OSL investigations at Hardisty, Alberta, Canada

This report is concerned with optically stimulated luminescence (OSL) dating investigations of sediments associated with, and enclosing artefacts of First Nations historic significance in the Battle River Valley area, near Hardisty, east central Alberta. The OSL ages reported here provide chronological control to the archaeological investigations at this site, led by Rob Wondrasek, which have identified thousands of historical artefacts, including projectile points and lithic fragments indicative of occupation. The investigations were commissioned by Enbridge, ahead of the construction of the Edmonton-Hardisty Pipeline, and form one part of a historic resources impact assessment study, to characterise the archaeological site, and evaluate/mitigate the impact of the pipeline related excavations. This report describes the background to the investigation, sampling, and luminescence analysis undertaken to generate sediment chronologies for the Hardisty sediment stratigraphies. Ken Munyikwa visited the archaeological investigations at Hardisty in June 2014 to sample key stratigraphic units within the sediment stratigraphies for OSL dating. Samples were collected from two profiles: from strata encompassing the artefact-bearing horizon, and from strata immediately beneath and overlying this horizon, thus providing terminus post quem (TPQ) and terminus ante quem (TAQ) on the age of this unit. Samples were submitted to the luminescence laboratories at SUERC for dating in August 2014. All samples were subjected to laboratory preparation of sand-sized quartz, and purity checked by scanning electron microscopy. Dose rates for the bulk sediment were evaluated using analyses of the uranium, thorium and potassium concentrations obtained by high resolution gamma spectrometry coupled with beta dose rate measurement using thick source beta counting. Equivalent doses were determined by OSL from 64 aliquots of quartz per sample using the quartz single-aliquot-regenerative (SAR) procedure. The material exhibited good OSL sensitivity and produced acceptable SAR internal quality control performance. Dose distributions from the aliquots were examined using radial plotting methods. All samples revealed some heterogeneity in their equivalent dose distribution, reflecting variable bleaching at deposition and indicating that each sample enclosed mixed-age materials. Age estimates were based on the weighted mean estimate of the stored dose, which weights the stored dose estimate towards the lowest population of equivalent doses, potentially representing the better bleached (at deposition) component. The quartz OSL ages reported herein for the sand sequences at Hardisty-1 and Hardisty-2, have provided the first means to assess the temporal distribution of artefacts within the Hardisty profiles, and furthermore provide TPQ and TAQ for the inferred occupational phases. The sediment chronologies established for each profile are internally coherent, spanning at HD-01 from 7.8 ± 0.7 ka (SUTL2692) to 11.7 ± 0.5 ka (SUTL2694), and at HD-02 from 4.5 ± 0.2 ka (SUTL2695) to 8.7 ± 0.5 ka (SUTL2697; Table 4-1). TPQ for the occupation of the Hardisty site is provided by SUTL2697 at 8.7 ± 0.5 ka. TAQ for the occupation of the Hardisty site is provided by SUTL2695 at 4.5 ± 0.2 ka

Luminescence investigations at Quendale (Broo Peninsula, Shetland)

