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At least 1,153 records · Page 64Linked to original sources

USGS1992

A geochemical investigation of selected areas in Greenville and Laurens Counties, South Carolina: Implications for mineral resources

The purpose of this study is to geochemically evaluate three areas within the Greenville 1° x 2° quadrangle (see index map) that have been shown by previous studies to contain anomalously high amounts of tin. Jackson and Moore (1992) reported the presence of cassiterite (SnO 2 )-bearing heavy-mineral concentrates from stream sediment samples that were collected during a regional geochemical reconnaissance of the Greenville 1° x 2° quadrangle. The data reported here confirm identified in selected heavy-mineral concentrate samples. In addition, anomalously high concentrations of barium, beryllium, lanthanum, and thorium are also reported for parts of the same areas. No significant mineral deposits are known to occur in the study areas. There was, however, minor production of monazite from several nearby localities (Sloan, 1908), and gold was produced from deposits in the northeastern part of Greenville County and nearby Spartanburg County (McCauley and Butler, 1966). The three areas selected for resampling are located in the Inner Piedmont physiographic province of South Carolina (see index map). The generalized tectonic setting of the region and the locations of the study is just north of Greenville, S.C. Much of it is within the moderately to steeply sloped terrane of Paris Mountain State Park where elevations reach approximately 600 m. Simpsonville, S.C., is neat the center of the second study area, and the southernmost study area is near Hickory Tavern, S.C. Both the Simpsonville and Hickory Tavern study areas are in more gently rolling Piedmont terrane. Each of the sampled areas is drained by tributaries of the Enoree and Reedy Rivers. Parts of three different thrust sheets underlie the region covered by this study (fig. 1); in ascending structural position, they are the Six Mile, Paris Mountain, and Laurens thrust sheets (Nelson and others, 1987). Nelson (1988, p. 7) described the contacts between these sheets as being along unnamed faults. The rocks in and around the study areas have undergone sillimanite-muscovite-grade metamorphism (Nelson, 1988, p. 9). Nelson (1988, p. 13) reports that the Six Mile thrust sheet was metamorphosed about 344 Ma. The geology of these sheets as described in this study, including geologic contacts, rock descriptions, and unit names, generally follows that of Nelson and others (1987, 1989). Within the Paris Mountain study area, rocks of the Paris Mountain thrust sheet predominate (fig. 2) and consist of a biotite-muscovite-sillimanite schist (EZsp) that has extensive lenses of fine- to medium- grained biotite granite gneiss (Pzgp). Areas of biotite granite gneiss that occur in the southern part of the Paris Mountain study area contain extensive pegmatitic and leucogranitic phases. These pegmatitic zones consist mostly of coarse-grained microcline feldspar and quartz with minor amounts of muscovite, biotite, and garnet. Smaller pegmatite lenses (<0.5 m thick) that occur within the biotite-muscovite-sillimanite schist of the Paris Mountain study area are generally of similar mineralogy, although some contain tourmaline crystals up to 5 cm in length. The Six Mile thrust sheet underlies the northern edge of the Paris Mountain study area, where it is composed of gneissic biotitic granites of the Caesars Head Granite (figs. 1 and 2). The northwestern part of the Simpsonville study area (figs. 1 and 3), within the Paris Mountain thrust sheet, is underlain by a biotite-muscovite-sillimanite schist (EZsp) that contains lenses of biotite granite gneiss (Pzgp). In the southeastern part of the Simpsonville study area, within the Laurens thrust sheet, biotite gneiss (EZgl), biotite granite gneiss (Pzgf), and minor amphibolite (EZal) are interlayered biotite (EZgl), granite gneiss (Dgg), and amphibolite (EZal) of the Laurens thrust sheet (fig. 4).

South Carolina↗

USGS1994

Mines, prospects, and occurrences of metallic (excluding gold), pegmatite, and rare-earth mineral commodities in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina

All of the known mines, prospects, and occurrences of metallic (excluding gold, pegmatite, and rare-earth mineral commodities for the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order for each county (fig. 1), the map number of each item, which correlates and locates the item on the accompanying Greenville 1° x 2° quadrangle map. The known name of the feature; the 7.5' topographic map on the which the commodity site is located; the Universal Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5' topographic map; the commodity; remarks; and references are also listed. Some locations are known, but many sites are not verified and their locations are only approximate. References are listed in References Cited and referred to by number to save space.

