Geology topics
Research about Yellowstone National Park
Source-linked reports with geographic coverage including Yellowstone National Park.
Hydrothermal minerology of research drill hole Y-3, Yellowstone National Park, Wyoming
The approximate paragenetic sequence of hydrothermal minerals in the Y-3 U. S. Geological Survey research diamond-drill hole in Lower Geyser Basin, Yellowstone National Park, Wyoming, is: hydrothermal chalcedony, hematite, pyrite, quartz, clay minerals (smectite and mixed-layer illite-smectite), calcite, chlorite, fluorite, pyrite, quartz, zeolite minerals (analcime, dachiardite, laumontite, stilbite, and yugawaralite), and clay minerals (smectite and mixed-layer illite-smectite). A few hydrothermal minerals that were identified in drill core Y-3 (lepidolite, aegirine, pectolite, and truscottite) are rarely found in modern geothermal areas. The alteration minerals occur primarily as vug and fracture fillings that were deposited from cooling thermal water. Refs.
Grizzly bear: habitat relationships in the Yellowstone area
Habitat use by grizzly bears ( Ursus arctos ) was studied from 1977 through 1979 in a 20,000-km 2 area with Yellowstone National Park in the center. Of 1826 aerial radio locations of 46 instrumental grizzlies, 90% were in timber. Three-fourths of the locations were 100 m or less from an edge between timber and an opening. Timber over 3 m tall with a canopy cover of 26-75% accounted for 50% of all activity sites from March through November. The Abies lasiocarpa/Vaccinium scoparium community alone contained 23% of the total activity sites and 35% of the forested activity sites. Of 507 observations of feeding activity, 45% were recorded in timber over 3 m tall with a canopy cover of 26-100%, 34% in timber with a 0.1-25% canopy cover, 20% in open habitats, and 3% in timber less than 3 m tall. Ninety-nine percent of examined day beds were in forested communities.
Use of pine nuts by grizzly and black bears in the Yellowstone area
The large seeds (pine nuts) of whitebark pine are commonly eaten in the spring (March-May) and fall (September-November) by grizzly and black bears in Yellowstone National Park and adjacent areas (Craighead and Craighead 1972, Blanchard 1978, Mealey 1980) and western Montana (Tisch 1961; J. Sumner and J. J. Craighead, unpubl. rep., Montant Coop. Wildl. Res. Unit, Univ. Montana, Missoula, 1973). Similar nuts from limber pine are eaten by grizzly bears on the east Rocky Mountain Front of northwestern Montana (Schallenberger and Jonkel, annual rep., Border Grizzly Project, Univ. Montana, Missoula, 1980). The nuts of the European stone pine ( P. cembra ) are an important food for brown bears ( U. arctos ) throughout the taiga zone in the Soviet Union (Pavlov and Zhdanov 1972, Ustinov 1972, Yazan 1972). Both the production of whitebark pine cones (Forcella 1977, Blanchard 1978, Mealey 1980) and the quantity of nuts consumed by bears vary annually (Mealey 1975, Blancard 1978). Pine nuts are also an important food for red squirrels in whitebark forests. In fall, squirrels remove cones from trees and cache them in middens. Bears as well as other mammalian and avian seed predators compete with squirrels for whitebark nuts (Forcella 1977, Tomback 1977). Confusion about the ripening process of whitebark pine cones has resulted in errors in the literature on the availability of pine nuts as a bear food. Whitebark cones are indehiscent and do not disintegrate (Tomback 1981). Vertebrate foraging probably leaves few, if any, seed-bearing cones on trees by late fall; the cones remaining abscise sometime thereafter (Tomback 1981). Because cones do not abscise or release their seed in fall, bears may obtain pine nuts in 2 ways. Black bears may climb whitebark pine trees and break off cone-bearing brnahces to feed on cones (Tisch 1961, Mealey 1975, Forcella 1977); or both black bears and grizzly bears may raid squirrel caches to feed on pine nuts (Tisch 1961, Craighead and Craighead 1972, Blanchard 1978). The purpose of this study was to determine (1) the major source of pine nuts for bears, (2) why cone scales do not appear in bear scat containing pine nuts, and (3) what factors influence bear use of pine nuts.
