Mikrotax:Developing a Genuinely Effective Platform for Palaeontological Geoinformatics

正Planktonic microfossils have played an enormously important role in modem earth science,notably including industrial hydrocarbon exploration and academic Deep Sea Drilling,providing essential data for age models and rich suites of palaeoceanographic data.Conversely this broad application has resulted in the development of detailed knowledge of planktonic microfossils and in stimulating study of them.Over 50 years of     

Hydrological change in the central interior of British Columbia,Canada: diatom and pollen evidence of millennial-to-centennial scale change over the Holocene

Diatom-based inferences of post-glacial hydrological change from a sedimentary record from Felker Lake, British Columbia, show millennial-scale pacing of climate over the past approximately 11670 calendar years with change at ca. 8140 cal. year BP, ca. 6840 cal. year BP, ca. 5700 cal. year BP, and ca. 2230 cal. year BP. Early postglacial diatom assemblages are dominated by fragilaroid taxa, suggesting that cool and moist climate conditions and relatively high lake levels prevailed at this time. Early Holocene warming near ca. 8140 cal. year BP promoted Cyclotella bodanica var. lemanica, a fall bloomer competitive in limnological conditions associated with warmer water and stratified conditions. Short-lived peaks of Stephanodiscus parvus/minutulus between ca. 6340 cal. year BP and ca. 5860 cal. year BP indicate periodic increases in nutrient availability and prolonged mixing likely associated with long cool and moist spring seasons. The diatom-inferred depth of Felker Lake increased during the mid-Holocene to reach a record high-stand at ca. 5860 cal. year BP. Large changes in hydrological variability and terrestrial vegetation at Felker Lake occurred after ca. 2230 cal. year BP when high-amplitude centennial-scale fluctuations in diatom-inferred lake depth and salinity are observed. Change is first documented in terrestrial vegetation at this time by a shift from open Pinus parklands to a landscape that periodically supported populations of Cupressaceae. Three record low-stand high-salinity events are reconstructed between ca. 1910 cal. year BP and ca. 1800 cal. year BP, ca. 1030 cal. year BP and ca. 690 cal. year BP, and ca. 250 cal. year BP and ca. 140 cal. year BP. The low lake-level episode of ca. 1030 cal. year BP–ca. 690 cal. year BP is coeval with the Medieval Warm Period (ca. 1000 cal. year BP–ca. 600 cal. year BP), a period of intense drought in western North America. Post-glacial hydrological change at Felker Lake is coherent with regional, hemispherical, and global paleoclimate events, suggesting that millennial-and centennial-scale shifts in water availability are a persistent feature of the climate of western North America.     

Simulation of Synthetic Exploration and Geometallurgical Database of Porphyry Copper Deposits for Educational Purposes

Natural Resources Research - The access to real geometallurgical data is very limited in practice, making it difficult for practitioners, researchers and students to test methods, models and...     

Investigation of a Complex Nocturnal Flow in Owens Valley,California Using Coherent Doppler Lidar

A study of an interesting meteorological episode over the Owens Valley, California, USA during the Terrain-Induced Rotor EXperiment was conducted using a recently adapted statistical interpolation method to retrieve wind-velocity vectors from Doppler lidar data. This vector retrieval method has been adapted from radar data assimilation techniques. Results show that the method allows better preservation of local variations in the flow field than other techniques. In addition, a high resolution Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS^®) run is used to understand the large-scale flow within the valley and compared with lidar retrievals. Observations from 1030 UTC to 1230 UTC (0230 local time to 0430 local time) on March 27, 2006 are presented. Lidar observations show complex and uncharacteristic flows such as sudden bursts of westerly cross-valley wind mixing with the dominant up-valley wind. Model results from COAMPS and other in-situ instrumentation are used to corroborate and complement these observations. The optimal interpolation technique for Doppler lidar data vector retrieval appears well suited for scenarios with complex spatial variations in the flow field.     

天然和人为地震活动性的对比研究

为了充分发挥现有的区域性、地方性数字地震台站在防震减灾中的作用，中国地震局地球物理研究所与美国达拉斯南卫理大学地球科学系合作开展“中美合作延庆一怀来盆地和海城地区天然和人为地震活动性的对比研究”。该合作项目以北京西北的延庆一怀来盆地与东北辽宁的海城地区作为流动地震观测试验场，计划在现有台网的基础上，在近震源与区域性的距离上布设15套由STS—2型宽频带数字地震仪组成的流动地震台网加密观测，以改善在区域性距离上台距过长、不利于分析、解释、研究所观测到地震记录的状况。2002年秋，双方在河北怀来一带首先架设了5个宽频带数字地震台并随即投入观测。到2003年3月上旬，中方又在预定地点架设了另5个宽频带数字地震台。目前，已建成的10个宽频带数字地震台仪器运行正常，运用已获得的研究区内天然和人为地震的高质量记录，合作双方按照计划开展了相关的研究工作。     

Recovery from imposex by a population of the dogwhelk, Nucella lapillus (Gastropoda: Caenogastropoda), on the southeastern coast of England since May 2004: A 52-month study

Over a 52-month period beginning in May 2004 and concluding in August 2008, and coinciding with the period over which TBT was banned as a ship anti-foulant globally, a population of the dogwhelk, Nucella lapillus, was studied for changes in population size and structure, and reproduction. During the study period, the size of the population of N. lapillus on the Mewsbrook Groyne at Littlehampton on the southeastern coast of England grew from ∼25 individuals to >500, i.e., a 20-fold increase. Similarly, population structure normalised to reveal a maximum age of up to ∼3 years. The numbers of egg capsules produced by the N. lapillus population also grew over the study, again by a factor of 20, and the length of the breeding season increased from 7 months in 2004-2005 and 2005-2006 to 11 months in 2006-2007 and 2007-2008. Such changes were reflected in the incidence of imposex from Vas Deferens Index Stages 3 and 4 in 2003 to zero commencing in 2008 and continuing into 2009.Due to a lack of confirmatory chemical data, the changes in population size, structure and reproduction herein reported upon for N. lapillus cannot be correlated positively with changes in ambient TBT levels, but they can and are correlated with freedom from imposex. This is the first time such a dramatic recovery from imposex, following the banning of TBT, has been documented.