This report is concerned with optically stimulated luminescence (OSL) investigations of sediment samples collected from ongoing University of Southern Maine archaeological excavations at the Links of Quendale, southern Shetland, investigating the early-modern township of Broo. 11 sediment samples were submitted to the luminescence laboratory at SUERC for OSL dating by Ian Simpson. This report summaries the protocols, and laboratory analysis, employed in quartz single aliquot regenerative (SAR) OSL dating, as used to construct an OSL chronology for wind-blown sands in proximity to the Broo excavations, in association with archaeological structures (5 samples), and for sands in the coastal and inland dune systems (6 samples). The chronology established for the inland sands, in contexts associated with the Broo 2 building and enclosure, spans from AD1540 ± 40 (SUTL2441) through to AD1810 ± 25 (SUTL2519), encompassing the archaeological period of interest. The dates obtained for sands within the enclosed and unenclosed areas to the immediate east and southwest of the excavated Broo site, are AD1760 ± 30 - AD1760 ± 25, and AD1810 ± 25 (SUTL2517-2518 and 2519, respectively), are consistent with the expectation that the clean sands which infill these structures, post-date the period in which the Broo township was abandoned. The coastal sand accumulations, as so far dated, yielded luminescence ages of 2380 ± 230 BC (SUTL2526), 1510 ± 270 BC (SUTL2527), AD 1030 ± 80 (SUTL2528), AD 1690 ± 50 (SUTL2529), AD 1720 ± 20 (SUTL2530) and a mixed-age sample with youngest component at AD 1955 ± 15 (SUTL2531), implying periods of sand mobilisation, synchronous with sand deposition in Orkney and northern Scotland, in the late Neolithic, the Early Bronze Age, the Norse period, the early-modern, and modern periods. This work suggests that the present-day physio-geographical setting of the Quendale Links, comprised of the coastal sand barrier, and the inland dune fields, is a product of a prolonged history of sand mobilisation, erosion and deposition from the Neolithic to the present day. Furthermore, the emerging temporal framework, coupled with the spatial distribution of dune forms across the Links, raises questions as to whether Little Ice Age storms were responsible for deposition, or erosive destruction of older dune-forms, and the re-mobilisation of this sediment. To test these ideas, profiling methods, both field- and laboratory- based, could be employed to obtain a more complete temporal and spatial characterisation of the dune systems and excavated sequences. Further OSL sampling and dating would be needed to define the vertical and lateral chronostratigraphies of the environmental features in the landscape and their relationships to archaeological structures

Geochronologies from the Kathmandu Valley UNESCO World Heritage Site: Optically Stimulated Luminescence measurement of monument foundation sediments and radiocarbon measurement of timbers

Nepal was struck by two major earthquakes on the 25th April and the 12th May 2015, which devastated large areas of the county, with substantial loss of life and livelihoods, and destroying both rural and urban infrastructure and property. The earthquakes and associated aftershocks damaged and destroyed much of Nepal’s unique cultural heritage, including monuments within the Kathmandu Valley’s UNESCO World Heritage Site of Universal Outstanding Value. These damaged monuments are currently subject to a major program of consultation, reconstruction and conservation. As part of this, geoarchaeological investigations are underway on the foundation sediments of the collapsed monuments within the damaged Durbar Squares of Hanuman Dhoka and Bhaktapur and the temple complex of Pashupati. This report summaries: a) the OSL investigations on foundation sediments to the Changu Narayan and Vatsala Temples (Bhaktapur) and Jaisideval, Kathamandap, Pashupati and Trailokya Mohan Temples (Kathmandu; Table 1).; b) the radiocarbon measurements from timbers salvanged from the Kasthsmandap monument

OSL Characterisation of Two Fluvial Sequences of the River Usmacinta in its Middle Catchment (SE Mexico)

The report summarizes luminescence profiling, initially using a SUERC PPSL system in Mexico, and laboratory analysis at SUERC, used to characterise the stratigraphy and interpret sedimentary processes in terrace deposits of the Usumacinta River, SE Mexico. This was then followed, by quantitative quartz OSL SAR dating of five sediment samples, aimed at defining the chronologicalframework of two sedimentary sequences, USU13-1 and USU13-2. In the wider region, the middle catchment of the Usumacinta River, contains numerous archaeological sites dating to the Maya Classic Period, including Bonampak, Yaxchilan and Piedras Negras. The broader aim of the investigation is to assess whether the two fluvial sequences contain a proxy record of environmental change through the archaeological period of interest. Initial luminescence profiling revealed that the stratigraphy in each profile was complex, reflecting multiple cycles of deposition, with signal maxima, followed by tails to lower intensities, possibly indicating deposition during extreme flood events, interleaved with periods of slower sedimentation, and potentially better luminescence resetting. Laboratory profiling reproduced the apparent maxima/trends in the field profiling dataset, confirming that both sections record complex depositional histories. Furthermore, the variations in stored dose estimates, and luminescence sensitivities with depth, confirm that the sections do not record simple age-depth progressions. Quantitative quartz OSL SAR dating was undertaken on five sediment samples. Given the information obtained from the field- and laboratory-profiles it is not surprising that the equivalent dose distributions for each sample showed considerable scatter, particularly so for the second section, USU13-2. Nevertheless, throughstatistical analysis, individual quartz OSL SAR ages were obtained for each sample. Individual dates fall into the Mayan Post-Classical Period to early modern Period, with statistical combinations pointing to a late 15th century accumulation of USU13-1, and the 18th century accumulation of the sediment within USU13-2. Interestingly, the three samples from section USU13-2, all show some aliquots which tail to higher equivalent doses; furthermore, in each sample, the mean value determined for this component is similar, suggesting that the sediment sampled in USU13-2, may be sourced from a 15th century or older accumulation upstream