Georgia, North Carolina, South Carolina↗

USGS1994

Gold occurrences in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina

All of the gold mines, prospects, placers, and occurrences known in the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order by county (fig. 1), the map number of each feature, which is located either on the accompanying Greenville 1° x 2° quadrangle map or figure 2. The known name of the feature; the 7.5' topographic map on the which the gold site is located (if known, within 25 ft or 7.6 m), the Universal Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5' topographic map; the commodity; remarks; and references are also listed. Some locations are known, but many sites are not verified and their locations are only approximate. References are listed in References Cited and referred to by number to save space.

Georgia, North Carolina, South Carolina↗

USGS1994

Mines, prospects, and occurrences of nonmetallic mineral commodities in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina

Mines, prospects, and occurrences of nonmetal mineral commodities in the Greenville 1° x 2° quadrangle are tabulated in this report. There are 488 symbols representing 579 mines, prospects, and occurrences located in the quadrangle. There are 379 symbols used for 466 features in Georgia, 106 symbols for 110 features in South Carolina, and 3 symbols for 3 features in North Carolina. The table lists, in consecutive orders for each county (fig. 1), the map number of each feature, which correlates and locates the item on the accompanying Greenville 1° x 2° quadrangle map. Also listed are the known name of the feature; the 7.5 topographic map on which the commodity site is located; the Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5’ topographic map; the commodity; remarks; and references. Some locations are known, but many sites are not verified and their locations are only approximate. Reference are listed in References Cited and referred to by number to save space. The generalized tectonic framework for the quadrangle is shown in figure 2.

Georgia, North Carolina, South Carolina↗

USGS1999

Extent of Pleistocene lakes in the western Great Basin

During the Pliocene to middle Pleistocene, pluvial lakes in the western Great Basin repeatedly rose to levels much higher than those of the well-documented late Pleistocene pluvial lakes, and some presently isolated basins were connected. Sedimentologic, geomorphic, and chronologic evidence at sites shown on the map indicates that Lakes Lahontan and Columbus-Rennie were as much as 70 m higher in the early-middle Pleistocene than during their late Pleistocene high stands. Lake Lahontan at its 1400-m shoreline level would submerge present-day Reno, Carson City, and Battle Mountain, and would flood other now-dry basins. To the east, Lakes Jonathan (new name), Diamond, Newark, and Hubbs also reached high stands during the early-middle(?) Pleistocene that were 25-40 m above their late Pleistocene shorelines; at these very high levels, the lakes became temporarily or permanently tributary to the Humboldt River and hence to Lake Lahontan. Such a temporary connection could have permitted fish to migrate from the Humboldt River southward into the presently isolated Newark Valley and from Lake Lahontan into Fairview Valley. The timing of drainage integration also provides suggested maximum ages for fish to populate the basins of Lake Diamond and Lake Jonathan. Reconstructing and dating these lake levels also has important implications for paleoclimate, tectonics, and drainage evolution in the western Great Basin. For example, shorelines in several basins form a stair-step sequence downward with time from the highest levels, thought to have formed at about 650 ka, to the lowest, formed during the late Pleistocene. This descending sequence indicates progressive drying of pluvial periods, possibly caused by uplift of the Sierra Nevada and other western ranges relative to the western Great Basin. However, these effects cannot account for the extremely high lake levels during the early middle Pleistocene; rather, these high levels were probably due to a combination of increased effective moisture and changes in the size of the Lahontan drainage basin.

Miscellaneous Field Studies Map↗

USGS1978

Mineralogical map showing the distribution and abundance of gold, scheelite, chalcopyrite, arsenopyrite, minium, and sapphire corundum in heavy-mineral concentrates in the Seward and Blying Sound quadrangles, Alaska

