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Catalog of earthquakes in southern Alaska: January-March 1978

The National Center for Earthquake Research of the U.S. Geological Survey (USGS) began a program of telemetered seismic recording in south-central Alaska in 1971. The principal objectives of this program have been to use data recorded by this network to precisely locate earthquakes in the active seismic zones of southern Alaska, to delineate seismically active faults, to assess seismic risk, to document potential premonitory earthquake phenomena, to investigate current tectonic deformation, and to study the structure and physical properties of the crust and upper mantle. A task fundamental to all of these goals is the routine cataloging of earthquake parameters for earthquakes located within and adjacent to the seismograph network. The initial network of 10 stations, 7 around Cook Inlet and 3 near Valdez, was installed in 1971. Each summer since then additions or modifications to the network have been made. By the Fall of 1973, 26 stations extended from western Cook Inlet to eastern Prince William Sound, and 4 stations were located between Cordova and Yakutat. A year later 20 additional stations were installed. Thirteen of these were placed along the eastern Gulf of Alaska with support from the National Oceanic and Atmospheric Administration (NOAA) under the Outer Continental Shelf Environmental Program to investigate the seismicity of the outer continental shelf (OCS) region of interest for oil exploration. During the subsequent years the region covered by the network has remained relatively fixed while effort has been made to improve the instrumentation and installation of the stations in order to make them more reliable. This earthquake catalog presents origin times, focal coordinates and magnitudes for 384 shocks occurring in the first quarter of 1978. Readings from a total of 62 stations were used to locate the shocks, including 11 stations operated by the NOAA Alaska Tsunami Warning Center (formerly Palmer Observatory), and 5 stations operated by the Geophysical Institute of the University of Alaska (U. of A.). Earthquakes in south-central Alaska as small as magnitude 3.0 have been routinely located by the National Earthquake Information Service of the USGS and its predecessor since the great Alaska earthquake of 1964 and published in the reports "Preliminary Determination of Epicenters" (PDE). In contrast the shocks included in this catalog are as small as magnitude 1.0 and most are smaller than magnitude 3.0. Data for the larger historic earthquakes in south-central Alaska have been tabulated by Meyers (1976). The locations of the stations of the USGS seismograph network are plotted in Figure 1 and listed in Table 1 along with the additional stations from which readings were obtained. The USGS stations have single, vertical-component seismometers except for GLB, PNL, RDT, SKN, and VLZ which also have two horizontal seismometers.

Alaska↗

Catalog of earthquakes in south-central Alaska, April - June 1972

The National Center for Earthquake Research of the U.S. Geological Survey (USGS) installed a network of eleven seismograph stations in south-central Alaska in the summer of 1971 to collect seismological data for investigating seismic and tectonic processes in the Cook Inlet region, for evaluating the seismic hazard in the Cook Inlet region and in the Chugach Mountains along the southern end of the route of the proposed trans-Alaska oil pipeline, and for studying the structure of the crust and upper mantle in south-central Alaska. The first recordings from the network were obtained in late September 1971. The first earthquakes to be located with data from the network occurred in October 1971. This earthquake catalog, which is the first to be compiled for the USGS Alaska network, presents origin times, focal coordinates and magnitudes for 210 shocks occurring in the second quarter of 1972 (except from June 15 to 23) in south-central Alaska, primarily in the Cook Inlet region. Readings from a total of 18 stations were used to locate the shocks. To supplement the readings from the 10 USGS stations that were operative during this quarter, arrival times were obtained from 6 stations operated by the Palmer Seismological Observatory of the National Oceanic and Atmospheric Administration (NOAA) and 2 stations operated by the Geophysical Institute of the University of Alaska (U of A). The data in this catalog are the most detailed and precise earthquake data compiled to date for earthquakes within the Cook Inlet region. Earthquakes in south-central Alaska as small as magnitude 3.0 have been routinely located by the National Earthquake Information Center of NOAA (currently the National Earthquake Information Service of USGS) since the great Alaska earthquake of 1964 and published in the reports "Preliminary Determination of Epicenters" (PDE). In contrast the shocks included in this catalog are as small as magnitude 1.0 and most are smaller than magnitude 3.0. Data for the larger historic earthquakes in south-central Alaska have been tabulated by Davis and Echols (1962) and U.S. Coast and Geodetic Survey (1966). The locations of the eleven stations of the NCER seismograph network are plotted in Figure 1 and listed in Table 1 along with the additional stations from which readings were obtained. The USGS stations have single, vertical-component seismometers except for NKA and SKL, which also have two horizontal seismometers. The station ERN was installed in the summer of 1971, however the telemetry circuit was not available until September 1972.