Factors influencing human-grizzly bear interactions in a backcountry setting
Interactins between humans and 7 species of wildlife, including grizzly bears ( Ursus arctos horribilis ), were investigated in backcountry areas of the Gallatin Range, Yellowstone National Park, during the summers of 1973 and 1974. Grizzly bear distribution, movements, and behavior and human behavior were examined. Because grizzlies utilized areas with elevations much in excess of the study area's average trail elevation, he likelihood of the off-trail party observing a grizzly bear was 3-4 times greater than that of a trail-traveling party. During the hiking season, grizzliess exhibited an elevational migration. The frequencies of on-trail and combined on- and off-trail observations and sign discoveries per party tended to peak during those periods that grizzlies were found at low elevations. Activitiy patterns of grizzlies at the point of first observation or after the bears had become aware of the human presence did not indicate behavioral traits likely to accentuate the possibilities of human-bear confrontations. Some backcountry travelers engaged in activites that could increase detrimental encounters with grizzly bears.
Chemical studies of selected trace elements in hot-spring drainages of Yellowstone National Park
No abstract available.
The natural food habits of grizzly bears in Yellowstone National Park, 1973-74
The natural food habits of grizzly bears ( Ursus arctos horribilis Ord) in Yellowstone National Park were investigated in 1973-74 to identify the grizzly's energy sources and trophic level(s), nutrient use, and distribution. Food consumption was determined by scat analysis and field observations. Food quality and digestibility were estimated by chemical analysis. Grizzlies were distributed in 3 distinctive feeding economies: valley / plateau , a grass/rodent economy where grizzlies were intensive diggers; mountain , primarily a grass/springbeauty/root economy where grizzlies were casual diggers; and lake , primarily a fish/grass economy where grizzlies were fishers. The economies occurred in areas with fertile soils; distribution of bears within each was related to the occurrence of succulent plants. The feeding cycle in the valley/plateau and mountain economies followed plant phenology. Grizzlies fed primarily on meat before green-up and on succulent herbs afterwards; meat, corms, berries, and nuts became important during the postgrowing season. Succulent grasses and sedges with an importance value percentage of 78.5 were the most important food items consumed. Protein from animal tissue was more digestible than protein from plant tissue. Storage fats were more digestible than structural fats. Food energy and digestibility were directly related. Five principle nutrient materials (listed with their percentage digestibilities) contributed to total energy intake: protein from succulent herbs, 42.8; protein and fat from animal material, 78.1; fat and protein from pine nuts, 73.6; starch, 78.8; and sugar from berries and fruits, digestibility undetermined. Protein from succulent herbs, with a nutritive value percentage of 77.3, was the grizzlies' primary energy source. Because succulent, preflowering herbs had higher protein levels than dry, mature herbs, grizzly use of succulent herbs guaranteed them the highest source of herbaceous protein. Low protein digestibility of succulent herbs was compenstated for by high intake. Grizzlies were digestively flexible and maximized use of protein from plant and animal sources. They were adapted to the most constant and abundant sources of protein: succulent herbs and animal material from open, fertile grasslands. Competition among grizzlies for animal food during the pregrowing season may be regulatory for the grizzly population. The grizzly population level can be partially accounted for by the grizzlies' status as secondary consumers during pregreen-up periods and primary consumers during the growing and postgrowing seasons. The essential environmental requirement was the availability of fertile grasslands and herblands interspersed with cover and capable of maintaining artiodactyls, rodents, and abundant nutritious herbs as sources of food.
Movements of radio-instrumented grizzly bears within the Yellowstone area
Grizzly bear ( Ursus arctos horribilis ) movement patterns were studied with the aid of 18 radio-instrumented grizzly bears in 1975 and 1976. Five bears gave minimal information because of death, transmitter failure, or loss of transmitters. Seasonal home range information is presented for 13 bears. Two bears, trapped inside Yellowstone National Park, included areas outside of the park in their home ranges. Twelve bears trapped outside included parts of the park in their home ranges. Three females with young gave no indication of having smaller home ranges than other individuals. Movement patterns prior to denning and dates of denning varied among individual bears.
