Quaternary Geochronology最新文献

{"title":"Towards accurate modelling of rock surface exposure dating using luminescence to estimate post-exposure erosion rate","authors":"Arbaz N. Pathan ,&nbsp;Rabiul H. Biswas ,&nbsp;Benjamin Lehmann ,&nbsp;Georgina E. King ,&nbsp;Frédéric Herman","doi":"10.1016/j.quageo.2024.101634","DOIUrl":"10.1016/j.quageo.2024.101634","url":null,"abstract":"<div><div>Depth-dependent luminescence in the top few millimetres of rock surface emerges as a potential tool to estimate rock surface exposure age and post-exposure erosion rate. It relies on the principle that the luminescence depth profile (LDP) propagates deeper with the time of sunlight exposure and moves to shallower depth with the erosion rate. The propagation of LDP is generally assumed to follow the first-order kinetic (FOK) model, except for a few recent studies. The FOK model predicts an exponential decay of infrared stimulated luminescence (IRSL) signal with light exposure time, which rarely corroborates experimental observation; IRSL signal decay is much slower than exponential decay. The faster decay of IRSL, predicted by the FOK model, results in faster propagation of LDP and thus always underestimates the exposure age and translates into a higher erosion rate. Interestingly, the slower-than-exponential decay of the IRSL signal can be better explained by general order kinetics (GOK). Thus, recent studies on rock surface luminescence dating have employed the GOK model. However, the GOK model is yet to be explored to predict post-exposure erosion rates. Here, we apply the GOK model and theoretically demonstrate the impact of the order of kinetics on the calibration and propagation of LDP in the presence of erosion and how the LDP's transient to steady state transition depends on the order of kinetics. We have performed a series of synthetic tests to assess the impact of selecting an incorrect model on the prediction of erosion rate. Finally, using the revised rate equation, the erosion rates are recalculated for natural samples (data available in the literature: Lehmann et al. (2019b)) and the impact of GOK on the predicted erosion rate is discussed.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101634"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid, effective screening of tar seep fossils for radiocarbon and stable isotope analysis","authors":"Robin B. Trayler ,&nbsp;Lauren E. Lopes ,&nbsp;Patricia A. Holroyd ,&nbsp;Sora L. Kim ,&nbsp;John R. Southon","doi":"10.1016/j.quageo.2024.101631","DOIUrl":"10.1016/j.quageo.2024.101631","url":null,"abstract":"<div><div>Tar seeps trap and preserve diverse fossil assemblages that reflect unique environmental histories. While the macro preservation of the fossils is usually good, preservation of organic bone collagen is often variable. Radiocarbon dating and stable isotope analysis of tar seep taxa can reveal distinct paleoecological insights but are complicated by the contamination from tar infiltration. Additionally, the removal of tar is complex and time-consuming. Therefore identifying fossils with preserved collagen prior to further investigation minimizes unnecessary damage to fossil collections and improves success rates for analyses that require organic preservation.</div><div>We used tar pit fossils where the collagen preservation state was independently known to test non-destructive (visual inspection) and minimally-destructive (infrared spectroscopy; FTIR) methods to determine the most reliable methods to identify bones with well preserved collagen. We found that while collagen is less often preserved in heavily weathered bones, visual cues alone are not a reliable indicator. Instead, the Water-Amide-on-Phosphate FTIR index is highly sensitive and specific at identifying fossils suitable for radiocarbon dating and stable isotope analysis. While our protocol and analysis code were developed using fossils from two California tar seep localities (McKittrick and Rancho La Brea), they are likely to be broadly applicable to other tar seep localities that have yielded fewer fossils, thus requiring even greater care when selecting specimens for further analysis.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101631"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to special issue LED 2023","authors":"Naomi Porat (Managing Guest Editor),&nbsp;Frank Preusser (Chief Editor)","doi":"10.1016/j.quageo.2024.101639","DOIUrl":"10.1016/j.quageo.2024.101639","url":null,"abstract":"","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101639"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel age constraints on offshore islets around Taiwan with implications for the northern Taiwan volcanic zone","authors":"Su-Chin Chang ,&nbsp;Mei-Fei Chu ,&nbsp;Wen-Shan Chen ,&nbsp;Stephen E. Cox ,&nbsp;Sidney R. Hemming","doi":"10.1016/j.quageo.2024.101636","DOIUrl":"10.1016/j.quageo.2024.101636","url":null,"abstract":"<div><div>Determining the exact age of volcanic activity in the Northern Taiwan Volcanic Zone (NTVZ) is essential for comprehending Taiwan's tectonic evolution. The timing and duration of the volcanic