OCT. 19, 1921 proceedings: geological society 425 



high-level water may occur hundreds or even thousands of feet above sea 

 level and is held up by definite rock structures such as dikes and interbedded 

 soils and imper\dous ash. 



The high-level water may belong to the main body of ground water or may 

 be a perched body of water not associated with the main body. This water 

 is valuable especially because it does not generally have to be lifted as does the 

 low-level water. The problems of its discovery relate to rock structure and 

 require geologic methods of investigation. The geologic studies should 

 indicate effective but inexpensive methods of prospecting. 



The low-level water is in some places non-artesian, but in other places 

 it occurs in artesian basins produced by nearly impervdous sedimentary 

 beds overlying the water-bearing lavas. The problems with respect to this 

 water relate chiefly to the quantities available and to contamination by sea 

 water. They require studies of the coasts with respect to emergence and sub- 

 mergence, the consequent development and position of sedimentary^ deposits, 

 and the effectiveness of these deposits in producing artesian conditions and 

 in protecting the ground water from sea w^ater. They also require quan- 

 titative studies of absorption, pumpage, head, and correlative salt content, 

 and studies of the underground leakage of wells and methods for conserving 

 the artesian supply. A valuable contribution to the methods of ground-water 

 investigation developed in the Hawaiian work is the use of current meters 

 for detecting leakage of wells. 



Prof. L. C. Graton spoke on the relation of secondary enrichment to to- 

 pography and ground water, and especially on the problem of the accumula- 

 tion of the iron minerals in gossan. 



Prof. Wm. M. Davis was invited by the President to address the Society, 

 and spoke on some reef limestones found in the floors of valleys penetrating 

 the lower slopes of the volcanoes on the Island of Oahu, and their bearing on 

 the diastrophic history of the Hawaiian Islands. 



348th meeting 



The 348th meeting was held at the Cosmos Club at 8 p.m., on Wednesday, 

 May 12, 1920. 



Regular Program 



Stratigraphy of the Bend Series and contiguous formations in north-central 

 Texas. 



P. V. Roundy: Micro-paleontology. 



M. I. Goldman: Lithology. 



The two papers were discussed by Messrs. Girty, Went worth, Heald, 

 David White, H. Bassler, Stose, Alden, Loughlin, and G. R. Mans- 

 field. 



Mr. Goldman's paper on Lithology of the ''Bend Series" and cmitiguoiis 

 formations of north-central Texas is the result of the study of a nearly complete 

 series of samples (representing mostly intervals of 10 feet) from 2400 to 4510 

 feet in the Seaman No. 1 well, Roxana Petroleum Corporation, Palo Pinto 

 County, Texas. In each sample as many types of ingredients as could be 

 recognized were differentiated under the hand lens, and their proportions 

 estimated. Peculiar types and at intervals the common types were made 

 into thin sections, studied under the compound microscope, and the proportion 

 of sand, clay, and lime in each type estimated. Three graphic logs were pre- 

 sented; one showing the estimated proportion of sand, clay, lime, sand flint 

 in each sample, another the usual type of graphic log showing the succession 

 of beds as indicated by the above examinations, the third the usual graphic 



