A groundwater tracing investigation as an aid of locating groundwater monitoring stations on the Mitchell Plain of southern Indiana   总被引：1，自引：0，他引：1  

Wanfang Zhou  Barry F. Beck  Arthur J. Pettit  Brad J. Stephenson 《Environmental Geology》2002,41(7):842-851

. A groundwater tracing study was conducted on the Mitchell Plain of southern Indiana to aid in the design of a karst groundwater monitoring program for a proposed landfill facility. Fluorescein and rhodamine WT dyes were introduced into sinkholes at the project site. On-site fluorometric analyses and concentration-dependent sampling were utilized at springs and a local stream for data resolution while minimizing delays between tracing events. As a result of this investigation, springs including a submerged spring that drain groundwater from the site have been identified and two groundwater monitoring stations have been established. The submerged spring was discovered in the streambed at intersections between prominent joints and solution-enlarged bedding-plane partings. It could not have been identified readily during a typical karst hydrogeologic inventory, nor would it have been detected by analyzing charcoal dye receptors with a spectrofluorophotometer.  相似文献   

Used Motor Oil as a Source of MTBE, TAME, and BTEX to Ground Water     

Ronald J. Baker  Eric W. Best  Arthur L Baehr 《Ground Water Monitoring & Remediation》2002,22(4):46-51

Methyl tert-butyl ether (MTBE), the widely used gasoline oxygenate, has been identified as a common ground water contaminant, and BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) have long been associated with gasoline spills. Because not all instances of ground water contamination by MTBE and BTEX can be attributed to spills or leaking storage tanks, other potential sources need to be considered. In this study, used motor oil was investigated as a potential source of these contaminants. MTBE in oil was measured directly by methanol extraction and gas chromatography using a flame ionization detector (GC/FID). Water was equilibrated with oil samples and analyzed for MTBE, BTEX, and the oxygenate tert-amyl methyl ether (TAME) by purge- and-trap concentration followed by GC/FID analysis. Raoult's law was used to calculate oil-phase concentrations of MTBE, BTEX, and TAME from aqueous-phase concentrations. MTBE, TAME, and BTEX were not detected in any of five new motor oil samples, whereas these compounds were found at significant concentrations in all six samples of the used motor oil tested for MTBE and all four samples tested for TAME and BTEX. MTBE concentrations in used motor oil were on the order of 100 mg/L. TAME concentrations ranged from 2.2 to 87 mg/L. Concentrations of benzene were 29 to 66 mg/L, but those of other BTEX compounds were higher, typically 500 to 2000 mg/L.  相似文献   

Comparative volcanology and petrology of the atlantic island-arcs     

P. E. Baker 《Bulletin of Volcanology》1968,32(1):189-206

Comparisons are made between the Lesser Antilles and the South Sandwich Islands, the recent volcanic island chains at the eastern margins of the Caribbean and Scotia arcs. Although situated in similar geological and structural environments there are differences in the type of volcanic activity which prevails in these two arcs and in the petrography and chemistry of the lavas emitted. There is good evidence that the South Sandwich Islands are in general appreciably younger than the islands of the Lesser Antilles. Basaltic rocks predominate in the South Sandwich Islands whereas andesite is the dominant rock-type of the Lesser Antilles. Many of the lavas of the South Sandwich Islands, including the andesites and dacites are aphyric whereas those of the Lesser Antilles are almost invariably porphyritic. The basalts of the South Sandwich Islands are of tholeiitic type and the series shows more pronounced iron enrichment than does that of the Lesser Antilles. Basalts of the South Sandwich Islands have a lower Fe₂O₃/FeO ratio, contain lower concentrations of K, Sr and Ba and higher Cr, Co and Ni than the basalts of the West Indies. It is thought that the South Sandwich Islands may represent a volcanic island-arc in the early stages of development and the Lesser Antilles a later stage.  相似文献   

Experimental constraints on depths of fractionation of mildly alkalic basalts and associated felsic rocks: Pantelleria,Strait of Sicily   总被引：1，自引：0，他引：1  

Gail A. Mahood  Don R. Baker 《Contributions to Mineralogy and Petrology》1986,93(2):251-264

