262 CHAMBERLIN— THE AGE OF THE EARTH. 



derived. In some districts they consist largely of carbonates, or of 

 sulphates ; in others of chlorides, or of silicates ; while the degree of 

 dominance varies greatly within each class. The solutions of the 

 ocean, however, are not identical with any of these, nor with a simple 

 mixture of them ; the ocean solutions are dominantly chlorides, but 

 constitute a combination which is quite distinctive. This implies that, 

 instead of a theoretical mixture of the land waters, an effective 

 chemico-physical reorganization takes place, a liquid metamorphism 

 of the heterogeneous land waters and their content into the homo- 

 geneous sea solution and its sediments. This is in a measure recog- 

 nized, but the recognition is inadequate if the change is regarded 

 simply as a liquid metamorphism. There is a neglected solid factor 

 in the form of silts and clays that is of critical importance. The 

 usual comparison is really between the clear waters of the streams — 

 which are mainly the outflowing ground waters of the land — and the 

 sea waters. The run-off and its contents — the wash-waters of the 

 land and their burden of mud — are neglected. But it is this run-off 

 water with its mud and the colloids that go with it which carry the 

 larger part of the acid radicals of the soil from which the basic radi- 

 cals were leached. The reunion of these acids with the alkalies in 

 the border of the ocean constitutes a critical part of the metamorphism 

 which gives rise to the ocean solutions and sediments. We will 

 return to this presently. 



3. The Larger Part of the Solutions now Flowing into the Ocean 

 Comes from the Sediments; the Lesser Part from the Igneous 

 Rocks. — This becomes the more suggestive when it is noted that the 

 sediments have been worked over repeatedly in some notable part; 

 some small part, perhaps hundreds of times ; some larger part, scores 

 of times; while some other large part perhaps has not been worked 

 more than once, unless we count in the many times most material is 

 handled in going from the parent rock to the ocean. That the sedi- 

 ments should still be able to yield saline solutions to the observed 

 extent raises a vital question into which it is necessary to inquire 

 before assuming the practical non-reversibility of the sodium solu- 

 tions. It is already well recognized that a part of this sustained 

 productiveness is due to sea-winds which carry salt inland from the 