Alaska↗

Fossil flora of the John Day basin, Oregon

For a number of years I have been gradually accumulating material for a thorough revision of the Tertiary floras of the Pacific slope. Fossil plants are known to occur at numerous points within this area, and their study and identification has already furnished valuable data bearing on the geological history of the region, and when still further exploited it is confidently expected that they will afford more exact data for the use of geologists. This investigation is progressing satisfactorily, and at no distant day it is hoped to have it in form for final publication. From time to time various members of the United States Geological Survey, as well as others not connected with this organization, have sent in small collections of fossil plants for determination. These have been studied and reported upon as fully as the condition of the problem permitted, so that the determinations could be immediately available to geologists, but with the reservation that none of the questions could be fully settled until all known material had been studied and properly correlated. The rich fossil plant deposits in the John Day Basin, as set forth more fully in the historical account which follows, have been known for a period of nearly fifty years, but their study has been carried on in a more or less desultory manner. There has also been considerable confusion as to the horizons whence these plants came. As various species of plants described originally from the John Day region were detected in various other localities in Oregon, and in surrounding areas, as central Washington, western Idaho, and northern California, it became more than ever apparent that a thorough study of all material obtainable from this type area would be necessary before any definite or satisfactory conclusions could be reached. The immediate incentive for this revision was furnished by the receipt of a considerable collection of plants, made by Dr. John C. Merriam in 1900 while he was in charge of an expedition into this region made under the auspices of the University of California. When these plants were submitted to me for study, it was thought possible to present their description, together with a revision of our knowledge of the previously known forms, within a space sufficiently small to permit the publication of the matter as an appendix to a paper on the general geology of the area, then in preparation by Dr. Merriam. But it soon became apparent that this could not be adequately done within the space available, and a short preliminary report was prepared for and published by Dr. Merriam. The results of a complete restudy of all available fossil plant material from the John Day Basin are now presented. I wish to record my great indebtedness to Dr. Merriam, who not only accompanied me at a considerable personal sacrifice on a trip through the region in 1901, but placed unreservedly at my disposal all material bearing in any way on the problem then in the paleontological museum of the University of California. To Dr. Arthur Hollick I am indebted for the loan of all material from the John Day region belonging to Columbia University, and now deposited in the New York Botanical Garden at Bronx Park. This material, together with the rich collections belonging to the United States National Museum, represents practically all now known to have come from the John Day Basin.

Oregon↗

Twenty-Sixth Annual Report of the Director of the United States Geological Survey, 1904-1905

