THE ASIAN TSUNAMI, ACADEMICS AND ACADEMIC RESEARCH     

Sophia Buranakul  Carl Grundy-Warr  Ben Horton  Lisa Law  Jonathan Rigg  May Tan-Mullins 《Singapore journal of tropical geography》2005,26(2):244-248

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Author Index     

Andrew L. Macumber  R. Timothy Patterson  Lisa A. Neville  Hendrik Falck 《Journal of Paleolimnology》2003,29(4):511-511

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STRANGE COUNTRIES AND SECRET WORLDS IN RUTH RENDELL'S CRIME NOVELS*     

Lisa Kadonaga 《Geographical review》1998,88(3):413-428

ABSTRACT. Mystery novels and academic geography have not often intersected. Yet crime fiction can incorporate spatial relationships and real-life regional characteristics. In recent decades mysteries have been freed from the long tradition of presenting elaborate puzzles, and now they feature human interactions in realistic settings. Writers like Ruth Rendell integrate place into their character development and plot lines. Rendell depicts changing urban landscapes in late-twentieth-century England and effectively explores contemporary British culture.  相似文献   

Ar/Ar ages and paleomagnetism of São Miguel lavas, Azores     

Catherine L. Johnson  Jan R. Wijbrans  Catherine G. Constable  Jeff Gee  Hubert Staudigel  Lisa Tauxe  Victor-H. Forjaz  Mrio Salgueiro 《Earth and Planetary Science Letters》1998,160(3-4):637-649

We present new ⁴⁰Ar/³⁹Ar ages and paleomagnetic data for São Miguel island, Azores. Paleomagnetic samples were obtained for 34 flows and one dike; successful mean paleomagnetic directions were obtained for 28 of these 35 sites. ⁴⁰Ar/³⁹Ar age determinations on 12 flows from the Nordeste complex were attempted successfully: ages obtained are between 0.78 Ma and 0.88 Ma, in contrast to published K–Ar ages of 1 Ma to 4 Ma. Our radiometric ages are consistent with the reverse polarity paleomagnetic field directions, and indicate that the entire exposed part of the Nordeste complex is of a late Matuyama age. The duration of volcanism across São Miguel is significantly less than previously believed, which has important implications for regional melt generation processes, and temporal sampling of the geomagnetic field. Observed stable isotope and trace element trends across the island can be explained, at least in part, by communication between different magma source regions at depth. The ⁴⁰Ar/³⁹Ar ages indicate that our normal polarity paleomagnetic data sample at least 0.1 Myr (0–0.1 Ma) and up to 0.78 Myr (0–0.78 Ma) of paleosecular variation and our reverse polarity data sample approximately 0.1 Myr (0.78–0.88 Ma) of paleosecular variation. Our results demonstrate that precise radiometric dating of numerous flows sampled is essential to accurate inferences of long-term geomagnetic field behavior. Negative inclination anomalies are observed for both the normal and reverse polarity time-averaged field. Within the data uncertainties, normal and reverse polarity field directions are antipodal, but the reverse polarity field shows a significant deviation from a geocentric axial dipole direction.  相似文献   

U-Pb zircon geochronology of late Neoproterozoic–Early Cambrian granitoids in Iran: Implications for paleogeography, magmatism, and exhumation history of Iranian basement     

Jamshid Hassanzadeh  Daniel F. Stockli  Brian K. Horton  Gary J. Axen  Lisa D. Stockli  Marty Grove  Axel K. Schmitt  J. Douglas Walker 《Tectonophysics》2008,451(1-4):71-96

Eurasia has largely grown to its present enormous size through episodic addition of crustal blocks by recurring birth and demise of oceans such as Paleotethys and Neotethys. Excluding the Kopet Dagh Mountains in the northeast, crystalline basement rocks of various dimensions are exposed in all continental tectonic zones of Iran. These rocks have traditionally been viewed as continental fragments with Gondwanan affinity and summarily been assigned Precambrian or younger ages, despite the fact that evidence from isotopic dating has largely been lacking. This study presents new ion microprobe and thermal-ionization zircon U-Pb geochronological data from granitoids and orthogneisses from several locations in central Iran and the Sanandaj–Sirjan structural zones to determine crystallization ages and investigate the origin and continental affinity of these various crustal fragments. The resulting U-Pb crystallization ages for the granites and orthogneisses range from late Neoproterozoic to Early Cambrian, matching the mostly juvenile Arabian–Nubian shield and Peri-Gondwanan terranes constructed after the main phase of Pan-African orogenesis. TIMS analyses of zircons with inherited cores from western Iran suggest that the Neoproterozoic crust of Iran might not be entirely juvenile, pointing to the potential presence of inherited older Proterozoic components as is common in the eastern Arabian shield. More importantly, the new zircon U-Pb crystallization ages unequivocally demonstrate that crystalline basement underlying the Sanandaj–Sirjan zone, central Iran, and the Alborz Mountains is composed of continental fragments with Gondwanan affiliation, characterized by wide spread late Neoproterozoic subduction-related magmatism. The exposure of these late Neoproterozoic–Early Cambrian basement rocks in the Iranian regions north of the Zagros is structurally controlled and linked to both large-scale crustal extension and exhumation during Mesozoic and Tertiary time as well as Tertiary collisional tectonics associated with the closure of Neotethys.  相似文献   

