The palaeoenvironment associated with a partial Iguanodon skeleton from the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks (Ockley, Surrey, UK), based on palynomorphs and ostracods

In 2001 a partial skeleton of an Iguanodon was discovered in the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks near Ockley, Surrey, UK. When the dinosaur was excavated, a detailed stratigraphic section was logged and 25 samples taken for palynological and micropalaeontological (ostracod and megaspore) analysis, including a detailed sample set of the dinosaur bed itself. Qualitative and quantitative analysis of the palynoflora revealed rich and well-preserved non-marine assemblages of pollen and spores, including early angiosperms, and freshwater green algae. Four types of angiosperm pollen are described and assigned to the genus Retimonocolpites Pierce, 1961, but left in open nomenclature. Some marine elements such as dinoflagellate cysts are identified as the result of reworking of Middle and Upper Jurassic sediments. The pollen/spore assemblages depict a vegetational change from principally gymnosperm-dominated assemblages at the base to principally pteridophyte-dominated assemblages at the top of the section. The dinosaur bed shows a pteridophyte-dominated assemblage, with a significantly high amount of the freshwater green alga Scenedesmus novilunaris He Cheng-quan et al., 1992. Samples close to the dinosaur bed yielded the first useful ostracod finds from Smokejacks Brickworks: well-preserved assemblages containing Cypridea clavata (Anderson, 1939), Damonella cf. pygmaea (Anderson, 1941), Stenestroemia cf. cressida Anderson, 1971 and Stenestroemia sp. A, and fragments and damaged valves of a thin-shelled ostracod, possibly belonging to Mantelliana Anderson, 1966. Those identified as Cypridea clavata show a wide range of morphological variety and in opposition to Anderson's (1967, 1985) taxonomic scheme, which would assign them to up to five different taxa, they are considered to be intraspecific variants of a single species. The possibilities and limitations of age determination of the Wealden sediments using palynomorphs and ostracods are discussed; distinct forms of early angiosperm pollen, together with the ostracod fauna, are consistent with an early Barremian age. Pollen and spores are discussed in terms of their parent plants and the reconstruction of vegetation and palaeoclimate. Palynology and ostracods give evidence for temporary freshwater conditions at the time when the Iguanodon died and the carcase was buried.     

Book reviews

THE IMPACT OF VOLCANIC HAZARDS AT RABAUL, PAPUA NEW GUINEA (Discussion Paper No. 33) by R. J. Blong and C. Aislabie. 17 × 25 cm, xiv and 207 pages. Institute of National Affairs: Port Morseby 1988 (ISBN 9980 77 086 4).

A PRACTICAL APPROACH TO SEDIMENTOLOGY by R. C. Lindholm. 15 × 23 cm, xviii and 279 pages. Allen & Unwin: London 1987 (ISBN 0 04 551132 2) $A45.00 (soft).

THE ATMOSPHERE AND WEATHER OF SOUTHERN AFRICA by R. A. Preston‐Whyte and P. D. Tyson. 18 × 24 cm, xiii and 375 pages. Oxford University Press: Cape Town 1988 (ISBN 0 19 570 514 9) R56.00 (hard); (ISBN 0 19 570 496 7) R39.14 (soft).

QUATERNARY PALEOCLIMATOLOGY: Methods of Paleoclimatic Reconstruction by R. S. Bradley. 15 × 23 cm, xvii and 472 pages. Allen & Unwin: Boston 1985 (ISBN 0 04 551067 9) $A69.95 (hard); (ISBN 0 04 551068 7) $A39.95 (soft).

PROCESSES IN PHYSICAL GEOGRAPHY by R. D. Thompson, A. M. Mannion, C. W. Mitchell, M. Parry and J. R. Townsend. 24 × 19 cm, xii and 380 pages. Longman: London 1986 (ISBN 0 582 30136) $A44.95.

PERSPECTIVES ON A DYNAMIC EARTH by T. R. Paton. 16 × 24 cm, 142 pages. Allen & Unwin: London 1986 (ISBN 0 04 55 0043 6) $A23.95 (soft).

LAND DEGRADATION AND SOCIETY edited by P. Blaikie and H. Brookfield. 15 × 23 cm. xxiv and 296 pages. Methuen: London 1987 (ISBN 0 416 40150 3) $A32.95 (soft).

