SEARCH · USGS Science
Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Owing to the good fortune of being stationed near the new volcano Parícutin when it first erupted, I was able to visit it when it was only a week old. As my observations have been recorded in full in a previous article [see 1 of “References” at end of paper], only a few of the more pertinent features are repeated here, in order to give a setting for the succeeding papers in this symposium.
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 specimens is numbered in the text, and in Table 1 is given the name of the collector and the place and date the rock was collected.
Parícutin's volcanic activity during its first year of life included a number of periods characterized by flowing lava. The length of time of individual periods ranged from a few days up to more than a month, and were separated by intervals during which little or no lava flowed at the surface. A cyclic activity is therefore obvious, and a more or less permanent record remains in the form of the lava‐flows. The complete cycle, however, is believed to consist essentially of four stages: (1) Flowing lava; (2) maximum gas activity from the central crater (without flow); (3) the rise of lava in the vent; (4) breaching of the cone in preparation for renewed flow.
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 of thousands of quartz‐axes; in an analysis of joints it consists of the measuring and plotting of thousands of joint‐attitudes. In each case limiting factors are required to give meaning to the accumulated data. The study of joints, to be significant, must be confined to an area with well‐integrated structural features. In quartz‐fabric studies discrimination between grain‐types is essential to the development of interpretable diagrams.
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 this year, in order to effect better technical and geographic coverage.
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 memorandum dated December 2, 1943, proposed three questions for consideration as an initial effort of the Sub‐Committee: (1) Should the coefficient of permeability depend only on the structure of the material, or should some other name be used to express this property in view of the fact that, as now generally used, the coefficient of permeability is not independent of properties of the fluid or the combined properties of the fluid and the material; (2) should a name be coined, or is there a suitable one in existence, for expressing the combined properties of the material and fluid for practical application in one local area; (3) what are the parameters that should be included in the equation of flow of fluids that relate only to the structure of the material.
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 along the highway have serious water‐shortages during the six‐month dry season from December to June, was selected as the country in which most of the work was to be done. The Direccion de Sanidad de Salvador, through its Director, Dr. V. A. SUTTER, provided a list of some 35 cities which suffered the most serious water‐shortages and each of these cities was visited. The geological and ground‐water conditions in the vicinity were studied by reconnaissance‐methods and remedial measures were recommended. In nearly every case the water‐shortage was due in large part to improper or incomplete development of the available supplies. Most municipalities obtained their water‐supplies from springs which either had inadequate flow or were improperly developed. In a few cases the spring‐flow was adequate but a large quantity of water was wasted either through poor distribution‐systems or through breaks in the line that conducted water from the spring to the city. Nearly all of the water works were unsanitary. In most places it appeared likely that adequate supplies can be obtained from wells at relatively shallow depth. In some places adequate supplies can be obtained by proper improvements of springs that are now in use. In a very few cases no remedy for the shortage of water could be suggested.
No abstract available.
This paper outlines certain fundamental principles in a graphic procedure which appears to be an effective tool in segregating analytical data for critical study with respect to sources of the dissolved constituents in waters, modifications in the character of a water as it passes through an area, and related geochemical problems. The procedure is based on a multiple‐trilinear diagram (Fig. 1) whose form has been evolved gradually and independently by the writer during the past several years through trial and modification of less comprehensive antecedent forms. Neither the diagram nor the procedure here described is a panacea for the easy solution of all geochemical problems. Many problems of interpretation can be answered only by intensive study of critical analytical data by other methods.
A brief though concise statement of the history of ground‐water studies on Long Island, beginning with the early water‐level observations in Brooklyn by STODDARD in 1854, was given by THOMPSON [see 7 of “References” at end of paper]. These and other early data were considered later by LEGGETTE [8]. He evaluated them by means of a graph of the cumulative departure of precipitation. More recent studies by LEGGETTE [9] and by the writer have lead to the procedure outlined in Part I of this paper [10], which was founded upon an empirical approach suggested by LEGGETTE and was later justified by analysis based on the theory of BOUSSINESQ [11].