Simultaneous thin section and phytolith observations of finely stratified deposits from Neolithic Çatalhöyük,Turkey: implications for paleoeconomy and Early Holocene paleoenvironment     

Lisa‐Marie Shillito 《第四纪科学杂志》2011,26(6):576-588

Simultaneous thin section and phytolith observations of finely stratified anthropogenic deposits from the Neolithic settlement of Çatalhöyük, Turkey, dated between 7400 and 6000 BC provide evidence for both the depositional context and phytolith assemblage of these deposits. Although extracted phytoliths provide a general picture of vegetation that supports existing evidence of a local wet marshland environment, comparisons with observations of phytoliths in situ indicate a diverse range of microcontexts, as well as depositional and post‐depositional processes that influence phytolith size. This has implications for studies that use conjoined phytolith size as a proxy for water availability and early agricultural practices. Observations indicate a significant background noise of phytoliths and micro‐charcoal in the deposits, linked to the frequent use of fire, which has implications for interpreting assemblages where phytolith counts are low, such as from floors of buildings. This study confirms the usefulness of phytoliths in providing information on human plant use and environment where the taphonomy of the deposits is clear, and provides new evidence for wet farming of at least some of the wheat found at the site. It also suggests there needs to be greater consideration of phytolith taphonomy, which can be provided to an extent by combining phytolith analysis with thin section micromorphology. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

The Late Pleistocene clastic deposits in the Romito Cave,southern Italy: a proxy record of environmental changes and human presence     

Massimiliano Ghinassi  Andrè C. Colonese  Zelia Di Giuseppe  Lisa Govoni  Domenico Lo Vetro  Giulia Malavasi  Fabio Martini  Silvia Ricciardi  Benedetto Sala 《第四纪科学杂志》2009,24(4):383-398

Clastic sediments deposited in caves and rock shelters bear peculiar sedimentological characteristics and have seldom been considered as a high‐resolution proxy record of climatic or environmental changes. The Romito Cave has its entrance at 275 m above sea level, about 25 km from the Tyrrhenian coast of Calabria, southern Italy. New archaeological excavation performed since 2000 has revealed a sedimentary succession spanning the record of Gravettian to Late Epigravettian cultures (Late Pleistocene). The present study focuses on the lower part (2.5 m thick) of the succession, where three main unconformity‐bounded stratigraphic units have been recognised (labelled RM1–3). Each unit consists of water‐lain deposits indicating high‐ to low‐competence flow, capped with anthropogenic deposits. The gradual deactivation and reactivation of the water drainage between 23 475 ± 190 and 16 250 ± 500 cal. a BP is correlated with regional precipitation changes due to the onset of dry climatic conditions of the Last Glacial Maximum. However, the deactivation of cave drainage after the deposition of unit RM3, around 15 400 ± 500 cal. a BP, deviates from the regional hydrological trend of progressively increasing water discharges and is attributed to the drainage cut‐off by probable cave wall collapses. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Investigations into the relationship between changes in internal moisture regimes and rock surface deterioration in cavernous sandstone features          下载免费PDF全文

Lisa Mol 《地球表面变化过程与地形》2014,39(7):914-927

Cavernous features commonly develop in sandstone, but their development over time remains enigmatic. It has been suggested that moisture movements within the rock mass play a key role in the location, development and dynamics of cavernous features. In this research the role of internal moisture movement is tested through monitoring moisture and surface deterioration dynamics in April 2008 and April 2009 within two large cavernous features (mega‐tafoni) in the Golden Gate Highlands National Park, South Africa (GGHNP). Data are presented from surveys of internal moisture (using electrical resistivity tomography, ERT), surface moisture (using a Protimeter) and deterioration (using surface hardness as recorded with an Equotip as a proxy for surface deterioration) across five 2.45 m long transects. In addition a high resolution temperature record is presented to assess the influence of micro‐climates within the caverns. The results indicate consistency in the gross spatial pattern of moisture flow within the rock mass over a one year period, but significant changes in mean moisture contents and in the fine detail of moisture patterning. Some noticeably weakened areas had developed within the central parts of the cavernous features, often linked to wetter subsurface conditions, supporting the theory that ‘core softening’ is a main driver of cavernous feature formation. However, in some areas surface hardening is also found to be associated with wetter subsurface conditions, supporting the theory that ‘case hardening’ is a main driver of cavernous feature formation. In addition, the presence of well‐established biofilms suggests an even more complex interaction between moisture, surface development and biological activity. A model is presented therefore which integrates this paradox by proposing a non‐linear relationship between moisture dynamics, facilitation of biofilm formation, and deterioration within cavernous features. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Cenozoic basin evolution beneath the southern McMurdo Ice Shelf, Antarctica     

