摘要
In this short note, we report the ages of five lava samples from a segment of the Eastern Lau Spreading Center （ELSC） and three samples from the Valu Fa Ridge （VFR） in the southern Lau Basin. These samples were collected in situ from the axes and flanks of the spreading centers in the basin. These ages provide a key to better understanding the spreading mode, crustal formation and overall tectonic evolution of the basin. Except for two basaltic andesites and one andesite, the lavas analyzed are basalts. The ages of the lavas from ELSC range from （1.45±0.15） Ma to （0.74±0.04） Ma whereas those from VFR range from （0.50±0.06） Ma to （0.32±0.27） Ma, and the basalts give the oldest ages. The relatively younger ages of the VFR lavas are consistent with proposed tectonic evolution of the southern Lau Basin, i.e., VFR is a propagating extension of ELSC. The occurence of older lavas close to or on spreading axes in the southern Lau Basin implies the complex tectonic evolution of the basin. These results underscore a need for further detailed geophysical and geological studies in the southern Lau Basin, in order to better clarify the crustal accretion tectonic evolution in this area.
In this short note, we report the ages of five lava samples from a segment of the Eastern Lau Spreading Center （ELSC） and three samples from the Valu Fa Ridge （VFR） in the southern Lau Basin. These samples were collected in situ from the axes and flanks of the spreading centers in the basin. These ages provide a key to better understanding the spreading mode, crustal formation and overall tectonic evolution of the basin. Except for two basaltic andesites and one andesite, the lavas analyzed are basalts. The ages of the lavas from ELSC range from （1.45±0.15） Ma to （0.74±0.04） Ma whereas those from VFR range from （0.50±0.06） Ma to （0.32±0.27） Ma, and the basalts give the oldest ages. The relatively younger ages of the VFR lavas are consistent with proposed tectonic evolution of the southern Lau Basin, i.e., VFR is a propagating extension of ELSC. The occurence of older lavas close to or on spreading axes in the southern Lau Basin implies the complex tectonic evolution of the basin. These results underscore a need for further detailed geophysical and geological studies in the southern Lau Basin, in order to better clarify the crustal accretion tectonic evolution in this area.
基金
The National Natural Science Foundation of China under contract Nos 41230960, 40906034 and 41276003
China Ocean Mineral Resources R&D Association (COMRA) under contract No. DY125-12-R-05
Youth Foundation for Marine Science of State Oceanic Administration,PRC under contract No. 2011303
China Postdoctoral Science Foundation under contract No. 201104616
Special Basic Research Funds for Central Public Research Institutes (First Institute of Oceanography, State Oceanic Administration, PRC) under contract Nos GY02-2008G38 and GY02-2010G20
the Taishan Scholar Program of Shandong Province