processes that formed the NTVZ remain uncertain despite the availability of geochronological, geochemical, and geophysical data. While extensive efforts have been directed towards investigating the age of the Tatun Volcanic Group, the primary feature of the NTVZ, many other aspects require further examination. This study concentrates on two offshore islets in the northern region of the NTVZ. We present new ⁴⁰Ar/³⁹Ar ages of 0.252 ± 0.018 Ma for a lava flow, representing an early stage of volcanic activity, and 0.118 ± 0.012 Ma for a dike, representing the latest stage of volcanic activity around Pengjia Islet. A sample collected from Mianhua Islet did not yield a reasonable age due to high uncertainty, likely attributable to young and low radiogenic argon. Field observations support the interpretation that volcanic activity on both islets is considerably younger than previously estimated. This study corroborates the hypothesis from geophysical studies that submarine NTVZ features to record a potentially active magmatic reservoir offshore of northern Taiwan. By refining our understanding of spatio-temporal patterns in volcanic activity, this study contributes to volcanic hazard assessment in Taiwan and surrounding areas.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101636"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pleistocene glacial advances and exposure age scatter in the Olympus Range, Antarctica: A study of cosmogenic 36Cl/3He in dolerites and 10Be in sandstones","authors":"Kate M. Swanger ,&nbsp;Jennifer L. Lamp ,&nbsp;Joerg M. Schaefer ,&nbsp;Gisela Winckler ,&nbsp;Irene Schimmelpfennig","doi":"10.1016/j.quageo.2024.101632","DOIUrl":"10.1016/j.quageo.2024.101632","url":null,"abstract":"<div><div>In three cirques in the western Olympus Range of the McMurdo Dry Valleys, Antarctica, previous advances of cirque glaciers are recorded by a sequence of three drifts in each of the cirques. We dated drift limits and the deposits on modern glaciers in two of these cirques, Dean and Dipboye, via cosmogenic ³He in pyroxene from 41 dolerite boulders, ³⁶Cl in pyroxene from 12 of those dolerites, and ¹⁰Be in quartz from 11 sandstone boulders. Exposure age scatter is high on all deposits. The ³He exposure ages across all deposits range from ∼35 to ∼2300 ka and ¹⁰Be exposure ages range from ∼7 to ∼435 ka. Coupled ³⁶Cl/³He from dolerites support constant exposure with erosion for nine of the 12 samples, while the other three might have experienced complex exposure-burial histories. Due to the mesa-butte topography and slow bedrock erosion rates, nuclide inheritance is the primary cause of age scatter in dolerites, accounting for &gt;1 Myr of exposure age error. Mean exposure ages from sandstones are 2–7 times younger than those from dolerites for the same deposits, indicating that inheritance is less common in sandstones in this region. Weathering analyses of sandstone boulders show an increase in average siliceous crust thickness and rock strength with deposit age, an example of case hardening. Based on both relative and exposure age dating, drift age increases with distance from the modern glaciers in both Dean and Dipboye cirques, with three advances during the past &lt;700 ka. However, due to high exposure age scatter, it cannot be determined if the three drifts are temporally correlated across the two cirques and therefore the drifts might record different glacial advances in Dean Cirque vs. Dipboye Cirque despite the apparent stratigraphic correlation of the drifts. This study has implications for drift depositional processes of cold-based glaciers and the importance of source-bedrock lithology and geomorphology on nuclide inheritance in Antarctica.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101632"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validating ex210Pb sediment dating methods applied to a large anthropogenically-impacted river basin","authors":"Stephen Anderson ,&nbsp;Natasha T. Dimova ,&nbsp;Scott Brande","doi":"10.1016/j.quageo.2024.101615","DOIUrl":"10.1016/j.quageo.2024.101615","url":null,"abstract":"<div><p>Sediment dynamics in five sites within the Mobile River Basin, Alabama, impacted by (i) dam-and-lock use, (ii) urbanization, (iii) industrial/mining practices, (iv) flooding, and (v) storm surge events were evaluated to understand better anthropogenic impacts on regional sediment budgets. Three widely used sediment dating models based on excess ²¹⁰Pb (ex²¹⁰Pb) (i.e., Constant Rate of Supply, CRS, Constant Initial Concentration, CIC, and Advective Dispersion Equation, ADE) and two recently developed ones (i.e., Porosity Variation, PV and Porosity Variation Without Diffusion, PVWD) were tested to determine their applicability to these anthropogenically altered lacustrine and coastal areas. To verify results from ex²¹⁰Pb models, we used conventional time markers, including regional hydrograph records and historical aerial images. We found that the traditionally used time-marker ¹³⁷Cs is no longer useful due to its current low inventories in the sediments. Drainage-to-lake area ratios were used to determine relative