Unusual breccias were noted at several places in the vicinity of Groundhog and Glacier Basins, about 13 miles east of Wrangell on the mainland of southeastern Alaska, in 1942 and 1943. They are similar in some respects to the clastic dikes in Colorado described by Burbank [see 1 of “References” at end of paper] and Haff [2], and to some explosion breccias in the Samoan Islands described by Stearns [3].
Explorers began to push into the vast uncharted areas of the West in 1804, when Captains Lewis and Clarke ascended the Missouri River, crossed the Rocky Mountains into the headwaters of the Columbia River, and followed that stream to the Pacific Ocean. The honor of being the first white man to see Great Salt Lake is claimed for a number of explorers and trappers who visited the region in the twenties and thirties of the Nineteenth Century. Among these were Etienne Provot and James Bridger, who were in the region in 1824–25, each quite unaware of the other's activities and discoveries. In 1833 Captain B. L. E. Bonneville dispatched a party from his camp at Green River, Wyoming, for the purpose of exploring Great Salt Lake. This party attempted to make a circuit of the lake, chart its outline, and trap all the streams en route, but the attempt was abandoned because the great barren salt plains west of the lake were so hazardous that the party was in grave danger of perishing.
The membership of the committee has been selected to afford good representation of geographic sections and of organizations engaged in runoff research. Some new members were added during the year in order to strengthen the representation of the committee in certain phases of runoff research. Norbert H. Leupold submitted his resignation in April because his work is no longer directly related to runoff‐research. At the beginning of the year members of the committee met to discuss its setup and plans for the future. The committee has two subcommittees, one dealing with floods and the other with subsurface‐flow. The question was considered whether progress might be facilitated by the addition of one or more additional committees dealing with logical classifications of the subject of runoff. The confusion in nomenclature and terminology relating to runoff was discussed,but it was thought that the present time was not fitting for comprehensive consideration of standardization. It was considered important that the writer of a paper dealing with runoff should make clear the usage of terms he follows In his paper. It was emphasized that there is still an important need for better understanding or liaison between groups dealing with the influence of land use on stream‐flow and those dealing with control and development of streams.
A partial differential equation is set up for radial flow in an elastic artesian aquifer into which there is vertical leakage in proportion to the drawdown. This differential equation is integrated to obtain two steady state solutions, one for the case of a well in an infinite aquifer, and the other for the case where the head is maintained constant along an outer boundary concentric with the well. In the second case, the solution of the non‐steady state is also obtained for flow towards a well discharging at a steady rate, the initial state being one of uniform head distribution. A table and some curves are given for one set of assumed values of three of the parameters of the system.
To Preston P. Macy, Superintendent of Olympic National Park, the Committee is indebted for the first data on the recession of the Blue Glacier, one of the major ice streams on Mount Olympus. Annual measurements to its terminus were begun in 1938, the year in which Olympic National Park was established, and such measurements, MACY states, will be continued in future years, circumstances permitting. Thus one more sizable glacier is added to the list of ice bodies in the western United States whose variations in length and volume in response to current climatic fluctuations are being observed from year to year.
Because of war‐imposed responsibilities of most agencies and individuals this year, no new programs were undertaken by the Committee, but the work of the Subcommittee on Permeability was continued, and a substantial progress report by C. E. Jacob, Acting Chairman, and by members of this Subcommittee follows this report as Appendices A to D. Following a suggestion by Max Suter, copies of this year's Committee report were sent to each member prior to publication and it is planned to follow this procedure in the future.
The Subcommittee on Permeability of the Permanent Research Committee on Ground Water of the Section of Hydrology, was organized in 1943 to provide for the open discussion of the terminology relating to permeability with a view toward the elimination of conflicting usages and the clarification and standardization of acceptable terms. Confusion had arisen not only in the units of measurement but also in the notation and nomenclature of permeability. It seemed desirable to have general agreement particularly in regard to the names of the different physical parameters in common use and their symbols.
In the development of terms and units for a new science such as ground‐water hydrology, which is based on physics, it would seem fitting to adopt the terminology that has become standard in other branches of physics such as heat and electricity. Darcy's law has its counterpart in similar laws in the other branches of physics.