Philadelphia Meeting of Geological Society . — Upham. 91 
will be directed in these summer meetings to field studies of 
important localities and especially remarkable features of the 
geology of the surrounding country, by joint excursions of the 
Society and the Association. 
Twenty-seven papers were presented at this meeting, of 
which we are enabled to give the following abstracts, with 
notes of ensuing discussions, through the kindness of the au¬ 
thors, and with much aid from the preliminary announcements 
distributed to the fellows of the Society, and especially from 
the report by Prof. J. F. Kemp in Science (new series, vol. hi, 
pp. 46-57, Jan. 10, 1896). The order is that of the program. 
Disintegration and Decomposition of Diabase at Medford ., Mass. 
George P. Merrill. Washington, P. C. (Read by title.) The paper 
deals with the chemical and physical changes which have taken place 
in the process of breaking down of the diabase as displayed at Medford. 
It gives analyses of fresh and decomposed materials and calculations 
showing the percentage amounts of the entire rock and of each constit¬ 
uent removed through solution. The decomposition is regarded as 
wholly postglacial. In closing some exceptions are taken to the com¬ 
monly accepted view that decomposition is more rapid in warm than in 
cold climates. 
The Geographic Relations of the Granites and Porphyries in the east¬ 
ern part of the Ozarks , Charles R. Keyes, Jefferson City, Mo. (Read 
by title.) As introductory, a brief statement of the general geologic 
features of the region is presented. A summary of opinion is given re¬ 
garding the origin of the massive crystallines and their present configu¬ 
ration: the results of recent investigations are also mentioned. The 
physiography of the district is outlined; there are recognized the Ter¬ 
tiary peneplain forming the general surface of the Ozark dome, and a 
lowland plain of denudation at a level 800 feet below the great one. The 
relations of theJn'incipal types of acid rocks to the lowland plain are 
pointed out. Incidentally, attention is called to the fact that the geo¬ 
logical age of the granite rocks is probably not Archman, as it has been 
heretofore generally considered. The absence of gneissic and schistose 
rocks in the massive crystalline area is a noteworthy fact. It is partic¬ 
ularly suggestive in the light of the recent discovery in a deep well bor¬ 
ing near Kansas City of real evidences of squeezed rocks. The hole, 
which was made by a diamond drill, reaches a depth of nearly 2,500 feet. 
The core at the bottom is one and seven-eighths inches in diameter. 
The last thirty feet are reported to be in the rock which examination 
shows to be a black mica schist, the cleavage planes of which have a 
dip of 35 degrees. If the natural inferences are correct, the entire Pale 
ozoic sequence from the base of the Upper Coal Measures has been 
passed through in a vertical distance of less than half a mile; the schis¬ 
tose floor upon which rest the unaltered sedimentaries has been reached 
