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New insights into the tectonic evolution of the Andaman basin, northeast Indian Ocean

หน่วยงาน National Institute Of Oceanography (NIO), India

รายละเอียด

ชื่อเรื่อง : New insights into the tectonic evolution of the Andaman basin, northeast Indian Ocean
นักวิจัย : KameshRaju, K.A. , Ramprasad, T. , Rao, P.S. , Rao, B.R. , Varghese, J.
คำค้น : magnetic anomalies , tectonics , seafloor spreading , swaths , bathymetry , seismic data , data analysis , magnetic data
หน่วยงาน : National Institute Of Oceanography (NIO), India
ผู้ร่วมงาน : -
ปีพิมพ์ : 2547
อ้างอิง : Earth and planetary science letters, Vol.221; 145-162p. , http://drs.nio.org/drs/handle/2264/1155
ที่มา : -
ความเชี่ยวชาญ : -
ความสัมพันธ์ : -
ขอบเขตของเนื้อหา : -
บทคัดย่อ/คำอธิบาย :

Multibeam swath bathymetry data acquired over an area of about 30 000 km 2 ,together with magnetic and single channel seismic data, have been analyzed to understand the tectonic evolution of the Andaman basin,northeast Indian Ocean. Swath bathymetry data revealed several morphotectonic features that divide the basin into a complex western part comprising arc-parallel seamount chains and N-S-trending fault systems and a relatively smooth eastern part. A SW-NE-trending spreading ridge bisects the basin.An offset of about 11.8 km at 94 degrees 21 minutes E longitude divides the spreading ridge into SW and NE segments. High-resolution bathymetry and magnetic data enabled us to identify two finer-scale segments over the SW part of the ridge that display distinct topographic fabric compared to the NE segment. Thin sediment cover and presence of axial seamounts characterize SW segments of the ridge whereas the NE segment has thick sediment cover and well-maintained rift valley. Kinematics of basin evolution, derived from the identification of the seafloor spreading magnetic anomalies, suggest very slow initial opening rates of about 1.6 cm/yr and an increase in the spreading rate to about 3.8 cm/yr from anomaly 2 to present, although this interpretation relies only on magnetic anomalies in the two westernmost segments.It is suggested that the true seafloor spreading started about 4 Ma in the Andaman backarc basin, rather than the 11 Ma postulated previously. Based on the integrated analysis of swath bathymetry, magnetic and seismological data that the basin has evolved as a consequence of extrusive tectonics that prompted extension and rifting along the plane joining the Sagaing and Semengko fault systems are infered. Extension by seafloor spreading during the past 4 Myr resulted in the formation of the deep Andaman backarc basin. This phase has also experienced westward propagation of the spreading center.

บรรณานุกรม :
KameshRaju, K.A. , Ramprasad, T. , Rao, P.S. , Rao, B.R. , Varghese, J. . (2547). New insights into the tectonic evolution of the Andaman basin, northeast Indian Ocean.
    : National Institute Of Oceanography (NIO), India.
KameshRaju, K.A. , Ramprasad, T. , Rao, P.S. , Rao, B.R. , Varghese, J. . 2547. "New insights into the tectonic evolution of the Andaman basin, northeast Indian Ocean".
    : National Institute Of Oceanography (NIO), India.
KameshRaju, K.A. , Ramprasad, T. , Rao, P.S. , Rao, B.R. , Varghese, J. . "New insights into the tectonic evolution of the Andaman basin, northeast Indian Ocean."
    : National Institute Of Oceanography (NIO), India, 2547. Print.
KameshRaju, K.A. , Ramprasad, T. , Rao, P.S. , Rao, B.R. , Varghese, J. . New insights into the tectonic evolution of the Andaman basin, northeast Indian Ocean. : National Institute Of Oceanography (NIO), India; 2547.