Introduction Remarks on the work of the year Branches of work The United States Geological Survey was created in 1879 for the purpose—as its name implies—of examining and reporting on the geologic structure and mineral resources and products of the national domain. To the adequate description of geologic formations and structure cartography is essential, and Congress early recognized this fact by making appropriations for the preparation of a geologic map of the United States. The topographic base map, in order to show with sufficient precision the relations of the geologic formations and the intricacies of the structure, must have a rather large scale and present considerable detail. No such map of this country existed in 1879, and its preparation was immediately begun. The waters of the country are of vast importance, and in a broad sense may be regarded as one of its greatest mineral resources. Hence, in the evolution of the work of the Survey, and especially in view of the great importance of the subject to the irrigation interests, Congress early began making appropriations for ascertaining the amount and quality of the surface and underground waters and when, in 1902, the service for the reclamation of arid lands was organized, that work naturally was placed in the hands of the Secretary of the Interior and by him intrusted to the Director of the Survey. The three great branches of work carried on by the Geological Survey are, therefore, the geologic, the topographic, and the hydrographic, and with these, more especially the latter, is conjoined the Reclamation Service ; publication and administration constitute necessary auxiliary branches. Along these great lines the work of the Survey has progressed without essential variation for many years. The changes made have been due to normal expansion rather than to radical departure in object or plan. State cooperation During the last fiscal year, State cooperation, as explained in previous reports, continued. Arrangements for cooperation in geologic work were made with five States, the total amount contributed by them being about \$8,000, and arrangements for cooperative topographic surveys were made with eleven States, the amount available for such surveys being thus increased by more than \$100,000. Reclamation service The work of the Reclamation Service during the last fiscal year was advanced as rapidly as was thought consistent with thoroughness and accuracy. Actual construction is now in progress on eight projects, as follows : Salt River, Arizona; Truckee-Carson, Nevada; Hondo, New Mexico ; Uncompahgre Valley, Colorado; Minidoka, Idaho; Belle Fourche, South Dakota ; North Platte, Wyoming and Nebraska ; and Shoshone, Wyoming. Proposals were received for work on the Laguna dam, Yuma project, California and Arizona; Huntley project, Montana, and the Fort Buford project, North Dakota and Montana. In several other States operations are at a point where advertisements for bids only await the removal of certain legal obstacles, the settlement of international difficulties, or the termination of delays on the part of local organizations or individuals. The organization of the body of men constituting the personnel of the Reclamation Service, whose field of operations covers so large a territory, though necessarily difficult, has been satisfactorily accomplished, and precedents have been established along approved lines. The general allotment of funds has been made with a view to the greatest benefit to the greatest number, and from the broad standpoint of the welfare of the country as a whole. One of the important features in the evolution of the irrigation work is the development of power, which the numerous dams and, drops in canals make possible. Plans were made to transmit the power being developed in many sections of the arid regions, by means of electricity, to points more or less distant, there to be used for raising underground waters, pumping waters lying above the line of gravity canals, or for various other purposes, and attention was also given to the character of the soils and of the water to be used upon them, the materials used in the construction of the works, and numerous other details incident to reclamation by irrigation. Coal-testing plant Under two special appropriations of \$30,000 each, carried by the urgent deficiency bill approved February 18, 1904, and the general deficiency bill approved April 27, 1904, the Director of the Geological Survey was authorized to construct and operate at the Louisiana Purchase Exposition a plant for testing the coals and lignites of the United States, in order to determine their fuel values and the most economic method of their utilization for different purposes, it being provided that all testing machinery and all coals and lignites to be tested 'should be contributed free of charge to the Government. For carrying out the provisions of these acts the Director appointed a committee, consisting of Edward W. Parker, Joseph A. Holmes, and Marius R. Campbell, to direct the construction and operation of the plant. This committee received the heartiest cooperation from the manufacturers of such equipment as was needed for the installation of the plant, from the railroad companies in freight concessions and transportation for the experts and their assistants, and from the coal operators in the furnishing of coal in carload lots for testing purposes. Although the utmost expedition was used in the construction of the plant, it was not until the first of September that the testing work actually began. Between the first of September and the close of the exposition 65 carload samples of coal for testing purposes were received, and the results of the investigation were published in a preliminary report issued as Geological Survey Bulletin No. 261. The coals tested were received from 17 States and Territories, and much valuable information regarding the best uses to which the different coals may be put was obtained. One of the most important facts developed during this investigation is the possibility of utilizing the vast lignite resources of the West in the manufacture of producer gas, it having been shown that a higher grade of this gas can be obtained from lignite than from ordinary bituminous and anthracite coal. The investigation also showed that the slack or fine coal produced at the dry, noncoking bituminous coal mines of the middle West, large quantities of which are now being wasted, can be profitably utilized by briquetting.

Annual Report↗

Geologic implications of gas hydrates in the offshore of India: results of the National Gas Hydrate Program Expedition 01

