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Bartz, M.*; King, G. E.*; Bernard, M.*; Herman, F.*; Wen, X.*; 末岡 茂; 塚本 すみ子*; Braun, J.*; 田上 高広*
Earth and Planetary Science Letters, 644, p.118830_1 - 118830_11, 2024/10
被引用回数：1 パーセンタイル：47.42(Geochemistry & Geophysics)The impact of climate on mountain relief is unknown, mainly due to the difficulties of measuring surface processes at the timescale of glacial-interglacial cycles. An appropriate setting for studying mountain erosion in response to Quaternary climate change is found in the Tateyama mountains in the Hida mountain range (northern Japanese Alps) due to distinct geomorphological features of glacial, periglacial, and fluvial processes. The Japanese Alps uplifted within the past ca 1-3 Myr and experienced multiple glaciations during the late Quaternary. We use ultra-low temperature thermochronometers based on the luminescence of feldspar minerals and the electron spin resonance (ESR) of quartz minerals, in combination with inverse modelling to derive rock cooling rates and exhumation rate histories at 10
-10
year timescales from 19 rock samples from three transects in the Tateyama region. While luminescence signals have already reached their upper dating limit, ESR signals (Al and Ti centres) yielded ESR ages of ca 0.3-1.1 Ma, implying surface processes active in the Pleistocene. Based on a negative age-elevation relationship, local relief reduction at a cirque-basin scale is identified over the past 1 Myr, whereas a positive age distribution with elevation for samples close to the mountain top does not follow this trend. Inverse modelling reveals rock cooling rates on the order of 30-80 deg. C/Ma, with slightly faster cooling for cirque-floor samples, which equate with erosion rates of 0.5-1 mm/yr that exceed rates from periglacial and fluvial processes in the same locality. Thus, our data suggest that Quaternary climate change coupled with distinct surface processes modified the slopes of the Tateyama mountains leading to a localised decrease in relief over the second half of the Quaternary, whilst the mountain peaks were unaffected by the relief reduction.
Bartz, M.*; King, G.*; Anderson, L.*; Herman, F.*; 末岡 茂; 塚本 すみ子*; 田上 高広*
no journal, ,
捕獲電子を用いた熱年代手法に基づいて、日本アルプス飛騨山脈の岩石試料を対象に冷却史の解明を試みた。
Bartz, M.*; King, G. E.*; Herman, F.*; Anderson, L.*; 末岡 茂; 塚本 すみ子*; 田上 高広*
no journal, ,
To resolve exhumation histories of the Japanese Alps throughout the Quaternary, we investigate the potential of ultra-low temperature thermochronometers based on the luminescence of feldspar minerals and electron spin resonance (ESR) of quartz minerals, in combination with inverse modelling to derive rock cooling rates and exhumation rates histories at 10-10 years timescales. We focus on the Tateyama region in the Hida range of the Japanese Alps. In total, 19 new samples were analyzed by luminescence and ESR thermochronometry. While most luminescence signals have already reached saturation, ESR signals (Al and Ti centres) still grow with dose and are suitable for determining finite exhumation rates in the Tateyama region. We used the ESR single aliquot regenerative additive (SARA) dose protocol for dose evaluation including protocol optimization (i.e., preheat-plateau test). We checked for sensitivity changes due to the high-temperature annealing step within the SARA procedure using SARA vs. single aliquot additive dose response, repeated dose points (i.e., recycling ratio) and dose recovery of an artificially zeroed sample. Thermal stabilities of the ESR signals were analysed by using isothermal decay experiments and simulations of the isothermal decay using the experimentally constrained kinetic parameters. Our experiments showed insignificant sensitivity changes during measurements, resulting in Al and Ti ages of between 0.3-0.9 Ma and 0.5-1.1 Ma, respectively. In general, thermal stability is lower for the Al centre compared to that of the Ti centre but simulations yielded valuable thermal stability over Quaternary timescales for both ESR centres. Inversions reveal rock cooling rates on the order of 30-80 deg. C/Ma, much lower than those of the luminescence thermochronometry technique, which helps to resolve erosion rates histories on the order of few mm/a. Thus, preliminary erosion rates of 
1 mm/a within the past 1 Ma could be inverted.
