Reference Chronology Research Articles

Dropped in the Ocean – 87Sr/86Sr as a provenance tool for ice-rafted Arctic driftwood

Provenance and age determinations of driftwood provide insights into Holocene Arctic Ocean surface currents and sea ice dynamics, with detailed reconstructions requiring a provenance methodology with fine temporal and spatial resolution. Determination of wood geographical provenance by genus data is limited by its spatially coarse resolution, while provenance by dendrochronological crossdating is reliant on available boreal forest reference chronologies which are abundant for recent centuries but more sparse for older periods of the Holocene. We present the development of novel techniques to refine the provenance of driftwood through radiogenic isotopic analysis ( 87 Sr/ 86 Sr). The use of geochemical techniques addresses limitations of current methods and opens the possibility of defining the role of atmospheric and oceanic circulation in sea ice and climatic changes throughout the Holocene at a finer spatial resolution than currently possible. This study investigates and develops geochemical 87 Sr/ 86 Sr fingerprinting of Arctic driftwood. To this end, it analyses driftwood samples from northern Svalbard and compares this technique with provenance regions obtained through dendrochronology, and with modelled and measured global 87 Sr/ 86 Sr reference databases. We conclude that the utilisation of 87 Sr/ 86 Sr ratios to establish provenance for Arctic driftwood has some potential, but identify important limitations in the method, concerning both the signal in samples and reference values required for provenance. Increased sample populations and source samples for calibration, as well as methodological improvements that address the likely overprinting linked to driftwood transport, are recommended to build upon this work. We conclude that at present dendro-provenancing continues to be the most powerful method to study sea ice dynamics from Arctic driftwood and suggest that given the high spatial granularity of 87 Sr/ 86 Sr across the boreal forest, this technique might only be usable in combination with previously developed provenance tools and reconstructions. This study provides a first step in the use of radiogenic isotopic analysis in a multi-proxy reconstruction of Holocene driftwood incursion onto high Arctic shorelines. • Driftwood is a novel tool for insights into Holocene Arctic sea ice dynamics. • Fine spatial and temporal resolution of driftwood provenance is needed. • Geochemical 87 Sr/ 86 Sr fingerprinting of Arctic driftwood is explored in this study. • 87 Sr/ 86 Sr shows some promise, with limitations in reference data and sample signals. • We conclude that a combined approach to driftwood provenance shows the most promise.

Absolute Age Determinations of Rural Basque Furniture Using Dendrochronology: A Pilot Study of Four Granary Chests and a Wardrobe

Dendrochronological research in NW Spain is aimed at developing reference chronologies of oak (Quercus sp.), which are suitable for absolute age determinations of cultural heritage from the Basque Country. So far, the main research interest has been on rural architecture such as farmhouses and barns. In order to extend the application range of Basque dendrochronology, the current study focuses on tree-ring research of rural furniture. In close consultation with the curators of cultural centre Gordailu (Irun), four granary chests and a wardrobe were selected for this pilot study. The tree-ring patterns of these objects significantly match against the new Basque reference chronologies, yielding absolute calendar years for the studied panels. The last-formed measured ring from the oldest granary chest in this collection dates to AD 1517. The other three chests have last-formed rings dating to AD 1580, 1665 and 1829, and the wardrobe has a last-formed ring dating to AD 1439. Sapwood ring counts from living oaks in this region were used to estimate the number of sapwood rings missing on the outside of the panels. Derived absolute and terminus post quem felling dates of wood were further refined by adding the estimated drying time of the wood based on information derived from traditional carpenters in this area. All dendrochronologically established construction dates constitute a correction or refinement of the original art-historical age determinations. In addition, the previously assigned provenance of one granary chest could be corrected. These results indicate that dendrochronology is an excellent method to refine our knowledge about the age, and in some cases the exact geographical provenance, of rural movable heritage in and from the Basque region. The fact that the previously established provenance of four of the studied objects within the Basque Country could not be refined further implies that most Basque reference chronologies at present are not sufficiently specific for assessing wood provenance on an intra-regional scale. This can be solved in the future by reassembling the data underlying these chronologies into homogeneous timber groups covering smaller, ecologically more similar, geographical growth areas.

