A small group of CAIs exhibit some fractionated and unknown nuclear (FUN) isotopic effects, e.g., O, Mg, Si, Ca, and Ti, and are called FUN inclusions. These FUN CAIs are characterized by large mass-dependent fractionation effects in Mg, Si, and O, and a few ‰ of mass-independent isotopic anomalies in various elements, such as Ca, Ti, Cr, Sr, Ba, Nd, and Sm. Despite their discovery for more than 40 years, the origin and formation of the FUN CAIs remain poorly constrained. In order to better identify and, subsequently, constrain the nature and origin of FUN CAIs, we have set up in situ LA-MC-ICPMS Mg isotopic analysis for CAI in thick meteorite slab, to quickly search for CAIs deficient in 26Mg, a common characteristic of FUN CAIs. Subsequently, CAIs with abnormal Mg isotopes have been extracted and prepared for NanoSIMS study, e.g., O, Mg, and/or Si, and also being prepared for further solution-based MC-ICPMS study. Approximately ~1mm thick sections of Allende and DAG192 (CO3) were prepared and subjected to in situ laser ablation MC-ICPMS, a 193nm Analyte G2 excimer laser coupled with a Nu-Plasma II, Mg isotopic analysis at IES. The spot size was 50 microns with 50 sec ablation time. San Calos ol, opx, and cpx and two glass standards BCR-2G and BIR-1G were studied and the results were comparable to published data, while San Calos opx was used as the main standard during the experiments. Preliminary results showed that while the Mg isotopes for majority of the CAIs from both Allende and DAG192 exhibited normal to positive 26Mg, due to the decay of 26Al, two CAIs from Allende showed resolvable 26Mg deficits of -1 to -1.5‰, and 0 to -0.5‰, respectively. With a typical 2-sigma SD of 0.33‰ for our Mg isotopic analysis, the first CAI showed clearly resolvable 26Mg deficit from both sides of the thick sections, while questionable for the second CAI. The potential FUN CAIs, consisting of fine-grained spinel and pyroxenes, have been extracted from the thick sections and prepared for NanoSIMS study. The preliminary O isotopic analysis of spinel grains show typical FUN O isotopic fractionations while intercepting the CCAM line at ~ -50‰ for both delta17O and delta18O. While more NanoSIMS isotopic analyses are currently undergoing, the preliminary results are quite encouraging about the future searches and understanding of FUN CAIs.

Iran is located in the continental collision zone between Arabia and Eurasia and consists of several micro-continents with the affinity of Gondwana, and its drifting history has close connection with the evolution of Tethys oceans. The widespread Late Neoproterozoic (Ediacaran) to Cambrian (ca. 600-500 Ma) granitoids and gneisses that built up the crystalline basement of Iran are regarded as part of the Cadomian magmatic arc resulting from the subduction of the Prototethys along the northern margin of Gondwana. The Cadomian rocks yield variable zircon Hf isotopic results of ε_Hf(T) values from +11 to -3 and Hf crustal model (T_DM^C) ages of ca. 0.9-1.7 Ga, implying that the magmas were formed by the melts of mixed depleted-mantle and Archean crustal sources. The Iranian micro-continents were then separated from the northern Gondwanan margin because of the birth of the Neotethys. The Carboniferous (349-311 Ma) A-type granitoids in northwestern Iran have well constrained the timing of initial phase of the Neotethyan opening, which yield zircon ε_Hf(T) values from +5 to -1 and T_DM^C ages of ca. 1.0-1.4 Ga that suggest the formation of these rocks involving the reworked Cadomian basement. The Middle Jurassic (~165 Ma) granitoids, mainly exposed along the Sanandaj-Sirjan zone, represent the early stage of products triggered by the subduction of the Neotethys beneath Iran and show similar zircon Hf isotopic compositions of ε_Hf(T) values from +5 to -3 and T_DM^C ages of ca. 0.9-1.4 Ga. The long-lasting Neotethyan subduction subsequently led to the occurrence of the Urumieh-Dokhtar magmatic arc with major activities during the Eocene to Oligocene (55-25 Ma), and this prolonged magmatic flare-up event has been widely identified across Iran and Armenia. The Eocene-Oligocene igneous rocks, along with other Miocene small-volume bodies, have dominantly positive zircon ε_Hf(T) values from +15 to -2 and much younger T_DM^C ages of ca. 0.2-1.2 Ga, which indicate the significant contribution of mantle inputs in the magmatic genesis and the important growth of newly formed continental crust during the Cenozoic in this particular segment of the Neotethyan orogenic belt.