THE PENGUIN DICTIONARY OF HUMAN GEOGRAPHY by B. Goodall. 13 × 20 cm, 509 pages. Penguin: Harmondsworth 1987 (ISBN 0 14 051095 8) $A19.95 (soft).

MAKING SENSE OF DEVELOPMENT: An Introduction to Classical and Contemporary Theories of Development and Their Application to South‐east Asia by P. W. Preston. 14 × 22 cm, xxi and 318 pages. Routledge & Kegan Paul: London 1986 (ISBN 0 7102 0813 8) $A87.95 (hard).

THE DEMOGRAPHIC DIMENSION IN INDONESIAN DEVELOPMENT by G. J. Hugo, T. H. Hull, V. J. Hull and G. W. Jones. 16 × 25 cm, xxv and 417 pages. Oxford University Press: Singapore 1987 (ISBN 0 19 582699 X) $A49.95 (hard).

GLOBAL ISSUES AND OUTLOOK IN PULP AND PAPER edited by G. F. Schreuder, 18 × 26 cm, ix and 302 pages. University of Washington Press: Seattle 1988 (ISBN 0 295 96642 4) $US40.00 (hard).

AN HISTORICAL GEOGRAPHY OF MODERN AUSTRALIA: The Restive Fringe (Cambridge Studies in Historical Geography No. 11) by J. M. Powell. 16 × 33 cm, xx and 400 pages. Cambridge University Press: Cambridge 1988 (ISBN 0 521 25619 4) $A39.95 (hard).

HISTORICAL GEOGRAPHY: Progress and Prospect edited by M. Pacione. 14 × 22 cm, 306 pages. Croom Helm: London 1987 (ISBN 0 7099 40467) $A27.50 (hard).

THE ROLE OF THEORY IN URBAN PLANNING: A Study of Metropolitan Planning in Perth, Western Australia (Geowest No. 24) by O. Yiftachel. 21 × 29 cm, 102 pages. Department of Geography, University of Western Australia: Nedlands 1987 (ISBN 0 86422 063 4).

SYDNEY INTO ITS THIRD CENTURY: Metropolitan Strategy for the Sydney Region by NSW Department of Environment and Planning. 21 × 29 cm, 72 pages. NSW department of Environment and Planning: Sydney 1988 (ISBN 0 7305 4312 9).

BUS SERVICES IN WESTERN SYDNEY: Private Bus Operators and Government Transport Departments (Monograph Series No. 3) by P. Tranter. 21 × 29 cm, v and 98 pages. Department of Geography and Oceanography, University College, Australian Defence Force Academy: Campbell, ACT 1988 (ISBN 0 7317 0036 8).

AGEING IN VICTORIA: An Electronic Social Atlas by A. L. Howe, P. Newton and P. Sharwood. 30 × 21 cm, 105 pages. National Research Institute for Gerontology and Geriatric Medicine, Mt. Royal Hospital and University of Melbourne: Melbourne 1987 (ISBN 0 958326 6 2) $A10.00 (soft).

READINGS IN AUSTRALIAN GEOGRAPHY: Proceedings of the 21st Institute of Australian Geographers’ Conference, Perth 10–18 May 1986, edited by A. Conacher. 21 × 29 cm, vi and 493 pages. Institute of Australian Geographers (WA Branch) and Department of Geography, University of Western Australia: Perth 1987 (ISBN 0 909678 30 B) $A25.00 (soft).

GEOGRAPHY RESEARCH PROJECTS: A Senior Student's Handbook by H. Binden and H. Williams. 18 × 26 cm, 149 pages. Edward Arnold Australia: Caulfield East 1988 (ISBN 0 7131 8311 X) $A 14.95 (soft).

OUR AMERICAN LAND: 1987 Yearbook of Agriculture, ix and 323 pages. US Government Printing Office, Washington, DC: 1987 $US9.50.

THE ENCYCLOPAEDIC DICTIONARY OF PHYSICAL GEOGRAPHY edited by A. Goudie et al. 17 × 24 cm, xvi and 528 pages. Basil Black‐well: Oxford 1988 (ISBN 0 631 15581 3) $A34.95 (soft).