The Indian National Gas Hydrate Program Expedition 01 (NGHP-01) is designed to study the occurrence of gas hydrate along the passive continental margin of the Indian Peninsula and in the Andaman convergent margin, with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. The NGHP-01 expedition established the presence of gas hydrates in the Krishna-Godavari and Mahanadi Basins, and the Andaman Sea. The expedition discovered in the Krishna-Godavari Basin one of the thickest gas hydrate accumulations ever documented, in the Andaman Sea one of the thickest and deepest gas hydrate stability zones in the world, and established the existence of a fully developed gas hydrate petroleum system in all three basins. The primary goal of NGHP-01 was to conduct scientific ocean drilling/coring, logging, and analytical activities to assess the geologic occurrence, regional context, and characteristics of gas hydrate deposits along the continental margins of India. This was done in order to meet the long-term goal of exploiting gas hydrate as a potential energy resource in a cost effective and safe manner. During its 113.5-day voyage, the D/V JOIDES Resolution cored and/or drilled 39 holes at 21 sites (1 site in Kerala-Konkan, 15 sites in Krishna-Godavari, 4 sites in Mahanadi, and 1 site in the Andaman deep offshore area), penetrated more than 9250 m of sedimentary section, and recovered nearly 2850 m of core. Twelve holes were logged with logging-while-drilling (LWD) tools and an additional 13 holes were wireline logged. The science team utilized extensive on-board laboratory facilities to examine and prepare preliminary reports on the physical properties, geochemistry, and sedimentology of all the data collected prior to the end of the expedition. Samples were also analyzed in additional post-expedition shore-based studies conducted in leading laboratories around the world. One of the specific objectives of this expedition was to test gas hydrate formation models and constrain model parameters, especially those that account for the formation of concentrated gas hydrate accumulations. The necessary data for characterizing the occurrence of in situ gas hydrate, such as interstitial water chlorinities, core-derived gas chemistry, physical and sedimentological properties, thermal images of the recovered cores, and downhole measured logging data (LWD and/or conventional wireline log data), were obtained from most of the drill sites established during NGHP-01. Almost all of the drill sites yielded evidence for the occurrence of gas hydrate; however, the inferred in situ concentration of gas hydrate varied substantially from site to site. For the most part, the interpretation of downhole logging data, core thermal images, interstitial water analyses, and pressure core images from the sites drilled during NGHP-01 indicate that the occurrence of concentrated gas hydrate is mostly associated with the presence of fractures in the sediments, and in some limited cases, by coarser grained (mostly sand-rich) sediments.

Marine and Petroleum Geology↗

Oxygen isotopes in nitrite: Analysis, calibration, and equilibration

Nitrite is a central intermediate in the nitrogen cycle and can persist in significant concentrations in ocean waters, sediment pore waters, and terrestrial groundwaters. To fully interpret the effect of microbial processes on nitrate (NO 3 - ), nitrite (NO 2 - ), and nitrous oxide (N 2 O) cycling in these systems, the nitrite pool must be accessible to isotopic analysis. Furthermore, because nitrite interferes with most methods of nitrate isotopic analysis, accurate isotopic analysis of nitrite is essential for correct measurement of nitrate isotopes in a sample that contains nitrite. In this study, nitrite salts with varying oxygen isotopic compositions were prepared and calibrated and then used to test the denitrifier method for nitrite oxygen isotopic analysis. The oxygen isotopic fractionation during nitrite reduction to N 2 O by Pseudomonas aureofaciens was lower than for nitrate conversion to N 2 O, while oxygen isotopic exchange between nitrite and water during the reaction was similar. These results enable the extension of the denitrifier method to oxygen isotopic analysis of nitrite (in the absence of nitrate) and correction of nitrate isotopes for the presence of nitrite in “mixed” samples. We tested storage conditions for seawater and freshwater samples that contain nitrite and provide recommendations for accurate oxygen isotopic analysis of nitrite by any method. Finally, we report preliminary results on the equilibrium isotope effect between nitrite and water, which can play an important role in determining the oxygen isotopic value of nitrite where equilibration with water is significant.

Analytical Chemistry↗

Cooperative investigation of precision and accuracy in chemical analysis of silicate rocks

This is the preliminary report of the first extensive program ever organized to study the analysis of igneous rocks, a study sponsored by the United States Geological Survey, the Massachusetts Institute of Technology, and the Geophysical Laboratory of the Carnegie Institution of Washington. Large samples of two typical igneous rocks, a granite and a diabase, were carefully prepared and divided. Small samples (about 70 grams) of each were sent to 25 rock-analysis laboratories throughout the world; analyses of one or both samples were reported by 34 analysts in these laboratories. The results, which showed rather large discrepancies, are presented in histograms. The great discordance in results reflects the present unsatisfactory state of rock analysis. It is hoped that the ultimate establishment of standard samples and procedures will contribute to the improvement of quality of analyses. The two rock samples have also been thoroughly studied spectrographically and petrographically. Detailed reports of all the studies will be published.

Analytical Chemistry↗

Water‐level fluctuations caused by Montana earthquake

The major earthquake of August 17, 1959, near the Montana‐Wyoming border had marked effects on water levels and artesian pressures in wells throughout the United States. Preliminary reports from field offices of the U. S. Geological Survey in 21 states show that water‐level fluctuations were automatically recorded in 136 observation wells. These wells for which records are available, and the maximum double amplitude of the fluctuations, are listed in Table 1.

