Magnetic-polarity stratigraphy of Siwalik Group sediments of Tinau Khola section in west central Nepal, revisited

スポンサーリンク

概要

• 論文の詳細を見る

• Remanent magnetization of sandstones sampled at 127 levels/sites throughout a 1710 m thick Siwaliks molasse sequence exposed along the Tinau Khola river in Nepal has been studied using thermal demagnetization. the magnetic remanence consists of: a secondary low-temperature component of normal polarity, unblocked mostly below 400-500℃. close to the present-day field, and a high-temperature characteristic remanence (ChRM) unblocked mostly between 600 and 685℃, represented by both normal and reverse polarities. Demagnetization behaviour and isothermal remanence acquisition indicate that the secondary component resides on goethite and maghemite/magnetite whereas specular haematite carries ChRM. Anisotropy of magnetic susceptibility data reveals primary depositional magnetic fabric as judged by oblate ellipsoids and subvertical tilt-corrected minimum susceptibility axes. A magnetic polarity sequence established using tilt-corrected ChRM directions from 124 levels reveals more details not found in the polarity stratigraphy worked out by Munthe et al. (1983). Comparison of the sequence with a standard polarity time-scale (Harland et al. 1989) suggests a depositional time range between c. 5.9 Ma (older than chron 3r) and 11 Ma (younger than chron 5r-2) for the section considered. According to new data, the horizon of Sivapithecus punjabiecus fells close to the reversal boundary at c. 8.54 Ma (the lower age limit of the normal polarity chron 4Ar-1). Hence, the hominoid should be regarded as of c. 8.5 Ma rather than 9.0-9.5 Ma as suggested by Munthe et al. (1983).

• For the Royal Astronomical Society, the Deutsche Geophysikalische Gesellschaft, and the European Geophysical Society by Blackwell Scientific Publicationsの論文

著者

• Gautam Pitambar

  北海道大学理学部地質学鉱物学教室

• Gautam P

  Hokkaido Univ. Sapporo Jpn

• Gautam Pitambar

  Coe For Neo-science Of Natural History Graduate School Of Science Hokkaido University

• Gautam Pitambar

  Hokkaido Univ.

• Gautam Pitambar

  Division Of Earth And Planetary Sciences Graduate School Of Science Hokkaido University

関連論文

• Magnetism and granulometry of Pleistocene sediments of Dhapasi section, Kathmandu (Nepal) : implications for depositional age and paleoenvironment
• Integration of magnetism and heavy metal chemistry of soils to quantify the environmental pollution in Kathmandu, Nepal
• Magnetic susceptibility of dust-loaded leaves as a proxy of traffic-related heavy metal pollution in Kathmandu city, Nepal
• 西南北海道洞爺湖東方の鮮新-更新統について : 堆積相・花粉層序・古地磁気層序
• Recent Advances in Research on Terrestrial and Marine sequences from the mid-Cretaceous Oceanic Anoxic Events (OAEs).
• Preface
• Environmental magnetic approach towards the quantification of pollution in Kathmandu urban area, Nepal
• Two Metamorphic Events of the Nepal Himalayas Prior and Posterior to India-Eurasia Collision
• Magnetic-polarity stratigraphy of Siwalik Group sediments of Tinau Khola section in west central Nepal, revisited
• Magnetic Properties of some late Paleozoic to Tertiary Sedimentary Rocks of Tansen Area, Lesser Himalaya, Nepal
• On the Nature of Remanence in the 1985 Andesitic Pumice with Self-Reversed Magnetization from Nevado del Ruiz, Colombia
• 513 Remanent magnetism and fission-track ages of some rocks from the Ampipal massif, the Lasser Himalaya, Nepal
• Paleomagnetism of the Northwestern Part of the Mahabharat Synclinorium, Lesser Himalaya, Nepal
• A Paleomagnetic Reconnaissance of some late Precambrian to Early Paleozoic Rocks of Tansen Area, Lesser Himalaya, Nepal
• Magnetic minerals and magnetic properties of the Siwalik Group sediments of the Karnali river section in Nepal
• Mapping of subsurface karst structure with gamma ray and electrical resistivity profiles : a case study from Pokhara valley, central Nepal
• Depositional chronology and fabric of Siwalik group sediments in Central Nepal from magnetostratigraphy and magnetic anisotropy
• Magnetic polarity stratigraphy of Siwalik Group sediments of Karnali River section in western Nepal
• Magnetostratigraphic dating of the prime-time sedimentary record of Himalayan tectonics and climate: new age constraints (13-10 Ma) from the Siwaliks of the Tinau Khola north section, Nepal
• Reflection of cross-disciplinary research at Creative Research Institution (Hokkaido University) in the Web of Science database: appraisal and visualization using bibliometry

もっと見る 閉じる

スポンサーリンク