Geochemical signature of orogenic hydrothermal activity in an active tectonic intersection zone,Alpine Fault,New Zealand   总被引：1，自引：0，他引：1  

J.?R.?Campbell  D.?CrawEmail author  R.?Frew  T.?Horton  C.?P.?Chamberlain 《Mineralium Deposita》2004,39(4):437-451

A highly faulted and fractured rock mass has developed at the intersection of the Alpine and Hope faults, two major active faults in the South Island, New Zealand. The Alpine Fault is an oblique dextral reverse fault at the late Cenozoic-Recent Pacific-Australian plate boundary. The Hope Fault is a strike-slip fault parallel to the plate convergence vector. Hydrothermal fluids driven by the active tectonic processes have passed through the fractured rock mass, causing localised rock alteration and vein formation. Mylonites in the Alpine Fault zone are crosscut by cm-scale veins of quartz and/or ankerite with minor sulphides, with cemented breccias in dilational jogs. Breccia clasts and immediate (cm-scale) host rocks have been variably impregnated with carbonates and quartz. This generation of veins, breccias and altered rocks is post-dated by cataclasite and fault gouge zones which have been cemented by calcite, illite, smectite and chamosite. Ankerite and calcite have ¹⁸O between +10 and +30, and ¹³C between 0 and –8. These minerals are inferred to have formed from water with variable components of both meteoric and crustally exchanged fluid. Rock alteration associated with ankerite–quartz veins has added arsenic (up to 200 ppm As), strontium, and some Y to the rocks. Host-rock mylonites (<2 ppm As) have been depleted in arsenic compared to their precursors (5–15 ppm As). This depletion of arsenic in the middle crust provides the source for arsenic in shallower-level vein systems.Editorial handling: N. White  相似文献   

The Gambler: (re)placing the desire of money     

Stephen Horton 《New Zealand geographer》2005,61(3):187-202

Abstract:  The Gambler conjures a world of myth: not as a fiction of human consciousness but as unconscious image-language. Its ambition is to write geography as material subject. In tracing the discourse written in the built environment the text ranges over the analyses of Marx and Freud and into the gestural worlds of Kafka and the blood sports of the ancient Colosseum. It discovers the myth of New Zealand horse racing, written in pictures in the local pub where virtual racing, abstracted from the living world, (dis)plays on the television screen. Here, finally, The Gambler comes to terms with loss.  相似文献   

Real-time measurement of volcanic SO2 emissions: validation of a new UV correlation spectrometer (FLYSPEC)     

Keith A. Horton  Glyn Williams-Jones  Harold Garbeil  Tamar Elias  A. Jeff Sutton  Peter Mouginis-Mark  John N. Porter  Steven Clegg 《Bulletin of Volcanology》2006,68(4):323-327

A miniaturized, lightweight and low-cost UV correlation spectrometer, the FLYSPEC, has been developed as an alternative for the COSPEC, which has long been the mainstay for monitoring volcanic sulfur dioxide fluxes. Field experiments have been conducted with the FLYSPEC at diverse volcanic systems, including Masaya (Nicaragua), Poás (Costa Rica), Stromboli, Etna and Vulcano (Italy), Villarica (Chile) and Kilauea (USA). We present here those validation measurements that were made simultaneously with COSPEC at Kilauea between March 2002 and February 2003. These experiments, with source emission rates that ranged from 95 to 1,560 t d⁻¹, showed statistically identical results from both instruments. SO₂ path-concentrations ranged from 0 to >1,000 ppm-m with average correlation coefficients greater than r ²=0.946. The small size and low cost create the opportunity for FLYSPEC to be used in novel deployment modes that have the potential to revolutionize the manner in which volcanic and industrial monitoring is performed.  相似文献   

Distribution of thermal areas on an active lava flow field: Landsat observations of Kilauea,Hawaii, July 1991     

Luke P. Flynn  Peter J. Mouginis-Mark  Keith A. Horton 《Bulletin of Volcanology》1994,56(4):284-296

A Landsat Thematic Mapper (TM) image acquired on 23 July 1991 recorded widespread activity associated with the Episode 48 of the Pu'u 'O'o-Kupaianaha eruption of Kilauea Volcano, Hawaii. The scene contains a very large number (>3500) of thermally elevated near infrared (0.8–2.35 m) pixels (each 900 m²), which enable the spatial distribution of volcanic activity to be identified. This activity includes a lava lake within Pu'u 'O'o cone, an active lava tube system (7.9 km in length) with skylights between the Kupaianaha lava shield and several ocean entry points, and extensive active surface flows (total area of 1.3 km²) within a much larger area of cooling flows (total16 km²). The production of an average flux density map from the TM data of the flow field, wherein the average flux density is defined in units of Wm^-2, allows for the chronology of emplacement of active and cooling flows to be determined. The flux density map reveals that there were at least three breakouts (>5000 Wm^-2) feeding active flows, but on the day that the data were collected the TM recorded a waning phase of surface activity in this area, based on the relatively large amount of intermediate power-emitting (cooling) flows compared to high power-emitting (active) flows. The production of a comparable flux density map for future eruptions would aid in the assessment of volcanic hazards if the data were available in near-real time.  相似文献   

Constraining sediment provenance for tsunami deposits using distributions of grain size and foraminifera from the Kujukuri coastline and shelf,Japan     

Jessica E. Pilarczyk  Yuki Sawai  Dan Matsumoto  Yuichi Namegaya  Naohisa Nishida  Ken Ikehara  Osamu Fujiwara  Chris Gouramanis  Tina Dura  Benjamin P. Horton 《Sedimentology》2020,67(3):1373-1392