THE CONSERVATION OF ECOSYSTEMS AND SPECIES by Gareth E. Jones, 14 × 22 cm, 277 pages. Croom Helm: London 1987 (ISBN 0 7099 1463 6) $A87.95 (hard).

SO CAME THEY SOUTH by R. Clancy and A. Richardson. 35 × 35 cm, 176 pages. Shakespeare Head: Sydney 1988 (ISBN 0 7302 0864 8) $A34.95.     

Bottom Simulating Reflector and Gas Seepage in Okinawa Trough： Evidence of Gas Hydrate in an Active Back-Arc Basin

To look for gas hydrate, 22 multi-channel and 3 single-channel seismic lines on the East China Sea (ECS) shelf slope and at the bottom of the Okinawa Trough were examined. It was found that there was indeed bottom simulating reflector (BSR) occurrence, but it is very rare. Besides several BSRs, a gas seepage was also found. As shown by the data, both the BSR and gas seepage are all related with local geological structures, such as mud diapir, anticline, and fault-controlled graben-like structure. However, similar structural "anomalies" are quite common in the tectonically very active Okinawa Trough region, but very few of them have developed BSR or gas seepage. The article points out that the main reason is probably the low concentration of organic carbon of the sediment in this area. It was speculated that the rare occurrence of gas hydrates in this region is governed by structure-controlled fluid flow. Numerous faults and fractures form a network of high-permeability channels in the sediment and highly fractured igneous basement to allow fluid circulation and ventilation. Fluid flow in this tectonic environment is driven primarily by thermal buoyancy and takes place on a wide range of spatial scales. The fluid flow may play two roles to facilitate hydrate formation:to help gather enough methane into a small area and to modulate the thermal regime.     

Exploration and discovery in Yellowstone Lake: results from high-resolution sonar imaging, seismic reflection profiling, and submersible studies

‘No portion of the American continent is perhaps so rich in wonders as the Yellow Stone’ (F.V. Hayden, September 2, 1874)Discoveries from multi-beam sonar mapping and seismic reflection surveys of the northern, central, and West Thumb basins of Yellowstone Lake provide new insight into the extent of post-collapse volcanism and active hydrothermal processes occurring in a large lake environment above a large magma chamber. Yellowstone Lake has an irregular bottom covered with dozens of features directly related to hydrothermal, tectonic, volcanic, and sedimentary processes. Detailed bathymetric, seismic reflection, and magnetic evidence reveals that rhyolitic lava flows underlie much of Yellowstone Lake and exert fundamental control on lake bathymetry and localization of hydrothermal activity. Many previously unknown features have been identified and include over 250 hydrothermal vents, several very large (>500 m diameter) hydrothermal explosion craters, many small hydrothermal vent craters (1–200 m diameter), domed lacustrine sediments related to hydrothermal activity, elongate fissures cutting post-glacial sediments, siliceous hydrothermal spire structures, sublacustrine landslide deposits, submerged former shorelines, and a recently active graben. Sampling and observations with a submersible remotely operated vehicle confirm and extend our understanding of the identified features. Faults, fissures, hydrothermally inflated domal structures, hydrothermal explosion craters, and sublacustrine landslides constitute potentially significant geologic hazards. Toxic elements derived from hydrothermal processes also may significantly affect the Yellowstone ecosystem.     

Near-vertical seismic reflection image using a novel acquisition technique across the Vrancea Zone and Foscani Basin, south-eastern Carpathians (Romania)

