1989 Fiscal Year Final Research Report Summary
LATE QUATERNARY SEISMO-TECTONIC STUDY IN THE CIRCUM-OACIFIC AREA --THE 2nd SURVEY--
Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants |
|Research Institution||YOKOHAMA NATIONAL UNIVERSITY |
OTA Yoko Department of Geography, Yokohama National University, 教育学部, 教授 (80017714)
NARANJO J.A. Servicio Nacional de Geologia y Mineria, Chile, 研究員
PASKOFF R. Department of Geography, University of Lyon, 教授
BERRYMAN K.R. Earth Deformation Section, New Zealand Geological Survey, 地殼変動研究室, 研究員
KOBA Motoharu Department of Geography, Kansai University, 文学部, 助教授 (40141949)
MIYAUCHI Takahiro Department of Geological Sciences, Chiba University, 理学部, 助手 (00212241)
|Project Period (FY)
|Keywords||Chile / New Zealand / Marine terrace / Active fault / Seismo-tectonic movement / Paleoseismicity / Quaternary dating / 古地震の復元|
This study aims to establish the late Quaternary seismo-tectonic movement in the Circum Pacific area. Field work was carried out in 1989 in the northern Chile and southeastern South Island, New Zealand. Quaternary chronology and rate of deformation will be discussed after the dating of samples by ESR, aminoacid and ^<14>C method. Main results are as follows:
New Zealand: (Kaikoura Peninsula: 1) Four steps of Pleistocene marine terraces and their progressive northwestward tilting were identified. 2) Episodic uplift during the Holocene are deduced from subdivided Holocene marine terraces.
Coastal area from Kaikoura Peninsula to Cape Campbell: 1) Two steps of Pleistocene marine terraces and their northward tilting were identified. 2) One marine terrace near Long Point indicates a downwarping. 3) Holocene marine terrace reaches 20 m in height suggests probable coseismic uplift.
Big Lagoon and Lake Grassemere: 1) An apparent upper limit of estuarine deposits is 2 m above sea level at the highest indicating that these areas are subsiding. No Holocene marine terraces exist.
Chile: Tongoy and La Serena: 1) A series of marine terraces were identified. 2) Differential uplift is observed in both areas. 3) Normal faults dislocating marine terraces are mapped. 4) Quebrada Teniante Fault shows repeated activities during the Quaternary and an apparent left-lateral offset. 5) No subdivided Holocene terraces exists.
Mejillones Peninsula: 1) Marine terraces, up to ca. 700m in height and composed of ca. 10 steps, show a continued uplift for long time. 2) many normal faults dislocate marine terraces and alluvial fans progressively.
Research Products (13 results)