Fibrous illite in oilfield sandstones – a nucleation kinetic theory of growth     

Mark Wilkinson  & R. Stuart Haszeldine 《地学学报》2002,14(1):56-60

Fibrous illite is one of the most important cements that grows within sandstones during burial, and the only one which is commonly dated using the K–Ar age technique. A small quantity of illite can dramatically reduce porefluid flow rates within a sandstone, thus making oil recovery uneconomic. Illite ages potentially correspond to geological events such as hydrocarbon filling of a sandstone reservoir, providing calibration to basin models. Yet the fundamental processes controlling fibrous illite growth are not understood. This contribution presents a new theory for illite growth within sandstones that explains the fibrous morphology of illite, the restricted range of illite K–Ar age dates compared to the age of the host sandstones, and the lack of 0-Myr-old illite reported. The growth of fibrous illite as an authigenic cement may be controlled by nucleation kinetics, and not by thermodynamic or growth kinetic considerations as has been previously assumed.  相似文献   

EURD: The Mission and the Stellar Absolute Fluxes of B-Type Stars     

Carmen Morales  Joaquín Trapero  José F. Gómez  Verónica Orozco  Alvaro Gimenez  Stuart Bowyer  Jerry Edelstein  Eric Korpela  Michael Lampton  Jeff Cobb 《Astrophysics and Space Science》2001,276(1):141-150

We present here stellar spectra of B stars obtained with the EURD spectrograph, one of the three instruments on board MINISAT-01. EURD is a spectrograph specially designed to detect diffuse radiation in thewavelength range between 350 and 1100 Å with 5 Å spectral resolution. EURD main scientific targets are: the spectrum of interstellar medium,atmospheric airglow, decaying neutrinos, Moon and early type stars.  相似文献   

Near-infrared imaging observations of the southern massive star-forming region G333.6−0.2     

Takuya Fujiyoshi  Craig H. Smith  Toby J. T. Moore  Stuart L. Lumsden  David K. Aitken  Patrick F. Roche 《Monthly notices of the Royal Astronomical Society》2005,356(3):801-809

We present near-infrared broad-band JHK ' images of the southern massive star-forming region G333.6−0.2. The slope of the K -luminosity function towards the region  (0.24 ± 0.01)  is considered to be equivalent to that expected for main-sequence stars in the solar neighbourhood. Point sources with their ( H − K ) colour greater than 1 are more likely to be located in extended emission and it is suggested that these objects are physically associated with the H  ii region.  相似文献   

Circumnuclear Star Formation in M100     

Stuart D. Ryder  Johan H. Knapen 《Astrophysics and Space Science》2001,276(2-4):405-412

Near-infrared (JHK) images of the nucleus of the barred spiral galaxy M100 (NGC 4321) have been obtained using a high-bandwidth tip-tilt secondary and fast guider system on the 3.8 m United Kingdom Infrared Telescope (UKIRT). The resulting images, with a resolution of 0.34″ at K, reveal for the first time a host of compact ‘knots’, which appear to be the result of a recent burst (or bursts) of star formation. Confirmation of this comes from K-band spectroscopy of these knots with CGS4 on UKIRT, which shows Brγ emission and CO absorption features. A comparison with starburst evolutionary models suggests ages for these knots of between 17 and 27 Myr, and a stellar population dominated by late-type supergiants. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The 2dF Galaxy Redshift Survey: spherical harmonics analysis of fluctuations in the final catalogue     

Will J. Percival  Daniel Burkey  Alan Heavens  y Taylor  Shaun Cole  John A. Peacock  Carlton M. Baugh  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Matthew Colless  Chris Collins  Warrick Couch  Gavin Dalton  Roberto De Propris  Simon P. Driver  George Efstathiou  Richard S. Ellis  Carlos S. Frenk  Karl Glazebrook  Carole Jackson  Ofer Lahav  Ian Lewis  Stuart Lumsden  Steve Maddox  Peder Norberg  Bruce A. Peterson  Will Sutherland  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2004,353(4):1201-1218

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The impact of The IGM on high-redshift Lyα emission lines     

Mark Dijkstra  Adam Lidz  J. Stuart B. Wyithe 《Monthly notices of the Royal Astronomical Society》2007,377(3):1175-1186

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Luminosity functions of Lyα emitting galaxies and cosmic reionization of hydrogen     

Mark Dijkstra  J. Stuart B. Wyithe  Zoltán Haiman 《Monthly notices of the Royal Astronomical Society》2007,379(1):253-259