Tectonic and sedimentary response to oblique and incipient continental - continental collision the easternmost Mediterranean (Cyprus)

The main objective of this work was to understand fundamental processes related to incipient continental collision through studying the tectonostratigraphic evolution of Cyprus, in its Easternmost Mediterranean context. This was achieved by compiling structural, sedimentological and stratigraphic evidence from Late Cenozoic to Recent sequences, and by applying palaeomagnetic and luminescence methods of dating. In particular, the basin-fill of the Neogene basins provides a temporal and palaeogeographic control to interpret syn-depositional and post-depositional structural assemblages. Four neotectonic deformation phases are recognised. The Polis and Pissouri Basins originated as Tortonian depocentres in response to syn-depositional W-E/WSW-ENE D1 extension. The Maroni Basin originated as a Tortonian depocentre in response to syn-depositional NW-SE D1 extension. The difference in extension direction between west and south-central Cyprus is attributed to the curvature of the Cyprus Arc. The Middle - Late Pliocene D2 extensional/transtensional phase re-orientated the Neogene basins and resulted in syn-depositional NW-SE extension. A kinematic change occurred at ~3 Ma, attributed to the collision of the Eratosthenes Seamount with an active trench, the ‘Cyprus Arc’. Early Pleistocene to Recent D3a transpression generated strike-slip faulting along E-W trends, conjugate left-lateral NNE-SSW-trending and right-lateral NNW-SSE-trending strike-slip faults and reactivated Tortonian D1 NW-SE and NE-SW structures. Middle Pleistocene to Recent D3b compression produced intense NE-SW contractional deformation orientated along NW-SE trends. Optically stimulated luminescence (OSL) dating was used as a tool to constrain the D3a/D3b events, by generating a chronology for their associated sediments. D3 transtensional lineaments originated in the early Pleistocene (174.1 ± 20.9 ka < D3a < 76.6 ± 16.43 ka), and are still active today (Cape Kiti: 38.1 ± 13.2 ka < D3a < 12.1 ± 0.1 ka). D3 compressional lineaments originated in the middle Pleistocene, and were still actively growing at 76.8 ± 31.6 ka. To constrain the timing of regional uplift in south and central Cyprus, a magnetostratigraphy was generated for the Plio-Pleistocene units of the Pissouri and Mesaoria Basins. The results indicate that rapid uplift began in the latest Pliocene (c. 2.14 – 1.95 Ma), coincident with the large-scale progradation of Gilbert-type fan deltas into the Pissouri Basin, and the incursion of large fluvial networks into the Mesaoria Basin. In light of the new evidence, three alternative models for the Early Cenozoic to Recent tectonostratigraphic evolution of Cyprus are considered: model 1, subduction/incipient collision; model 2, advanced collision; and model 3, transpression. Some difficulties exist in detail, with all three models. However, at present the working hypothesis is as follows: areas to the east of Cyprus (Syria, S Turkey) were in a collisional setting from Mid-Miocene time onwards. Cyprus remained in an oceanic embayment (Levant Sea) further west and subduction continued during Miocene time. Compressional processes may have been active at depth during this time. Southward extension (trench roll-back) was taking place at a high structural level in S Cyprus, as with many other convergent margin settings (e.g. SW Peloponnese; Aleutians; Sunda arc). Subsequently, the collision of the Eratosthenes Seamount with the Cyprus Arc obstructed subduction and initiated rapid uplift of the Troodos Massif. The initial manifestation of this kinematic change was the generation of E-W-trending strike-slip faults and the development of conjugate left-lateral NNE-SSW-trending and right-lateral NNW-SSE-trending strike-slip faults. Transpression resulted in the reactivation of D1/D2 E-W, NE-SW and NW-SE structures. Subsequent deformation is documented in a compressional lineament in SW Cyprus. In addition, the over-riding plate in southwest Cyprus still appears to be undergoing gravity spreading outwards from the developing collision zone

Cancer event rate and mortality with thienopyridines: a systematic review and meta-analysis

