Summary of recent volcanic activity     

Rick?WundermanEmail author 《Bulletin of Volcanology》2003,65(6):458-459

  相似文献   

Smithsonian Institution''s Global Volcanism Network     

Rick Wunderman 《Bulletin of Volcanology》2001,63(5):360-361

  相似文献   

Evidence for Holocene climate variability from the sediments of a Scottish remote mountain lake     

Richard W. Battarbee  Nigel G. Cameron  Paul Golding  Stephen J. Brooks  Roy Switsur  Doug Harkness  Peter Appleby  Frank Oldfield  Roy Thompson  Don T. Monteith  Andrew McGovern 《第四纪科学杂志》2001,16(4):339-346

High resolution sampling of sediment cores covering approximately the last 4000 yr from Lochan Uaine, a small corrie loch in the Scottish Cairngorm Mountains, show quasi‐periodic cycles in organic matter (measured as percentage loss on ignition). Analysis of these cycles show correspondences between loss on ignition, δ¹³C values and chironomid head capsule abundance. We interpret the changes as reflecting changes in lake productivity and hypothesise that they are driven by climate variability. However, it is not yet clear whether the periods of relatively high organic matter production and preservation are associated with colder or with warmer conditions. Nevertheless the results indicate the value of using sediments from remote, undisturbed mountain lakes as recorders of Holocene climate variability. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Guitarrero Cave: Early man in the Andes | Edited by Thomas F. Lynch. Studies in Archaeology Series. Academic Press,New York, 1980. xviii + 328 pp., $24.00 (cloth)     

John W. Rick 《Quaternary Research》1981,16(2):259-260

  相似文献   

Lake Baikal: Some topical aspects of current research     

Roger J. Flower  David Ryves  Richard W. Battarbee  Johannes Mueller  Michael Sturm 《Journal of Paleolimnology》1999,22(2):223-224

  相似文献   

Trace-element heterogeneity in rutile linked to dislocation structures: Implications for Zr-in-rutile geothermometry     

Rick Verberne  Hugo W. van Schrojenstein Lantman  Steven M. Reddy  Matteo Alvaro  David Wallis  Denis Fougerouse  Antonio Langone  David W. Saxey  William D. A. Rickard 《Journal of Metamorphic Geology》2023,41(1):3-24

The trace-element composition of rutile is commonly used to constrain P–T–t conditions for a wide range of metamorphic systems. However, recent studies have demonstrated the redistribution of trace elements in rutile via high-diffusivity pathways and dislocation-impurity associations related to the formation and evolution of microstructures. Here, we investigate trace-element migration in low-angle boundaries formed by dislocation creep in rutile within an omphacite vein of the Lago di Cignana unit (Western Alps, Italy). Zr-in-rutile thermometry and inclusions of quartz in rutile and of coesite in omphacite constrain the conditions of rutile deformation to around the prograde boundary from high pressure to ultra-high pressure (~2.7 GPa) at temperatures of 500–565°C. Crystal-plastic deformation of a large rutile grain results in low-angle boundaries that generate a total misorientation of ~25°. Dislocations constituting one of these low-angle boundaries are enriched in common and uncommon trace elements, including Fe and Ca, providing evidence for the diffusion and trapping of trace elements along the dislocation cores. The role of dislocation microstructures as fast-diffusion pathways must be evaluated when applying high-resolution analytical procedures as compositional disturbances might lead to erroneous interpretations for Ca and Fe. In contrast, our results indicate a trapping mechanism for Zr.  相似文献   

Eolian processes,ground cover,and the archaeology of coastal dunes: A taphonomic case study from San Miguel Island,California, U.S.A.     

Torben C. Rick 《Geoarchaeology》2002,17(8):811-833

Geomorphological evidence and historical wind records indicate that eolian processes have heavily influenced San Miguel Island environments for much of the Late Quaternary. The island is almost constantly bombarded by prevailing northwesterly winds, with peak velocities exceeding 75 km/h and wind gusts reaching over 100 km/h. These strong winds played an important role in the location, formation, and preservation of the island's more than 600 archaeological sites. Excavation and surface collection at a stratified Middle and Late Holocene archaeological site on the island's north coast suggest that wind related disturbances result in significant displacement of light fish bones, produce concentrations of shellfish and heavy mammal bones, and cause significant abrasion, etching, and polishing of bones, shells, and artifacts. These data illustrate that wind not only alters surface materials but can significantly disturb subsurface deposits to a depth of at least 20 cm. Working in concert with a variety of taphonomic processes, wind can play a fundamental role in the preservation of archaeological sites and careful scrutiny during excavation and laboratory analysis is required to delineate its effects. © 2002 Wiley Periodicals, Inc.  相似文献