Mid-Eocene granites in Sakhalin reveal a new period of juvenile crustal growth in Cenozoic Northeast Asia after a magma gap from 56 to 45 Ma. In South Sakhalin, this study presents new whole-rock geochemical and Sr-Nd isotopic data, together with zircon U-Pb ages and Hf isotope ratios, of granitic rocks and associated dikes from the Okhotsk and Aniva plutons. The two plutons emplaced in the Mid-Eocene show contrasting geochemical characteristics. The Okhotsk granites (44 to 42 Ma) have transitional I- and A-type granite features, and contains rare inherited zircons. The Aniva granites (40 Ma), essentially biotite-cordierite bearing, possess typical S-type features. This suite has abundant inherited zircons dated from 48 to 2446 Ma. Whole-rock Sr-Nd and zircon Hf isotopic data indicate that the genesis of the two plutons involved partial melting of mixed sources with dominant juvenile crustal components and magma mixing between underplated mantle-derived magmas and crustal partial melts. The Okhotsk granites have εNd (T) values of +3.1 to +3.7, initial 87Sr/86Sr ratios of 0.7047 to 0.7048, and zircon εHf (T) values of +11 to +16. The Aniva granites have εNd (T) values of +0.5 to +0.9 and initial 87Sr/86Sr ratios of 0.7052 to 0.7055, and zircon εHf (T) values of +4 to +12. According to Sr-Nd and Nd-Hf isotopic mixing calculations, the proportion of the juvenile component (=mantle-derived materials) is estimated to be more than 70%, and that of the upper crust component is less than 30% in the sources of the Okhotsk and Aniva plutons. We further argue that, based on Nd and Hf isotopic constraints, the Okhotsk and Aniva granites are correlated to the Mid-Eocene granites in the western and eastern parts, respectively, of the Hidaka terrane in Hokkaido. From the Sikhote-Alin area to Sakhalin and Hokkaido, the increase in juvenile sources and the decrease in recycled crustal materials are exhibited in the Nd isotopic signatures of the granitoids from early Cretaceous to Miocene. The granitic magmatism in South Sakhalin and Hokkaido may be the most prominent example of juvenile crustal growth among these areas.

There has been a long-standing debate over the rock formation beneath the Ilan Plain. Is the rock formation associated with the Hsuehshan Range belt which lies in the north of the plain or with the Backbone Range belt which is situated in the south? Two deep wells, HTL01 (2200m) and HTL02 (2800m), were drilled by the project of Taiwan National Energy Program-Phase II to evaluate the geothermal potential of the Ilan Plain. This study is attempt to apply petrography and mineral assemblages of cuttings taken from these two wells to delineate the rock formation beneath the Ilan Plain.The slate with a well-developed cleavage exits in 450m-1250m of HTL01, and meta-sandstone appears incrementally from 1350m to 2050m, and then diminishing with well cleavage developing in 2050m-2200m. The entire cuttings of HTL01 accommodate quartz, kaolinite and illite, but chlorite found only from 1150m to 1250m. The slate with a well-developed cleavage exits in 500m-1300m of HTL02, and meta-sandstone gradually emerge from 1300m to 2800m, but few slate and meta-sandstone found between 2050m and 2200m. The entire cuttings of HTL02 contain quartz, kaolinite and illite with quartz and illite appeared only between 1900m and 2200m. It suggests that the rock formation of HTL01 and HTL02 rather belongs to the Hsuehshan Range belt than the Backbone Range belt.