末岡 茂; 岩野 英樹*; 檀原 徹*; 平田 岳史*; Kranz-Bartz, M.*; King, G. E.*; 田上 高広*
no journal, ,
飛騨山脈では、中新世
第四紀の極めて若い花崗岩が露出していることで知られているが、特に黒部地域では、地温勾配が高い領域に沿って変形が集中した結果、このような若い花崗岩が露出した可能性が指摘されている。本研究では、このような変形集中帯の範囲の推定と、変形集中帯と若い花崗岩の分布域の対応の検討を目的として、黒部地域の南西にあたる立山地域で熱年代解析およびジルコンU-Pb年代測定を行った。ジルコンU-Pb年代は約200Ma以上の船津トーナル岩類に対応される年代を示したことから、今回測定した地点では若い花崗岩の分布は確認できなかった。一方、ジルコンFT年代は約30-9Ma、アパタイトFT年代は約9-2Maの若い値を示した。アパタイトFT年代に基づくと、削剥速度は約0.6-2.8mm/yrと推定され、黒部地域には及ばないものの、世界の変動帯と比べても上位の値となった。黒部地域に沿った地温勾配が高いゾーンに変形が集中した結果、黒部地域から立山地域を含む飛騨山脈の中心部が座屈変形を起こし、もっとも隆起・削剥が速い黒部地域でのみ深部から若い花崗岩が露出するに至った可能性が考えられる。
Bartz, M.*; King, G.*; Anderson, L.*; Herman, F.*; 末岡 茂; 塚本 すみ子*; Ahadi, F.*; Gautheron, C.*; Delpech, G.*; Schwarz, S.*; et al.
no journal, ,
Electron spin resonance (ESR) thermochronometry has the potential to resolve continuous erosion histories from rapidly eroding settings over 10 time scales. These time periods are defined by persistent oscillations between warm and cold states. However, questions about the relationship between climate and erosion remain unanswered. We further develop ESR thermochronometry of quartz (Al and Ti centres) to answer these questions in the Tateyama region in the Hida Mountains of Japan. In the result, the Al and Ti centres in quartz can successfully be inverted to unravel rock cooling histories. As future work, all ESR signals will be converted together with OSL data, providing further constraints on their thermal histories.
ne valley incision?King, G. E.*; Wen, X.*; Bartz, M.*; Anderson, L.*; Bossin, L.*; 塚本 すみ子*; Li, Y.*; Herman, F.*; 小形 学; 末岡 茂
no journal, ,
To determine a rock cooling history using ESR thermochronometry, signal accumulation and signal thermal loss must be robustly determined within the laboratory. We have collected a series of geological samples including rocks from boreholes that have known isothermal histories to investigate the potential of this technique. Our objective is to use the latter rocks to confirm the validity of our laboratory measurements and data-fitting/numerical models. Specifically, we have investigated known-thermal history samples from the MIZ1 borehole (Japan) and the KTB borehole (Germany) as well as samples from Sion in the Western European Alps. Preliminary data reveal that the ESR dose response and thermal decay of different quartz samples is highly variable. Whereas the Al-centre of some samples exhibits linear dose response to laboratory irradiation up to 15 kGy, the Al-centre of other samples exhibits exponential, or double exponential growth and saturates at doses of 3-4 kGy. The Ti-centre of most samples is well described by a single saturating exponential function, however samples from the MIZ1 borehole exhibit pronounced sub-linearity in the low-dose response region. Furthermore, whereas for some samples the Al-centre is less thermally stable than the Ti-centre, for other samples the inverse is observed. These observations suggest that a uniform measurement protocol and data-fitting approach may not be appropriate for quartz ESR data. Inversion of two KTB samples yielded temperatures within uncertainty of borehole temperature, however results for the MIZ1 borehole are more variable and can only recover temperature at best within c.a. 10%. Investigations into the cause of the poor results for the MIZ1 borehole are ongoing (i.e. measurement protocol, data-fitting/numerical model) and will be discussed. Preliminary data from Sion are promising and reveal consistent cooling rates.
Bartz, M.*; King, G. E.*; Herman, F.*; Anderson, L.*; 末岡 茂; 塚本 すみ子*; 田上 高広*
no journal, ,
The interaction between rates of Earth surface processes, climate and tectonics determines the landscape in mountain regions. The Japanese Alps uplifted throughout the Quaternary and now reach elevations of up to 3,000 m. However, quantifying relief changes in response to tectonic activity, magmatism and Late Quaternary glaciation is challenging due to the young age of the Japanese Alps and the difficulty of measuring surface processes at the timescale of glacial-interglacial cycles. Here, we use ultra-low temperature thermochronometers based on the luminescence of feldspar minerals and the electron spin resonance (ESR) of quartz minerals, in combination with inverse modelling to derive rock cooling rates and time series of exhumation rates at 10-10 years timescales. We focus on the Tateyama region in the Hida range of the Japanese Alps, which was glaciated during the late Quaternary period. In total, 19 new samples were analyzed by luminescence and ESR thermochronometry. While most luminescence signals have already reached their upper dating limit, ESR signals (Al and Ti centres) yielded ESR ages of between 0.5-0.9 Ma. In general, thermal stability is lower for the Al centre compared to that of the Ti centre, but both centres constrain similar exhumation rates. Inversions reveal rock cooling rates on the order of 30-80 deg. C/Ma, which can be inverted to exhumation rates of less than 1 mm/a within the past 1 Ma. In the next step, we will relate the exhumation rates to the glacial and tectonic history of the Tateyama region.
