title: Selection and treatment of data for radiocarbon calibration: An update to the International Calibration (IntCal) criteria

authors: Reimer, Paula J.

abstract: High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14C/12C in these archives, including a discussion of the various methods used to derive an independent absolute timescale and uncertainty. The types of data required for the current IntCal database and calibration curve model are tabulated with examples.

text: Selection and treatment of data for radiocarbon calibration: An update to the International Calibration (IntCal) criteria High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14C/12C in these archives, including a discussion of the various methods used to derive an independent absolute timescale and uncertainty. The types of data required for the current IntCal database and calibration curve model are tabulated with examples.

year: 2013

title: The genomic footprint of coastal earthquake uplift

authors: Parvizi, Elahe

subjects: Science & Technology

abstract: Theory suggests that catastrophic earth-history events can drive rapid biological evolution, but empirical evidence for such processes is scarce. Destructive geological events such as earthquakes can represent large-scale natural experiments for inferring such evolutionary processes. We capitalized on a major prehistoric (800 yr BP) geological uplift event affecting a southern New Zealand coastline to test for the lasting genomic impacts of disturbance. Genome-wide analyses of three co-distributed keystone kelp taxa revealed that post-earthquake recolonization drove the evolution of novel, large-scale intertidal spatial genetic ‘sectors’ which are tightly linked to geological fault boundaries. Demographic simulations confirmed that, following widespread extirpation, parallel expansions into newly vacant habitats rapidly restructured genome-wide diversity. Interspecific differences in recolonization mode and tempo reflect differing ecological constraints relating to habitat choice and dispersal capacity among taxa. This study highlights the rapid and enduring evolutionary effects of catastrophic ecosystem disturbance and reveals the key role of range expansion in reshaping spatial genetic patterns.

text: The genomic footprint of coastal earthquake uplift Theory suggests that catastrophic earth-history events can drive rapid biological evolution, but empirical evidence for such processes is scarce. Destructive geological events such as earthquakes can represent large-scale natural experiments for inferring such evolutionary processes. We capitalized on a major prehistoric (800 yr BP) geological uplift event affecting a southern New Zealand coastline to test for the lasting genomic impacts of disturbance. Genome-wide analyses of three co-distributed keystone kelp taxa revealed that post-earthquake recolonization drove the evolution of novel, large-scale intertidal spatial genetic ‘sectors’ which are tightly linked to geological fault boundaries. Demographic simulations confirmed that, following widespread extirpation, parallel expansions into newly vacant habitats rapidly restructured genome-wide diversity. Interspecific differences in recolonization mode and tempo reflect differing ecological constraints relating to habitat choice and dispersal capacity among taxa. This study highlights the rapid and enduring evolutionary effects of catastrophic ecosystem disturbance and reveals the key role of range expansion in reshaping spatial genetic patterns.

year: 2020

title: Dendroarchaeology in New Zealand: extending the range of archaeologically useful species beyond kauri (Agathis australis)

authors: Boswijk, Gretel

abstract: Accurately establishing calendar dates for Māori wooden objects would place them in a secure temporal context and enable aspects of manufacturing and use to be explored within and between sites, and across time. Dendrochronology has the potential to produce accurate and precise calendar dates for wooden artefacts but in New Zealand application of this technique to Māori cultural material is limited as there is almost no overlap between wood species found in archaeological contexts and tree-species with proven suitability for tree-ring dating. Here we identify five archaeologically-useful species – kahikatea (Dacrycarpus dacrydioides), matai (Prumnopitys taxifolia), miro (Prumnopitys ferruginea), rimu (Dacrydium cupressinum) and totara (Podocarpus totara) – and assess their potential for dendrochronology. Of these, matai, miro and totara are identified as species that should be the subject of further comprehensive dendrochronological investigation.

text: Dendroarchaeology in New Zealand: extending the range of archaeologically useful species beyond kauri (Agathis australis) Accurately establishing calendar dates for Māori wooden objects would place them in a secure temporal context and enable aspects of manufacturing and use to be explored within and between sites, and across time. Dendrochronology has the potential to produce accurate and precise calendar dates for wooden artefacts but in New Zealand application of this technique to Māori cultural material is limited as there is almost no overlap between wood species found in archaeological contexts and tree-species with proven suitability for tree-ring dating. Here we identify five archaeologically-useful species – kahikatea (Dacrycarpus dacrydioides), matai (Prumnopitys taxifolia), miro (Prumnopitys ferruginea), rimu (Dacrydium cupressinum) and totara (Podocarpus totara) – and assess their potential for dendrochronology. Of these, matai, miro and totara are identified as species that should be the subject of further comprehensive dendrochronological investigation.

year: 2019