JULT 8, 1910] 



SCIENCE 



63 



plants. The organic constituents of the solution 

 while important for plants, have only a minor 

 interest for geology, but the inorganic constitu- 

 ents have a great importance for both. The soil 

 solution is a medium for the transport of mineral 

 substances, and the phenomena involved, which 

 have been studied from an agronomic point of 

 view, probably have also an importance in the 

 study of secondary enrichments and similar 

 problems. 



Soils are far more heterogeneous than rooks. 

 All the common rock-forming minerals are present 

 in most soils, because of the actions of various 

 mixing agencies, especially transportation by 

 water and wind. These minerals dissolve quickly 

 and are hydrolized by the water. This is the 

 process of weathering. As fast as the hydrolized 

 products are removed, the minerals continue to 

 dissolve. If these were the only considerations, 

 however, we should expect to find the same solu- 

 tion in all soils, under the same conditions of 

 temperature, etc. But disturbing factors enter the 

 problem. Prominent are the specific actions of 

 dissolved carbon dioxide and oxygen. Most impor- 

 tant are the phenomena of absorption, which are 

 very marked with most soils. The distribution of 

 a dissolved substance between an absorbent and a 

 solvent is dependent upon the relative quantities 

 present. Therefore the individual physical and 

 chemical peculiarities of a soil will affect the 

 composition of the soil solution. Experimental 

 investigation, however, shows that the differences 

 in the mineral content of soil solutions under sim- 

 ilar climatic conditions are always relativelj' 

 small. A consideration of the disposal of the 

 rainfall in the soil shows that of the portion which 

 enters the soil the greater part returns to the 

 surface, and is of a higher concentration than the 

 seepage waters. Consequently there is a tendency 

 for the dissolved mineral substances to accumulate 

 at or near the surface. This is actually realized 

 in some arid and semi-arid regions. In humid 

 areas, excessive amounts are washed into the 

 drainage or back into the subsoil to again slowly 

 move towards the surface with the capillary 

 waters. 



Some Evidences of Recent Subsidence on the New 

 England Coast: Charles A. Davis. 

 Localities examined in Maine, New Hampshire, 

 Massachusetts and Connecticut all show subsi- 

 dence : ( 1 ) By the drowned coast characterized 

 by fiords, wide estuaries, valleys extending out to 

 sea and shore lines that have clearly migrated 



inland in recent times. (2) By the occurrence 

 below tide-level, both inside and outside the pres- 

 ent beaches, of submerged roots of trees of exist- 

 ing species, unquestionably in place as they grew.. 

 (3) By deposits of fresh-water peat now lying 

 below tide-level and being actively eroded by the 

 sea. (4) By positive engineering record that the 

 masonry sills and floor of the old dry dock at 

 Charlestown Navy-yard in 1903 were 0.71 foot 

 lower relative to mean sea-level than seventy-twO' 

 years previous, while they stood at exactly the 

 same level in respect to points on solid ground. 

 ( 5 ) By the salt marshes which occur wherever the 

 gradient of the coastal region is slight. Tlie 

 structure of these marshes shows that they have 

 been formed: (a) By gradual submergence of 

 fresh-water deposits, which may include tree re- 

 mains. (6) By the increase in thickness of the 

 peat formed by the grasses growing on the present 

 surface of the salt marshes, of which Spartina 

 patens (Ait.) Muhl. and Distichlis spicata (L.) 

 Greene, are by far the most generally distributed 

 and important species. 



These grow only in places covered not more 

 than about four hours each day by salt water, 

 i. e., where they are just reached by ordinary 

 high tides, while areas above and below these 

 levels are occupied by entirely different plant 

 species. The two species mentioned form a very 

 characteristic and easily recognizable peat and its 

 occurrence in beds ten or more feet thick, reach- 

 ing continuously from the present surface of salt 

 marshes to below low-water mark, with possibly 

 fresh-water peat below this, is indisputable evi- 

 dence that there has been subsidence equivalent 

 in amount to the thickness of the salt-marsh beds, 

 and at a rate exactly equivalent to the rate of 

 upbuilding of the turf formed by the two grasses 

 mentioned; this rate must be generally small. 



No evidence has been found indicating that 

 salt marshes lie in depressions, formed by inden- 

 tations in the shore line which are in process of 

 being cut off by barrier beaches, and which have 

 been filled either by salt- or fresh-water vegeta- 

 tion; the structure of the deposits and the con- 

 tours of the bottoms of the marshes examined 

 being entirely against such an hypothesis. 



Fox Hills Sandstone and " Ceratops Beds " in 

 South Dakota, North Dakota and Eastern Wy- 

 oming: T. W. Stanton. 



In the area adjacent to the Missouri River in 

 northern South Dakota and southern North Da- 

 kota the latest marine Cretaceous formation i? 



