MINI-MACtm—A new generation dual—Band surveyor     

Ladd  Jonathan W.  Welshe  Robert G.  Brown  Alison  Sturza  Mark 《Journal of Geodesy》1986,60(3):221-228

Summary Litton Divisions presently produce both high accuracy GPS surveyors and low—cost GPS navigation sets. Aero Service'sMACROMETER ^R Interferometric Surveyors, have become the standard against which GPS surveying equipment is measured. Litton Aero Products has developed a highly digitized, low costL ₁,C/A code GPS card set. The integration of these technologies had led to the development of a low-cost, high-precision, GPS survey system which can be configured with or without a codelessL ₂ capability. TheMINI-MAC surveying system is the first member of the new generation of GPS survey systems resulting from this joint development. The system design is described in this paper, and initial survey test results using a prototypeMINI-MAC surveying system are presented.  相似文献   

INDUSTRIAL PHOTOGRAMMETRY: NEW DEVELOPMENTS AND RECENT APPLICATIONS   总被引：3，自引：0，他引：3  

C. S. Fraser  D. C. Brown 《The Photogrammetric Record》1986,12(68):197-217

Over the past decade, photogrammetry has been increasingly applied as a precise three dimensional measuring tool in industrial and engineering works. Analytical photogrammetry is now routinely employed in tasks of measurement as diverse as machine tool inspection and fixture checking, structural deformation monitoring, the provision of control databases to guide industrial robots and the measurement of structures in earth orbit. Traditional photogrammetric techniques and instrumentation are usually inappropriate for industrial work and the development of complete, fully integrated close range photogrammetric systems has recently gained considerable impetus. This paper details some of the significant new developments in industrial photogrammetry, with particular reference to technological advances in the Simultaneous Triangulation and Resection System (STARS) designed by Geodetic Services, Inc. for industrial photograininetry. Practical aspects of industrial measurement are also presented in a review of some of the varying tasks that GSI has carried out in recent years. Emphasis is placed on demonstrating the flexibility, accuracy, reliability and economy of photogrammetry, as well as the progress made in automating this measurement technique.  相似文献   

Quantitative chemical characterization of vitrinite concentrates using pyrolysis-gas chromatography. Rank variation of pyrolysis products     

J.T. Senftle  S.R. Larter  B.W. Bromley  J.H. Brown 《Organic Geochemistry》1986,9(6)

A series of hand-picked vitrinite samples from the Lower Kittanning Seam, Pennsylvania have been examined using quantitative pyrolysis-gas chromatography. These vitrinites ranged in rank from 0.59 to 1.71% reflectance, a rank range from high volatile C bituminous to low volatile bituminous. High molecular weight pyrolysis products included alkyl aromatic and phenolic compounds. Attempts have been made to correlate the pyrolysis product composition to rank parameters including vitrinite reflectance, volatile matter yield, carbon content, atomic H/C ratio and Rock-Eval determined T_max. Total yield of phenols was found to be strongly and inversely rank related. A clear relationship between C₈ alkyl-benzene yield and rank was not found for the sample set.  相似文献   

A petrographic and fluid inclusion comparison of silver-poor and silver-rich zinc-lead ores,N.E. Washington State     

Philip E. Brown  Gaafar A. Ahmed 《Mineralium Deposita》1986,21(2):156-163

Many of the zinc-lead deposits of NE Washington State are poorly known examples of Mississippi Valley Type (MVT) mineralization. This study compares inclusion fluids from the Josephine Breccia ores with the later cross-cutting sulfide-bearing quartz veins. The breccia ores are cemented mainly by open space fillings of dolomite, sphalerite, quartz, galena, jasperoid and calcite. Replacement is of minor importance. Ore and gangue deposition occurred over the range 150–250 °C with most of the temperatures less than 200 °C. The aqueous brines typically contain 17–23 equivalent weight percent NaCl with often substantial amounts of Ca and/or Mg chlorides. Homogenization temperatures do not delineate any cooling or paragenetic sequence. The cross-cutting vein quartz contains CO₂-rich inclusions with overall densities usually less than 0.7 g/cc and homogenization temperatures from 250–325 °C. Sulfur isotope analyses yield two populations with the quartz vein ores being lighter (<13 permil CDT) than the average for the conformable ores. The later veins are not remobilized MVT sulfides but represent a separate, high-silver period of mineralization.  相似文献   

Gravity and magnetic expression of the concealed basic and ultrabasic bodies in Chalkidhiki,Northern Greece     

Gregory N. Tsokas 《Pure and Applied Geophysics》1995,144(1):117-134

The anomalies which are shown on the gravity and aeromagnetic data of the Chalkidhiki peninsula of Northern Greece reveal the presence of three concealed dense and magnetized bodies. The ophiolitic belt which continues northwards of the geophysical anomalies suggests that they are caused by structures which belong to it. Multiple source Werner deconvolution shows that the lower surfaces of buried bodies in Toroneos Gulf and the one onshore are concave upwards. The northern concealed body has a width of 16 kilometers, while the southern one is 8 kilometres in width. A three-dimensional model, well constrained, gives an estimate of the dimensions of the onshore feature. The edges of the bodies, delineated by the terracing method, are formed by faults along the trend of the Hellenides orogenic belt. The edges of the body in the outer part of Toroneos Gulf may be associated with seismic swarms that occurred in the 1980s.  相似文献   