Lisa Johnston  Gary S. Wilson  Andrew R. Gorman  Stuart A. Henrys  Huw Horgan  Roger Clark  Tim R. Naish   《Global and Planetary Change》2008,62(1-2):61-76

Fifty-two kilometres of multi-channel seismic reflection data were acquired from the southern McMurdo Ice Shelf (SMIS) during potential drill site investigations for the Antarctic Drilling (ANDRILL) program. The survey was acquired atop 110 to 220 m of floating ice and extended across ablation and accumulation zones of the ice shelf. Seismic processing was tailored to the ice shelf environment, including: datum static corrections to account for changes in the thickness and average velocity of the near-surface firn layer, and changes in the surface elevation across the survey area; residual static corrections to account for near-surface ice shelf irregularities; and two-step predictive deconvolution to suppress ice and firn layer multiples. A model for the ice shelf thickness was also incorporated in the interval velocity model during depth conversion to ensure that the ice shelf structure did not impose non-static shifts on the seismic section.The depth converted CMP stacked sections reveal several N to NE trending normal faults, that offset reflective horizons by up to 150 m within the lower part of the section and form a broad east-dipping, half-graben structure. The seafloor possesses trough and arch morphology in parallel with the half-graben structure. These features are interpreted as the southern extension of the Terror Rift. The rift succession comprises a dislocated (?)early-Miocene synrift package and a relatively undeformed (?)late-Miocene post-rift package separated by an erosional unconformity. The post-rift package infills and onlaps the rift topography, and drapes over the graben system, reaching a maximum thickness of 400 m. Throughout the post-rift phase, the basin was also influenced by Neogene volcanism, evidenced by three small volcanic features within the seismic profiles, and associated successions of inferred volcanic material. An angular unconformity within the post-rift succession is interpreted as a flexural horizon related to the load of Mount Discovery and/or Mount Morning. Up to 150 m of flexural moat fill occurs above this surface at ~ 20 km from the load centres. The post-rift succession also includes several glacio-geomorphic features, the orientation and morphology of which indicate an approximately SW to NE ice flow direction during a mid-Miocene grounding event and a SE to NW ice flow direction during Quaternary ice sheet grounding events.The thickness and lower extent of the rift succession was not able to be determined because signal-to-noise ratio and vertical resolution were low at these depths. Strata from an earlier, Paleogene, rift episode may underlie the Terror Rift succession, or it may be directly underlain by acoustic basement. A Paleogene rift episode has previously been proposed based on the occurrence of Eocene fossiliferous erratics around the margin of the SMIS and the structural setting revealed by the SMIS seismic reflection profiles is consistent with this hypothesis.  相似文献   

Environmental Factors Associated With Natural Methane Occurrence in the Appalachian Basin          下载免费PDF全文

Lisa J. Molofsky  John A. Connor  Thomas E. McHugh  Stephen D. Richardson  Casper Woroszylo  Pedro J. Alvarez 《Ground water》2016,54(5):656-668

The recent boom in shale gas development in the Marcellus Shale has increased interest in the methods to distinguish between naturally occurring methane in groundwater and stray methane associated with drilling and production operations. This study evaluates the relationship between natural methane occurrence and three principal environmental factors (groundwater redox state, water type, and topography) using two pre‐drill datasets of 132 samples from western Pennsylvania, Ohio, and West Virginia and 1417 samples from northeastern Pennsylvania. Higher natural methane concentrations in residential wells are strongly associated with reducing conditions characterized by low nitrate and low sulfate ([NO₃^?] < 0.5 mg/L; [SO₄^2?] < 2.5 mg/L). However, no significant relationship exists between methane and iron [Fe(II)], which is traditionally considered an indicator of conditions that have progressed through iron reduction. As shown in previous studies, water type is significantly correlated with natural methane concentrations, where sodium (Na) ‐rich waters exhibit significantly higher (p<0.001) natural methane concentrations than calcium (Ca)‐rich waters. For water wells exhibiting Na‐rich waters and/or low nitrate and low sulfate conditions, valley locations are associated with higher methane concentrations than upland topography. Consequently, we identify three factors (“Low NO₃^? & SO₄^2?” redox condition, Na‐rich water type, and valley location), which, in combination, offer strong predictive power regarding the natural occurrence of high methane concentrations. Samples exhibiting these three factors have a median methane concentration of 10,000 µg/L. These heuristic relationships may facilitate the design of pre‐drill monitoring programs and the subsequent evaluation of post‐drill monitoring results to help distinguish between naturally occurring methane and methane originating from anthropogenic sources or migration pathways.  相似文献