A case study on geomorphology: Tree-ring-based confirmation of the formation year of Lake Kaindy after the 1911 Kemin earthquake in Almaty (Kazakhstan)

Lake Kaindy, which is located in the Kazakhstan side of the Tien Shan Mountains is one of the most famous places in the World due to having sunken Picea schrenkiana Fisch. & C.A.Mey. trees within the Lake. The purpose of the study is to find the dead years of the sunken trees in the lake and therefore to confirm the formation time of Kaindy Lake, and if there is an effect of the 1911 Kemin earthquake on the tree-ring width of Picea schrenkiana around the lake. Eight wood pieces and two increment cores from the sunken trees were taken to find the formation time of the lake. For building a reference chronology to date these sunken woods, a total of 43 increment cores from 25 trees of Picea schrenkiana were extracted by using an increment borer 50 cm long. Four sunken trees were dated to 1912, and dating statistics which are Gleichlaufigkeit value (percentage of parallel variation), t-tests (TV, TVB, TVBP), and CDI (crossdating index) were calculated as 74%(***), 3.3(**), 7.9(***), 9.7(***) and 57, respectively, and all are significant. According to the 11-year event analysis, the ratio of decrease after the earthquake is 34% in older trees, and 20% in younger ones. One of the main reasons for long-term decreasing growth may be breaking the root tips and dying the roots with the effect of the violent vibration in the earthquake. With this dendrogeomorphological study, the formation date of Lake Kaindy was determined as 1911 and the local information was confirmed with tree-ring data. After the year of the great earthquake, a long-term dry period occurred up to the years of 1930s. Tree-ring results showed that the affected trees from the earthquake produced narrower rings during this dry period.

The dendrochronological proof of origin of oak churches located in the Czech Republic

Transcarpathian wooden churches started to dilapidate after World War I. To preserve the architectural heritage, five oak churches were transported from the region to the territory of today's Czech Republic. However, an exact date of their construction and origin of wood have not been specified and evidenced in literature. In this study, 63 samples have been collected and processed using standard dendrochronological methods. Three Baroque churches, coming from the Mukachevo district, were absolutely dated thanks to the preserved waney edge or sapwood tree rings to periods 1734–1744, 1753–1755, and 1783–1795. Two other churches, representing Gothic architecture, were transported from a more eastern part of Transcarpathian Ukraine. One of them was dated to the period after 1655 and the other could not be reliably dated using available reference chronologies. The created mean tree-ring width series representing individual churches showed strong correlations with the reference chronologies for Slovakia and northern Romania whereas correlations with the only Ukrainian chronology (Lviv region) were negligible. This could suggest low Transcarpathian tree-ring coherency and may indicate the need to create a dense network of regional tree-ring width chronologies in the regions surrounding the Carpathian Mountains.

A Driftwood‐Based Record of Arctic Sea Ice During the Last 500 Years From Northern Svalbard Reveals Sea Ice Dynamics in the Arctic Ocean and Arctic Peripheral Seas

AbstractWe present a 500‐year history of naturally felled driftwood incursion to northern Svalbard, directly reflecting regional sea ice conditions and Arctic Ocean circulation. Provenance and age determinations by dendrochronology and wood anatomy provide insights into Arctic Ocean currents and climatic conditions at a fine spatial resolution, as crossdating with reference chronologies from the circum‐Arctic boreal forests enables determination of the watershed the driftwood originated from. Sample crossdating may result in a wide range of matches across the pan‐boreal region, which may be biased toward regions covered by the reference chronologies. Our study considers alternate approaches to selecting probable origin sites, by weighting scores via reference chronology span and visualizing results through spatiotemporal density plots, as opposed to more basic ranking systems. As our samples come from naturally felled trees (not logged or both), the relative proportions of different provenances are used to infer past ocean current dominance. Our record indicates centennial‐to decadal‐scale shifts in source regions for driftwood incursion to Svalbard, aligning with Late Holocene high variability and high frequency shifts in the Transpolar Drift and Beaufort Gyre strengths and associated fluctuating climate conditions. Driftwood occurrence and provenance also track the northward ice formation shift in peripheral Arctic seas in the past century. A distinct decrease in driftwood incursion during the last 30 years matches the observed decline in pan‐Arctic sea ice extent in recent decades. Our new approach successfully employs driftwood as a proxy for Arctic Ocean surface circulation and sea ice dynamics.

