Application of fluorescence lifetime measurements on single petroleum-bearing fluid inclusions to demonstrate multicharge history in petroleum reservoirs

Petroleum-bearing fluid inclusions emit fluorescent light when excited with UV or visible light. The fluorescence decay time of the emission is dependent upon the wavelengths of the excitation and emission light, and the chemical composition of the petroleum oil. In general heavy oils have short lifetimes, whereas the emission from light oils is much longer lived. One can thus use plots of the fluorescence lifetime versus emission wavelength ( τ – λ plots), to show even subtle changes in the chemical composition of the entrapped oil. As a consequence, these τ – λ plots can be used for fluid inclusion research to discriminate different oil populations in situ . In particular, it is demonstrated that τ – λ plots discriminate two sets of inclusion oils in each of four North Atlantic basins [Jeanne d'Arc Basin (Newfoundland), Porcupine Basin (Ireland), Clair field West of Shetland (UK) and Kangerlussuaq Basin (East Greenland)] where multistage oil charge is inferred from other geological evidence.     

STUDY OF ROMAN ANCHOR FROM THE DEAD SEA SHORE*

A wooden Roman anchor was discovered at the retreating shore of the Dead Sea, north of Ein Gedi. The anchor's wood material was coated by a thick veneer of aragonite and gypsum crusts. The wood was dated by radiocarbon to the early Roman time in the Levant. Lead isotope analyses carried out on the Pb–Fe–Cu anchor material (remains of the anchor's metal parts) yielded ratios that indicate origin of the metal in Italian ores (maybe Tuscan). For the wooden part of the anchor a local tree was used.     

Meteorological influences on the spatial and temporal variability of NO2 in Toronto and Hamilton

The spatial and temporal variability of nitrogen dioxide (NO₂) concentrations and their relationships with meteorology was evaluated in the Toronto–Hamilton urban airshed. NO₂ concentrations were highest in the early morning and late evening. Mean concentrations were highest in winter, although individual one-hour NO₂ concentrations were found to be highest in summer. Wind direction was the strongest control on hourly NO₂ concentration, and temperature and wind speed also had an effect. Our analysis of NO₂ concentration variation by wind direction showed that areas downwind of major highways, urban centres and industry were exposed to higher pollutant concentrations. Seasonal patterns of NO₂ concentration displayed significant spatial heterogeneity, in particular, in Toronto. Onshore winds sheltered coastal inhabitants from the full extent of NO₂ exposure they would otherwise experience. Seasonal variations in meteorology and emissions mean that the degree of spatial variability in NO₂ concentrations changes from season to season. This study will help to improve existing land-use regression-based NO₂ prediction models by incorporating meteorological controls on NO₂ distributions for health effect studies.