Uniformitarianism Revisited: a Comparison Between Modern and Ancient Orogens (IGCP Project 453)     

J.B. Murphy  J.D. Keppie   《Gondwana Research》2000,3(4):554-555

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http://www.sciencedirect.com/science/article/pii/S1674987111001113   总被引：1，自引：0，他引：1  

R. Damian Nance  Gabriel Guti errez-Alonso  J. Duncan Keppie  Ulf Linnemann  J. Brendan Murphy  Cecilio Quesa  Rob A. Strachan  Nigel H. Woodcock 《地学前缘(英文版)》2012,3(2):125-135

The Rheic Ocean was one of the most important oceans of the Paleozoic Era.It lay between Laurentia and Gondwana from the Early Ordovician and closed to produce the vast Ouachita-Alleghanian -Variscan orogen during the assembly of Pangea.Rifting began in the Cambrian as a continuation of Neoproterozoic orogenic activity and the ocean opened in the Early Ordovician with the separation of several Neoproterozoic arc terranes from the continental margin of northern Gondwana along the line of a former suture.The rapid rate of ocean opening suggests it was driven by slab pull in the outboard lapetus Ocean.The ocean reached its greatest width with the closure of lapetus and the accretion of the periGondwanan arc terranes to Laurentia in the Silurian.Ocean closure began in the Devonian and continued through the Mississippian as Gondwana sutured to Laurussia to form Pangea.The ocean consequently plays a dominant role in the Appalachian-Ouachita orogeny of North America,in the basement geology of southern Europe,and in the Paleozoic sedimentary,structural and tectonothermal record from Middle America to the Middle East.Its closure brought the Paleozoic Era to an end.  相似文献   

Rifts,arcs and orogens in space and time: a volume in honor of J. Duncan Keppie—an introduction     

J. Brendan Murphy  R. Damian Nance  Jaroslav Dostal  Cecilio Quesada 《International Journal of Earth Sciences》2014,103(5):1181-1186

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The Australia telescope 20 GHz survey: hardware, observing strategy, and scanning survey catalog     

Paul Jacob Hancock  Paul Roberts  Michael J. Kesteven  Ronald D. Ekers  Elaine M. Sadler  Tara Murphy  Marcella Massardi  Roberto Ricci  Mark Calabretta  Gianfranco de Zotti  Philip G. Edwards  Jennifer A. Ekers  Carole A. Jackson  Mark Leach  Chris Phillips  Robert J. Sault  Lister Staveley-Smith  Ravi Subrahmanyan  Mark A. Walker  Warwick E. Wilson 《Experimental Astronomy》2011,32(2):147-177

The Australia Telescope 20 GHz (AT20G) survey is a large area (2?? sr), sensitive (40 mJy), high frequency (20 GHz) survey of the southern sky. The survey was conducted in two parts: an initial fast scanning survey, and a series of more accurate follow-up observations. The follow-up survey catalog has been presented by Murphy et al. (MNRAS 402:2403, 2010). In this paper we discuss the hardware setup and scanning survey strategy as well as the production of the scanning survey catalog.  相似文献   

Detection of CH₃D on Titan     

Bruno Bézard  Conor A. Nixon  Donald E. Jennings 《Icarus》2007,191(1):397-400

We report the detection of ¹³CH₃D in Titan's stratosphere from Cassini/CIRS infrared spectra near 8.7 μm. Fitting simultaneously the ν₆ bands of both ¹³CH₃D and ¹²CH₃D and the ν₄ band of CH₄, we derive a D/H ratio equal to and a ¹²C/¹³C ratio in deuterated methane of , consistent with that measured in normal methane.  相似文献   

Post-orogenic exhumation of an auriferous terrane: the paleoplacer potential of the Early Carboniferous St. Marys Basin, Canadian Appalachians     