Chemical weathering plays a vital role in controlling long-termed climatic fluctuation and landscape development. In particular, silicate minerals are attacked by protons produced from the transformation of atmospheric carbon dioxide into carbonic acid, releasing monovalent and divalent cations with bicarbonate into rivers and enabling the net removal of CO₂. The rates of silicate weathering have been correlated to various factors, such as lithology, temperature, runoff, and erosion rate for major river systems, providing a basis to assess the atmospheric CO₂ drawdown over a geological time scale. For comparison, small river systems in rapidly uplifting orogenic belts are characterized by short transport path and residence time, and often associated with torrential runoff and sediment discharge. River channels are deeply incised, producing large quantities of fresh materials and mineral surface readily for weathering processes. The patterns and reaction pathways of chemical weathering in such river systems and its impacts on the global solute budget and long-termed climatic fluctuation remain largely unknown. In this study, we carried out periodic field campaigns to sample various materials (river, creeks, seeps, hot springs, and suspended particulates) in a small river system in southeastern Taiwan where the uplift and exhumation is rapid. The analyses yielded that calcium, sulfate, and bicarbonate were the major ions in river, creek, and seep samples. Sulfate concentrations were highly correlated with divalent cations, but exhibited a weak and no correlation with the yields of suspended particulate, and the concentrations and isotopic compositions of dissolved inorganic carbon, respectively. Screening of 16S rRNA genes further suggests that pyrite oxidation is at least partly mediated by microbial processes. These data combined with isotopic compositions of sulfate suggest that pyrite oxidation, carbonate weathering, and mixing processes mostly account for the solute variation pattern. While carbon isotopic compositions indicate multiple sources of dissolved inorganic carbon, partial pressures of CO₂ often exceed the atmospheric equilibrium saturation state. These results suggest that instead of a sink such a river system is prone to CO₂ emission.

Monitoring of groundwater chemistry in seismically-active regions has been carried out since the 1980s in Taiwan. Change in groundwater chemistry has been observed before earthquakes and is proposed as a precursor signal since the 1980s in Taiwan. However, the biweekly/monthly sampling interval was commonly performed, some short-term precursory anomalies may not be caught due to the low sampling frequency. We designed an automatic sampling apparatus for the retrieval and temporal analysis of water geochemistry. The device was composed of the syringes connected to glass bottles with the septum for collecting fluids each day, which was installed at the Chelungpu Fault Drilling Project (TCDP) drilling well in central Taiwan for observing the discharge of fluids. The stable isotope ratios for oxygen and hydrogen anomalies of ~ +0.6‰ and +2.0‰, respectively, relative to the local background measured in groundwater were observed as the potential seismic precursor, one month before the Nantou earthquake (M6.2) in central Taiwan. The findings could be explained by the mixture between the different chemical concentrations from groundwater and surrounding formations through water-rock interaction, which may be associated with pre-seismically induced changes of permeability or opening of preexisting micro-fractures along the fault zones due to high fluid pressure. We suggest that the geochemical anomaly in groundwater could be useful for future researching on the earthquake precursor.

Methane is a potent greenhouse gas. Among all possible sources, wetlands are estimated to account for more than one third of the overall methane emission, ranking the greatest natural contributor. The exact quantity of methane released from such environment to the atmosphere is, however, controlled by the interplay between microbial production and consumption. While tidal wetlands represent a critical transition witnessing intensive material and energy exchange between terrestrial and marine realms, uncovering methane production and consumption impacted by tidal inundation would provide mechanistic constraints to refine the estimates of methane emission on various temporal and spatial scales. In this study, field campaigns combined with laboratory experiments were employed to investigate the factors controlling methane emission in wetlands distributed along the Dan-Tsui river in northern Taiwan under different degrees of tidal inundation. Flux measurements indicated that methane emission was negatively and positively correlated with sulfate/chloride concentration and temperature, respectively. Methane emission was also the greatest during the lowest tide. Porewater geochemistry further indicated that while metabolic zonation (sulfate reduction, anaerobic methanotrophy, and methanogenesis) prevailed, methane production was apparently confined at great depths by high sulfate during high tide but stimulated at shallow depths during low tide. Abundant methane (mM scaled) produced during low tide fueled anaerobic and aerobic methanotrophy near surface. While a majority of methane produced was consumed by anaerobic methanotrophy, methane production apparently surpassed methanotrophy, leading to higher emission when compared with that during high tide. In addition, potential rates of aerobic methane oxidation were neither correlated with methane emission fluxes nor oxygen penetration, and pmoA gene abundances during different tidal phases, suggesting that methane emission is not controlled by initial population size, oxygen availability, and methane oxidation and production capacity individually. Overall, temperature and sulfate availability related to tidal inundation appear to be the first order control of methane emission. Factors modulating microbial physiological capacities and activities for methane production and consumption are also important to constrain the mechanistic bases for methane emission.