Developing tree-ring chronologies from New Zealand matai (Prumnopitys taxifolia) and miro (Prumnopitys ferruginea) for archaeological dating: Progress and problems

This paper describes attempts to develop tree-ring chronologies from New Zealand matai (Prumnopitys taxifolia) and miro (Prumnopitys ferruginea). These tree species have been recovered from Māori archaeological contexts, including as objects such as canoes and palisade posts. Dendrochronology offers the potential to establish accurate and precise calendar dates for wooden objects but relies on cultural use of species that are also suitable for tree-ring analysis, and the availability of calendar-dated reference chronologies for crossdating wood of unknown age. We used archived cross-section and core samples from seven sites in central North Island, and nineteen core samples collected in 2019 from matai and miro trees at Pureora Forest Park for our analysis. Some of these samples came from long lived trees, with ring counts indicating ages up to 800 years old. We found that both matai and miro exhibit considerable variability in ring clarity and ring width. They also have ring anomalies affecting the reliability of ring-width series. Miro was very challenging, and no tree sequences were built for this species. Tree-ring sequences were built for several matai samples but no secure inter-tree matches were identified. Further analysis of matai samples is required to establish reliable tree ring patterns for inter-tree and inter-site crossmatching.

Dating of non-oak species in the United Kingdom historical buildings archive using stable oxygen isotopes

Stable oxygen isotope dendrochronology is an effective precision-dating method for fast grown, invariant (complacent) tree-rings and for trees growing in moist, temperate climatic regions where growth may not be strongly controlled by climate. The method works because trees preserve a strong common isotopic signal, from summer precipitation, and therefore do not need to be physiologically stressed to record a dating signal. This study explores the working hypothesis that whilst tree species may differ in their eco-physiology, leaf morphology and wood anatomy they will record an isotopic signal in their growth rings that is sufficiently similar to enable their precise dating against isotopic reference chronologies developed using dated oak tree rings from the same region. Modern and historical samples from six species (sweet chestnut, English elm, ash, alder, European beech and black poplar) were analysed and their oxygen isotopic variability was compared against an oak master chronology previously developed for central southern England. Whilst differences in the relative strength of the agreement between the different species and the master chronology are apparent, the potential for interspecies dating is demonstrated convincingly. The ability to date non-oak species using stable oxygen isotopes opens-up new opportunities for science-based archaeology and will improve understanding of a largely-unexplored, but significant part of the European historical buildings archive.

The Danish royal flagship gribshunden – Dendrochronology on a late medieval carvel sunk in the Baltic Sea

The Royal flagship Gribshunden carried the Danish King Hans on its way to the city of Kalmar in Sweden when the ship sank in the summer of 1495. The ship caught fire while anchored north of the Stora Ekö Island and sank to the seafloor, where it lies to this day. The wreck was rediscovered in the 1970s and is remarkably well preserved. Since 2001, scientific investigations have been performed on the wreck by various organizations. In total, 13 dendrochronological samples from different parts of the ship construction have been collected and analyzed with standard dendrochronological methods with respect to age and provenance. The results show that all dated samples could have been felled during the winter season of 1482/83, although only one sample contains sapwood and waney edge. The highest correlations are obtained from reference chronologies that originate from the River Meuse drainage area, with correlations peaking around the city of Namur in Belgium. Most likely, the ship was constructed in a shipyard close to the mouth of the River Meuse in the southern Netherlands. It seems King Hans realized the potential of the new ship type represented by Gribshunden, but his shipwrights did not have the knowledge to build such a ship in Denmark. Instead, he purchased the ship from abroad. This study highlights late medieval economic and political connections throughout northern Europe.