runoff and atmospheric radionuclide contributions. Statistical analysis of physical properties such as porosity, bulk and dry density, water content, and sediment geochemical compositions were utilized to support sediment transport and site development hypotheses. When constructing the sediment history at each site using these proxies, we found that the CIC and ADE models produced unreliable ages because of violation of requirements for exponentially decreasing porosity and ex²¹⁰Pb activity with depth. We found that two new models, PV and PVWD, that account for heterogeneous porosity, produced more reliable sediment depositional ages. These two models produced ages with lower uncertainties than the CRS model, outperforming the other conventional models tested. We conclude that the PV and PVWD models are more applicable for environments experiencing erosional and abrupt depositional events, which in our study resulted from dam construction and storm-surge events. Model sensitivity analysis showed that decreasing average particle density produces younger sediment ages by the PV and PVWD models. Higher ex²¹⁰Pb activity analytical uncertainty resulted in lower sedimentation rates and higher estimated ages by all five models.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101615"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating age modeling into a hierarchical Bayesian framework for inferring the pattern and rate of past sea-level changes from uncertainty-prone proxy data","authors":"Shi-Yong Yu","doi":"10.1016/j.quageo.2024.101617","DOIUrl":"10.1016/j.quageo.2024.101617","url":null,"abstract":"<div><p>Inferring the pattern and rate of past sea-level changes from uncertainty-prone proxy records requires formal statistical analyses, preferably in a hierarchical framework. The commonly used error-in-variables method treats the relative sea level as a collection of random variables drawn from the multivariate Gaussian distribution. However, this method does not make any use of prior information about the sea-level index points as constraints in the inferential process, thereby leading to anomalously large uncertainties for the time periods when observational data are absent. Here, a hierarchical Bayesian model of past sea-level changes is presented. Specifically, the stochastically varying relative sea level is modeled as a piecewise linear process with an additive independent Brownian increment arriving in a Gaussian fashion. The treatment of temporal uncertainties associated with the sea-level index points in the partially observed proxy records also differs from the existing methods. Instead of calibrating the radiocarbon ages individually, the corresponding calendar ages are treated as random variables and inferred recursively according to their temporal order. Illustrative studies using synthetic and real-world data demonstrate the promise of this model.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101617"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Survival of the brightest? pIRIR dating of volcanic sediments in Sulawesi, Indonesia, using micro-aliquots of K-rich feldspar","authors":"Mariana Sontag-González ,&nbsp;Bo Li ,&nbsp;Kieran O'Gorman ,&nbsp;Basran Burhan ,&nbsp;Budianto Hakim ,&nbsp;Adam Brumm ,&nbsp;Richard G. Roberts","doi":"10.1016/j.quageo.2024.101638","DOIUrl":"10.1016/j.quageo.2024.101638","url":null,"abstract":"<div><div>Volcanic sediments are challenging to date with luminescence-based methods. Both main minerals used for dating—quartz and K-rich feldspar—commonly have suboptimal luminescence properties when of volcanic origins, primarily a low signal intensity and, for K-rich feldspars, high rates of anomalous fading. The present work provides a case study of sediment samples from the Leang Bulu Bettue (LBB) archaeological site in Indonesia, a key site in our understanding of the early human occupation of the island of Sulawesi. We show that currently available state-of-the-art methods can provide robust optical ages for volcanic sediments. Through various reliability tests, we establish the suitability of a post-IR IR stimulated luminescence (pIRIR) standardised growth curve (SGC) procedure for D_e estimation of ‘micro-aliquots’ containing 5–10 grains of K-rich feldspar, and then combine this method with estimates of environmental dose rate to determine 10 new reliable and finite optical ages for the sedimentary deposits at LBB. Furthermore, by applying the L_nT_n method to circumvent truncation of the D_e distribution caused by the non-linearity of the dose response curve in the higher dose range, we could extend the site's luminescence-based chronology to span the interval ∼15–210 ka. The new chronology is in keeping with previous radiocarbon and U-series ages for the site's upper layers. We show that the low fading rate of micro-aliquots relative to using large aliquots composed of hundreds of grains lies in a brightness-based selection. By targeting bright grains with low fading rates, the need for fading corrections is greatly reduced and they can be made with a smaller uncertainty propagated through into the final age estimate, resulting in optical ages of improved accuracy and precision for volcanic sediments.