King, G. E.*; Bossin, L.*; Kranz-Bartz, M.*; Wen, X.*; Schmidt, C.*; Herman, F.*; 小形 学; 末岡 茂
no journal, ,
Electron spin resonance (ESR) dating of quartz minerals offers a significant advantage over luminescence dating because of its later signal saturation. Whereas the luminescence thermochronometry system is limited to areas experiencing very rapid rock cooling (exhumation) of tens of mm/yr, recent studies have shown that ESR thermochronometry can resolve rates of <1 mm/yr over Quaternary timescales. However, the method has not yet been validated against samples with known thermal histories. To this end, we have investigated six known-thermal history samples from the MIZ1 borehole, Tono, Japan. The natural trapped-charge concentration of the different samples was constrained using a single-aliquot regenerative dose measurement protocol. As the samples had similar properties, we constructed a standardised growth curve to alleviate measurement times. Signal saturation of the Al-centre occurred at ~60 kGy and at ~7 kGy for the Ti-centre. Whereas the Al-centre exhibited single-saturating exponential growth, the Ti-centre exhibited significant sub-linearity in the low dose region, within which the natural trapped-charge concentrations were interpolated. The thermal stability of the different samples was measured using an isothermal holding experiment, whereby samples were dosed in the laboratory before being held at four fixed temperatures for durations ranging from 0 min to 10 h. As the thermal signal loss of the different samples was similar, we were able to fit all samples to derive a single set of thermal kinetic parameters. Finally, the data were inverted for borehole temperature using a Monte-Carlo approach. Whereas the Al-centre of all samples recovered borehole temperature within 1 sigma, the Ti-centre data failed to recover temperature, yielding temperatures ~20-30 deg. C above borehole temperature. The cause is likely related to the observed sub-linearity of the dose response curves which may be indicative of sensitivity change throughout analysis.
Bartz, M.*; King, G. E.*; Anderson, L.*; Herman, F.*; 末岡 茂; 塚本 すみ子*; 田上 高広*
no journal, ,
The Japanese Alps uplifted throughout the Quaternary and reached elevations of up to 3,000 m. However, understanding the interaction between rates of Earth surface processes, tectonics and climate is challenging, partly due to the difficulties of measuring changes in the rates of Earth surface processes at the timescale of glacial-interglacial cycles. In particular, the youth of the Japanese Alps has made measurement of their exhumation histories complicated. Here we investigate the potential of ultra-low temperature thermochronometers based on the luminescence and electron spin resonance (ESR) of feldspar and quartz minerals respectively for understanding changes in exhumation rates. We focus on Tateyama (Hida range), which was glaciated during the late Quaternary period. In total, eight samples were analysed by luminescence and ESR thermochronometry. While most luminescence signals have already reached their upper dating limit, ESR signals give insights into Pleistocene exhumation rates. We measured the ESR dose response and thermal decay properties of all samples, specifically targeting the Al and Ti centres. In general, thermal stability is higher for the Ti signals, resulting in ESR ages of between 0.5-0.9 Ma, although some signals are close to or above the upper dating limit of the Ti centre. In contrast, the Al signal still grows with time and is suitable for determining finite exhumation rates. Initial inversions reveal rock cooling rates on the order of 80 deg. C/Ma, which can be inverted to preliminarily rates of rock exhumation of <3 mm/a within the past 1 Ma. In the next step, we will relate these rates to the climatic (glacial) and tectonic history of the Tateyama region.
King, G.*; Bartz, M.*; Bossin, L.*; Wen, X.*; 塚本 すみ子*; Herman, F.*; 小形 学; 末岡 茂
no journal, ,
Electron spin resonance dating of quartz minerals offers a significant advantage over luminescence dating because of its later signal saturation. We are seeking to exploit this to build upon earlier studies in the development of a thermochronometry system capable of resolving rock cooling rates throughout the Quaternary. In order to determine a rock cooling history, it is necessary to constrain both signal accumulation and signal thermal loss robustly within the laboratory. We have collated a series of geological samples including rocks from boreholes that have known isothermal histories to investigate the potential of this technique. Our objective is to use the latter rocks to confirm the validity of our laboratory measurements and data-fitting/numerical models. Specifically, we have investigated known-thermal history samples from the MIZ1 borehole (Japan) and the KTB borehole (Germany). Preliminary data reveal that the ESR dose response and thermal decay of different quartz samples is highly variable.