Dendrochronological analysis and radiocarbon dating of charcoal remains from the multi-period site of Uşaklı Höyük, Yozgat, Turkey

In the current study we use methods in dendrochronological dating, radiocarbon dating and wiggle-matching analysis to accurately date charcoal samples collected from the archaeological site of Uşaklı Höyük, Yozgat, Turkey. These data contribute to the understanding of the stratigraphical relationships in three different contexts of this multi-period mound. The examined charcoal materials were identified as cedar (Cedrus sp.) and oak (Quercus sp.). The analysis of the cedar samples resulted in establishing a floating chronology with a length of 49 rings. Further analysis of the material revealed that secure dendrochronological dating against the existing reference chronologies cannot be achieved for any of the Uşaklı Höyük samples selected for dendrochronology. This is due to the insufficient length of the developed mean chronology (49 rings), the shortness of single tree-ring sequences (max. 34 rings for cedar and 23 for oak) and the scarcity of reference chronologies that can be used for cross-dating. Therefore, we use radiocarbon tests and wiggle-matching analysis as the main dating method. Radiocarbon testing and further analysis of absolute dating of the charcoal pieces point to three different archaeological periods: the wooden post found in Room 433 of Building III is dated to the range of 1415 – 1363 BCE (2σ), confirming the assumption that it was an architectural element of the original construction of this Late Bronze Age/Hittite building. Radiocarbon dating results of charcoal pieces from the filling of Pit 330, 1008 – 905 BCE (2σ), can only be used tentatively and require cross-checking against additional samples and other organic material from the same context. The results of radiocarbon dating of charcoal samples associated with the Iron Age stone glacis built on top of Building III (763 – 486 BCE, 2σ) confirm that they are associated with the Iron Age occupation at Uşaklı Höyük.

The Suceava oak chronology: A new 804 years long tree-ring chronology bridging the gap between central and south Europe

Although the importance of centuries-long tree ring width oak chronologies in dating wood, eastern European regions are still lacking a reference chronology. To fill this geographical gap, we combined living and historical chronologies from the Moldova region, including part of Romania and the Republic of Moldova. Here we present the “Suceava oak chronology” as the first 804 years long chronology continuously covering the 1216–2019 period. Our analyses further revealed the strong teleconnection of the Suceava oak chronology with south European ones. The link between Romania and northern Turkey chronologies is of particular importance in the context of the high abundance of undated subfossil and archaeological/historical oak wood in eastern Europe and intense wood trades with central Europe in XV-XVII centuries. The availability of the Suceava oak chronology will provide a good base for precise dating and climatic reconstructions.

Latewood Ring Width Reveals CE 1734 Felling Dates for Walker House Timbers in Tupelo, Mississippi, USA

Dendroarchaeology is under-represented in the Gulf Coastal Plain region of the United States (US), and at present, only three published studies have precision dated a collection of 18th–19th-century structures. In this study, we examined the tree-ring data from pine, poplar, and oak timbers used in the Walker House in Tupelo, Mississippi. The Walker House was constructed ca. the mid-1800s with timbers that appeared to be recycled from previous structures. In total, we examined 30 samples (16 pines, 8 oaks, and 6 poplars) from the attic and crawlspace. We cross-dated latewood ring growth from the attic pine samples to the period 1541–1734 (r = 0.52, t = 8.43, p < 0.0001) using a 514-year longleaf pine (Pinus palustris Mill.) latewood reference chronology from southern Mississippi. The crawlspace oak samples produced a 57-year chronology that we dated against a white oak (Quercus alba L.) reference chronology from northeast Alabama to the period 1765–1822 (r = 0.36, t = 2.83, p < 0.01). We were unable to cross-date the six poplar samples due to a lack of poplar reference chronologies in the region. Our findings have two important implications: (1) the pine material dated to 1734 represents the oldest dendroarchaeology-confirmed dating match for construction materials in the southeastern US, and (2) cross-dating latewood growth for southeastern US pine species produced statistically significant results, whereas total ring width failed to produce significant dating results.