Pantelleria, Italy, is a continental rift volcano consisting of alkalic basalt, trachyte, and pantellerite. At 1 atm along the FMQ buffer, the least-evolved basalt (Mg #= 58.5% norm ne) yields olivine on the liquidus at 1,180° C, followed by plagioclase, then by clinopyroxene, and by titanomagnetite and ilmenite at 1,075°. After 70% crystallization, the residual liquid at 1,025° is still basaltic and also contains apatite and possibly kaersutite. A less alkalic basalt shows the same order of phase appearance. Glass compositions define an Fe-enrichment trend and a density maximum for anhydrous liquids that coincides with a minimum in Mg#.During the initial stages of crystallization at 1 atm, liquids remain near the critical plane of silica-undersaturation until, at lower temperatures, Fe-Ti oxide precipitation drives the composition toward silica saturation. Thus the qtz-normative trachytes and pantellerites typically associated with mildly ne-normative basalts in continental rifts could be produced by low-pressure fractional crystallization or by shallow-level partial melting of alkali gabbro. At 8 kbar, clinopyroxene is the liquidus phase at 1,170° C, followed by both olivine and plagioclase at 1,135°. Because clinopyroxene dominates the crystallizing assemblage and plagioclase is more albitic than at 1 atm, liquids at 8 kbar are driven toward increasingly ne-normative compositions, suggesting that higher-pressure fractionation favors production of phonolitic derivatives.Natural basaltic samples at Pantelleria are aphyric or contain 1–10% phenocrysts of plag olcpx or ol>cpx, with groundmass Fe-Ti oxides and apatite. The lack of phenocrystic plagioclase in two of the lavas suggests that crystallization at slightly higher PH₂O may have destabilized plagioclase relative to the 1-atm results, but there is no preserved evidence for significant fractionation at mantle depths as clinopyroxene is the least abundant phenocryst phase in all samples and contains only small amounts of octahedral Al. The liquid line and phenocryst compositions match more closely the 1-atm experimental results than those at 8 kbar.Although major-element trends in natural liquids and crytals reflect low-pressure fractionation, minor- and trace-element concentrations preserve evidence of multiple parental liquids. Scatter in variation diagrams exceeds that attributable to crystal accumulation in these phenocryst-poor rocks, and the large range in concentrations of P and Ti at high MgO contents cannot be produced by polybaric fractionation nor by mixing with coexisting felsic magmas. Sr and O isotope ratios rule out significant interaction with crystalline upper crust, Mesozoic shelf sediments, or Tertiary evaporites. Positive correlations of compatible and incompatible elements suggest that the basalts are not simply related to one another by closed-system fractional crystallization of a single parental magma. Increasing Ce/Yb with Ce suggests that these relations are not a product of mixing within a replenished magma chamber, nor of mixing with more felsic members of the suite, which have smaller Ce/Yb ratios. Low-pressure fractional crystallization of ol+cpx+ plag±oxides from slightly different parental magmas produced by varying degrees of melting of garnet-bearing peridotite is a possible scenario.Small and infrequently replenished magma reservoirs in this continental rift environment may account for the strongly differentiated nature of the Pantellerian basalts. There is no correlation between Mg# and eruptive frequency, in part because concentration of volatiles in residual liquids offsets the effect of Fe-enrichment on melt density, such that strong Fe-enrichment is no hindrance to eruption.  相似文献   

Upwelled spectral radiance distribution in relation to particulate matter in sea water     

Dennis K. Clark  Edward T. Baker  Alan E. Strong 《Boundary-Layer Meteorology》1980,18(3):287-298

Spectral analysis of water color and concurrent measurements of the relative concentration of various particulate and dissolved constituents within a broad range of water types are necessary to quantify ocean color observations and successfully relate them to various biological and physical processes that can be monitored by remote sensing. Some of the results of a Nimbus-G prelaunch cruise in connection with the Coastal Zone Color Scanner (CZCS) experiment, which was carried out in the Gulf of Mexico in October 1977, are presented and discussed. Based upon a small but diverse sample of near-surface measurements, it appears possible to estimate total suspended particulate matter (SPM) to useful accuracies by forming ratios of the spectral radiances measured at wavelengths falling near the centers of certain CZCS bands, viz., 440 nm: 550 nm and 440 nm : 520 nm. Furthermore, the analysis suggests a very high degree of covariation between SPM and phytoplankton pigments except for certain well-defined special cases.Contribution number 401 from NOAA/ERL/PMEL, Seattle, Washington, U.S.A.  相似文献   