The DACIA PLAN (Danube and Carpathian Integrated Action on Process in the Lithosphere and Neotectonics) deep seismic sounding survey was performed in August–September 2001 in south-eastern Romania, at the same time as the regional deep refraction seismic survey VRANCEA 2001. The main goal of the experiment was to obtain new information on the deep structure of the external Carpathians nappes and the architecture of Tertiary/Quaternary basins developed within and adjacent to the seismically-active Vrancea zone, including the Focsani Basin. The seismic reflection line had a WNW–ESE orientation, running from internal East Carpathians units, across the mountainous south-eastern Carpathians, and the foreland Focsani Basin towards the Danube Delta. There were 131 shot points along the profile, with about 1 km spacing, and data were recorded with stand-alone RefTek-125s (also known as “Texans”), supplied by the University Texas at El Paso and the PASSCAL Institute. The entire line was recorded in three deployments, using about 340 receivers in the first deployment and 640 receivers in each of the other two deployments. The resulting deep seismic reflection stacks, processed to 20 s along the entire profile and to 10 s in the eastern Focsani Basin, are presented here. The regional architecture of the latter, interpreted in the context of abundant independent constraint from exploration seismic and subsurface data, is well imaged. Image quality within and beneath the thrust belt is of much poorer quality. Nevertheless, there is good evidence to suggest that a thick (10 km) sedimentary basin having the structure of a graben and of indeterminate age underlies the westernmost part of the Focsani Basin, in the depth range 10–25 km. Most of the crustal depth seismicity observed in the Vrancea zone (as opposed to the more intense upper mantle seismicity) appears to be associated with this sedimentary basin. The sedimentary successions within this basin and other horizons visible further to the west, beneath the Carpathian nappes, suggest that the geometry of the Neogene and recent uplift observed in the Vrancea zone, likely coupled with contemporaneous rapid subsidence in the foreland, is detached from deeper levels of the crust at about 10 km depth. The Moho lies at a depth of about 40 km along the profile, its poor expression in the reflection stack being strengthened by independent estimates from the refraction data. Given the apparent thickness of the (meta)sedimentary supracrustal units, the crystalline crust beneath this area is quite thin (< 20 km) supporting the hypothesis that there may have been delamination of (lower) continental crust in this area involved in the evolution of the seismic Vrancea zone.     

A closed-loop EKF and multi-failure diagnosis approach for cooperative GNSS positioning

Current cooperative positioning with global navigation satellite system (GNSS) for connected vehicle application mainly uses pseudorange measurements. However, the positioning accuracy offered cannot meet the requirements for lane-level positioning, collision avoidance and future automatic driving, which needs real-time positioning accuracy of better than 0.5 m. Furthermore, there is an apparent lack of research into the integrity issue for these new applications under emerging driverless vehicle applications. In order to overcome those problems, a new extended Kalman filter (EKF) and a multi-failure diagnosis algorithm are developed to process both GNSS pseudorange and carrier phase measurements. We first introduce a new closed-loop EKF with partial ambiguity resolution as feedback to address the low accuracy issue. Then a multi-failure diagnosis algorithm is proposed to improve integrity and reliability. The core of this new algorithm includes using Carrier phase-based Receiver Autonomous Integrity Monitoring method for failure detection, and the double extended w test detectors to identify failure. A cooperative positioning experiment was carried out to validate the proposed method. The results show that the proposed closed-loop EKF can provide highly accurate positioning, and the multi-failure diagnosis method is effective in detecting and identifying failures for both code and carrier phase measurements.     

Modeling spatially non-stationary land use/cover change in the lower Connecticut River Basin by combining geographically weighted logistic regression and the CA-Markov model

Simulating land use/cover change (LUCC) and determining its transition rules have been a focus of research for several decades. Previous studies used ordinary logistic regression (OLR) to determine transition rules in cellular automata (CA) modeling of LUCC, which often neglected the spatially non-stationary relationships between driving factors and land use/cover categories. We use an integrated geographically weighted logistic regression (GWLR) CA-Markov method to simulate LUCC from 2001–2011 over 29 towns in the Connecticut River Basin. Results are compared with those obtained from the OLR-CA-Markov method, and the sensitivity of LUCC simulated by the GWLR-CA-Markov method to the spatial non-stationarity-based suitability map is investigated. Analysis of residuals indicates better goodness of fit in model calibration for geographically weighted regression (GWR) than OLR. Coefficients of driving factors indicate that GWLR outperforms OLR in depicting the local suitability of land use/cover categories. Kappa statistics of the simulated maps indicate high agreement with observed land use/cover for both OLR-CA-Markov and GWLR-CA-Markov methods. Similarity in simulation accuracy between the methods suggests that the sensitivity of simulated LUCC to suitability inputs is low with respect to spatial non-stationarity. Therefore, this study provides critical insight on the role of spatial non-stationarity throughout the process of LUCC simulation.