Pump-and-Treat Accomplishments: A Review of the Effectiveness of Ground Water Remediation in Santa Clara Valley, California   总被引：1，自引：0，他引：1  

Gregory Bartow  Clifton Davenport 《Ground Water Monitoring & Remediation》1995,15(2):140-146

Pump and treat has been successful in significantly reducing the volatile organic contaminant concentrations in ground water in Santa Clara Valley. California. The California Regional Water Quality Control Board. San Francisco Bay Region, currently oversees 61 sites in Santa Clara Valley with operating pump-and-treat systems, of which 42 sites have been extracting ground water since at least 1987. This review- evaluates the effects of ground water extraction on contaminant concentrations at 37 of those 42 sites. The evaluation focuses on trichloroethane, trichloroethene, and dichloroethane, as these were the most prevalent contaminants encountered at the sites. The majority of sites obtained greater than 90 percent reduction in maximum concentrations for one or more of the three contaminants. While only one of the 37 sites obtained maximum contaminant levels (MCL) for all contaminants, six of the sites included in the analyses reached MCLs for one or more of the sampled contaminants, and an additional seven of the sites are near MCLs for al least one contaminant. Our findings indicate that, while pump and treat successfully reduced maximum concentrations al most of the sites reviewed, successful attempts to reduce maximum contaminant concentrations to below MCLs are limited.  相似文献   

Distribution and abundance of macroinvertebrates on certain connecticut tidal marshes,with emphasis on dominant molluscs     

Paul E. Fell  Nancy C. Olmstead  Elaine Carlson  William Jacob  Diane Hitchcock  Gregory Silber 《Estuaries and Coasts》1982,5(3):234-239

The distribution of macroinvertebrates on Connecticut tidal marshes corresponds well with that reported for other marshes along the Atlantic and Gulf coasts of the United States. The greatest densities and biomass of the ribbed mussel,Geukensia demissa, were found on marshes in the central and western part of the state where both the annual production ofSpartina alterniflora and tidal range are large. *** DIRECT SUPPORT *** A01BY019 00011  相似文献   

Oxygen isotope geothermometry and stability of lawsonite and pumpellyite in the Shuksan Suite,North Cascades,Washington     

E. H. Brown  J. R. O'Neil 《Contributions to Mineralogy and Petrology》1982,80(3):240-244

Metamorphic temperatures of 330°–400° C are inferred for rocks from the Shuksan blueschist terrane in the North Cascades, Washington. The temperatures are calculated from ¹⁸O fractionations between coexisting quartz and magnetite using the equations of Bottinga and Javoy (1973). Pressures of approximately 7 kilobars are indicated by the Jadeite content of clinopyroxene coexisting with quartz+albite. Published experimental and theoretical studies of the stability of lawsonite and pumpellyite are consistent with the oxygen isotope temperatures and occurrence of these minerals in the Shuksan Suite.  相似文献   

Composition and origin of clasts and inclusions in the Abee enstatite chondrite breccia     

Derek W. Sears  Gregory W. Kallemeyn  John T. Wasson 《Earth and Planetary Science Letters》1983,62(1):180-192

The concentrations of 25 major, minor and trace elements have been determined in four clasts, a metal-rich inclusion and two dark metal-poor inclusions from the Abee enstatite chondrite. The clasts are heterogeneous, displaying 2-fold enrichments or depletions in some elements. The data suggest that there are two generations of metal, one with low, the other with high concentrations of refractory siderophiles. The other elemental patterns can be understood in terms of variations in the abundance of major minerals. We infer that Sc and Mn are located largely in the niningerite ((Fe,Mg)S), V in the troilite (FeS) and rare earth elements in the oldhamite (CaS).Heterogeneities among the clasts are probably primary, resulting from the accretion-agglomeration process, although shock processes in a regolithic setting remain a possibility provided that they were followed by a period of metamorphism sufficient to erase petrologic evidence.In the dark inclusions the concentrations of the rare earths, Eu excepted, are 4 × higher than mean EH levels; this infers enhanced amounts of CaS. The dark inclusions are low in siderophiles, Sc, Mn, K, Na and Al, implying low amounts of metal, niningerite and feldspar. The origin of the dark inclusions is unclear; they do not appear to be the result of a simple, single-stage process.  相似文献   

Stratiform copper deposits and interactions with co-existing atmospheres, hydrospheres, biospheres and lithospheres     

A.C. Brown  F.M. Chartrand 《Precambrian Research》1983,20(2-4)

Fundamental evidence from world-class stratiform copper deposits repeatedly indicates that they originated by a two-stage mineralization process: a syn-diagenetic enrichment of the host sediment in iron sulfide, followed by a sub-surface addition of copper during early diagenesis of the sediment. In contrast to the previously favored syngenetic hypothesis, which suggested an open equilibration between atmosphere, hydrosphere, biosphere and upper lithosphere during mineralization, the two-stage model implies that only the initial deposition of iron sulfides should take place with open exchanges between the upper “spheres”. The sub-surface emplacement of copper should occur in relative isolation from surface environments and, therefore, the occurrence and distribution of stratiform copper deposits through time and space should not be used to make direct interpretations of contemporaneous conditions in the upper “spheres”.  相似文献