Geology and geochemistry of the mansion pyroclast fall succession,St. Kitts     

P. E. Baker 《Bulletin of Volcanology》1980,43(2):303-310

Some 4000 years ago Mt. Misery volcano was in a particularly active state, emitting a sequence of pyroclastic deposit that are widely distributed over the island and show a compositional range from basalt (SiO₂ 48%) to andesite (SiO₂ 62%). The type section at Mansion, on the east coast, has been the subject of a study byBaker andHolland (1973). Of special interest in this succession is the intimate association of basic and relatively salic products. It constitutes a detailed record of a short period (a few centuries?) in the volcano’s history, which properly interpreted may tell us something of the processes of magmatic differentiation and replenishment. The compositional patterns may also provide some guide to the course likely to be followed in future eruptions. Some degree of caution is necessary in considering the chemistry of pyroclastic rocks, which between eruption and deposition may have been influenced by aerial fractionation or winnowing processes. There may also be problems of partial redistribution, weathering and also the inclusion of accessory or accidental lithic fragments. Isopach maps show that deposition of the Mansion succession was partly governed by the prevailing ENE wind. The total thickness varied from about 45 m at a distance of 4 km west of the crater compared with about half that thickness an equal distance east of the crater. The more complete sections occur on the eastern, windward side, whereas on the west much of the upper part has been removed, presumably by mudflows and floods. The marked unconformity over the basic cinder zone in western sections makes correlation with eastern sections more difficult. Sharp changes in composition and eruptive pattern tend to be heralded by particularly coarse horizons which usually contain fragments of coarse grained cumulates: these were presumably dislodged by the influx of new magma from depth. The coarsest horizon of all precedes the most basic phase in the middle of the sequence, when basalt flows were also discharged. It is not possible to identify individual basaltic horizons over any distance in the field but correlation does become possible when chemical profiles are integrated with stratigraphic data. It is generally sufficient to correlate by means of one elemente.g. Mg. The basaltic units are both thicker and coarser to the west of Mt. Misery. The most mafic beds have been found at Mansion in the east, probably because of the westward winnowing of the least dense fractions. Units of coarse greenish angular andesitic lapilli which occur near the top of the succession are the most amenable to wider correlation. There are three major units of these lapilli though often only one is exposed. Though indistinguishable in the field chemical analysis reveals that the middle unit is decidedly more basic and this becomes a useful criterion in correlation. It has been demonstrated that there are slight but significant variations in the chemistry of the upper unit over St. Kitts. Samples from the west are relatively enriched in SiO₂ (61.5%) compared with those to the east of the crater (59.0%). The pattern of variation can be matched closely to the isopachs, pointing to an influence of the wind on the ultimate composition of the deposits: presumably the less dense fractions were enhanced downwind. As a test of consistency, four samples were analysed from different heights in a single unit of andesitic lapilli but there was no significant difference. The results suggest that when conventional stratigraphic methods fail, chemical profiles may play a useful role. The pattern of variation in these profiles also suggests that basaltic andesites and perhaps some andesites are derived by fractional crystallization of basaltic magma. However, other andesites which break the pattern and appear suddenly in large volume may have a quite independent origin.  相似文献   

Peralkaline acid volcanic rocks of oceanic islands     

P. E. Baker 《Bulletin of Volcanology》1974,38(2):737-754

Occurrences of peralkaline acid volcanic rocks on oceanic islands are reviewed. Peralkaline differentiates are usually associated with mildly alkaline or transitional basalts and often with related sodic intermediate rocks. A compositional gap between basaltic and salic rocks is not invariably present. Although a comenditic end member is more usual in the oceanic suites, pantellerites are particularly well developed on Socorro Island and also on Gran Canaria where they form extensive ignimbrite sheets. There may be a genetic distinction between peralkaline rocks of islands which lie near the crests of oceanic rises and those which are built on broad submarine plateaux.  相似文献   