Bomb-produced radiocarbon age validation of Greenland halibut (Reinhardtius hippoglossoides) suggests a new maximum longevity

Bomb-produced radiocarbon (14C) was used to validate age estimates of Greenland halibut (Reinhardtius hippoglossoides) using a stained otolith cross-section method. The Δ14C in eastern Bering Sea (EBS) Greenland halibut otoliths was compared to both EBS and Gulf of Alaska (GOA) Pacific halibut (Hippoglossoides stenolepis) otolith reference chronologies to evaluate which reference chronology was most suitable, and to quantitatively estimate age determination bias. Using Bayesian analysis and a coupled-function model, the Δ14C in the Greenland halibut showed greatest similarities to the Δ14C in the GOA reference chronology. Although the model indicated under ageing, the bias was not large. Assigning an age less than the true age by more than a one year is about 73%, and less than the true age by more than 2 years is only about 25%. When considering the age at which Greenland halibut is only 7.5% of its maximum longevity (50+ years) and that the probability of underageing by 3 years being less than 5%, it is likely that between-age-reader variation will cancel out any systematic bias that exists in the age determination protocols. Prior to the use of stained cross-sections the maximum age was 38 years, now a maximum age of 53 years is supported.

Measuring tree-ring widths using the CooRecorder software application

We present a brief overview of how to measure tree-ring widths in the software application CooRecorder (Cybis Elektronik & Data AB) for tree-ring analysis complementing two video tutorials. The first tutorial covers the basics of opening files, measuring ring widths, preliminary crossdating with a reference chronology, and setting dates. The second tutorial covers setting earlywood-latewood boundaries, measuring across cracks, inserting locally absent or missing rings, manual adjustments, and metadata. The video tutorials can be found here https://www.youtube.com/watch?v=c-GNKHVUj9I and here https://www.youtube.com/watch?v=xO7Phc93xyM&t=3s. Videos have been closed-captioned in English. Video is also accessible via Mendeley Data, https://doi.org/10.17632/r3v7236kkz.1.

Radiocarbon in otoliths of tropical marine fishes: Reference Δ14C chronology for north Caribbean waters.

Reef fishes support important fisheries throughout the Caribbean, but a combination of factors in the tropics makes otolith microstructure difficult to interpret for age estimation. Therefore, validation of ageing methods, via application of Δ14C is a major research priority. Utilizing known-age otolith material from north Caribbean fishes, we determined that a distinct regional Δ14C chronology exists, differing from coral-based chronologies compiled for ageing validation from a wide-ranging area of the Atlantic and from an otolith-based chronology from the Gulf of Mexico. Our north Caribbean Δ14C chronology established a decline series with narrow prediction intervals that proved successful in ageing validation of three economically important reef fish species. In examining why our north Caribbean Δ14C chronology differed from some of the coral-based Δ14C data reported from the region, we determined differences among study objectives and research design impact Δ14C temporal relationships. This resulted in establishing the first of three important considerations relevant to applying Δ14C chronologies for ageing validation: 1) evaluation of the applicability of original goal/objectives and study design of potential Δ14C reference studies. Next, we determined differences between our Δ14C chronology and those from Florida and the Gulf of Mexico were explained by differences in regional patterns of oceanic upwelling, resulting in the second consideration for future validation work: 2) evaluation of the applicability of Δ14C reference data to the region/location where fish samples were obtained. Lastly, we emphasize the application of our north Caribbean Δ14C chronology should be limited to ageing validation studies of fishes from this region known to inhabit shallow water coral habitat as juveniles. Thus, we note the final consideration to strengthen findings of future age validation studies: 3) use of Δ14C analysis for age validation should be limited to species whose juvenile habitat is known to reflect the regional Δ14C reference chronology.

Well-designed mountain houses feature the only dated Pinus sylvestris type timbers in the southern French Alps

In the Southern French Alps, the Cervières Valley (near Briançon city) has traditional houses in which wood plays an important role, both in the buildings’ structures and in the activities of the humans who lived there. The six studied farms bear witness to an architecture perfectly adapted to the mountain environment and to the daily and seasonal activities of the inhabitants. Dendrochronology has revealed four major phases of logging from the 16th to the 19th century. The 90 sampled timbers are from larch and Scots pine type, and are of similar age and calibre. The choice of species for building was probably made on the basis of their proximity to the building site. However, until now we have not yet identified any Scots pine t. from before the 18th century in the buildings: does this represent a sampling bias or forest reality? Future historical and pedo-anthracological studies should provide answers. Although archaeological Scots pine is a recalcitrant species in dendroarchaeology in the Southern Alps, probably due to the presence of too many missing rings, in this study a Scots pine t. average has been dated on a larch reference chronology for the first time. This dating is supported by archaeological observations.