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Tectonic controls on drainage evolution and development of terminal alluvial fans, southern Pyrenees, Spain     

Stuart J. Jones 《地学学报》2004,16(3):121-127

An understanding of how drainage patterns respond to tectonics can provide an insight into past deformational events within mountain belts and where sediment flux is supplied to depositional basins. The transverse rivers draining the Spanish Pyrenees show sudden diversions to axial courses and the capture of lateral systems producing large trunk rivers that break through the thrust front at structurally controlled points. The drainage reorganization from the initial regularly spaced pattern in the Late Eocene caused by the growth of thrust‐controlled topography influenced the location of outlets into the Ebro basin. The headward capture and merger of rivers as a result of structural diversion formed two large terminal fan systems during the Oligo‐Miocene along the Pyrenean thrust front. The early structural topographic controls on drainage evolution will have long‐term effects on sedimentation and stratigraphic architecture of foreland basins. This will only be maintained as long as there is tectonic uplift and the river systems strive to re‐attain a regular drainage spacing across the orogenic belt as partly achieved in the Pyrenees.  相似文献   

The remarkable fossils from the Early Cretaceous Jehol Biota of China and how they have changed our knowledge of Mesozoic life: Presidential Address,delivered 2nd May 2008     

Michael J. Benton  Zhou Zhonghe  Patrick J. Orr  Zhang Fucheng  Stuart L. Kearns 《Proceedings of the Geologists' Association. Geologists' Association》2008,119(3-4):209-228

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The noble gas geochemistry of natural CO₂ gas reservoirs from the Colorado Plateau and Rocky Mountain provinces, USA     

Stuart M.V. Gilfillan  Chris J. Ballentine  Dave Blagburn  Scott Stevens  Martin Cassidy 《Geochimica et cosmochimica acta》2008,72(4):1174-1198

Identification of the source of CO₂ in natural reservoirs and development of physical models to account for the migration and interaction of this CO₂ with the groundwater is essential for developing a quantitative understanding of the long term storage potential of CO₂ in the subsurface. We present the results of 57 noble gas determinations in CO₂ rich fields (>82%) from three natural reservoirs to the east of the Colorado Plateau uplift province, USA (Bravo Dome, NM., Sheep Mountain, CO. and McCallum Dome, CO.), and from two reservoirs from within the uplift area (St. John’s Dome, AZ., and McElmo Dome, CO.). We demonstrate that all fields have CO₂/³He ratios consistent with a dominantly magmatic source. The most recent volcanics in the province date from 8 to 10 ka and are associated with the Bravo Dome field. The oldest magmatic activity dates from 42 to 70 Ma and is associated with the McElmo Dome field, located in the tectonically stable centre of the Colorado Plateau: CO₂ can be stored within the subsurface on a millennia timescale.The manner and extent of contact of the CO₂ phase with the groundwater system is a critical parameter in using these systems as natural analogues for geological storage of anthropogenic CO₂. We show that coherent fractionation of groundwater ²⁰Ne/³⁶Ar with crustal radiogenic noble gases (⁴He, ²¹Ne, ⁴⁰Ar) is explained by a two stage re-dissolution model: Stage 1: Magmatic CO₂ injection into the groundwater system strips dissolved air-derived noble gases (ASW) and accumulated crustal/radiogenic noble gas by CO₂/water phase partitioning. The CO₂ containing the groundwater stripped gases provides the first reservoir fluid charge. Subsequent charges of CO₂ provide no more ASW or crustal noble gases, and serve only to dilute the original ASW and crustal noble gas rich CO₂. Reservoir scale preservation of concentration gradients in ASW-derived noble gases thus provide CO₂ filling direction. This is seen in the Bravo Dome and St. John’s Dome fields. Stage 2: The noble gases re-dissolve into any available gas stripped groundwater. This is modeled as a Rayleigh distillation process and enables us to quantify for each sample: (1) the volume of groundwater originally ‘stripped’ on reservoir filling; and (2) the volume of groundwater involved in subsequent interaction. The original water volume that is gas stripped varies from as low as 0.0005 cm³ groundwater/cm³ gas (STP) in one Bravo Dome sample, to 2.56 cm³ groundwater/cm³ gas (STP) in a St. John’s Dome sample. Subsequent gas/groundwater equilibration varies within all fields, each showing a similar range, from zero to ∼100 cm³ water/cm³ gas (at reservoir pressure and temperature).  相似文献