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101638"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A method to date rock engravings using luminescence – tested at Murujuga, Western Australia","authors":"Luke A. Gliganic ,&nbsp;Jo McDonald ,&nbsp;Caroline Mather ,&nbsp;Lloyd T. White","doi":"10.1016/j.quageo.2024.101633","DOIUrl":"10.1016/j.quageo.2024.101633","url":null,"abstract":"<div><div>Rock engravings are globally ubiquitous, provide evidence for symbolic behaviours, and demonstrate connections to country and the desire to communicate with other humans. However, rock engravings have proven difficult to date. The development of luminescence rock surface dating approaches has the potential to address this deficiency in applicable dating techniques. Specifically, luminescence rock surface exposure dating methods can be used to tell how long a rock surface has been exposed to sunlight, thus providing a potential avenue to date rock engravings. Here, we present results from laboratory and field bleaching experiments from the Murujuga rock art complex in Western Australia. Four major art-bearing lithologies are petrographically characterised and tested for useable luminescence signals. Three bleaching experiments are conducted: two in the laboratory and one at the study area. The gabbro and microgranite lithologies are shown to be bleachable and show potential for rock surface burial dating. The microgranite can be used to accurately estimate exposure duration over the timescales tested in all experiments, demonstrating promising potential to date rock engravings.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101633"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Downstream change of luminescence sensitivity in sedimentary quartz and the rearrangement of optically stimulated luminescence (OSL) components along two large rivers","authors":"Gergő Magyar ,&nbsp;Tamás Bartyik ,&nbsp;Rastko S. Marković ,&nbsp;Dávid Filyó ,&nbsp;Tímea Kiss ,&nbsp;Slobodan B. Marković ,&nbsp;Viktor Homolya ,&nbsp;Alexia Balla ,&nbsp;Gábor Bozsó ,&nbsp;Sándor Baranya ,&nbsp;Helena Alexanderson ,&nbsp;Tin Lukić ,&nbsp;György Sipos","doi":"10.1016/j.quageo.2024.101629","DOIUrl":"10.1016/j.quageo.2024.101629","url":null,"abstract":"<div><div>Recently, it has been proposed that the luminescence sensitivity of quartz grains, i.e. their luminescence response to unit dose, might be used for sediment fingerprinting. Sensitivity is determined both by the origin of quartz grains and the sedimentary processes they underwent. However, a more detailed understanding of the factors influencing sensitivity is essential in order to expand and specify the applicability of the parameter in sediment sourcing and geomorphological studies alike. In the present research, we examined the spatial changes of sensitivity parameters of coarse grain quartz in modern sediments of the largest rivers of the Carpathian Basin, Central Europe, to determine the role of source areas and transportation distance.</div><div>Based on the luminescence analysis of 39 samples, quartz extracts with a Carpathian origin (catchment of the Tisza River) have a significantly higher sensitivity, except the LM-OSL medium component, than those originating from the Alpine domain (catchment of the Danube River). No clear relationship could be identified between natural sensitisation and transportation distance. In terms of the Tisza the observed downstream increase of quartz sensitivity is due to high sensitivity quartz grains supplied by its tributaries. In the meantime, a recurring change was observed along the Danube, which can be attributed mostly to local erosional processes. Consequently, tributaries and erosion can overprint the potential downstream sensitisation of quartz grains in large rivers.</div><div>Meanwhile, in terms of the Danube on sections where a significant downstream increase was detected in LM-OSL fast component sensitivity, LM-OSL medium component sensitivity systematically decreased. Additionally, during laboratory sensitisation, the CW-OSL sensitivity of Danube samples increased considerably, whereas changes were more moderate in the case of Tisza samples. Moreover, in the case of Tisza-related quartz extracts, the 110 °C TL sensitivity and the LM-OSL fast and medium components showed a strong correlation, indicating the stability of luminescence processes (trapping and recombination). Whereas, in the case of the Danube both LM-OSL components show a weak correlation with the 110 °C TL intensity. All these indicate that Alpine-origin quartz grains are more susceptible to the rearrangement of electron traps and/or recombination centres, which can also be an indicator of sediment sources in Quaternary studies in the region.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101629"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S187110142400133X/pdfft?md5=3fcb6cb7f96d41c8107832afd6502199&pid=1-s2.0-S187110142400133X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}