135. (In Chinese, English abstract.) Inst. of Oceanol., Acad. Sinica, People's Republic of China.

87:5043 Reid, G. and J. McManus, 1987. Sediment ex-

changes along the coastal margin of the Moray Firth, eastern Scotland. J. geol. Soc., Lond., 144(1):179-185. Dept. of Oceanogr., Univ. Col- lege of North Wales, Menai Bridge, Gwynedd, LL59 5EY, UK.

87:5044 Wyatt, A.R., 1987. Shallow water areas in space and

time. J. geol. Soc., Lond., 144(1): 115-120.

Application of modern hypsometric relationships to former continental blocks allows calculation of the shallow sea area around each block for any given sea level. Using Hallam's (1984) sea level curve for the post-Triassic, shallow sea area curves have been drawn for each continental block, as well as a global curve of shallow sea area with time. As the response of a block to sea level change depends upon the size of the block, the cumulative curve does not vary in a straightforward manner with respect to sea level. Predictions of organic diversity change with sea level change must take account of this non-linear rela- tionship. Dept. of Geol., Univ. College of Wales, Aberystwyth, Dyfed SY23 3DB, UK.

D80. Reefs and atolls

87:5045 Aharon, Paul, R.A. Socki and Lui Chan, 1987.

Dolomitization of atolls by seawater convection flow. Test of a hypothesis at Niue, South Pacific. J. Geol., 95(2):187-203.

The core of the former atoll on Niue Island, South Pacific, is extensively doiomitized. A detailed stable isotope study reveals that the dolomites are uni- formly enriched in ~80 and ~3C relative to their carbonate precursor; the Sr isotope ratios are equally constant with depth. The observed isotopic com- positions point to seawater as the dominant dolomi- tizing fluid. A model of seawater convection is proposed for atoll dolomitization on the basis of a thermal gradient between the atoll and the ambient ocean water. Seawater is drawn through the atoll margin and transferred upward by convective flow delivering Mg to the sites of dolomite precipitation. Dept. of Geol., Louisiana State Univ., Baton Rouge, LA 70803-4101, USA.

87:5046 Moore, J.G. and J.F. Campbell, 1987. Age of tilted

reefs, Hawaii. J. geophys. Res., 92(B3):2641-2646.

Limestones from two submerged carbonate reefs preserved as submarine terraces between Molokai