Eos, Transactions, American Geophysical Union↗

Palæomagnetism of Hawaiian lava flows

PALÆOMAGNETIC investigations of volcanic rocks extruded in various parts of the world during the past several million years have generally revealed a younger sequence of lava flows magnetized nearly parallel to the field of a theoretical geocentric axial dipole, underlain by a sequence of older flows with exactly the opposite direction of remanent magnetization. A 180-degree reversal of the geomagnetic field, occurring near the middle of the Pleistocene epoch, has been inferred by many workers from such results 1–3 . This is a preliminary report of an investigation of 755 oriented samples collected from 152 lava flows on the island of Hawaii, selected to represent as many stratigraphic horizons as possible. (Sampling details are indicated in Table 1.) This work was undertaken because Hawaii's numerous thick sequences of lava flows, previously mapped as Pliocene to Historic by Stearns and Macdonald 4 , and afterwards assigned ages ranging from later Tertiary to Recent, by Macdonald and Davis 5 , appeared to offer an ideal opportunity to examine the most recent reversal of Earth's field.

Nature↗

Observations of ocean circulation and sediment transport experiment offshore of Fire Island, NY

Researchers from the U.S. Geological Survey (USGS) Woods Hole Coastal and Marine Science Center (WHCMSC), in collaboration with Coastal Carolina University (CCU) and University of South Carolina (USC), conducted a scientific field study to investigate the ocean circulation and sediment transport processes offshore of Fire Island, NY. Although the physical processes along the entire linear extent of Fire Island (~50 km) are of interest to the project, one particular region of focus is at the western end of the island where offshore sand ridges out to depths of 20 m extend across the inner shelf and connect to the near-shore bar system. The primary objective was to measure the physical processes around the sand ridges, including circulation patterns, wave parameters, bottom stress, and suspended sediment. Transects of instrumentation were positioned along and across the crests and troughs of the ridge field. A site at the top of a ridge and a site at the bottom of an adjacent trough were each populated with two tripods designed to provide high-resolution measurements near the sea-bed to record sediment re-suspension events. Measurements at these two sites include near bottom velocity profiles, acoustic Doppler velocimeters, pressure, optical transmission and backscatter at high sampling rates. Other measurements include upward looking velocity profiles, temperature, salinity, sonar images and profiles, and sediment size classes. Five smaller tripods were deployed to complete lines alongshore and across shore over a 5 km area to provide a regional picture. These tripods recorded upward looking velocity profiles and near bottom temperature, pressure and salinity. Surface buoys marked the position of the tripods and collected surface measurements at six of the sites. One buoy gathered meteorological measurements. The sites were occupied from January to April, 2012. This deployment was similar to previous efforts off Cape Hatteras, NC, in 2009, and is part of an ongoing effort to understand regional patterns in circulation and sediment transport and the interaction of inner shelf and near shore processes. New instrumentation for the USGS was introduced, including a variety of current and wave measurement equipment, acquisition and telemetry in near-realtime of the weather data, time series sonar imaging equipment, and anti-fouling wipers. Preliminary results suggest a complex and subtle relationship between wind and across shore current velocity in this region, and a more straightforward relationship between winds and alongshore currents. This paper also includes a preliminary report on the effectiveness of new measurement techniques used during this experiment.

New York↗

Blood parasites of birds of the District of Columbia and Patuxent Research Refuge vicinity

Recently a number of surveys of blood parasites of birds have been made in different parts of this country by different workers, the general purpose of which was to further the knowledge of the distribution and pathogenicity of these protozoa. This paper treats the distribution of parasites found in sampling miscellaneous birds of the District of Columbia and vicinity and contains a preliminary report on the more important phase of the problem of pathogenicity.