Reconnaissance geochemical and mineralogical sampling was done in the Seward and Blying Sound quadrangles during 1975 and 1976 as part of the Alaska Mineral Resources Assessment Program (AMRAP). These maps show the distribution and abundance of gold, scheelite, chalcopyrite, arsenopyrite, minium and sapphire corundum in heavy-mineral concentrates. Heavy-mineral concentrate samples were collected at 525 sites from active channels and, locally, from the interface of streambeds with intermediate- to low-tide beaches. The heavy-mineral concentrates were obtained by panning stream sediments in the field to remove most of the light minerals. The panned samples were sieved though a 20-mesh (0.8 mm) screen in the laboratory, and the minus-20 mesh fraction was further separated with bromoform (specific gravity: 2.86) to remove any remaining light-mineral grains. Magnetite and other strongly magnetic heavy minerals were removed from the heavy-mineral fraction by using a hand magnet. The remaining sample was passed through a Frantz Isodynamic Separator 1 and a nonmagnetic fraction was obtained at a setting of 0.6 amperes. A split of this nonmagnetic fraction was examined for its mineralogic content using a binocular microscope and X-ray diffraction. The nonmagnetic concentrates primarily contain muscovite, sphene, zircon, apatite, rutile, and anatase. Small amounts of other minerals such as gold, scheelite, minium, sapphire corundum, and most sulfides will also be found in this fraction. 1 The use of trade names is for descriptive purposes only and does not constitute endorsement of those products by the U.S. Geological Survey.

Alaska↗

USGS1962

Antimony in the United States, exclusive of Alaska and Hawaii

The principal sources of antimony in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. The types of deposits are indicated by shape of symbols and the relative importance of the deposits is indicated by size of symbols. In the locality index the localities are listed by States and are keyed by numbers to the map. Localities are distinguished by name of mine, prospect, or geographic area, and their coordinates are given to the nearest minute of latitude and longitude. Geologic relations of each occurrence are characterized briefly. The text and map were compiled from published and unpublished information, and at least one reference is given for each locality if reports on it have been published.

Continental United States↗

USGS1962

Bismuth in the United States, exclusive of Alaska and Hawaii

The bismuth-bearing deposits in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. In compiling the map the deposits were classified into two categories: 1) those that have produced bismuth or are regarded as potential sources based on available information (in general, this category includes the minable base- and precious-metal depos its whose ores or concentrates are reported to contain at least 0.02 percent bismuth); and 2) deposits that have been reported to contain bismuth but which are either unappraised or are regarded as having no potential importance as sources of the metal. The map also shows by stipple pattern various segments of the southern Piedmont gold belt, which extends from northern Virginia southwestward to Alabama. Numerous gold deposits within this belt contain very minor quantities of bismuth and are, therefore, of general interest. Each deposit or group of deposits is numbered on the map by state and identified in the index. The index gives the name of each locality, the coordinates to the nearest minute of latitude and longitude, the principal metals in the ore, a very brief geologic description, and references to published reports if any. Both published and unpublished data have been used in compiling this map.

Mineral Investigations Resource Map↗

USGS1962

Magnesite and brucite in the United States, exclusive of Alaska and Hawaii

The important deposits of magnesite (MgCO 3 ) and brucite (MgO.H 2 O) in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. Single deposits and groups of deposits are shown by geometric symbols according to four size categories based on estimated production plus reserves. These categories are: less than 10,000 tons, 10,000 to 100,000 tons, 100,000 to 1,000,000 tons, and more than 1,000,000 tons. Occurrences of mineralogic interest only are not shown. All map locations are numbered consecutively in each State and keyed to the locality index. The geographical coordinates in the locality index represent the centers of the geometric symbols. Thus, the same coordinates are assigned to all deposits covered by a group symbol. The map was compiled from published reports and data in the files of the United States Geological Survey. The names, geographic coordinates, and geologic types of deposits are given in the locality index. The principal published reports used in compiling the map are listed in the selected references. The main types of commercial deposits of magnesite in the United States are: (1) replacement bodies in limestone and dolomite; (2) replacements and veins in serpentine; and (3) sedimentary beds. Other magnesite deposits of varied origin and less common occurrence include beds associated with talc, chlorite, and mica schists; and veins and lenses in altered tuffs. Brucite is a relatively rare mineral of secondary origin which usually accompanies other magnesian minerals, particularly magnesite and hydromagnesite, and is associated with carbonate rocks and serpentine. Magnesite was first mined in California in 1886, and the State was the only domestic producer until the development of the Washington deposits began in 1916. In recent years, the main production of magnesite has been from Stevens County, Washington, and Nye County, Nevada. Production in California has been intermittent since 1945. Magnesite deposits in Texas were mined during and immediately after World War II. At present (1961) the only brucite deposits being worked are those at Gabbs, Nye County, Nevada. They have been mined almost continuously since 1935.

