Emplacement Mechanism of the Older Ryoke Granites in the Yanai District, Southwest Japan, with Special Reference to Extensional Deformation in the Ryoke Metamorphic Belt

The Ryoke metamorphic rocks in the Yanai district, southwest Japan show geological and rock structures produced by three different phases of ductile deformation. During the first phase (D1), a distinct foliation parallel to lithologic layering was formed under the thermal peak conditions during the low-pressure facies series Ryoke metamorphism, which is ascribed to the sheet-like intrusion of the older Ryoke granites. The second phase deformation (D2) led to the formation of mylonitic shear zones and nappes. The deformation of the third phase (D3) was responsible for the formation of the upright folds with E-W trending axes. In the metamorphic rocks of the Tsuzu area, which is placed in the northern part of the Yanai district, are often found melt-filled fractures of minor scales, which cut across their foliation. The deformation related to the formation of these melt-filled fractures resulted commonly from the foliation parallel extension. The overall movement picture inferred from the melt-filled fractures appears to be of the shear sense for the top to the north. The formation of the melt-filled fractures was responsible for the intrusion of the older Ryoke granites. Asymmetric textures such as extensional crenulation cleavage (ECC) and rotation of porphyroblasts, which grew under the thermal peak of the low-pressure facies series metamorphism, are also formed in the metapelites. The shear sense read from the asymmetric textures is the top to the north, though fairly dispersed. This is harmonic with the overall movement picture inferred from the melt-filled fractures. Therefore it can be said that the overall movement picture of the D1. deformation of the metamorphic rocks in the Tsuzu area during and immediately before the intrusion of the older Ryoke granites appears to have been of the same style of extension tectonics. Consequently, the D1 deformation occurred under extensional stress regime and the older Ryoke granites intruded in extensional fracture zones at intermediate crustal depths. The nappes of the metamorphic rocks and older granites were formed during the D2 deformation probably under compressional stress regime

Alteration Reaction and Mass Transfer via Fluids with Progress of Fracturing along the Median Tectonic Line, Mie Prefecture, Southwest Japan

We have analyzed mass transfer in the cataclasite samples collected from the Median Tectonic Line, southwest Japan, in which the degree of fracturing is well correlated with the bulk rock chemical compositions determined by the X-ray fluorescence (XRF) analysis. The results of “isocon” analysis indicate not only a large volume increase up to 110% but also the two-stage mass transfer during cataclasis. At the first stage from the very weakly to weakly fractured rocks, the weight percents of SiO2, Na2O, and K2O increase, while those of TiO2, FeO, MnO, MgO, and CaO decrease. At the second stage from the weakly to moderately and strongly fractured rocks, the trend of mass transfer is reversed. The principal component analysis reveals that the variation of chemical compositions in the cataclasite samples can be mostly interpreted by the mass transfer via fluids and by the difference in chemical composition in the protolith rocks to lesser degree. Finally, the changes in the modal composition of minerals with increasing cataclasis analyzed by the X-ray diffraction (XRD) with the aid of “RockJock” software clearly elucidate that the mass transfer of chemical elements was caused by dissolution and precipitation of minerals via fluids in the cataclasite samples

From symplectic cohomology to Lagrangian enumerative geometry

We build a bridge between Floer theory on open symplectic manifolds and the enumerative geometry of holomorphic disks inside their Fano compactifications, by detecting elements in symplectic cohomology which are mirror to Landau-Ginzburg potentials. We also treat the higher Maslov index versions of LG potentials. We discover a relation between higher disk potentials and symplectic cohomology rings of anticanonical divisor complements (themselves related to closed-string Gromov-Witten invariants), and explore several other applications to the geometry of Liouville domains.Comment: 47 pages, 13 figures; v2: reference fixes, minor correction

SHRIMP U-Pb ages of the Karasaki mylonites in western Shikoku, Japan

唐崎マイロナイトの優白質角閃岩マイロナイトについて, ジルコンのSHRIMP U-Pb年代測定を行った結果, 1試料からの8粒子は114.2±3.9～102.3±4.5Ma(±1σ)の年代値を示した.マイロナイト化した優白質角閃岩は, SiO_2含有量が低い(49wt.%)ことと, 主として角閃石, 曹長石, 緑泥石および緑簾石のモード比の違いによる数百μm～数mm幅の顕著な層状構造を有することから, 玄武岩質火山岩または火山砕屑岩に由来する砂岩を原岩としている可能性が高い.優白質角閃岩マイロナイト中の丸みを帯びたジルコンは, ある程度遠方より運搬される過程で円磨された可能性が高いこと, マグマから晶出したジルコンに特徴的なオシレトリー累帯構造が認められることから, 砕屑性起源のジルコンであると判断される.また, その年代値が約110Maの狭い範囲を示す事実は, ジルコンが"古領家帯"に帰属すると考えられる真穴帯の大島変成岩や肥後帯の約110Ma深成岩類のみに由来する可能性を示唆する.したがって, 本論において初めて"古領家帯"中にアルビアン以降の堆積岩源変成岩が存在していることが明らかとなった.Zircon U-Pb isotope ages have been analyzed by the Sensitive High Resolution Ion MicroProbe (SHRIMP) in an leucocratic amphibolite mylonite from the Karasaki mylonites, western Shikoku, Japan which has been considered to belong to the "Paleo-Ryoke" belt. Eight zircon grains from the sample yielded U-Pb ages of Albian (Early Cretaceous) ranging from 114.2 ± 3.9 Ma to 102.3 ±4.5 Ma (± 1σ errors). The protolith of the mylonitized leucocratic amphibolite has been inferred to be basaltic volcanic sandstones, because the SiO_2 content is low (49 wt.%), and the leucocratic amphibolite (consisting of albite and epidote rich, and chlorite and epidote rich layers alternates with amphibole rich and chlorite rich layers on the order of a few mm, suggestive of original sedimentary layering. All the zircon grains can be inferred to be detrital based on both the facts that they were abraded possibly due to sedimentation processes, and that they show oscillatory zoning indicating igneous (primary) texture. The small range of U-Pb ages varying ca. 110 Ma suggests that the zircon grains in the volcanic sandstones were supplied only from the Oshima metamorphic rocks of the Maana belt and the Higo plutonic rocks of the Higo belt whose U-Pb zircon ages were dated as ca. 110 Ma. The fact clearly indicates that the metamorphic rocks (Karasaki mylonites) originated from post-Albian sediments also constitute as a new member of the "Paleo-Ryoke" belt

