o-Ca cium- Calmodulin Kinase Mutant Mice

tuffs do not result from pyroclastic flow and hence are not true pyroclastic flow deposits. They do not explain the processes they envision, but in this situation pyroclastic emplacement without some form of lateral flow is clearly impossible, even in near-vent locations. 18. M. J. Branney and R. S. J. Sparks, J. Geol. Soc. London 147, 919 (1990). 19. For example, halloysite, smectites, sericite, montmorillonite, kaolinite, and illite. 20. R. L. Allen, Econ. Geol. 83,1424 (1988). 21. P. W. Lipman, Geol. Soc. Am. Bull. 87, 1397 (1976). 22. L. Draper, Marine Geol. 5, 133 (1966); P. D. Komar, J. Sed. Petrol. 44,169 (1974); B. Butnam et al., J. Geophys. Res. 84, 1182 (1979). 23. See K. T. Pickering et al., Deep Marine Environments (Unwin Hyman, London, 1989). 24. R. S. J. Sparks, Bull. Volcanol. 48, 3 (1986). 25. K. V. Cashman and R. S. Fiske, Science 253, 275 (1991). These authors described a fallout deposit resting above a coeval hot-emplaced (-4500C) flow deposit, which we suggest is most likely to have formed from the material that would not be incorporated into the convective column above the vent. 26. P. Kokelaar, Bull. Volcanol. 48, 275 (1986), figure 4. A bell-shaped exclusion zone postulated to occur above the vent was referred to in that case as a "cupola of steam," because the explosivity involves bulk incorporation of water in the eruptive conduit, so that the gas of the erupted dispersion is dominated by (nonmagmatic) steam; see P. Kokelaar, J. Geol. Soc. London 140, 939 (1983). 27. P. D. Rowey et al., U.S. Geol. Surv. Prof. Pap. 1250 (1981), p. 489. 28. Compare with R. S. Fiske and T. Matsuda, Am. J. Sci. 262, 76 (1964). 29. H. Ohmoto and B. J. Skinner, Econ. Geol. Monogr. 5, 1 (1983). 30. P. Kokelaar, Geol. Soc. Am. Bull., in press. 31. C. J. Busby-Spera and J. Saleeby, Geologic Guide to the Mineral King Area, Sequoia National Park, California (Society of Economic Paleontologists and Mineralogists, Los Angeles, 1987). 32. T. G. Gloppen and R. J. Steel, Soc. Econ. Paleontol. Mineral. Spec. Publ. 31, 49 (1981). 33. Supported by a NATO collaborative research grant 910549 and NSF grant EAR9018606 (to C.B.). We are grateful to G. Lloyd for assistance with production of the SEM image and to M. J. Branney, R. V. Fisher, S. Self, and R. S. J. Sparks for reviews of a draft of the article.