Aegean Trees and Timbers: Dendrochronological Survey of the Island of Symi

The current study presents the results of the first dendrochronological survey performed over the East Aegean island of Symi. Research Highlights: Dendrochronological research of the East Aegean region is of paramount importance since dendrochronological data from the region, and especially the islands, are still limited. Background and Objectives: The main aim of the study is to explore the dendrochronological potential of the island, focusing on the dating of historical wood and buildings as well as dendroprovenancing. Materials and Methods: A total of 57 wood samples were collected from historical timber from windmills and architectural elements, including doors and warehouse planks, while 68 cores were collected from the three dominant tree species of the island—Cupressus sempervirens, Pinus brutia, and Quercus ithaburensis subsp. macrolepis—in an attempt to develop local reference chronologies that could be useful in dating historical timber Results: Of the historical timber, at least nine different species have been detected, with conifers representing the majority of the collected material. In total, 56% of the dendroarchaeological samples, belonging to four different species, were dated absolutely. According to cross-dating and dendroprovenancing results, Pinus nigra, Cedrus sp., and Quercus sp. represent timber imported from present-day Turkey while the fir samples collected from the windmills originate from Central Europe. The use of local timber is also highly probable although it could not be confirmed by the reference chronologies developed for the three dominant tree species of the island. Conclusions: The results of the study reveal the dendrochronological potential of the island from both dendroarchaeological and dendroecological perspectives. The finding that most of the wood was imported mainly from Turkey highlights the importance of timber trade with the Turkish mainland during the mid-18th and 19th centuries. Chronologies developed from living trees could be used in future studies for dating historical material while further research would increase our understanding of past timber trade and the island’s history.

High resolution reconstruction of modern charcoal production kilns: An integrated approach combining dendrochronology, micromorphology and anthracology in the French Pyrenees

Numerous charcoal kiln remains can still be found throughout the world, evidencing wood harvesting related to former industries. These remains represent effective sources and tools for studying (i) pre-industrial pressures on forest resources and (ii) past strategies related to woodland management. However, radiocarbon dating (AMS), which is the main tool to reconstruct the chronology of past charcoal manufacturing activity, doesn't provide sufficiently accurate dating, especially for the post-1650 period, due to the broad probability range of the dates resulting from wiggles in the calibration curve. In order to overcome the radiocarbon dating limitation and therefore refine the chronology of modern charcoal manufacturing, this paper proposes to apply an integrated approach combining archaeology, micromorphology, anthracology and dendrochronology. To characterise the archaeological record of a target charcoal kiln terrace from the “Forêt de Bernadouze”, located in a historical iron production valley of the Northern Pyrenees, we combined classical stratigraphic analysis with a micromorphological study. The results highlight the multiperiod nature of the terrace, i.e. a palimpsest of multiple charcoal production episodes, revealing two major phases marked by an abandonment period between them. Subsequently, we constructed a beech charcoal-ring (n = 49) chronology cross-dated with the new “Forêt de Bernadouze” reference chronology from freshly felled, living beech trees (n = 24) to obtain the annual resolution of charcoal ring formation. Based on the new reconstructed master chronology covering the 1879–2016 period, we were able to calibrate the charcoal-ring chronology for the 1881–1941 period. Consequently, we (i) dated the charcoal production activity performed on the target terrace during the 1924–1942 period and (ii) identified a shift in the rate of use of the terrace, from one-off to high-intensive use. This study also provides new insights regarding (i) the particular nature of the archaeological record and (ii) the operating and timing of past charcoal-making practices in connection with silvicultural treatments.

Methodologies for dating wooden artefacts

In recent years, constant progress has been made with regard to wood-dating techniques. In Italy, both the number and length of dendrochronological reference chronologies have increased so that by now the last 10,000 years are almost completely covered. This indispensable dating method has provided new ways for studying archaeological and prehistoric finds. New technologies have remarkably improved the sampling techniques, which today, in most cases, are very effective and non-evasive. Modern software now allows easy data management and statistical analyses. Apart from dendrochronology, the diffusion of isotope analysis has also had great impetus. With regard to radiocarbon dating, the calibration curve has been enriched by new data, and several peaks of cosmic emissions have been identified that, in future, can be instrumental in improving dating precision. Apart from radiocarbon, the isotope analyses of O, H and Sr, especially if linked with dendrochronology, allow to refine the information regarding dating and, in many cases, permits to determine the timber’s provenance and even to define precisely the environmental conditions for the growth of the tree, from which the wood has been obtained. Today, finally, we can assert that all wood can be dated. Only the precision of dating still varies but constant progress is being made in that regard, too.

