Rock-magnetic and Paleomagnetic Studies on Sediment Cores from Lake Baikal

富山大学　理学部　地球科学

バイカル湖堆積物の岩石磁気学的測定による過去250万年の古気候変動の解析

取得学位：博士(理学)，学位授与番号：博甲第266号，学位授与年月日：平成10年9月30日,学位授与年：199

Polarity reversals of remanent magnetization in a sedimentary core from Northwind Ridge, western Arctic Ocean

We studied the remanent magnetization of a sedimentary core PC2 (6.48m length) drilled during the MR99-K05 cruise of JAMSTEC in the western Arctic Ocean. Discrete specimens and u-channel samples were used in the study. In the discrete specimens, the change of remanent magnetization with depth show many clear polarity reversals in both inclination and declination. Furthermore, most reversals in discrete specimens correlated well with those in the u-channel samples. Core PC2 is characterized by distinct alternations of dark gray and brownish layers. Through comparison of lithostratigraphic cycles with glacial-interglacial cycles (referring to R.L. Phillips and A. Grantz, Geol. Soc. Am. Bull., 109, 1101, 1997), sedimentary cycles of core PC2 are correlated to marine isotope stages up to MIS-8. This indicates that polarity reversals of remanent magnetization in core PC2 are geomagnetic excursions in the Brunhes epoch. Comparison with the previously known geomagnetic excursions shows that the polarity reversals are clear and have long duration in core PC2. This feature may be related to characteristic geomagnetism around the western Arctic Ocean

ヒト末梢血・培養細胞を用いた大気汚染物質の免疫毒性評価法の開発

名古屋大学 / 金沢大学医薬保健研究域医学系近年、PM2.5 などの大気汚染による喘息やアレルギー性鼻炎の悪化が、統計調査や動物実験によって示唆されている。大気汚染に含まれる化学物質によって、花粉・ダニなどのアレルゲンが、よりアレルギーを起こしやすい形に変化したり、アレルギーに関与する細胞が影響を受けたりする可能性が考えられる。このような化学物質によるアレルギーの悪化のしやすさを、採取した血液を使って簡単に調べる方法の開発を試みた。Recently, exacerbation of asthma and allergic rhinitis due to air pollution has reported using epidemiologic data and animal experiments. It is possible that chemicals contained in air pollution modify allergen (ex. pollen, mite) to enhance antigenicity, or affect cells involved in allergy. In this research, we tried to develop a convenient method to estimate these exacerbation of allergy on personal level using peripheral human blood.研究課題/領域番号:25340056, 研究期間(年度):2013-04-01 – 2016-03-3

ROCKMAGNETIC ANALYSIS OF SEDIMENTARY SEQUENCES FOR PALEO-ENVIRONMENTAL RESEARCH

Rockmagnetic analyses are conducted to examine their utility for paleo-environmental research on the following three sedimentary sequences : (1) samples from the Omma Formation of central Japan; (2) cores drilled off the Noosa Heads, Australia; (3) a core drilled from Honnor Submarine Valley, Antarctica. The sequences (1) and (2) show clear variation of magnetic properties consistent with the changes of depositional environment which correspond to the change of sedimentary circumstances such as Quaternary glacial-interglacial change. Three drilled cores of sequence (2) show high values in magnetic susceptibility during the time range from 14 to 18ka. The age of the sequence (3) is inferred to be beyond the Holocene, however, a preliminary result of magnetic susceptibility for the core shows no remarkable variation

ANALYSIS OF FINE STRUCTURE OF CHERT AND BIF BY MEASUREMENT OF HIGH RESOLUTION MAGNETIC FIELD AND SCANNING X-RAY ANALYZED MICROSCOPE

The fine structure of chert and BIF was analyzed by magnetic measurement and Scanning X-ray Analyzed Microscope. The magnetic study was done by the HFD system of magnetic field analysis with high Tc (superconducting critical temperature) SQUID. We examined that the HFD system measures the vertical magnetic field around the magnetized sample at high space resolution. The HFD system was applied to Inuyama chert which has a pinkbed layer at the Triassic/Jurassic boundary. The magnetic field at the upper part of the pinkbed layer showed the upward direction and that of the lower chert layer showed the downward direction. Taking the results of rock magnetic study and Scanning X-ray Analyzed Microscope (SXAM) into consideration, the upward magnetic field corresponds to reversed magnetization at the pinkbed layer, which suggests the short reversed polarity in the Nuanetsi normal geomagnetic polarity zone (E. McELHINNY and J. BUREK, Nature, 232,98,1971; D.V. KENT et al., J. Geophys. Res., 100,14965,1995). The HFD measurement of BIF of Antarctica showed the clear striped structure of BIF. The results in this study indicate that HFD measurement with the analysis by SXAM becomes an useful method to investigate the fine structure of geological samples