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I. Barnes

Publications and source records attributed to I. Barnes.

17 recordsLinked to original sources
USGS1988

The role of mantle CO2 in volcanism

Carbon dioxide is the propellant gas in volcanic eruptions and is also found in mantle xenoliths. It is speculated that CO2 occurs as a free gas phase in the mantle because there is no reason to expect CO2 to be so universally associated with volcanic rocks unless the CO2 comes from the same source as the volcanic rocks and their xenoliths. If correct, the presence of a free gas in the mantle would lead to physical instability, with excess gas pressure providing the cause of both buoyancy of volcanic melts and seismicity in volcanic regions. Convection in the mantle and episodic volcanic eruptions are likely necessary consequences. This suggestion has considerable implications for those responsible for providing warnings of impending disasters resulting from volcanic eruptions and earthquakes in volcanic regions.

Applied Geochemistry↗
USGS1987

Liquid carbon dioxide of magmatic origin and its role in volcanic eruptions

Natural liquid carbon dioxide is produced commercially from a 2.5-km-deep well near the 4,500-yr-old maar volcano, Mount Gambier, South Australia. The carbon dioxide has accumulated in a dome that is located on the extension of a linear chain of volcanic activity. A magmatic origin for the fluid is suggested by the geological setting, δ 13 C PDB of –4.0‰, for the CO 2 (where PDB represents the carbon-isotope standard), and a relatively high 3 He component of the contained helium and high 3 He/C ratio (6.4 x 10 −10 ). The 3 He/ 4 He and He/Ne ratios are 3.0 and > 1,370 times those of air, respectively. The CO 2 , as collected at the Earth's surface at 29.5 °C and 75 bar, expands more than 300-fold to form a gas at 1 atm and 22 °C. We suggest that liquid CO 2 or high-density CO 2 fluid (the critical point is 31.1 °C, 73.9 bar) of volcanic origin that expands explosively from shallow levels in the Earth's crust may be a major contributor to 'phreatic' volcanic eruptions and maar formation. Less violent release of magmatic CO 2 into crater lakes may cause gas bursts with equally disastrous consequences such as occurred at Lake Nyos, Cameroon, in August 1986.

Nature↗
USGS1985

Mineral-water reactions in metamorphism and volcanism

Low-temperature (120??C and less) metamorphism of graywacke, granite and andesite yields zeolites and precursor gels by reaction with fresh water but low-greenschist facies by reaction with salt (sea)water. ?? 1985.

Chemical Geology↗
USGS1984

Volatiles of Mount St. Helens and their origins

Analyses have been made of gases in clouds apparently emanating from Mount St. Helens. Despite appearances, most of the water in these clouds does not issue from the volcano. Even directly above a large fumarole ??D and ?? 18O data indicate that only half the water can come from the volcano. Isotopic and chemical evidence also shows the steam in the volcano (-33.0 per mol ??D) from which a condensate of 0.2 N HCI was obtained is not a major cause of the explosions. The steam in the volcano is derived from a metamorphic brine in the underlying Tertiary meta andesite. The gas that caused the explosive eruptions is carbon dioxide. ?? 1984.

Journal of Volcanology and Geothermal Research↗
USGS1983

The nature of carbon dioxide waters in Snaefellsnes, western Iceland

Over 20 occurrences of thermal and non-thermal waters rich in carbon dioxide are known in the Snaefellsnes Peninsula of western Iceland. On the basis of the thermal, chemical and isotopic characteristics of these waters, and hydrological considerations, it is concluded that they represent meteoric waters which have seeped to variable depths into the bedrock. Ascending carbon dioxide gas originating from intrusions or the mantle mixes with the meteoric waters to produce carbon dioxide waters: at considerable depth in the case of the thermal carbon dioxide waters but close to the surface in the case of cold carbon dioxide waters. The occurrence of carbon dioxide waters cannot be regarded as evidence for underground geothermal reservoirs.

Geothermics↗
USGS1978

Present day serpentinization in New Caledonia, Oman and Yugoslavia

Geochemical evidence for modern low-temperature serpentinization has been found in three new localities. Apparently the low-temperature reactions are a common mode of formation of the lizardite-chrysotile and brucite assemblage. Possibly the 18O content of serpentine formed at low temperatures is in part inherited from the pyroxene and olivine. ?? 1978.

