scholarly journals Refinement and utilization of the marine climate proxy Arctica islandica: An ideal replication strategy for stable isotope studies and an investigation into the shell growth and hydrographic variability of Georges Bank (Northwestern Atlantic)

2018 ◽  
Author(s):  
Jared Daniel Brenzink Ballew
2000 ◽  
Vol 53 (2) ◽  
pp. 236-246 ◽  
Author(s):  
Thomas M. Marchitto ◽  
Glenn A. Jones ◽  
Glenn A. Goodfriend ◽  
Christopher R. Weidman

AbstractAnnual growth bands of mollusk shells record several types of paleoenvironmental information, including geochemical proxies for water properties and morphological characteristics of growth and mortality. Sclerochronology, the marine counterpart of dendrochronology, offers a way to link individual shells together to form long continuous records of such parameters. It also allows for precise dating of recent shells and identification of contemporaneous fossil individuals. The longevity of the ocean quahog Arctica islandica (commonly >100 yr) makes this species well suited for sclerochronology. Band width records of contemporaneous A. islandica specimens from the same region exhibit high correlations (ρ = 0.60–0.80 for spans of ≥30 bands), indicating some common environmental influences on shell growth. By adopting several strict criteria, fossil (dead-collected) shells can be linked into composite sclerochronologies. A seven-shell 154-yr chronology was constructed for Georges Bank using three live-collected and four dead-collected shells. Band width matching indicates that the dead-collected individuals died in A.D. 1950, 1971, 1978, and 1989. Sclerochronological age assignments were verified using aspartic acid racemization dating. Construction of a 1000-yr sclerochronology is judged to be feasible using the described methods.


2009 ◽  
Vol 19 (2) ◽  
pp. 297-308 ◽  
Author(s):  
A. Tessone ◽  
A. F. Zangrando ◽  
G. Barrientos ◽  
R. Goñi ◽  
H. Panarello ◽  
...  

1994 ◽  
Vol 23 (6) ◽  
pp. 357-361 ◽  
Author(s):  
Kimberly O. O'Brien ◽  
Steven A. Abrams

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1819-1826 ◽  
Author(s):  
Randy Culp ◽  
G V Ravi Prasad

Radiocarbon and stable isotope determination in foods, flavors, and beverages, for the authentication of source material and process of formation, is a well-established method of identity used in industry. New methods of provenance determination, using stable isotopes of oxygen and hydrogen, have added to the host of other isotopic methods used for characterizing natural or botanically derived products. The unambiguous determinant of a product's fossil fuel origin be it from petroleum, natural gas, or coal, is through the measurement of its 14C content. The 14C content can also be used to determine the fraction dilution of recently grown and harvested material with that derived from fossil fuel, and even confirms the vintage of agricultural products based on the well-established decrease of bomb-produced atmospheric 14C. This paper documents 14C measurements at the University of Georgia's Center for Applied Isotope Studies accelerator mass spectrometry and stable isotope laboratories, over the last 3 yr, for 10 important flavoring compounds. By establishing an accurate and current level of 14C in botanically derived products, we were able to confirm a particular source for vanilla production, the most popular consumer flavor in the marketplace. Over the years, vanilla extract has been produced less and less from vanilla beans (Vanilla planifolia), particularly those from Madagascar and the Comoros Islands, and more from other botanical precursors such as ferulic acid, clove oil, and guaiacol. We report isotopic data to support this precursor for vanilla production based on high 14C levels accumulated during the tree's life, incorporated in the tree rings and their associated stable isotope abundances.


2020 ◽  
pp. 75-88 ◽  
Author(s):  
D.W. Hopkins ◽  
R.E. Wheatley ◽  
D. Robinson

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