Maryland↗

Hydrocarbons in sediment of the Weddell Sea, Antarctica

Heavy hydrocarbons (about C15+) are ubiquitous but minor components in sediment from three sites (692, 693, and 694) drilled during Ocean Drilling Program (ODP) Leg 113. This preliminary report is the first to describe the distribution of some of these hydrocarbons in sediment of the Weddell Sea. Samples from Sites 692 and 693, located on a mid-slope bench along the margin of Queen Maud Land, span a time interval from Early Cretaceous to Pleistocene. In samples from the Tertiary portion of the record, having an average organic-carbon content of about 0.2%, n-alkanes are common and are characterized by populations that indicate both marine and terrigenous sources. In contrast, samples from the Cretaceous portion of the record, having an average organic carbon content of about 4%, contain mixtures of hydrocarbons in which n-alkanes are secondary in abundance to the isoprenoid hydrocarbons, pristane and phytane. Diasterenes, sterenes, and hopenes are present in anomalously high concentrations and indicate immaturity. The Cretaceous hydrocarbons appear to be mainly primary, whereas the Tertiary hydrocarbons contain compounds which indicate that the sediment, along with its organic content, has been recycled. Samples from Site 694, located in the Weddell Sea on the abyssal plain, range in age from late Miocene to early Pliocene.

Proceedings of the Ocean Drilling Program: Scienti↗

Altitudes between Lake Superior and the Rocky Mountains

In the survey of Lake Agassiz, a preliminary report of which forms Bulletin No. 39, it was found necessary to ascertain the altitudes determined within its area by railroad surveys as the basis for leveling along the shore lines of that glacial lake, and learning their relations in height to each other, to the great lakes of the St. Lawrence and Nelson Rivers, and to the ocean. From the time of the first observations and description of the upper beaches of Lake Agassiz by the author in 1879 and 1881, for the Geological Survey of Minnesota, and especially since the work was extended in 1885, under the U. S. Geological Survey, to include both sides of this lacustrine area in Minnesota and North Dakota now drained by the Red River of the North, much attention has been given to this collection of altitudes, and to the means of referring them to the sea level. The greater part of Lake Agassiz, however, was in Manitoba and adjacent British Territory, stretching north to the Saskatchewan; and in 1887, jointly for the Geological Surveys of the United States and of Canada, the author continued his examination of the beaches and deltas on the west side of the lake along a distance of a hundred miles north from the international boundary, across the prairie region of southwestern Manitoba, the leveling in this work being based on the altitudes of the Canadian Pacific Railway and its branches and connecting railways.

Bulletin↗

Stratigraphic sections of the Phosphoria formation in Idaho, 1949, part 1

The U. S. Geological Survey has recently measured and sampled the Phosphoria formation at many localities in Idaho and other western states. These data. will not be fully synthesized and analyzed for several years, but segments of the data, accompanied by little or no interpretation, are published as preliminary reports as they are assembled. This report, which contains abstracts -of many of the sections measured in southeastern Idaho (fig. 1), is one of this series and is the fourth report on Idaho; it includes about half the data gathered in Idaho in 1949. The field and laboratory procedures adopted in these investigations are described rather fully in a previous report (McKelvey and others, 1953a).

Idaho↗

The Fire Clay and Whitesburg coals in the Hyden quadrangle, Leslie, Clay, and Perry Counties, Kentucky

This preliminary report on the coal in the Hyden quadrangle, Kentucky, presents data on two of the principal commercial coals. The Fire Clay is the most valuable commercial coal in the quadrangle, and locally the Whitesburg bed is of minable thickness. Special emphasis has been placed on determining the thickness, extent, composition, and structure of these beds, and on obtaining an accurate estimate of the coal reserves.

Kentucky↗

General hydrogeology of the aquifers of Mesozoic age, Upper Colorado River Basin - excluding the San Juan Basin - Colorado, Utah, Wyoming, and Arizona

The objective of the Upper Colorado Regional Aquifer Systems Analyses (RASA) project is to assess quantitatively the occurrence, movement, and availability of water stored in rock formations underlying the basin. This is one of a series of preliminary reports that describe what is currently known (1984) about the geometry and hydrologic properties of the aquifer systems, and the chemistry of the water in known or potential aquifers. This report provides the foundation needed for the assessment of the ground-water resources of the region. The report describes only part of the hydrologic system; that is, formations of Mesozoic age. Younger and older formations significant to the hydrologic system are described in other reports.

Arizona, Colorado, Utah, Wyoming↗

Geology and zinc-lead-barite deposits in the area east of Cuba City, Wisconsin

The current study of the Wisconsin-Illinois-Iowa zinc-lead district (fig. 1) was begun in 1942, with the major emphasis placed on detailed mapping of geologic structure and ore deposits. Preliminary reports for several areas in the mining district have been prepared, and the present study of the are east of Cuba City, Wis., is a continuation of that program.

Wisconsin↗