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Abstract. The penetration of plasma sheet ions into the inner magnetosphere is very important to the inner magnetospheric dynamics since plasma sheet ions are one of the major particle sources of ring current during storm times. However, the direct observations of the inner boundary of the plasma sheet are fairly rare due to the limited number of satellites in near equatorial orbits outside 6.6 R E . In this paper, we used the ion data recorded by TC-1 from 2004 to 2006 to study the distribution of inner boundary of ion plasma sheet (IBIPS) and for the first time show the observational distribution of IBIPS in the equatorial plane. The IBIPS has a dawn-dusk asymmetry, being farthest to the Earth in the 06:00 08:00 LT bin and closest to the Earth in the 18:00-20:00 LT bin. Besides, the IBIPS has also a day-night asymmetry, which may be due to the fact that the ions on the dayside are exposed more time to loss mechanisms on their drift paths. The radial distance of IBIPS decrease generally with the increase of Kp index. The mean radial distance of IBIPS is basically larger than 6.6 R E during quiet times and smaller than 6.6 R E during active times. When the strength of convection electric field increases, the inward shift of IBIPS is most significant on the night side (22:00-02:00 LT). For Kp ≤ 0 + , only 16% of IBIPSs penetrate inside the geosynchronous orbit. For 2 ≤ Kp < 3 + , however, 70% of IBIPSs penetrate inside the geosynchronous orbit. The IBIPS has weak correlations with the AE and Dst indexes. The average correlation coefficient between R i and Kp is −0.58 while the correlation coefficient between R i and AE/Dst is only −0.29/0.17. The correlation coefficients are local time dependent. Particularly, R i and Kp are highly correlated (r = −0.72) in the night sector, meaning that the radial distance of IBIPS R i in the night sector hasCorrespondence to: J. B. Cao (jbcao@cssar.ac.cn) the good response to the Kp index These observations indicate that Kp plays a key role in determining the position of IBIPS.

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We examined the lithostratigraphy and deformation structures of the accreted pelagic rocks in Lake Hamana area, Central Japan, based on a detailed field mapping and the radiolarian ages. The constructed lithostratigraphy is composed of Lopingian (Upper Permian) grey chert, black chert, black claystone with a high carbon content of 4.85-6.78 wt%, siliceous claystone, black chert, and Anisian (Middle Triassic) grey chert, in the ascending order. The symmetry in the lithostratigraphy and the change in the radiolarian ages with respect to black carbonaceous claystone are presumed to represent a deep-sea anoxic event that occurred across the Permian-Triassic (P-Tr) boundary. The P-Tr boundary black carbonaceous claystone suffered from an intense shear, resulting in blocks of siliceous claystone in the scaly black claystone matrix. In places, the sheared terrigenous rocks composed of sandstone blocks in the mudstone matrix are intercalated into the pelagic rocks, possibly representing complex mélange forming processes during the development of the Jurassic accretionary complex.