Tsunami deposits preserved in the geological record provide a more comprehensive understanding of their patterns of frequency and intensity over longer timescales; but recognizing tsunami deposits can prove challenging due to post-depositional changes, lack of contrast between the deposits and surrounding sedimentary layers, and differentiating between tsunami and storm deposition. Modern baseline studies address these challenges by providing insight into modern spatial distributions that can be compared with palaeotsunami deposits. This study documents the spatial fingerprint of grain size and foraminifera from Hasunuma Beach and the Kujukuri shelf to provide a basis from which tsunami deposits can be interpreted. At Hasunuma Beach, approximately 50 km east of Tokyo, the spatial distribution of three common proxies (foraminiferal taxonomy, foraminiferal taphonomy and sediment grain size) for tsunami identification were mapped and clustered using Partitioning Around Medoids cluster analysis. Partitioning Around Medoids cluster analysis objectively discriminated two coastal zones corresponding to onshore and offshore sample locations. Results show that onshore samples are characterized by coarser grain sizes (medium to coarse sand) and higher abundances of Pararotalia nipponica (27 to 63%) than offshore samples, which are characterized by finer grain sizes (fine to medium sand), lower abundances of Pararotalia nipponica (2 to 19%) and Ammonia parkinsoniana (0 to 10%), higher abundances of planktonics (15 to 58%) and species with fragile tests including Uvigerinella glabra. When compared to grain-size and foraminiferal taxonomy, foraminiferal taphonomy; i.e. surface condition of foraminifera, a proxy not commonly used to identify tsunami deposits, was most effective in discriminating modern coastal zones (identified supratidal, intertidal and offshore environments) and determining sediment provenance for tsunami deposits at Kujukuri. This modern baseline study assists the interpretation of tsunami deposits in the geological record because it provides a basis for sediment provenance to be determined.  相似文献   

‘The health event’: Everyday, affective politics of participation     

Peter Kraftl  John Horton 《Geoforum》2007,38(5):1012-1027

This paper is about a single event: a conference (A.K.A. ‘the health event’) held in the English East Midlands in July 2005, at which findings from a policy-led research project regarding young people’s health needs were fed back to research participants. The paper foregrounds some of the everyday work, happenings, emotions, conversations and materialities which were fundamentally constitutive of ‘the health event’ and, thus fundamentally constituted the moments of affirmative, politically-charged participation which could and did happen therein. Thus the paper bears witness to the sorts of practices, minutiae and highs and lows which are surely fundamentally constitutive of participation, policy and politics per se, but which (despite the growing visibility of nonrepresentational theories) are typically absent from salient accounts of participation, Children’s Geographies and Post-medical Geographies.  相似文献   

Simulating conservative tracers in fractured till under realistic timescales     

Helmke MF  Simpkins WW  Horton R 《Ground water》2005,43(6):877-889

Discrete-fracture and dual-porosity models are infrequently used to simulate solute transport through fractured unconsolidated deposits, despite their more common application in fractured rock where distinct flow regimes are hypothesized. In this study, we apply four fracture transport models--the mobile-immobile model (MIM), parallel-plate discrete-fracture model (PDFM), and stochastic and deterministic discrete-fracture models (DFMs)--to demonstrate their utility for simulating solute transport through fractured till. Model results were compared to breakthrough curves (BTCs) for the conservative tracers potassium bromide (KBr), pentafluorobenzoic acid (PFBA), and 1,4-piperazinediethanesulfonic acid (PIPES) in a large-diameter column of fractured till. Input parameters were determined from independent field and laboratory methods. Predictions of Br BTCs were not significantly different among models; however, the stochastic and deterministic DFMs were more accurate than the MIM or PDFM when predicting PFBA and PIPES BTCs. DFMs may be more applicable than the MIM for tracers with small effective diffusion coefficients (De) or for short timescales due to differences in how these models simulate diffusion or incorporate heterogeneities by their fracture networks. At large scales of investigation, the more computationally efficient MIM and PDFM may be more practical to implement than the three-dimensional DFMs, or a combination of model approaches could be employed. Regardless of the modeling approach used, fractures should be incorporated routinely into solute transport models in glaciated terrain.  相似文献   

COMPUTER MAPPING CONFERENCE     

Frank E. Horton  Clifford E. Tiedemann 《The Professional geographer》1967,19(6):358-358

  相似文献   

Ultraviolet ion chamber measurements of the solar minimum brightness temperature     

J. H. Carver  B. H. Horton  G. W. A. Lockey  Bryan Rofe 《Solar physics》1972,27(2):347-353

The solar ultraviolet flux in the wavelength bands 1580–1640 Å and 1430–1470 Å (FWHM) has been measured using photon ion chambers carried on the satellite WRESAT I (1967-118A). These observations of the integrated ultraviolet flux from the entire disk indicate a value of (4570 ± 50) K for the solar temperature minimum. The results are compared with other estimates of the minimum value of the solar brightness temperature.Died August, 1971.  相似文献   

PALEOGENE(?) DEPOSYSTEMS AND BASIN EVOLUTION IN THE EASTERN TIBETAN PLATEAU: NANGQIAN AND XIALAXIU BASINS   总被引：1，自引：0，他引：1  

Brian K. Horton    Zhou Jiangyu  Matt S. Spurlin  An Yin  Wang Jianghai 《地学前缘》2000,(Z1)

PALEOGENE(?) DEPOSYSTEMS AND BASIN EVOLUTION IN THE EASTERN TIBETAN PLATEAU: NANGQIAN AND XIALAXIU BASINS  相似文献