Geochimica et Cosmochimica Acta↗
USGS1975

Short chain aliphatic acid anions in oil field waters and their contribution to the measured alkalinity

High alkalinity values found in some formation waters from Kettleman North Dome oil field are due chiefly to acetate and propionate ions, with some contribution from higher molecular weight organic acid ions. Some of these waters contain no detectable bicarbonate alkalinity. For waters such as these, high supersaturation with respect to calcite will be incorrectly indicated by thermodynamic calculations based upon carbonate concentrations inferred from traditional alkalinity measurements

Geochimica et Cosmochimica Acta↗
USGS1973

Silica-carbonate alteration of serpentine: Wall rock alteration in mercury deposits of the California Coast Ranges

Chemical, isotopic, and thermodynamic properties have been measured of CO 2 -rich ground waters in the central California Coast Ranges. The acidic CO 2 -rich waters react with serpentine to form silica-carbonate rock, the host rock of many mercury deposits in the Coast Range of California. In part the waters are of a metamorphic origin and in part the waters are locally derived meteoric waters. The CO 2 is entirely derived from metamorphic reactions at depth. Depending on the relative importance of several reactions, the relative abundances of silica and carbonate minerals vary in the silica-carbonate rock. If the CO 2 -rich fluids react directly with peridotite or dunite, massive magnesite deposits may form. © 1973 Society of Economic Geologists, Inc.

California↗
USGS1972

Metamorphic assemblages and the direction of flow of metamorphic fluids in four instances of serpentinization

Fluids related to Serpentinization are of at least three types. The first reported (Barnes and O'Neil, 1969) is a fluid of local meteoric origin, the chemical and thermodynamic properties of which are entirely controlled by olivine, orthopyroxene, brucite, and serpentine reactions. It is a Ca +2 -OH −1 type and is shown experimentally to be capable of reacting with albite to yield calcium hydroxy silicates. Rodingites may form where the Ca +2 -OH −1 type waters flow across the ultramafic contact and react with siliceous country rock. The second type of fluid has its chemical composition largely controlled before it enters the ultramafic rocks, but reactions within the ultramafic rocks fix the thermodynamic properties by reactions of orthopyroxene, olivine, calcite, brucite, and serpentine. The precipitation of brucite from this fluid clearly shows that fluid flow allows reaction products to be deposited at a distance from the point of solution. Thus, textural evidence for volume relations during Serpentinization may not be valid. The third type of fluid has its chemical properties fixed in part before the reactions with ultramafic rocks, in part by the reactions of orthopyroxene, olivine, and serpentine and in part by reactions with siliceous country rock at the contact. The reactions of the ultramafic rock and country rock with the fluid must be contemporaneous and require flow to be along the contact. This third type of fluid is grossly supersaturated with talc and tremolite, both found along the contact. The occurrence of magadiite, kenyaite, mountainite, and rhodesite along the contact is probably due to a late stage low-temperature reaction of fluids of the same thermodynamic properties as those that formed the talc and tremolite at higher temperatures. Oxygen isotope analyses of some of these minerals supports this conclusion. Rodingites form from Ca +2 -rich fluids flowing across the contact; talc and tremolite form from silica-rich fluids flowing along the contact. Isotopic analyses of the fluids indicate varied origins including unaltered local meteoric water and connate water. Complexion Spring water may be a sample of only slightly altered Jurassic or Cretaceous sea water.

Contributions to Mineralogy and Petrology↗
USGS1971

C13 and O18 compositions in some fresh-water carbonates associated with ultramafic rocks and serpentinites: Western United States

All carbonates associated with the ultramafic rocks and serpentinites of the western United States are shown by their stable isotope ratios to be of near-surface, low-temperature origin. These include vein materials that have been previously classified as hydrothermal. New laboratory and natural data were obtained on the equilibrium isotope relations between hydromagnesite and water. The origins of travertines in the ultramafic area are easily distinguished on the basis of their stable isotope ratios. The extremely heavy isotope ratios of nesquehonites suggest an intricate evaporating-film mechanism of formation.

