Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorY. Suganumaen_US
dc.contributor.authorT. Hamadaen_US
dc.contributor.authorS. Tanakaen_US
dc.contributor.authorM. Okadaen_US
dc.contributor.authorH. Nakayaen_US
dc.contributor.authorY. Kunimatsuen_US
dc.contributor.authorH. Saegusaen_US
dc.contributor.authorS. Nagaokaen_US
dc.contributor.authorB. Ratanasthienen_US
dc.description.abstractA paleomagnetic study has been conducted on the Miocene Chiang Muan Formation in northern Thailand, in order to provide a chronology for the earliest large-bodied Miocene hominoid in Southeast Asia. The Chiang Muan Formation is mainly composed of clay, silt and sand beds, indicating lacustrine and fluvial environments. Paleomagnetic samples were collected from 124 horizons along an approximately 150 m thick section from the Chiang Muan Formation at the opencast Chiang Muan Mine. Rock magnetic experiments and stepwise thermal demagnetizations revealed that the main carrier of the magnetization of the sediments is magnetite and the samples have stable magnetization. Exceptionally, stable magnetization is also carried by hematite, which is represented by red colored sediments. Characteristic remanent magnetization (ChRM) directions, calculated by the principal component analysis, revealed normal or reversed polarities of magnetization, which allow the application of the reversal test of McFadden and McElhinny [McFadden, P.L., McElhinny, M.W., 1990. Classification of the reverse test in paleomagnetism. Geophys. Int. 103, 725-729]. The mean paleomagnetic directions of the normal and reversed polarities passed the reversal test with a classification C, indicating that the Chiang Muan Formation preserved the primary magnetization. In total, five normal and four-reversed polarity zones are recognized from the studied section. Based on paleontological age constraints, this magnetostratigraphic column of the Chiang Muan Formation correlates best with Chron C5AAn-C5n of the geomagnetic polarity time scale (GPTS) from the geological time scale (GTS2004) developed by Gradstein et al. [Gradstein, F., Ogg, J., Smith, A. (Eds.) 2004. A Geological Time Scale 2004. Cambridge Univ. Press, Cambridge, UK, p. 589]. This correlation revealed that sedimentation of the Chiang Muan Formation began approximately at 13 Ma and continued until 9.8 Ma with a mean sedimentation rate of approximately 4.2 cm/ky. The age of the earliest Southeast Asian hominoid is between 12.4 and 13.0 Ma. © 2006 Elsevier B.V. All rights reserved.en_US
dc.subjectAgricultural and Biological Sciencesen_US
dc.subjectEarth and Planetary Sciencesen_US
dc.titleMagnetostratigraphy of the Miocene Chiang Muan Formation, northern Thailand: Implication for revised chronology of the earliest Miocene hominoid in Southeast Asiaen_US
article.title.sourcetitlePalaeogeography, Palaeoclimatology, Palaeoecologyen_US
article.volume239en_US Institute of Advanced Industrial Science and Technologyen_US Universityen_US University of Educationen_US Universityen_US Universityen_US of Hyogo, Kobeen_US Universityen_US Mai Universityen_US
Appears in Collections:CMUL: Journal Articles

Files in This Item:
There are no files associated with this item.

Items in CMUIR are protected by copyright, with all rights reserved, unless otherwise indicated.