The interaction of hydrous fluids and melts with dry rocks of the lithospheric mantle has pronounced effects on its viscoelastic and chemical properties due to the formation of compositionally distinct secondary phases. In addition, melt percolation and the associated metasomatic alteration of mantle rocks may also facilitate alteration of the pre–existing rock texture and olivine crystallographic preferred orientation (CPO) and thus seismic properties. Here we explore the relationship between mantle metasomatism, deformation and seismic anisotropy using subduction–related mantle xenoliths from the Penghu Islands, western Taiwan. The investigated xenoliths have equilibrated at upper lithospheric mantle conditions (879°C to 1127 °C) and show distinct variations in their chemical composition, texture and olivine CPO allowing for the classification of two distinct groups. Group 1 xenoliths show a porphyroclastic texture, olivine grains are mostly characterized by [100]–axial pattern symmetries and are chemically depleted. In contrast, chemically enriched Group 2 xenoliths are characterized by a dominantly fine–grained equigranular texture and olivine frequently displays [010]–axial pattern symmetries. The different chemical compositions are indicative of cryptic and modal to stealth metasomatic alteration of Group 1 and Group 2 xenoliths, respectively. Furthermore, the observed olivine [100]–axial pattern of Group 1 xenoliths reflects deformation by dislocation creep under high temperature, low pressure and dry conditions, whereas olivine [010]–axial patterns of Group 2 xenoliths imply activation of olivine [001] glide planes along preferentially wetted (010) grain boundaries. This correlation indicates that the variation in olivine CPO symmetry from [100]– to [010]–axial pattern in Penghu xenoliths results from deformation and intracrystalline recovery by subgrain rotation during metasomatic alteration induced by melt percolation. The microstructural observations and olivine CPO combined with petrological and geochemical data suggest that Group 1 xenoliths preserve microstructural and chemical characteristics of an old, probably Proterozoic lithosphere, while Group 2 xenoliths record localized Miocene deformation associated with wall–rock heating and metasomatism related to melt circulation. Furthermore, the observed transition of olivine CPO from [100]–axial pattern to [010]–axial pattern by deformation in the presence of variable melt fractions and associated metasomatic alteration can be inferred to have a significant effect on physical properties of mantle rocks.

To investigate the dietary shift that occurred during the transition from the Jomon to Yayoi period which saw the arrival of agriculture in Japan, we performed isotope analysis and radiocarbon dating on human tooth dentine and enamel excavated from archaeological sites in Gunma and Nagano Prefecture. Carbon and nitrogen stable isotope analysis of collagen extracted from dentine showed an average increase of 4.2‰ in δ¹³C between samples from Early Jomon and Last Jomon /Yayoi samples, while δ¹⁵N remained low with no significant change. A major candidate for the cause of this shift is C4 plants, represented by millets, that have a high δ¹³C and low δ¹⁵N. Carbon stable isotope analysis of enamel, on which plants have a more prominent effect compared to collagen, also showed an average increase of 5.2‰. These results suggest the adoption of millet in the Last Jomon to Yayoi period. Further examination that takes the variation of diet-to-eater isotopic spacing between herbivores and carnivores into consideration is in progress, in pursuit of a more quantitative evaluation of millet use.

Late Holocene Paleoclimate and Environmental Reconstructions of Northeast China by High Resolution Stalagmite RecordsJui-Lin Wang1, Hong-Chun Li1,2*, Horng-Sheng Mii31 Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan, ROC2 School of Geographical Sciences, Northeast Normal University, Changchun, Jilin 130024, China3 Department of Earth Sciences, National Taiwan Normal University, Taipei 11677, Taiwan, ROC Two stalagmites, DSH-1 (7-cm long) and DSH-2 (10-cm long), were collected from Diaoshuihu Cave (43o20’32”N, 125o50’35”, 610 m a.s.l.) in southeast Changchun, Jilin, China in summer 2017. They grew on mud debris of an ancient groundwater flow channel inside the cave and contained significant detritus with yellowish color. 210Pb dating and 14C dating were used to determine the chronology of the stalagmites. The former indicates that both of them have modern deposition and the latter establishes the chronology of the stalagmites which cover 4600-year EAMS climatic record. The two stalagmites show a brief growth hiatus at 0.84-cm depth in DSH-1 and 1-cm depth in DSH-2. Above this hiatus, the stalagmites have lighter color and less detritus. The stalagmites were subsampled at 0.1~0.2 mm intervals for d18O and d13C analyses. A total of 486 measurements for DSH-1 and 698 measurements for DSH-2 of d18O and d13C analyses were made over the past 4800 years. The records of the two stalagmites exhibit similar stable isotopic patterns, demonstrating that they are good paleoclimate records. Based on the chronology determined by 210Pb dating and 14C dating, the stable isotope records compare with the local annual precipitation (1905~2012), warm season rainfall, air temperature, and TSI (Total Solar Irradiance). The comparison between stable isotope records and precipitation shows lighter d18O and d13C corresponding to higher rainfall. Good comparison between the d18O and TSI shows heavier d18O is corresponding to lower TSI, and vice versa. The d13C records co-varies with d18O before 1910 C.E., reflecting that surface vegetation (shown by the d13C) above the cave was mainly influenced by wetness (reflected by the d18O). It is interesting to see that both d18O and d13C values were lower, reflecting wetter climates during the Little Ice Age. A very dry and poor vegetation episode appeared between 1300 and 1400 yr BP. The study area is near the north boundary of East Asian Summer Monsoon and shows quite different precipitation patterns on decadal scales from central and south China, which should be very interesting for climatic study. Key words: Stalagmite, Stable isotope record, Late Holocene

