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Petroleum Geological Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Chronology is the record of events in the order of their time of occurrence. Geo-chronology is the science of the determination of the age of rock and related geo-events and the arrangement of them in time sequence. The geological events which a sedimentary rock has gone through can be compiled from the study of litho-logy, litho-stratigraphy, bio-stratigraphy and magneto-stratigraphy.
Offshore site investigation
Published in White David, Cassidy Mark, Offshore Geotechnical Engineering, 2017
Geochronology (e.g. Carbon 14 dating) is used to determine the age of the sample, which is particularly useful in evaluating sedimentation rates and gaps in the chronology, for example due to erosion or mass transport events.
Comparing paleo reconstructions of warm and cool season streamflow (1400–2018) for the North and South Saskatchewan River sub-basins, Western Canada
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2023
Samantha A. Kerr, Yuliya Andreichuk, David Sauchyn
Sampling and chronology preparation, as well as cross-dating the tree-ring chronologies, followed standard dendrochronological procedures (Stokes and Smiley 1968; Fritts 1976, Cook et al. 1990). A full description of the methodology used for building the tree-ring chronologies can be found in Sauchyn, Vanstone, and Perez-Valdivia 2011. A minimum of 20–30 trees and two samples/tree were obtained at each chronology location. Samples collected from both living (cores) and dead (disks) trees were sanded with progressively finer sand paper to make distinct annual (RW-), EW-, and LW- growth rings clearly visible. Within conifer species, there are two distinct layers visible within the annual ring, which are directly related to seasonal changes in light, temperature, and moisture (Fritts 1976). EW, which is produced early in the growing season when soil moisture is abundant or least sufficient, is composed of low-density light-coloured cells, while LW, which is produced later in the growing season, when growth becomes moisture and/or temperature limited, has smaller darker cells which have thicker walls (Fritts 1976). The development of these separate measurements and chronologies often provides greater sub-annual information on the influence of the regional hydroclimate (St. George 2014; Torbenson et al. 2016; Sauchyn and Ilich 2017; Howard, Stahle, and Feng 2019; Lopez et al. 2019; Torbenson 2019; Welsh, Smith, and Coulthard 2019; Coulthard et al. 2021; Stahle et al. 2020; Wise 2021; Kerr, Andreichuk, and Sauchyn 2021).
Historical impacts of mink fur farming on chironomid assemblages from shallow lakes in Nova Scotia, Canada
Published in Lake and Reservoir Management, 2022
J. Campbell, N. Libera, J. P. Smol, J. Kurek
Core chronology was established using standard 210Pb dating methods (Schelske et al. 1994, Appleby 2001). Freeze-dried sediments were placed into plastic tubes that were sealed with a silicone septum and epoxy and left for 2 weeks to allow for secular equilibrium. The Constant Rate of Supply (CRS) model (Appleby and Oldfield 1978) was used to establish sediment age with ±1 standard error based on measured decays of 210Pb, 214Pb, and 137Cs in a well-type germanium crystal detector. 214Pb was used as a proxy for supported 210Pb and where appropriate, 137Cs was used as an independent marker for 1963, which corresponds to the banning of nuclear weapons testing (Appleby 2001).