Deep structure under Yellowstone National Park U.S.A.: A continental "hot spot"
In order to understand the origin of long-lived loci of volcanism (sometimes called “hot spots”) and their possible role in global tectonic processes, it is essential to know their deep structure. Even though some work has been done on the crustal, upper-mantle, and deep-mantle structure under some of these “hot spots”, the picture is far from clear. In an attempt to study the structure under the Yellowstone National Park U.S.A., which is considered to be such a “hot spot”, we recorded teleseisms using 26 telemetered seismic stations and three groups of portable stations. The network was operated within a 150 km radius centered on the Yellowstone caldera, the major, Quaternary volcanic feature of the Yellowstone region. Teleseismic delays of about 1.5 sec are found inside the caldera, and the delays remain high over a 100 km wide area around the caldera. The spatial distribution and magnitude of the delays indicate the presence of a large body of low-velocity material with horizontal dimensions corresponding approximately to the caldera size (40 km × 80 km) near the surface and extending to a depth of 200–250 km under the caldera. Using ray-tracing and inversion techniques, it is estimated that the compressional velocity inside the anomalous body is lower than in the surrounding rock by about 15% in the upper crust and by 5% in the lower crust and upper mantle. It is postulated that the body is partly composed of molten rock with a high degree of partial melting at shallow depths and is responsible for the observed Yellowstone volcanism. The large size of the partially molten body, taken together with its location at the head of a 350 km zone of volcanic propagation along the axis of the Snake River Plain, indicates that the volcanism associated with Yellowstone has its origin below the lithosphere and is relatively stationary with respect to plate motion. Using our techniques, we are unable to detect any measurable velocity contrast in the mantle beneath the low-velocity body, and, hence, we are unable to determine whether the Yellowstone melting anomaly is associated with a deep heat source or with any deep phenomenon such as a convection plume, chemical plume, or gravitational anchor.
Recent crustal uplift in Yellowstone National Park
Comparison of precise leveling measurements made in 1923 with those made in 1975, 1976, and 1977 reveals that the 600,000-year-old Yellowstone caldera is being uplifted relative to its surroundings. Maximum relative uplift since 1923 is in excess of 700 millimeters - about 14 millimeters vertically per year. The most likely cause of this rapid and unusually large surface deformation is a recent influx of molten or partially molten material to a location within the crust beneath Yellow-stone National Park.
Preliminary study of wastewater movement in Yellowstone National Park, Wyoming, October 1976 through September 1977
Studies were made from October 1976 through September 1977 to determine the effects on lakes and streams of wastewater effluents that percolate from sewage lagoons at four sites in Yellowstone National Park. Ground-water mounds have built up under the lagoons as percolation of effluents occurred. Percolating effluents mix with ground water and move down the hydraulic gradient in a direction generally perpendicular to the water-level contours. Maps showing chloride and sulfate concentrations, specific conductance of water in wells, and water-level contours indicate the most likely areas and directions of movement of percolating effluents.
Chemical analyses of waters from geysers, hot springs, and pools in Yellowstone National Park, Wyoming, from 1974 to 1978
Waters from geysers, hot springs, and pools of Yellowstone National Park have been analyzed by numerous investigators extending back nearly ten decades. Large compilations of complete major ion analyses of the thermal waters have been reported by Gooch and Whitfield (1888) 38 analyses; Allen and Day (1935) 94 complete and 127 partial major ion analyses, Rowe and others (1973) 166 analyses including many previous chemical analyses of the same feature; and Thompson and others (1975) 242 complete and 299 partial major ion analyses. Smaller compilations of the thermal water chemistry have been reported by Douglass (1939) 12 analyses; White and others (1963) 6 analyses; and Scott (1964) 10 analyses. Partial chemical analyses have been reported by White and others (1956) and by Morey and others (1961) for dissolved silica; Noguichi and Nix (1963) for dissolved silica and major anions; Araki and Noguichi (1969) for dissolved silica, molybdenum, vanadium, and major anions. Here we report 422 complete major ion analyses from 330 different locations of geysers, hot springs, and pools, collected from 1974 to 1978. Many of the analyses from Upper, Midway, Lower, and Norris Geyser Basin are recollections of features previously reported.
Preliminary map of earthquake epicenters in Yellowstone Park and vicinity 1973-1978
No abstract available.
Climate and reproduction of grizzly bears in Yellowstone National Park
Controversy surrounds the conflicts between the requirements of human safety and the preservation of grizzly bears ( Ursus arctos horribilis ) in western North America. It has been difficult to separate the effect of factors such as the closure of garbage dumps from that of the climate. It has also proved difficult to relate climatic data to changes in the populations of large mammals. I report here a correlation of climatic change with fluctuations in the sizes of litters of grizzly bears born in Yellowstone National Park, Wyoming, during 1958–1976. The decrease in litter sizes observed since the closure of garbage dumps seems to be largely a consequence of unfavourable weather during the periods of the final fattening of the mother, winter sleep, birth, lactation and early spring foraging. This study represents one of the few times that the effects of climate have been demonstrated for large omnivorous or carnivorous mammals.