Mineral Investigations Resource Map↗

USGS1962

Mercury in the United States, exclusive of Alaska and Hawaii

This map shows the location of mercury districts and deposits in the United States (exclusive of Alaska and Hawaii). The map was compiled from published reports and from data in the files of the Geological Survey. All map locations are numbered consecutively in each state and names, geographic coordinates, and selected references are given in the Index.

Mineral Investigations Resource Map↗

USGS1963

High-alumina kaolinitic clay in the United States, exclusive of Alaska and Hawaii

The general distribution of high-alumina kaolinitic clay deposits in the United States (exclusive of Alaska and Hawaii) is shown on the accompanying map. The locations of mines, pits, and prospects are shown by appropriate symbols. Certain clay-bearing areas are shown by patterns that designate the geologic age of the deposits. The locations are numbered consecutively by states and are keyed to an index which lists the name of the deposit, county, and principal references. Only significant references on the size, quality, and geologic occurrence of deposits are listed. Some of the data for the map and index were compiled by John W. Hosterman and the late Leona Boardman.

Mineral Investigations Resource Map↗

USGS1964

Placer gold occurrences in Alaska

The following references give data on localities of placer gold by quadrangle and are keyed by number within each quadrangle to locations shown on map. The quadrangle boundaries and names used on the map are those selected by the U. S. Geological Survey for topographic mapping in Alaska on a scale of 1:250,000. The references cited for each group of localities are the most complete or most recent descriptions as of December 31, 1960.

Alaska↗

USGS1965

Barite in the United States, exclusive of Alaska and Hawaii

The mineral barite, barium sulfate, is the chief source of barium and its compounds needed for many industrial processes and products. Barite is found the world over and is abundant and widely distributed throughout the United States. The barite deposits of the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. The principal geologic type of deposit is indicated by the shape of symbol and the relative importance of the deposit is indicated by the size of symbol. This text lists localities by State, and index numbers are keyed to the map. Localities are distinguished by name of mine, prospect, or geographic area; their coordinates are given to the nearest minute of latitude and longitude. Geologic relations of each occurrence, if known, are summarized briefly. The text and map were compiled from published and unpublished information, and at least one reference is given for each locality, if reports have been published. The listings in some States are preceded by a principal reference which is a major source of information about deposits in those States.

Mineral Investigations Resource Map↗

USGS1965

Tin in the United States, exclusive of Alaska and Hawaii

The principal deposits and occurrences of tin minerals in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. Although some very minor occurrences are included to indicate the extent of distribution, those in which only trace amounts of tin have been found spectrographically or geochemically have been omitted. Unverifiable reported occurrences of tin-bearing minerals have been excluded also. Known tin-bearing deposits in the conterminous United States are small, few in number, and widely scattered; only small amounts of tin concentrates are being recovered at the present time (1964). The total amount of metallic tin produced since 1950, mainly as a by-product of molybdenum ores, is less than 500 tons, and the total production from all sources prior to 1950 is similar. Map locations are shown by symbols, the shapes of which denote different geologic types of occurrence; some areas of scattered occurrences in pegmatites are shown by a stippled pattern. Occurrences are numbered by State on the map and identified by number in the index. The index also gives the geographic coordinates, brief geologic descriptions, and references to the principal published reports. The more important or better known localities are named on the map.

Mineral Investigations Resource Map↗

USGS2001

Geologic map and database of the Roseburg 30' x 60' quadrangle, Douglas and Coos Counties, Oregon