Introduction Thienopyridines are a class of antiplatelet drugs widely used in cardiovascular disease prevention and treatment. A recent concern has come to light regarding the safety of thienopyridines because of the possible risk of malignancy. We therefore performed a systematic review and meta-analysis to evaluate the association between thienopyridine exposure and malignancy. Methods We searched the MEDLINE and EMBASE databases in March 2016 for studies that evaluated incident cancer and cancer mortality with and without exposure to thienopyridines. Relevant studies were identified, and data were extracted and analysed using random-effects meta-analysis. Results A total of nine studies (six randomised controlled trials and three cohort studies) that included 282,084 participants were included. The cancer event rate with clopidogrel and prasugrel was 3.25% and 1.58% respectively. When compared with standard aspirin or placebo, thienopyridines are not significantly associated with cancer mortality and event rate (odds ratio [OR] 1.12, 95% confidence interval [CI] 0.80–1.56, n = 3; and OR 0.92, 95% CI 0.52–1.64, n = 2, respectively. Further analyses examining clopidogrel showed no significant association with cancer event rate or malignancy-related death. When comparing prasugrel with clopidogrel, no significant association was noted for cancer event rate (OR 1.10, 95% CI 0.89–1.37, n = 2]. Subanalyses according to cancer location showed that thienopyridines are not significantly associated with malignancy mortality and/or incidence. Conclusions Our results suggest that there is currently insufficient evidence to suggest that thienopyridine exposure is associated with an increased risk of cancer event rate or mortality

Functional Imaging of Human Vestibular Cortex Activity Elicited by Skull Tap and Auditory Tone Burst

The current study characterizes brain activation in response to two modes of vestibular stimulation: skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either the vestibulo-spinal reflex (saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)), or the ocular muscle response (utricle-mediated ocular VEMP (oVEMP)). Some researchers have reported that air-conducted skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for the subjects. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of cortical activity. Both forms of stimulation target the otolith response, which provides a measurement of vestibular function independent from semicircular canals. This is of high importance for studying otolith-specific deficits, including gait and balance problems that astronauts experience upon returning to earth. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that skull taps elicit similar patterns of cortical activity as the auditory tone bursts, and previous vestibular imaging studies. Subjects wore bilateral MR compatible skull tappers and headphones inside the 3T GE scanner, while lying in the supine position, with eyes closed. Subjects received both forms of the stimulation in a counterbalanced fashion. Pneumatically powered skull tappers were placed bilaterally on the cheekbones. The vibration of the cheekbone was transmitted to the vestibular system, resulting in the vestibular cortical response. Auditory tone bursts were also delivered for comparison. To validate our stimulation method, we measured the ocular VEMP outside of the scanner. This measurement showed that both skull tap and auditory tone burst elicited vestibular evoked myogenic potentials, indicated by eye muscle responses. We further assessed subjects' postural control and its correlation with vestibular cortical activity. Our results provide the first evidence of using skull taps to elicit vestibular activity inside the MRI scanner. By conducting conjunction analyses we showed that skull taps elicit the same activation pattern as auditory tone bursts (superior temporal gyrus), and both modes of stimulation activate previously identified vestibular cortical regions. Additionally, we found that skull taps elicit more robust vestibular activity compared to auditory tone bursts, with less reported aversive effects. This further supports that the skull tap could replace auditory tone burst stimulation in clinical interventions and basic science research. Moreover, we observed that greater vestibular activation is associated with better balance control. We showed that not only the quality of balance (indicated by the amount of body sway) but also the ability to maintain balance for a longer time (indicated by the balance time) was associated with individuals' vestibular cortical excitability. Our findings support an association between vestibular cortical activity and individual differences in balance. In sum, we found that the skull tap stimulation results in activation of canonical vestibular cortex, suggesting an equally valid, but more tolerable stimulation method compared to auditory tone bursts. This is of high importance in longitudinal vestibular assessments, in which minimizing aversive effects may contribute to higher protocol adherence

