GARPIER I am not a scientist so I don't have the answer, but here is the question: Presumably as the rivers enter into the oceans, they carry with them minerals including salt. (Right or wrong?) That being the case would not the amount of salt being added to the oceans every year over the course of millions of years -(Presupposing a very old age to the earth, which I don't) - sooner or later make the oceans uninhabitable like the Dead Sea is today? Anyone have any ideas? TOMR The components of salts, like sodium and calcium, end up being fixed (incorporated into) by clay minerals like montmorillonite. GARPIER I’m not sure I understand what this has to do with figuring out how long it took for the oceans to reach their present levels of salt content. Can you elaborate on this for me please? Thanks I am being sincere when I ask this. I thought that evolutionists believed in uniformitarianism- the idea that the natural processes we see now have always worked that way and at the same rate. Right or wrong? LOGIC BOT Uniformitariansim states that the natural laws and mechanisms that control the universe stay the same. For example we assume certain properties of gravity to be the same, to come to conclusions about stars, and early cosmology. Think of it like this. Gravity works at a constant, but the results depend on the mass of the two objects, how close they are etc. THE BARBARIAN The early uniformitarians were simply saying that the existing rules for the universe always worked that way. That doesn't mean gradualism, although they recognized that most of the time, gradual change is the rule. The uniformitarians never meant to exclude floods, earthquakes, volcanic eruptions, etc. They knew these happened, and included them in their theories. But they rejected the idea of sudden lurches in the rules. Because there wasn't any evidence for that (still isn't) they didn't include that kind of thing. So discontinuous phenomena are not a problem for science. TALKING RAIN To answer your original question. There is a mechanism that removes salt from the ocean at approximately the same rate that it enters it. It is fixed in the sediment that collects at the bottom of the sea, both by physical processes and by biological processes. Eventually plate techtonics drives this sediment into oceanic trenches where it is melted with the ocean floor and perhaps later belched up by a coastal volcano where it waits to be dissolved by a river and taken back into the ocean. A long and very interesting cycle unfolding over millions of years. TOMR My point about clay minerals incoporating certain components of salts actually relates directly to your original question. I'll try to be more explicit. The potassium, magnesium, and sodium ions (charged atoms)that are components of salt get taken out of solution by clay minerals. Some calcium goes into the water from the clays, so these clay particles can be thought of as mini water softeners. Calcium is removed from water by organisms that build their skeletans of aragonite or calcite (both of these minerals are calcium carbonate). The clay minerals that transfer these cations may be suspended in the water or lie on the bottom surface. At any rate, the seas have at least these two buffering mechanism keeping the salt content of the water static under normal circumstances. As Joe alluded to, under conditions of high net evaporation this mechanism may not work and salts will precipitate from the water. In short, the components of salts are removed from the water by ion exchange on clay particles and by skeleton building organisms, keeping the salt content of the seas from increasing. For further details you could check out any book on hydrogeochemistry such as "the geochem. of natural waters" by James Drever. He has further references to study in this area of water chemistry. Also, uniformitarianists consider the processes today to have shaped the world as we see it today. This doesn't imply that the same *rates* that are observed today have always applied. * * Whoops, I described water hardening up there, not softening. My bad. GARPIER Thanks for the information Tom. I think I understand what you are saying and I appreciate it.