Titanium behavior in quartz during retrograde hydration: Occurrence of rutile exsolution and implications for metamorphic processes in the Sør Rondane Mountains, East Antarctica

AbstractIn the central Sør Rondane Mountains, East Antarctica, orthopyroxene felsic gneiss (OPG) was converted to hornblende-biotite felsic gneiss (HBG) by hydration that accompanied the intrusion of pegmatite. The retrograde HBG contains exsolved rutile in quartz. The composition of orthopyroxene and clinopyroxene in OPG suggests a temperature of 840°C (interpreted as the near-peak temperature), and the composition of hornblende and plagioclase in HBG suggests a temperature of 670–700°C (interpreted as the temperature during hydration). Ti concentrations in quartz were measured using an electron probe micro-analyzer, and Ti-in-quartz thermometers were applied. Measured Ti concentrations were 110ppm (equivalent to 760–820°C) for homogeneous quartz from OPG and 35ppm (650–700°C) for an exsolution-free area of a quartz grain from HBG. The pre-exsolution Ti concentration in quartz from HBG was reconstructed with 100μm beam diameter and 25kV of accelerating voltage, giving 103ppm, similar to the value obtained for homogeneous quartz in OPG. The temperatures obtained using a Ti-in-quartz thermometer are consistent with those estimated using other thermometers. Although analysis of the main constitute minerals in HBG yields the conditions of hydration, the reconstructed pre-exsolution Ti content in quartz within HBG yields the pre-hydration conditions. Thus, the Ti-in-quartz thermometer is a potentially powerful tool with which to identify the peak or near-peak temperature conditions, even for retrogressed metamorphic rocks

Geology of eastern Muhlig -Hofmannfjella and Filchnerfjella in Dronning Maud Land, East Antarctica; A preliminary report of a Japan-Norway-Germany joint geological investigation

The geological history of Filchnerfjella and surrounding areas (2゜E to 8゜E) in central Dronning Maud Land,East Antarctica,is constructed from metamorphic and igneous petrology,and structural investigations.The geology of Filchner-fjella consists mainly of metamorphic rocks accompanied by intrusive rocks.Two stages of metamorphism can be recognized in this area.The earlier stage metamorphism is defined as a porphyroblast stage (garnet,hornblende,and sillimanite stable), and the later one is recognized as a symplectic stage (orthopyroxene and cordieritestable).Taking metamorphic textures and geothermobarometries into account,the rocks experienced an early high-P/medium-T followed by a low-P and high-T stage. Partial melting took place during the low-P/high-T stage,because probable melt of leucocratic gneiss contains cordierite.The field relationships and petrography of the syenite at Filchnerfjella are similar to those of post-tectonic plutons from central Dronning Maud Land,and most of the post-tectonic intrusive rocks have within-plate geochemical features.The structural history in Filchnerfjella and surrounding areas can be divided into the Pan-African stage and the Meso to Cenozoic stage that relates to the break-up of Gondwana

Geologic connection between Dronning Maud Land and Enderby Land

The Tenth Symposium on Polar Science/Ordinary sessions: [OG] Polar Geosciences, Wed. 4 Dec. / Entrance Hall (1st floor), National Institute of Polar Researc

Phase Lag Analyses on Ictal Scalp Electroencephalography May Predict Outcomes of Corpus Callosotomy for Epileptic Spasms

