Publications

The small collection of lava‐flows, bombs, and ashes from Parícutin, which are to be briefly described, was obtained from several sources and is far from being as completely representative of the volcanic history of the region as one might wish. Until, however, an adequate study is made, these specimens may serve to give some idea of the broader aspects of the local petrography. Each of the 17 spe

The most important factor which would reduce confusion in fabric analyses is the expanded use of partial diagrams. The purpose of this paper is to stress the significance of partial diagrams in a consideration of some confusing aspects of petrofabrics.Any statistical study results in the accumulation of a mass of detail. In quartz‐fabric analyses the detail consists of the measuring and plotting o

The Chairman extends an apology to G. W. MUSGRAVE for omission of his name from the list of members given in the report of the Committee on Ground Water for 1942–43.The response from members of the Committee in general has been very gratifying and is much appreciated. Four new members, Messrs. H. F. BLANEY, EDWARD BURWELL, Jr., A. N. SAYRE and V. T. STRINGFIELD have been added to the Committee thi

In June, 1943, the United States Geological Survey assigned two ground‐water geologists, A. N. SAYRE and G. C. TAYLOR, Jr., to study water‐supply problems in Central America for the Coordinator of Inter‐American Affairs and to make recommendations for remedial measures to provide water for cities and towns, especially along the Inter‐American Highway. El Salvador, where a large number of towns alo

A report by O. E. MEINZER, published as Appendix B of the annual report of the Committee for 1942–43 [Trans. Amer. Geophys. Union, Part II, pp. 418–420, 1943], describes in some detail the previous work of the United States Geological Survey and cooperating agencies on ground water for war purposes.The geologists from the staff of the Geological Survey listed in that report and several other groun

A variety of units and names of units relating to permeability have been used and are being used by different investigators. This Sub‐Committee was recently organized to provide an open forum for persons of different background and experience to present their views in an orderly manner. Thirteen members representing diverse fields of activity have been chosen. To these, L. K. WENZEL, Chairman, by

No abstract available.

In interpretation and use of basic hydrological data as basis for planning any public works for conservation or control of water, there is great need for a careful and thorough analysis of the precipitation‐runoff relations. Moreover, when such relations may have been worked out for one particular basin, experience has shown that extreme caution must be used in any attempt to apply these relations

A new method is presented here for differentiating magnesite from dolomite in crushed materials. This method is based on the essentially different temperatures at which these minerals undergo thermal decomposition. The resulting lowly birefringent periclase is easily distinguished microscopically from the highly birefringent dolomite. This method is based on the ease of recognition of the periclas

Fluorspar from Newfoundland, eighth ranking producer of the world, comes entirely from the St. Lawrence district. Here pre-Cambrian lavas and pyroclastics, Cambrian sedimentary rocks, Ordovician (?) volcanic and sedimentary rocks, and a Paleozoic alaskite-granite comprise the bedrock.Epithermal fluorite veins occupy steeply dipping fault fissures in granite, rhyolite porphyry, and lamprophyre. Ele

The beryllium deposits at Iron Mountain, near the northern end of the Sierra Cuchillo in Sierra and Socorro Counties, New Mexico, are unusual products of contact metamorphism. They occur in irregular bodies of tactile formed by replacement of Paleozoic limestone, generally at or near contacts with small intrusive masses of rhyolite, aplite, and fine-grained granite. The metamorphism took place in

No abstract available.