Book reviews     

Trevor Langford‐Smith  Jim Walmsley  Sue Baker  Edward Linacre  Philip Hirsch  Nigel Thrift 《The Australian geographer》1989,20(2):202-216

GRIFFITH TAYLOR: Antarctic scientist and pioneer geographer (Carleton Library Series No. 145) by M. Sanderson. 15 x 23 cm, xi and 218 pages. Carleton University Press: Ottawa 1988 (ISBN 0 88629 068 6) $C24.95 (hard); (ISBN 0 88629 068 X) $C14.95 (soft) plus postage.

LAND, WATER AND PEOPLE: Geographical essays in Australian resource management edited by R. L. Heathcote and J. A. Mabbutt. 14 x 21 cm, xiii and 266 pages. Allen & Unwin: Sydney 1988 (ISBN 0 04 303008 4) $A24.95 (soft).

ENVIRONMENTAL GEOGRAPHY: Book One by J. Paine, H. McLean and G. Mayhew. 19 x 25 cm, 389 pages. Macmillan: Melbourne 1988 (ISBN 0 333 43073 5) $A28.95 (soft).

Climate Impact Assessment Program (1975) Impacts of climate change on the biosphere, Monograph No. 5, US Department of Transportation, Washington DC.

SMALL‐SCALE AGRICULTURE edited by J. Hirst, J. Overton, B. Allen and Y. Byron. 18 x 25 cm, xii and 210 pages. Commonwealth Geographical Bureau and Department of Human Geography, Australian National University: Canberra 1988 (ISBN 0 7316 3609 0) $A 10.00 (soft).

THE BRITTLE RIM: Finance, Business and the Pacific Region by M. T. Daly and M. I. Logan. 15 × 23 cm, 263 pages, Penguin Books: Ring‐wood 1989 (ISBN 0 14 012095 5) $A24.99 (soft)

THE END OF ORGANISED CAPITALISM by S. Lash and J. Urry. 15 x 23cm, 383 pages. Polity Press: Cambridge 1987 (ISBN 07456 00697) $A34.95 (soft).

THE POLITICS OF DEVELOPMENT: An Introduction to Global Issues by J. L. Seitz. 15 x 23 cm, xiii and 194 pages. Basil Blackwell: New York 1988 (ISBN 0 631 15801 4) $A27.95 (soft).

DEVELOPING WITH FOREIGN INVESTMENT edited by V. Cable and B. Persaud. 16 x 24 cm, viii and 327 pages. Croom Helm: London 1987 (ISBN 0 7099 4825 5) $A87.95 (hard).

PLANNING SYDNEY'S FUTURE by P. Spearritt and C. DeMarco, 21 x 27 cm, and 150 pages. Allen & Unwin: Sydney 1988 (ISBN 0 04 324014 3) $A17.95 (soft).

THE RICHEST LODE: Broken Hill 1888–1988 by R. J. Solomon. 22 x 28 cm, 424 pages. Hale & Iremonger: Sydney 1988 (ISBN 0 86806 333 9).

CONTEMPORARY ISSUES IN DEVELOPMENT (North Australia: Progress and Prospects, Volume 1) edited by D. Wade‐Marshall and P. Loveday. xiii and 310 pages. North Australia Research Unit, Australian National University: Darwin 1988 (ISBN 07315 0335 X).

NEW CALEDONIA OR KANAKY? The Political History of a French Colony (Pacific Research Monograph No. 16) by J. Connell. National Centre for Development Studies, Australian National University: Canberra 1987 (ISBN 0 7315 05123).

DISEASE ECOLOGY by Andrew Learmonth. 15 x 23 cm, 456 pages. Basil Blackwell: Oxford 1988 (ISBN 0 631 15799 9) $A46.00 (soft).

QUALITATIVE METHODS IN HUMAN GEOGRAPHY edited by J. Eyles and D. M. Smith. 15 x 23 cm, xiii and 272 pages. Polity Press: Cambridge 1988 (ISBN 0 7456 0371 8) $A34.95 (soft).

