δ13C Measurements from the Irish Oak Chronology

Measurements of the stable isotope ratio 13C/12C, relative to PDB, were made for fractionation correction purposes on all oak samples used in the Irish oak 14C calibration curve. Stable isotope data have not been published previously. We have collated the stable isotope data from the calibration work, carried out some further measurements to investigate anomalies in the original results, and generated tables of data that include site and tree information pertaining to both stable isotopes and source material for 14C calibration measurements. The data suggest that land-grown trees tend to be isotopically lighter than bog-grown wood, and that the Irish trees used in the calibration exercise tend to be isotopically heavier than those from Scotland and England. Preliminary analysis of the data is given.

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Stable isotopes and predation marks shed new light on ammonoid habitat depth preferences

Scientific Reports ◽

10.1038/s41598-021-02236-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Marcin Machalski ◽

Krzysztof Owocki ◽

Zofia Dubicka ◽

Oksana Malchyk ◽

Weronika Wierny

Keyword(s):

Stable Isotopes ◽

Stable Isotope ◽

Late Cretaceous ◽

Late Paleozoic ◽

Planktic Foraminifera ◽

Habitat Depth ◽

Local Populations ◽

Isotope Data ◽

Geochemical Studies ◽

Stable Isotope Data

AbstractAmmonoids are extinct cephalopods with external shells which predominated in many late Paleozoic and Mesozoic marine ecosystems. Stable isotope data from ammonoid shells constitute primary tools for understanding their palaeohabitats. However, in most sedimentary successions globally the aragonitic shells of ammonoids are dissolved during fossilisation process and therefore not available for geochemical studies. We overcome this taphonomic bias by analysing the better preservable calcitic elements of the ammonoid jaws (aptychi). We study moulds and aptychi of two successive members, temporal subspecies in our interpretation, of a scaphitid evolutionary lineage from a Late Cretaceous chalk succession in Poland. In order to reconstruct their habitat depth preferences, we apply the powerful combination of stable isotope data from aptychi and co-occurring benthic and planktic foraminifera with an analysis of predation marks preserved on scaphitid specimens. On this basis we conclude that the populations of the older subspecies led a nektic, and those of the younger subspecies, a nektobenthic lifestyle. The shift in habitat depth preferences took place probably as a response of local populations to the shallowing of the sea. Previous studies largely assumed stable depth preferences for ammonoid species, genera and even higher clades. Our study casts doubts over such generalizations by pointing out that ammonoids could have been more flexible in their depth-related behaviour than anticipated.

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Feasibility of Species Origin Traceability by Hydrogen Stable Isotopes: Sample Case of Lymantria dispar L. (Lepidoptera: Erebidae)

Forests ◽

10.3390/f11111209 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1209

Author(s):

Zeshi Qin ◽

Juan Shi

Keyword(s):

Stable Isotopes ◽

Stable Isotope ◽

Lymantria Dispar ◽

Isotope Ratio ◽

Sampling Site ◽

Stable Isotope Ratio ◽

Grid Data ◽

Fast Tracking ◽

Thermo Fisher Scientific ◽

Fisher Scientific

Lymantria dispar L. (Lepidoptera: Erebidae) is an international quarantine pest with many hosts, widely distributed in Asia, Europe, and America. L. dispar is distributed mainly in the Eastern Monsoon Region of China. Currently, the most effective means of prevention and control of this pest are timely monitoring and early warning. However, their implementation is usually hampered by the lack of feasible methods and tools for fast tracking and traceability. Stable isotope technology can be used for material traceability, but in China, it is rarely employed for insect traceability. Therefore, using L. dispar as an example, we conducted a case study to explore the feasibility of using hydrogen stable isotopes for pest-source traceability. The grid data of hydrogen stable isotopes of global precipitation were downloaded from the Online Isotopes in Precipitation Calculator (OIPC; Bowen and Revenaugh, 2003, Bowen, 2017), and then, a zoning map of hydrogen stable isotopes of precipitation in mainland China was constructed using ArcGIS 10.4.1 (Esri, Redlands, CA, USA). The wings of 284 L. dispar adults captured in five regions in China were selected as experimental samples. A Finnigan Delta V Advantage Isotope Ratio Mass Spectrometer (Thermo Fisher Scientific, Inc., Waltham, Massachusetts, U.S.) and a Flash 2000 HT Elemental Analyzer (Thermo Fisher Scientific, Inc., Waltham, Massachusetts, U.S.) were used to measure the hydrogen stable isotope (δ2H) value of the samples. Then, using the recorded local precipitation hydrogen stable isotope of the sampling site, we performed a data simulation using R software (v.3.2.1; R Development Core Team, Vienna, Austria). A linear regression equation was next established: y = 1.186x − 13.247, where x represents the hydrogen stable isotope ratio of precipitation and y denotes the hydrogen stable isotope ratio of L. dispar. The t-test, F-test, and R2 test results confirmed the high significance and matching with the simulation data used in the model. To further verify the accuracy of the model, L. dispar samples from Chengdu in Sichuan Province were collected for model back-testing. The verification results also evidenced that the actual source of the L. dispar sample can be obtained based on the method applied and the model developed in this paper.

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Calculation and Interpretation of Inter-laboratory Variation in Isotope Delta (δ) Values Using Real Interpretative Differences

Forensic Anthropology ◽

10.5744/fa.2020.0050 ◽

2021 ◽

Author(s):

Lesley Chesson ◽

Thuan Chau ◽

Amelia Edwards ◽

Gregory Berg

Keyword(s):

Stable Isotope ◽

Isotope Ratio ◽

Careful Consideration ◽

Stable Isotope Ratio ◽

Bone Collagen ◽

Ratio Analysis ◽

Court System ◽

Isotope Data ◽

Isotope Ratio Analysis ◽

Stable Isotope Ratio Analysis

Building on applications in anthropology, the use of stable isotope ratio analysis of human bone collagen to investigate an individual’s life history is becoming more commonplace in the forensic science community. Careful consideration of the resultant isotope delta (δ) values, particularly in regard to their accuracy and reliability, is paramount when introducing isotope data into the U.S. court system. In this study, we use a simple framework to calculate real interpretative difference (RID) values for collagen (“col”) and assess isotope data comparability for sample analysis (RIDanalysis) as well as sample preparation/analysis combined (RIDcombined). The RIDcombined values of 0.59‰ for δ13Ccol and 0.91‰ for δ15Ncol are similar to more complex, published calculations of inter-laboratory variability in the stable isotope analysis of skeletal remains, but they are easier to calculate and intuitively elegant. The RIDcombined as well as RIDanalysis values presented here allow users to examine multiple sources of inter-laboratory isotopic variation (preparation, analysis, and both together) in a two-step process whereby a RID value is constructed and then tested. Implementation of this RID approach will provide surety for the legal and research communities in forensic applications of stable isotope ratio analysis.

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