Review Paper on Composite Leading Index Creation for Forecasting the Bangladeshi Financial Sector

In perspective of the economic vulnerability faced by banks in financial sector, this study mirrors the methodology used by Shumway (2001) – the dynamic hazard model that is able to forecast systemic risk in financial market arena. Here, the terminology followed is based on the CAMELS framework variables: capital adequacy, asset, management, earnings, liquidity and sensitivity to market risk. The objective of this study is to construct a macroprudential indicator (MPI) for the case of Bangladeshi financial market. The result will then be tested for robustness with macro-stress test. Lagged independent variables will be used in the simple hazard model to allow early prediction of MPI in the year in which the crisis happens. The empirical findings can be used as a guideline for the Bangladesh Government and policy makers in accessing, examining and forecasting the health of the Bangladeshi financial system and formulate suitable financial system policies for control. MPI generates information about systemic risk allowing the detection of potential economic crises functioning as an early warning indicator. Government and policy makers will be able to make early preparation in cushioning any potential crises by means of the MPI. Thus the impact of the crises could be minimized and eventually reduce its impact on the Bangladesh economy. The specific objectives are to assemble a novel MPI that is able to recommend early signals of financial market vulnerability, to identify the MPI turning points and establish a comprehensive reference chronology for Bangladeshi financial market and to evaluate the predictive performance of newly constructed MPI on characterizing Bangladeshi financial sector.

Integrated Pliocene-Pleistocene magnetostratigraphy and tephrostratigraphy of deep-sea sediments at IODP Site U1424 (Yamato Basin, Japan Sea)

Sediments from the semi-enclosed Japan Sea are sensitive to paleoclimatic perturbations and they offer great opportunities for many regional and global paleoceanographic and paleoclimatic studies. These studies often require a robust chronology. However, due to rare preservation of calcareous microfossils and drastic changes in surface water salinity during glacial lowstands, the construction of a traditional oxygen isotope stratigraphy for Japan Sea sediments is often difficult. Here, we use sediments recovered at Integrated Ocean Drilling Program (IODP) Expedition 346 Site U1424 to build an integrated Pliocene-Pleistocene reference magnetostratigraphy and tephrostratigraphy for sedimentary sequences from the region. Rock magnetic experiments indicate that magnetic remanence of Site U1424 sediments are carried primarily by (titano)magnetite with small contributions from high coercivity minerals (e.g., hematite) and possibly iron sulphides (pyrrhotite and/or greigite). Dark-colored sediments appear to contain less (titano)magnetite probably due to reductive diagenesis under euxinic conditions. Natural remanent magnetization (NRM) of u-channel samples covering a continuous ~ 167.6 m sediment sequence at Site U1424 was repeatedly measured at 1 cm intervals before and after stepwise demagnetization. Despite lower NRM intensity in dark-colored sediments, NRM directional data from both dark- and light-colored sediments are considered suitable for the construction of magnetostratigraphy. Site U1424 sediments clearly recorded the majority of the polarity chrons and subchrons within the last ~ 4.89 Myr, with the Cobb Mountain subchron, the end of Kaena subchron, and the onset of Nunivak subchron less well preserved. Sixteen tephra layers from the site were sampled for chemical composition analyses and the results were correlated to reference tephrostratigraphy of the region. Ages of the identified tephras are consistent with and can be well integrated with the magnetostratigraphy. The resulting age model suggests that sedimentation rates at Site U1424 range between ~ 1.7 and 7.6 cm/kyr with an average of ~ 3.3 cm/kyr. The acquired magnetostratigraphy and tephrostratigraphy at Site U1424 provide a reference chronology that can be correlated with and transferred to other sediment sequences in the region to study paleoceanographic and paleoclimatic changes of the region as well as their links to other regional and global changes.Graphical abstract