GEOGRAPHICAL SYSTEMS AND SYSTEMS OF GEOGRAPHY: Essays in Honour of William Warntz edited by W. J. Coffey. 14 x 21 cm, 211 pages. Department of Geography, University of Western Ontario: London, Ontario 1988 (ISBN 0 7714 09747) $C30.00 (soft).  相似文献   

Isotopic archives of sulphate in speleothems     

Peter M. Wynn  Ian J. Fairchild  Andy Baker  James U.L. Baldini  Frank McDermott 《Geochimica et cosmochimica acta》2008,72(10):2465-2477

The hemispheric impact of industrial emissions upon atmospheric sulphur loading is reflected in the sulphur depositional history recorded in cores from ice sheets. However, these do not reveal regional variations. Recently deposited speleothems are used here as archives of regional sulphur depositional history at two locations within the United Kingdom and Ireland. δ³⁴S-so₄ and δ¹⁸O-so₄ present within speleothem carbonate are measured for the first time as part of a dual isotope approach to decode the speleothem sulphur record. The largely refractory nature of δ³⁴S-so₄ under oxidising conditions enables source provenance of atmospheric SO₂, whereas the complex cycles of isotopic exchange and fractionation during incorporation of oxygen into sulphate molecules enable δ¹⁸O-so₄ signatures to yield insights into ambient environmental conditions and biogeochemical cycling in the ecosystem above the cave. δ³⁴S-so₄ values extracted from speleothem carbonate formed within Browns Folly Mine, UK, range from +3.5 to +5.5‰ and δ¹⁸O-so₄ +10.3 to +13.7‰. Both signatures lie within the range expected from sulphate deposition in industrial locations and reflect the transfer of sulphate into speleothem calcite with little fractionation. However, δ¹⁸O-so₄ signatures at Crag Cave, western Ireland, are isotopically heavier than expected and approach isotopic equilibrium with δ¹⁸O-h₂o under reducing conditions. Dual isotope analysis of δ³⁴S-so₄ and δ¹⁸O-so₄ optimises the correct identification of sulphur sources and biogeochemical cycling prior to incorporation into the speleothem record. At carefully selected cave sites where drip water flowpaths into the cave remain oxic, speleothems hold the potential to retain records of atmospheric sulphur loading at the local and regional scale.  相似文献   

Mixed messages in iron oxide–copper–gold systems of the Cloncurry district,Australia: insights from PIXE analysis of halogens and copper in fluid inclusions     

Timothy Baker  Roger Mustard  Bin Fu  Patrick J. Williams  Guoyi Dong  Louise Fisher  Geordie Mark  Chris G. Ryan 《Mineralium Deposita》2008,43(6):599-608

Proterozoic rocks of the Cloncurry district in NW Queensland, Australia, are host to giant (tens to hundreds of square kilometers) hydrothermal systems that include (1) barren regional sodic–calcic alteration, (2) granite-hosted hydrothermal complexes with magmatic–hydrothermal transition features, and (3) iron oxide–copper–gold (IOCG) deposits. Fluid inclusion microthermometry and proton-induced X-ray emission (PIXE) show that IOCG deposits and the granite-hosted hydrothermal complexes contain abundant high temperature, ultrasaline, complex multisolid (type 1) inclusions that are less common in the regional sodic–calcic alteration. The latter is characterized by lower salinity three-phase halite-bearing (type 2) and two-phase (type 3) aqueous inclusions. Copper contents of the type 1 inclusions (>300 ppm) is higher than in type 2 and 3 inclusions (<300 ppm), and the highest copper concentrations (>1,000 ppm) are found both in the granite-hosted systems and in inclusions with Br/Cl ratios that are consistent with a magmatic source. The Br/Cl ratios of the inclusions with lower Cu contents are consistent with an evaporite-related origin. Wide ranges in salinity and homogenization temperatures for fluid inclusions in IOCG deposits and evidence for multiple fluid sources, as suggested by halogen ratios, indicate fluid mixing as an important process in IOCG genesis. The data support both leaching of Cu by voluminous nonmagmatic fluids from crustal rocks, as well as the direct exsolution of Cu-rich fluids from magmas. However, larger IOCG deposits may form from magmatic-derived fluids based on their higher Cu content.  相似文献