Quantitative and semi–quantitative analyses using a portable energy dispersive X–ray fluorescence spectrometer: Geochemical applications in fault rocks, lake sediments, and event deposits

Abstract

Quantitative and semi-quantitative procedures using a portable energy dispersive X-ray fluorescence spectrometer (portable XRF) were applied to geochemical studies in fault rocks, lake sediments, and soils, including paleotsunami deposits. The results obtained are as follows: 1) Correlation coefficients (r 2 ; measured values by portable XRF versus reported values) for working curves of major elements obtained using powdered reference standard materials were 0.70-0.99 with p < 0.01, except for Mg, and r 2 values for the trace elements were 0.72-0.99 with p < 0.05, except for Cl, Ba, and U. 2) In the fault rocks from Central Japan (e.g., Shiraki-Nyu fault, Atera faults; powdered and nonpowdered rock fragment samples), measured values of K, Ca, Ti, Mn, Fe, Rb, Sr, Zr, and Th contents obtained using portable XRF are consistent with the reported values (r 2 = 0.47-0.90, with p < 0.01). Clear Fe and Mn enrichments and K and Rb depletions were observed within the gouges of the Shiraki-Nyu fault from Central Japan.3) The depth profiles of chemical components in lake sediments (powdered) from the Noto Peninsula in Central Japan measured using portable XRF methods were similar to those measured using the stationary-type XRF (r 2 = 0.61 in Ti and r 2 = 0.40 in Zr contents, with p < 0.05). 4) For paleotsunami deposits on the Pacific coast of northeast Japan, the chemical components and titanium-normalized values (Si/Ti, Ca/Ti, Sr/Ti, and As/Ti) in powdered samples measured using portable XRF correlated well with those in a previous study measured using stationary-type XRF (r 2 = 0.84-0.98, with p < 0.01). Cluster analyses of geochemical data conducted using portable XRF were useful to characterize event deposits on the north Sendai Plain.In each kind of sample, the element concentration values (

Geochemical characteristics of paleotsunami deposits from the Shizuoka plain on the Pacific coast of middle Japan

“…The concentrations were calibrated using the standard reference materials JA-1, JA-2, JA-3, JB-1a, JB-2, JB-3, JF-2, JGb-1, JGb-2, JR-1, JR-2, JR-3, JLk-1, JSd-1, JSd-2, JSd-3, JSl-1, JSl-2, JSO-2 (The National Institute of Advanced Industrial Science and Technology, Japan; https://gbank.gsj.jp/geostandards/welcome.html), NIST2704, NIST2709, NIST2710, NIST2711 (National Institute of Standards and Technology, USA; NIST, 1993aNIST, , 1993bNIST, , 2000NIST, , 2002, SO-1, SO-2, SO-3, SO-4 (National Research Council, Canada;Roubault et al, 1970), JSAC0401, JSAC0402, JSAC0403, and JSAC0411 (The Japan Society for Analytical Chemistry). Quantification procedures by the EDXRF using pressed powder pellets have been well studied by Matsunami et al (2010), Yamasaki et al (2011Yamasaki et al ( , 2015Yamasaki et al ( , 2016, Kuwatani et al (2014), Watanabe et al (2020Watanabe et al ( , 2021, and Nara et al (2021). In previous study for tsunami deposits from north Sendai plain, total contents of major elements were ~90-100 mass% in most case (Watanabe et al, 2020).…”

“…Generally, geochemical characteristics of tsunami deposits are site-specific (Chagué- Goff et al, 2017), e.g., in the cases of different hinterlands, sediment sources, sedimentation dates, topographic and lithological conditions (Chagué- Goff et al, 2012aGoff et al, , 2012bGoff et al, , 2014Szczuciński et al, 2012;Shinozaki et al, 2015Shinozaki et al, , 2016. In previous studies on Japan, geochemical studies of paleotsunami deposits were limited to the Pacific coast of Tohoku (e.g., Goff et al, 2020;Watanabe et al, 2020Watanabe et al, , 2021 and Miyazaki plain in Kyusyu island (Niwa et al, 2020). Therefore, we carry out a geochemical analysis of the paleotsunami deposit from the Shizuoka plain, to propose simple methods for identifying marine incursion generated from a tsunami disaster in the Pacific coast of middle Japan.…”

LA-ICPMSを用いた宮崎平野津波堆積物中のジルコンのU–Pb年代測定

“…To detect the paleotsunami deposits, geological and geochemical techniques were effective tools in many cases (e.g., Niwa et al, 2020) . Geochemical discrimination methods were also applied to characterize the event deposits in coastal areas (Chagué-Goff et al, 2017;Watanabe et al, 2020Watanabe et al, , 2021a . Furthermore, heavy minerals including zircon were well studied for tsunami geology to estimate the past inundation area by earthquakes and tsunamis in the south Miyazaki plain, Pacific coast 地学雑誌 Journal of Geography (Chigaku Zasshi) 132 (4) 353361 2023 doi:10.5026/jgeography.132.353 of southwest Japan (Watanabe et al, 2022) .…”