Geochimica et Cosmochimica Acta↗
USGS1971

Calcium-magnesium carbonate solid solutions from Holocene conglomerate cements and travertines in the Coast Range of California

Two calcium-magnesium carbonate solid solutions form Holocene travertines and conglomerate cements in fresh water stream channels of the Coast Range of California. Calcite does not yield the {015} diffraction maximum. The {006} diffraction maximum is lacking over most of the range of composition of calcite. Calcite has compositions from CaCO 3 to Ca 0.5 Mg 0.5 CO 3 . Dolomite yields both the {006} and {015} diffraction maxima over its entire composition range, Ca 0.6 Mg 0.4 CO 3 to Ca 0.5 Mg 0.5 CO 3 . The Ca-Mg carbonates form in isotopic equilibrium and thermodynamic disequilibrium from dispersion of Ca 2+ -rich water into CO 3 2− -rich water within the alluvium. The stable isotope data suggest that all the Mg-rich carbonates are primary precipitates and not a result of Mg-substitution in precursor CaCO 3 . There is a correlation between δC 13 and Mg content of the carbonates which predicts a 5%. fractionation of C 13 between dolomite and calcite at sedimentary temperatures. C 14 is incorporated in Ca-Mg carbonates forming from C 13 -poor meteoric waters and C 13 -rich waters from Cretaceous sediments. C 14 ages of the Ca-Mg carbonates are apparent, and cannot be corrected to absolute values. Solution rates of calcite decrease with increasing MgCO 3 content; dolomite dissolves slower than any calcite.

California↗
USGS1970

Metamorphic waters from the Pacific tectonic belt of the west coast of the United States

Waters unusually rich in ammonia, boron, carbon dioxide, hydrogen sulfide, and hydrocarbons are found in more than 100 localities along the Pacific coast of the United States. The waters are believed to be products of low-grade metamorphism of marine sediments. The marine sedimentary rocks would have to be tectonically emplaced below crystalline rocks in many places. Mercury are deposits are probably also products of the low-grade metamorphism.

Pacific coast↗
USGS1969

The relationship between fluids in some fresh alpine-type ultramafics and possible modern serpentinization, western United States

Calcium hydroxide waters issue from four partly serpentinized Alpine-type ultramafic bodies in the western United States. The occurrence of calcium-hydroxide-type water is restricted to fresh Alpine-type ultramafic rocks. The calcium hydroxide waters are unsaturated with Mg end-member olivine and pyroxene but supersaturated with Mg end-member brucite and serpentine and thus have chemical potentials to cause Serpentinization. The calcium hydroxide waters are isotopically similar to the common magnesium bicarbonate meteoric waters peculiar to ultramafic rocks and serpentinites. Some Serpentinization is apparently a near-surface phenomenon occurring at present. The Serpentinization takes place at nearly constant composition, except for loss of CaO. © 1969, The Geological Society of America, Inc.

Geological Society of America Bulletin↗
USGS1967

Geochemical evidence of present-day serpentinization

Ultrabasic ( p H > 11) water issues from some fresh ultramafic bodies. The properties of the ultrabasic solutions are believed to be due to current reactions yielding serpentine from primary olivines and pyroxenes. The low concentrations of divalent iron. divalent magnesium, and dissolved silica from the serpentinization require an increase in rock volume.

Science↗
USGS1965

Geochemistry of Birch Creek, Inyo County, California a travertine depositing creek in an arid climate

A small stream in eastern California was studied in detail to determine the causes of travertine deposition from the stream. Although the ground water feeding the stream is slightly supersaturated to just saturated with calcite, the ground water is supersaturated with CO 2 with respect to the overlying air. The water becomes increasingly supersaturated with calcite in a downstream direction as CO 2 loss to the air and by photosynthesis exceeds the rate of precipitation of calcite. Water loss by evaporation was below detection and does not play an important role in calcite deposition in this case. The water loss is by seepage through the stream bed. Observations showed variations in HCO − 3 , pH, discharge, Ca +2 , relative humidity, water and air temperatures, and dissolved CO 2 . Comparisons of observed and equilibrium states are given for five sampling stations along the stream.

California↗