Objective: We aimed to clarify the patterns of ictal power and phase lag among bilateral hemispheres on scalp electroencephalography (EEG) recorded pre-operatively during epileptic spasms (ESs) and the correlation with the outcomes following corpus callosotomy.Methods: We enrolled 17 patients who underwent corpus callosotomy for ESs before 20 years of age. After corpus callosotomy, seven patients did not experience further ESs (favorable outcome group), and the remaining 10 patients had ongoing ESs (unfavorable outcome group). We used pre-operative scalp EEG data from monopolar montages using the average reference. The relative power spectrum (PS), ictal power laterality (IPL) among the hemispheres, and phase lag, calculated by the cross-power spectrum (CPS) among symmetrical electrodes (i.e., F3 and F4), were analyzed in the EEG data of ESs from 143 pre-operative scalp video-EEG records. Analyses were conducted separately in each frequency band from the delta, theta, alpha, beta, and gamma range. We compared the means of those data in each patient between favorable and unfavorable outcome groups.Results: Among all frequency bands, no significant differences were seen in the individual mean relative PSs in the favorable and unfavorable outcome group. Although the mean IPLs in each patient tended to be high in the unfavorable outcome group, no significant differences were found. The mean CPSs in the delta, theta, and gamma frequency bands were significantly higher in the unfavorable than in the favorable outcome group. Using the Youden index, the optimal cutoff points of those mean CPS values for unfavorable outcomes were 64.00 in the delta band (sensitivity: 100%, specificity: 80%), 74.20 in the theta band (100, 80%), and 82.05 in the gamma band (100, 80%). Subanalyses indicated that those CPS differences originated from pairs of symmetrical electrodes in the bilateral frontal and temporal areas.Significance: Ictal power and laterality of the ictal power in each frequency band were not associated with the outcomes of CC; however, the phase lags seen in the delta, theta, and gamma frequency bands were larger in the unfavorable than in the favorable outcome group. The phase lags may predict outcomes of CC for ESs on pre-surgical scalp-ictal EEGs

Safety analysis of two different regimens of uracil–tegafur plus leucovorin as adjuvant chemotherapy for high-risk stage II and III colon cancer in a phase III trial comparing 6 with 18 months of treatment: JFMC33-0502 trial

PURPOSE: The JFMC33-0502 trial is a phase III clinical study designed to determine the most appropriate duration of postoperative adjuvant chemotherapy with uracil–tegafur (UFT) plus leucovorin in patients with stage IIB or III colon cancer. We report the interim results of preplanned safety analyses. METHODS: Patients with stage IIB or III colon cancer who had undergone curative resection were randomly assigned to receive UFT (300 mg/m(2)) plus leucovorin (75 mg/day) for 6 months (control group, 4 weeks of treatment followed by a 1-week rest, five courses) or for 18 months (study group, 5 days of treatment followed by a 2-day rest, 15 courses). Treatment status and safety were evaluated. RESULTS: A total of 1,071 patients were enrolled, and 1,063 were included in safety analyses. Treatment completion rate at 6 months was 74.0 % in the control group and 76.7 % in the study group. Treatment completion rate in the study group at 18 months was 56.0 %. The overall incidence of adverse events (AEs) was 75.3 % in the control group and 77.6 % in the study group. The incidences of grade 3 or higher AEs were low in both groups. During the first 6 months, the incidences of the subjective AEs were significantly lower in the study group. CONCLUSIONS: Oral UFT plus leucovorin given by either dosage schedule is a very safe regimen for adjuvant chemotherapy. In particular, 5 days of treatment followed by a 2-day rest was a useful treatment option from the viewpoint of toxicity even when given for longer than 6 months. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00280-014-2461-5) contains supplementary material, which is available to authorized users

Retrograde metamorphism of Vesthaugen, north Sør Rondane Mountains, East Antarctica

第3回極域科学シンポジウム/第32回極域地学シンポジウム 11月30日（金） 統計数理研究所 ３階セミナー

Metamorphic textures and garnet REE derived from anatexis of Fe-rich granulite in Vesthaugen, Sør Rondane Mountains, East Antarctica

第6回極域科学シンポジウム[OG] 地圏11月16日（月）　国立極地研究所１階交流アトリウ

Newly obtained data for geologic unit boundaries at central part of Sør Rondane Mountains

第2回極域科学シンポジウム/第31回極域地学シンポジウム 11月17日（木） 国立極地研究所　2階大会議室前フロ

Isobaric cooling retrograde metamorphism in Dronning Maud Land, East Antarctica.

第2回極域科学シンポジウム/第31回極域地学シンポジウム 11月17日（木） 国立極地研究所　2階大会議室前フロ