Reconstruction of Holocene Climate Change in Siberia Altai Region with StalagmiteYou-Syuan Chen1, Jian-Jun Yin2, Tatiana Blyakharchuk3, Hong-Chun Li1*, Horng-Sheng Mii4, Zong-Ren Peng5, Chuan-Chou Shen11Department of Geosciences, National Taiwan University, Taipei 106, Taiwan, 2Key Laboratory of Karst Dynamics, Institute of Karst Geology, CAGS, Guilin 541004, China, 3Institute for monitoring of climatic and ecological systems, Siberian branch of Russian Academy of Sciences (IMCES SB RAS), Tomsk, Russia, 4Department of Earth Sciences, National Taiwan Normal University, Taipei 106, Taiwan, 5Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 402, Taiwan High latitude region is very sensitive to climate change especially as the current warming causes significant changes in high latitudes. Therefore, paleoclimate reconstruction for high latitude regions is important. In this study, we reconstruct the first high-resolution stalagmite record of Russian Altai region. The sample site is Nadezhda Cave (52º38.872’N, 88º39.194’E, 550m a.s.l.), where is located in Shoria National Park belonging to northwestern Siberian Altai-Sayan Mountains. Surrounded by Russia – Mongolia – China – Kazakhstan, this region connects the Arctic Monsoon from the north, Westerly passing through and Siberian High shrouded in the east. The climate there is humid Continental pattern (Koppen classification Dfb) with average temperatures of -20℃ in January and 20℃ in July. The snow cover stays from October to the next April. The average annual precipitation is about 400mm and about half of the precipitation is accumulated in summer. We collected a 22 cm long stalagmite HOP-1 in summer, 2016. When the sample was collected, there was still ice in the cave. The sample was already stopped growing when we collected it. Very low U content (238U = ~70 ppb) and relatively high Th content (232Th = 2~9.3 ppb) of the stalagmite resulted in unsuccessful 230Th/U dating (-262 ± 284 yr BP on the top and -19,935 ± 22,246 yr BP at the bottom). A total of 21 AMS 14C dates from 21 horizons of the stalagmite are in good age sequences and provide a detailed chronology, showing that the stalagmite grew from about 6,000 yr BP to about 400 yr BP. Two programs were used to reconstruct the age model, the rbacon package of R software and the Ager program of Arand software. As the rbacon model was smoothing the growth rates whereas the Ager model showed more details of the changing growth rates, we choose the Ager model. The average growth rate was about 20yr/mm. At about 50mm, 90mm and the bottom of the stalagmite the growth rates declined to about 100yr/mm. For those slow growth periods, both δ18O and δ13C became heavier probably due to dry climatic conditions. The stable isotope samples were drilled at 0.2-0.5mm interval. A total of 1007 measurements from the stalagmite were obtained. The δ18O values range from -10‰ to -15‰ with an average of -13‰ (VPDB), and the δ13C values range from -3‰ to -10‰ with an average of -6‰. Both δ18O and δ13C records have about 0.1 ky cycle. Unlike the stalagmite records in East Asia Monsoon region which often appear a decreasing trend from middle Holocene to late Holocene, the HOP-1 δ18O record does not have such a trend. The δ18O record compares well with the pollen record of this region. Before 1.8 ka, the δ13C record co-varies with the δ18O record, indicating the vegetation was mainly controlled by moisture change. After 1.8 ka, the δ13C did not co-vary with the δ18O and sometimes showed opposite trends. This may be caused by temperature influence on vegetation after the significant cooling. During the past 4 ka, we could find 8 dry events at 0.5 ka, 1.2 ka, 1.3 ka, 1.7-1.9 ka, 2.1-2.9 ka, 3 ka, 3.4 ka, and 3.7 ka, respectively.