Phosphorus in hydrothermal waters of Yellowstone National Park, Wyoming
Ninety-seven hot-spring and geyser samples (field acidified to pH<1.4 with HCl or HNO 3 ) from Yellowstone National Park, Wyo., were analyzed for PO 4 -P using reduced molybdenum-blue and the selective arsenate reducing agent, metabisulfite-thiosulfate. The PO 4 -P concentrations ranged from below detection limit (~1-73 micrograms per liter). Twenty-five springs had PO 4 -P concentrations exceeding 6.8 μ g/L; seven spring samples exceeded 20 μg/L. Elevated PO 4 -P contents were invariably associated with mixed springs, as evidenced by diluted chloride concentrations and, commonly, subboiling temperatures, low pH's, and elevated calcium concentrations. Alkaline high-chloride (>400 milligrams per liter) hydrothermal waters from Upper and Norris Geyser Basins had PO 4 -P concentrations below 2 μg/L and represent the low end of the range of PO 4 -P contents in natural waters.
Conductive heat flows in research drill holes in thermal areas of Yellowstone National Park, Wyoming
In convection systems with boiling springs, geysers, fumaroles, and other thermal features, the modes of heat flow become increasingly complex as a single liquid phase at depth rises into the near-surface environment where heat flows by convection of liquid and vapor and by conduction in high thermal gradients. This paper is mainly concerned with the changing patterns of conductive heat flow as related to channels of subsurface convective flow and to horizontal distance from spring vents. The primary data consist of temperatures measured in 13 cored drill holes as drilling progressed. Some temperatures plot convincingly on straight-line segments that suggest conductive gradients in rocks of nearly constant thermal conductivity. Temperature gradients and the conductive component of total heat flow nearly always decrease drastically downward; the gradient and heat flow of the lowest depth interval recognized in each hole is commonly only about 10 percent of the highest interval; the changes in gradient at interval boundaries are commonly interpreted as channels of near-boiling water or of cooler meteoric water. Temperature reversals are probably related to inflowing cooler water rather than to transient effects from recent changes. Some temperatures plot on curved segments that probably indicate dispersed convective upflow and boiling of water in ground penetrated by the drill hole. Other similar curved segments are too low in temperature for local boiling and are probably on the margins of hot upflow zones, reflecting conductive cooling of flowing water. The conifers of Yellowstone National Park (mainly lodgepole pine) seem to have normal growth characteristics where near-surface conductive heat flow is below about 200 heat-flow units (1 HFU = 10 -6 cal/cm 2 = 41.8 mW/m 2 ). Most areas of abnormal "stunted" trees (low ratio of height to base diameter, and low density of spacing) are characterized by conductive heat flows of about 250 to 350 HFU. The critical factor affecting growth is probably the seasonal maximum soil temperature at the root depths preferred by each form, rather than the heat flow as such. Heat flows up to 300 HFU are greatly dominated near the surface by conduction and are little affected by convection within the measured intervals. With increasing total heat flow above 300 HFU, the convection component, as indicated by snowfall calorimetry, becomes increasingly important. Snowfall calorimetry and tree growth as related to heat flow are calibrated by the heat-flow data considered here. Both snowfall calorimetry and tree growth patterns can be extrapolated rapidly, although without high precision, to thermal areas that lack subsurface data.
Iron in water near wastewater lagoons in Yellowstone National Park, Wyoming
High dissolved-iron concentrations have been noted in water in wells used to monitor effluent that percolates from wastewater disposal lagoons near Old Faithful in Yellowstone National Park. The concentration of dissolved iron in water in a well increased from 80 μ g/L (micrograms per liter) before a nearby lagoon was .used for disposal of effluent to 17000 μ g/L after the lagoon was used. The effluent contained 180 μ g/L of dissolved iron, and nearby Iron Spring Creek contained 30 μ g/L or less of dissolved iron above and below the lagoons. Organic carbon, nitrogen, and sulfur in the effluent as methane, ammonia, and hydrogen sulfide are oxidized to carbon dioxide, nitrate, and sulfate, respectively, in the unsaturated zone and possibly in the saturated zone as ground water moves through sand and gravel toward Iron Spring Creek. This oxidation results in simultaneous reduction of iron in the sand and gravel from the insoluble ferric phase to the soluble ferrous phase. As ground water high in dissolved iron discharges at land surface near the stream, oxygen from the atmosphere oxidizes the iron back to the insoluble ferric phase, and ferric hydroxide precipitates. Ferric hydroxide also precipitates in some of the monitoring wells. Iron bacteria and other organisms are associated with the precipitates.