King, G. E.*; Wen, X.*; Bartz, M.*; Bossin, L.*; 塚本 すみ子*; Li, Y.*; Herman, F.*; 小形 学; 末岡 茂
no journal, ,
Whereas the luminescence thermochronometry system is limited to areas experiencing very rapid rock cooling (exhumation) of 10s of mm/yr, our data indicate that ESR thermochronometry can resolve rates of 1 mm/yr over Quaternary timescales. To determine a rock cooling history using ESR thermochronometry, signal accumulation and signal thermal loss must be robustly determined within the laboratory. We have collected a series of borehole samples with known isothermal histories to investigate the potential of this technique. Our objective is to use the latter rocks to confirm the validity of our laboratory measurements and data-fitting/numerical models by using the ESR-thermochronometry method to recover their known in-situ temperatures. Specifically, we have investigated known-thermal history samples from the MIZ1 borehole (Japan) and the KTB borehole (Germany). Preliminary data reveal that the ESR dose response and thermal decay of different quartz samples is highly variable. Whereas the Al-centre of some samples exhibits linear dose response to laboratory irradiation up to 15 kGy, the Al-centre of other samples exhibits exponential, or double-exponential growth and saturates at doses of 3-4 kGy. The Ti-centre of most samples is well described by a single saturating exponential function, however samples from the MIZ1 borehole exhibit pronounced sublinearity in the low-dose response region. Furthermore, whereas for some samples the Al-centre is less thermally stable than the Ti-centre, for other samples the inverse is observed. These observations suggest that a uniform measurement protocol and data-fitting approach may not be appropriate for quartz ESR data.
Anderson, L.*; Bartz, M.*; King, G.*; Fox, M.*; Herman, F.*; Stalder, N.*; Biswas, R.*; 末岡 茂; 塚本 すみ子*; Ahadi, F.*; et al.
no journal, ,
Optically stimulated luminescence (OSL) and electron spin resonance (ESR) thermochronometry have the potential to resolve continuous erosion histories from rapidly eroding settings. These thermochronometers are viable over the past few hundred thousand to a million years. These time periods are defined by persistent oscillations between warm and cold states. During the Quaternary, fundamental questions about the relationship between climate and erosion remain unanswered. With further development, the OSL and ESR thermochronometers could answer these questions. To realize this potential new strategies are required to invert low-temperature thermal histories for erosion rates. Here, we explore the use of PeCUBE (Braun, 2003), a three-dimensional finite-element model that simulates heat conduction and advection in the upper crust. As a training dataset we use cooling histories derived from eight samples from the Tateyama region in the Hida Mountains of Japan. The flexibility of PeCUBE allows us to quantify the role of time varying surface temperatures between glacial and interglacial periods. In high-relief settings the three-dimensionality of the topography, for example between valleys and ridges, can substantially perturb rock temperatures. PeCUBE allows us to quantify and remove these confounding topographic effects. We additionally explore the role of changing topographic relief on time varying thermal fields and erosion rates. Lastly, we explore a generous range of model parameters to quantify the sensitivity and robustness of our inversions.
Kranz-Bartz, M.*; King, G. E.*; Bernard, M.*; Herman, F.*; Wen, X.*; 末岡 茂; 塚本 すみ子*; Braun, J.*; 田上 高広*
no journal, ,
The influence of Quaternary climate on mountain topography remains a topic of debate, largely due to the challenges associated with measuring surface processes over the recent geological past. A compelling location to investigate mountain erosion in response to Quaternary climate change is found in the Tateyama Mountains, part of the northern Japanese Alps, due to its distinct geomorphological features. The Japanese Alps uplifted within the last 1-3 million years and have undergone multiple glaciations during the late Quaternary. In this study, we employ novel ultra-low temperature thermochronometres based on the luminescence and electron spin resonance (ESR) from feldspar and quartz, respectively, in combination with inverse modelling to derive rock cooling and exhumation rate histories on timescales of 10-10 years within the Tateyama region. The four luminescence signals have already reached their upper dating limit, indicating maximum exhumation rates of ca. 1-1.5 mm/yr. In contrast, ESR signals from Al and Ti centres provided ESR ages ranging ca. 0.3-1.1 Ma, suggesting that surface processes were active during the Pleistocene. A negative age-elevation relationship reveals a reduction in local relief at the scale of the cirque basin over the past million years. However, a positive age-elevation trend observed in samples from near the mountain summit deviates from this pattern. Inverse modelling shows rock cooling rates ranging 20-80
C/Myr, with slightly faster cooling in cirque-floor samples. Thermal kinematic modelling reveals erosion rates of 0.5-1 mm/yr in the cirque basin, which are higher than those observed from periglacial and slope processes in the same area. Our data suggest that Quaternary climate change, coupled with distinct surface processes, has significantly altered the slopes of the Tateyama mountains, leading to a localized decrease in relief within individual cirque basins during the second half of the Quaternary.