The Roseburg 30' x 60' Quadrangle covers the southeastern margin of the Oregon Coast Range and its tectonic boundary with Mesozoic terranes of the Klamath Mountains (see figures 1 and 2 in pamphlet, also shown on map sheet). The geologic framework of the Roseburg area was established by the pioneering work of Diller (1898), Wells and Peck, (1961) and Ewart Baldwin (1974) and his students (see figure 3 in pamphlet, also shown on map sheet). Baldwin and his students focussed on the history of the Eocene Tyee basin, where the sediments lap across the tectonic boundary with the Mesozoic terranes and record the accretion of the Coast Range basement to the continent. Others have examined the sedimentary fill of the Tyee basin in detail, recognizing the deep marine turbidite facies of the Tyee Formation (Snavely and others, 1964) and proposing several models for the Eocene evolution of the forearc basin (Heller and Ryberg, 1983; Chan and Dott, 1983; Heller and Dickinson, 1985; Molenaar, 1985; see Ryu and others, 1992 for a comprehensive summary). Along the eastern margin of the quadrangle, both the Tyee basin and the Klamath terranes are overlain by Eocene volcanic rocks of the Western Cascade arc (Walker and MacLeod, 1991). The thick Eocene sedimentary sequence of the Tyee basin has significant oil and gas potential (Armentrout and Suek, 1985; Gautier and others, 1993; Ryu and others, 1996). Although 13 deep test wells have been drilled in the Roseburg quadrangle (see figure 2 and table 1 in pamphlet, also shown on map sheet), exploration to date has been hampered by an incomplete understanding of the basinï¿½s tectonic setting and evolution. In response, the Oregon Department of Geology and Mineral Industries (DOGAMI) initiated a five year assessment of the oil and gas potential of the Tyee basin. This map is a product of a cooperative effort by the U. S. Geological Survey, Oregon State University, and DOGAMI to systematically map the sedimentary facies and structure of the Tyee basin. New geologic mapping of twenty-eight 7.5' quadrangles is summarized on the map (see figure 3, also shown on map sheet), and the digital database contains geologic information suitable for both 1:100K and 1:24K scale analysis. DOGAMI has published a compilation and synthesis of previous mapping (Niem and Niem, 1990), a basin-wide sequence stratigraphic model and correlations (Ryu and others, 1992), and a report on the oil and gas potential (Ryu and others, 1996). Readers interested in the oil and gas potential of the Roseburg quadrangle should use the map in combination with Ryu and others (1996) to address specific stratigraphic units and structural plays. Stratigraphic terminology for the Tyee basin adopts the type sections, formation names, and framework of Ryu and others (1992, 1996), which were developed concurrently with the mapping and are recognized throughout the basin. For detailed discussion of nomenclature, type sections, lithology, thickness and distribution, age, contact relationships, and depositional environment of stratigraphic units, the reader is referred to Ryu and others (1992). In this report we focus on the spatial, temporal, and structural relationships between units revealed by geologic mapping. Map unit ages (see figure 4 in pamphlet, also shown on map sheeet) are adjusted slightly from Ryu and others (1992, 1996) to fit new coccolith age determinations (D. Bukry, cited in pamphlet), paleomagnetic polarity data (Simpson, 1977 and new data cited in pamphlet), and the time scale of Berggren and others (1995).

Oregon↗

USGS2000

Research, methodology, and applications of probabilistic seismic-hazard mapping of the Central and Eastern United States; minutes of a workshop on June 13-14, 2000, at Saint Louis University

The U.S. Geological Survey (USGS) is updating and revising its 1996 national seismic-hazard maps for release in 2001. Part of this process is the convening of four regional workshops with earth scientists and other users of the maps. The second of these workshops was sponsored by the USGS and the Mid-America Earthquake Center, and was hosted by Saint Louis University on June 13-14, 2000. The workshop concentrated on the central and eastern U.S. (CEUS) east of the Rocky Mountains. The tasks of the workshop were to (1) evaluate new research findings that are relevant to seismic hazard mapping, (2) discuss modifications in the inputs and methodology used in the national maps, (3) discuss concerns by engineers and other users about the scientific input to the maps and the use of the hazard maps in building codes, and (4) identify needed research in the CEUS that can improve the seismic hazard maps and reduce their uncertainties. These minutes summarize the workshop discussions. This is not a transcript; some individual remarks and short discussions of side issues and logistics were omitted. Named speakers were sent a draft of the minutes with a request for corrections of any errors in remarks attributed to them. Nine people returned corrections, amplifications, or approvals of their remarks as reported. The rest of this document consists of the meeting agenda, discussion summaries, and a list of the 60 attendees.