Urban gardens in Antiquity : the case of Gerasa/Jerash in Jordan

Funding: the Carlsberg Foundation, the Danish National Research Foundation (grant 119), the Deutsche Forschungsgemeinschaft, the Deutscher Palästina-Verein, the Danish EliteForsk Award and H. P. Hjerl Hansens mindefondet for Dansk Palæstinaforskning. Financial support for the OSL analyses was provided by the Scottish Alliance for Geoscience, Environment and Society (SAGES).In the Eastern Mediterranean, where some of the earliest known urban cities are located, relatively little is known about urban soils in archaeological contexts. Red Mediterranean Soil (RMS) is a hallmark of the Mediterranean region while the impact of long-term urbanization on RMS material is understudied. In this article we present evidence of RMS from the longue durée cityscape of Jerash, Jordan, to determine how humans have used, modified and impacted RMS material in an urban context. Thin-sections were made of twelve RMS samples, and micromorphological studies on several in-situ but disturbed soils adjacent to bedrock were conducted, spanning the initial surface soil disturbances in the Hellenistic and Roman period occupation, as well as transported RMS material spanning the Roman through Umayyad periods (until the earthquake of 749 CE). We compared the on-site inner-urban red soils to natural RMS in the area and found that some characteristics reflect their origin in the Pleistocene soils, while other traits reflect human impact related to urban activities. The majority of the on-site samples contained evidence comparable to modern centers, including changes of structure, texture, inclusions, as well as high levels of contamination of heavy metals and phosphorus (P), which combined are strong signs of urban activity. Evidence including textural pedofeatures, fragmented peds, mixed fabrics, sorting of silt-sized material likely reflect the use of RMS in urban gardens and cultivation. Black carbon inclusions within the fabric contain evidence for burning of organic matter in connection with various anthropogenic activities, likely re-dispersed via aeolian and water erosion processes. Heavy metal enrichments, which are associated with production and artisanal activities, may also have been disseminated by both aeolian and surface water processes, possibly in conjunction with irrigation undertaken with polluted water. Contrasting soil fabrics and inclusion features observed in thin section together with elemental analayses characterizes the nature of urban cultivation in its environmental context at Jerash, where city life was maintained for over 800 years. With cultivated soils in urban areas increasingly evidenced in archaeological stratigraphies from different regions of the world, our approach offers new insight into the vital contributions that these soils and their management has made to the food security, resilience and longevity of early city life.Publisher PDFPeer reviewe

Luminescence dating of soils and sediments from Jerash, Jordan

The urban site of Jerash, Jordan is recognised as one of the great cities of the classical Middle East and has been the subject of ongoing systematic archaeological investigations since the 1920s. Its significance lies in its location on limestone geology in one of the more fertile areas of the Ajlun Highlands in northern Jordan with a good water supply, a number of springs and its central position in regional trade routes. The hinterland context of the city is yet to be considered and is a significant omission given the importance of water and its management together with the agricultural systems dependent on water in supporting urban development. Landscape chronologies are vital to the establishment of city and hinterland relationships and in this working papers we assess the value and significance of optically stimulated luminescence (OSL) measurement in this endeavour. Our findings so far suggest a measurement cluster range of ca. 480 BC – 250 BC in landscapes underlying the city and a dominant trend of sediments infilling the adjacent Wadi Suf between 640 ± 240 AD and 1400 ± 60 AD reflecting land management changes in a soil environment sensitive to degradation

Assessing the potential of syn-rift sediments for geochronological dating and its implications for the development of Makanjira-Shire basin in south Malawi Rift

The Upper Shire River basin, located within the zone of progressive interaction and linkage between the southern Malawi Rift and Shire Rift Zone, East Africa, presents an early-stage rift setting where rapid denudation processes take place and have profound influence on the geomorphological evolution of the region. The basin is key to the understanding of mechanisms involved in propagation and growthin young rifts. Although the tectonics in the region are well studied, lack of age constraints due to well-dated strata poses challenges in the understanding of the timing and mechanisms of rift evolution in this section of the south Malawi Rift. We used syn-rift sediments deposited from the rift shoulders to test the applicability of OSL and radiocarbon dating techniques in a poorly dated data-constrained region of the Malawi Rift. Our results suggest that proper sampling strategy is paramount in using the OSL technique for dating in areas of high dosage such as the one under consideration. However, the technique offers potential for use in these areas. Furthermore, we conclude from these findings that the evolution of the Upper Shire basin was triggered by tectonic movements along the Makongwa scrap that were responsible for redirecting the Likwenu River into the in the Zomba Graben through the Upper Shire at least during the Upper Pleistocene.Publisher PDFPeer reviewe