Improvement of Open Bite and Stomatognathic Function in an Axenfeld- Rieger Syndrome Patient by Orthodontic Sectional Arch Mechanics: Clinical Considerations and the Risk of Orthodontic Tooth Movement

Orthodontists need to understand the orthodontic risks associated with systemic disorders. Axenfeld-Rieger syndrome (ARS) is a rare autosomal dominant disorder with genetic and morphological variability. The risks of orthodontic treatment in ARS patients have been unclear. Here we describe the correction of an anterior open bite in a 15-year-old Japanese female ARS patient by molar intrusion using sectional archwires with miniscrew implants. An undesirable development of external apical root resorption (EARR) was observed in all intrusive force-applied posterior teeth during the patient’s orthodontic treatment, suggesting that ARS patients have a higher risk of EARR than the general population

A Case of Intraductal Papillary Neoplasm of the Bile Duct with Stromal Invasion

Intraductal papillary neoplasm of the bile duct (IPNB) represents biliary papillary tumors mainly growing and is considered to be of relatively low-grade malignancy. Here we report a case of IPNB in whom the poorly differentiated component deeply infiltrated the bile duct wall. A 77-year-old male had an invasive carcinoma of the bile duct 3 cm in size. He underwent right hemihepatectomy with combined resection of the extrahepatic bile duct. Papillary growing tumor was observed in the common bile duct and the right posterior Glisson's pedicle was invaded. Histologic finding showed papillary adenocarcinoma in the surface layer superficially extending to the epithelium of the surrounding bile duct. In the subserosal layer, the tumor represented poorly differentiated adenocarcinoma. The tumor was diagnosed as invasive bile duct carcinoma arising from IPNB

Clinical significance of portal vein embolization before right hepatectomy

Background/Aims: To identify clinical significances of portal vein embolization (PVE) prior to major hepatectomy, we examined clinical parameters and outcome after right hepatectomy in patients who underwent PVE. Methodology: The subjects were 30 patients who underwent PVE (PVE group), and 52 patients (non-PVE), in whom PVE was considered unnecessary, followed by right hepatectomy for hepatobiliary cancer. Results: Total hepatic volume after PVE (1068±268 ml) tended to increase compared with before PVE (p=0.059). After PVE, the change in hemi-liver volume was 8.9±6.0%. Increases in hepatic volume of non-embolized left liver before and at 4 weeks after hepatectomy between the PVE and non-PVE groups were similar. Changes in hepatic volumes before and after PVE were not significantly influenced by background liver disease. After PVE, the functional liver volume (419±185cm 3) was significantly lower than morphological volume (564±165cm3) in the embolized liver (p<0.05). Although preoperative liver function was worse in the PVE group compared with non-PVE, serious hepatic complications were rarely observed in the PVE group. Conclusions: Marked changes in hepatic volume were noted after PVE in patients with impaired liver function and those who need large-volume right hepatectomy, especially in functional volume, suggesting that PVE is a useful procedure to prevent postoperative liver failure

Usefulness of Omental Wrapping to Prevent Biliary Leakage and Delayed Gastric Emptying in Left Hepatectomy

Background/Aims: To identify the clinical significance of the omental wrapping (OW) technique after left hepatectomy to reduce bile leakage and delayed gastric emptying. We examined clinical and surgical parameters after left hepatectomy with or without biliary reconstruction in 79 patients. Methodology: This was a retrospective study of data from 14 patients undergoing OW compared to 65 patients in the control group. Results: Bile leakage and delayed emptying after hepatectomy were observed in 15 and 11 patients, respectively. Gender, background liver function, liver diseases and preoperative liver function tests were not significantly different between both groups. Prevalence of extent of hepatectomy, existence of segment 1 resection, biliary-enteric anastomosis, operating time and blood loss were also not significantly different between groups. Prevalence of bile leakage was similar between the OW and the control group (14 vs. 20%) (p=0.91). Prevalence of delayed gastric emptying was not significantly different between groups, but this complication was not observed in the OW group in comparison with the control group (0% vs. 20%) (p=0.31). Prevalence of other complications and hospital stay after hepatectomy were similar between groups.Conclusions: Significant differences for preventing left hepatectomy related complications were not found; however, it is possible that OW could reduce delayed gastric emptying