Open-File Report↗

USGS2000

Preliminary volcano-hazard assessment for the Katmai volcanic cluster, Alaska

The world’s largest volcanic eruption of the 20th century broke out at Novarupta (fig. 1) in June 1912, filling with hot ash what came to be called the Valley of Ten Thousand Smokes and spreading downwind more fallout than all other historical Alaskan eruptions combined. Although almost all the magma vented at Novarupta, most of it had been stored beneath Mount Katmai 10 km away, which collapsed during the eruption. Airborne ash from the 3-day event blanketed all of southern Alaska, and its gritty fallout was reported as far away as Dawson, Ketchikan, and Puget Sound (fig. 21). Volcanic dust and sulfurous aerosol were detected within days over Wisconsin and Virginia; within 2 weeks over California, Europe, and North Africa; and in latter-day ice cores recently drilled on the Greenland ice cap. There were no aircraft in Alaska in 1912—fortunately! Corrosive acid aerosols damage aircraft, and ingestion of volcanic ash can cause abrupt jet-engine failure. Today, more than 200 flights a day transport 20,000 people and a fortune in cargo within range of dozens of restless volcanoes in the North Pacific. Air routes from the Far East to Europe and North America pass over and near Alaska, many flights refueling in Anchorage. Had this been so in 1912, every airport from Dillingham to Dawson and from Fairbanks to Seattle would have been enveloped in ash, leaving pilots no safe option but to turn back or find refuge at an Aleutian airstrip west of the ash cloud. Downwind dust and aerosol could have disrupted air traffic anywhere within a broad swath across Canada and the Midwest, perhaps even to the Atlantic coast. The great eruption of 1912 focused scientific attention on Novarupta, and subsequent research there has taught us much about the processes and hazards associated with such large explosive events (Fierstein and Hildreth, 1992). Moreover, work in the last decade has identified no fewer than 20 discrete volcanic vents within 15 km of Novarupta (Hildreth and others, 1999, 2000, 2001; Hildreth and Fierstein, 2000), only half of which had been named previously—the four stratovolcanoes Mounts Katmai, Mageik, Martin, and Griggs; the cone cluster called Trident Volcano; Snowy Mountain; and the three lava domes Novarupta, Mount Cerberus, and Falling Mountain. The most recent eruptions were from Trident Volcano (1953–74), but there have been at least eight other, probably larger, explosive events from the volcanoes of this area in the past 10,000 years. This report summarizes what has been learned about the volcanic histories and styles of eruption of all these volcanoes. Many large earthquakes occurred before and during the 1912 eruption, and the cluster of Katmai volcanoes remains seismically active. Because we expect an increase in seismicity before eruptions, seismic monitoring efforts to detect volcanic unrest and procedures for eruption notification and dissemination of information are included in this report. Most at risk from future eruptions of the Katmai volcanic cluster are (1) air-traffic corridors of the North Pacific, including those approaching Anchorage, one of the Pacific’s busiest international airports, (2) several regional airports and military air bases, (3) fisheries and navigation on the Naknek Lake system and Shelikof Strait, (4) pristine wildlife habitat, particularly that of the Alaskan brown bear, and (5) tourist facilities in and near Katmai National Park.

Alaska↗

USGS2000

SMSIM--Fortran programs for simulating ground motions from earthquakes: Version 2.0.--a revision of OFR 96-80-A

A simple and powerful method for simulating ground motions is based on the assumption that the amplitude of ground motion at a site can be specified in a deterministic way, with a random phase spectrum modified such that the motion is distributed over a duration related to the earthquake magnitude and to distance from the source. This method of simulating ground motions often goes by the name "the stochastic method." It is particularly useful for simulating the higher-frequency ground motions of most interest to engineers, and it is widely used to predict ground motions for regions of the world in which recordings of motion from damaging earthquakes are not available. This simple method has been successful in matching a variety of ground-motion measures for earthquakes with seismic moments spanning more than 12 orders of magnitude. One of the essential characteristics of the method is that it distills what is known about the various factors affecting ground motions (source, path, and site) into simple functional forms that can be used to predict ground motions. SMSIM is a set of programs for simulating ground motions based on the stochastic method. This Open-File Report is a revision of an earlier report (Boore, 1996) describing a set of programs for simulating ground motions from earthquakes. The programs are based on modifications I have made to the stochastic method first introduced by Hanks and McGuire (1981). The report contains source codes, written in Fortran, and executables that can be used on a PC. Programs are included both for time-domain and for random vibration simulations. In addition, programs are included to produce Fourier amplitude spectra for the models used in the simulations and to convert shear velocity vs. depth into frequency-dependent amplification. The revision to the previous report is needed because the input and output files have changed significantly, and a number of new programs have been included in the set.

Open-File Report↗