L. C. Jennex  J. B. Murphy  A. J. Anderson 《Mineralium Deposita》2000,35(8):776-790

The St. Marys Basin of mainland Nova Scotia, Canada, consists of Late Devonian–Early Carboniferous clastic rocks of the Horton Group deposited in the waning stages of the ca. 420–360 Ma Acadian orogeny in the Canadian Appalachians. Clast lithologies and lithogeochemical analyses indicate that the detritus was predominantly derived from the Meguma terrane that occurs to the south of the basin. The Meguma terrane contains abundant mesothermal gold deposits that are coeval with peak magmatic activity from ca. 380 to 370 Ma and underwent rapid uplift and erosion between ca. 370 and 360 Ma. Within the St. Marys Basin, the contact between the lacustrine Little Stewiacke River Formation and the fluviatile Barrens Hills Formation is interpreted to represent a shoreline and a potentially favorable environment for depositing paleoplacer gold. Geochemical analyses of lithologies adjacent to this contact indicate that the siltstones are predominantly derived from Meguma terrane metasedimentary rocks, whereas the sandstones and conglomerates are predominantly derived from Meguma terrane granitoids. Geochemical and mineralogical analysis indicate the accumulation of heavy minerals including zircon and gold. Micron-scale (<150 μm) gold identified in the matrix of the conglomerates has a “nuggety” appearance and flakey microtexture indicative of a detrital origin. This observation indicates that the mesothermal deposits were exhumed by the latest Devonian, consistent with regional tectonic syntheses that invoke rapid uplift of the Meguma terrane following peak orogenic activity. This study suggests that favorable depositional environments for paleoplacer deposits may occur in Horton Group rocks that are derived from the Meguma terrane. Received: 27 May 1999 / Accepted: 16 May 2000  相似文献   

Using Raman spectroscopy to improve our understanding of geological fluids     

Pamela Murphy 《岩石学报》2000,16(4)

Using Raman spectroscopy to improve our understanding of geological fluidsMurphy andRoberts.1995.Geochim.Cosmochim.Acta,59:4809～4824 Murphy andRoberts.1997.ChemicalGeology,135:1～20 Murphy,Stevens andL aGrange.2000.Geochim.Cosmochim.Acta,64:479～494 Sam son andWalker.2000.CanadianMineralogist,38:35～43…  相似文献   

Predicting post-fire debris flow grain sizes and depositional volumes in the Intermountain West,United States     

Sara Wall  Brendan P. Murphy  Patrick Belmont  Larissa Yocom 《地球表面变化过程与地形》2023,48(1):179-197

Post-fire debris flows represent one of the most erosive consequences associated with increasing wildfire severity and investigations into their downstream impacts have been limited. Recent advances have linked existing hydrogeomorphic models to predict potential impacts of post-fire erosion at watershed scales on downstream water resources. Here we address two key limitations in current models: (1) accurate predictions of post-fire debris flow volumes in the absence of triggering storm rainfall intensities and (2) understanding controls on grain sizes produced by post-fire debris flows. We compiled and analysed a novel dataset of depositional volumes and grain size distributions (GSDs) for 59 post-fire debris flows across the Intermountain West (IMW) collected via fieldwork and from the literature. We first evaluated the utility of existing models for post-fire debris flow volume prediction, which were largely developed for Southern California. We then constructed a new post-fire debris flow volume prediction model for the IMW using a combination of Random Forest modelling and regression analysis. We found topography and burn severity to be important variables, and that the percentage of pre-fire soil organic matter was an essential predictor variable. Our model was also capable of predicting debris flow volumes without data for the triggering storm, suggesting that rainfall may be more important as a presence/absence predictor, rather than a scaling variable. We also constructed the first models that predict the median, 16th percentile, and 84th percentile grain sizes, as well as boulder size, produced by post-fire debris flows. These models demonstrate consistent landscape controls on debris flow GSDs that are related to land cover, physical and chemical weathering, and hillslope sediment transport processes. This work advances our ability to predict how post-fire sediment pulses are transported through watersheds. Our models allow for improved pre- and post-fire risk assessments across diverse ranges of watersheds in the IMW.  相似文献   

西加拿大波利尔平原地表水富营养化管理技术     

E. E. Prepas  T. P. Murphy  G. Lawrence  P. A. Chambers  R. D. Robarts  W. M. Tonn  J. M. Burke  S. Reedyk 《湖泊科学》1998,10(S1):25-30

Surface waters in western Canada often experience eutrophication-related problems with water quality, specifically high internal phosphorus loading rates and excessive phytoplankton and macrophyte production, that lead to water column anoxia and restricted fisheries habitat. A group of researchers from across Canada were involved for a seven-year period in cooperative programs for surface water quality management in western Canada, based at the University of Alberta. This paper summarises information on two techniques, hypolimnetic oxygenation and lime (Ca₂CO₃ and Ca(OH)₂) application, used in western Canada (specifically, the province of Alberta) to manage eutrophication in standing waters (lakes and reservoirs).  相似文献   

VSOP monitoring of the Quasar 1928+738     

D. W. Murphy  S. J. Tingay  R. A. Preston  D. L. Meier  D. L. Jones  J. C. Guirado  A. Polatidis  J. E. Conway  H. Hirabayashi  H. Kobayashi  Y. Murata 《New Astronomy Reviews》1999,43(8-10)

We present the results from a campaign to monitor the relatively low redshift (z=0.3) circumpolar superluminal quasar 1928+738 with VSOP during the first Announcement of Opportunity period. The four epochs of data show that there have been substantial structural changes in this source near the core on the time-scale of a few months.  相似文献