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西太平洋暖池晚第四纪370kaBP以来的黏土矿物含量呈现明显的冰期-间冰期旋回变化,蒙脱石(62%～91%)为主要的黏土矿物,含量在冰期时增高,间冰期时下降;绿泥石(4%～21%)、伊利石(4%～12%)和高岭石(2%～10%)含量依次递减,三者具有相同的变化型式,并与蒙脱石含量的变化呈镜像关系.研究认为,以蒙脱石为主的黏土矿物是陆源碎屑成因,绝大部分来自新几内亚岛的河流输入.黏土矿物含量在冰期-间冰期旋回上的变化与海平面升降有关.在海平面较低时,新几内亚岛的河流物质更容易穿越狭窄的陆架,直接输入向西流动的次表层流,汇入赤道潜流而最终沉积至西太平洋暖池核心区.蒙脱石含量的岁差周期反映了物源区新几内亚岛的机械剥蚀强度,表现为河流径流量的大小,受控于降雨量的分布,指示了赤道辐合带(ITCZ)在轨道尺度上的经向迁移.
The content of clay minerals in the western Pacific warm pool since 370ka BP has obvious glacial-interglacial swirling changes. Montmorillonite (62% -91%) is the main clay mineral, which content increases during glacial period and declines during interglacial period ; Chlorite (4% ~ 21%), illite (4% ~ 12%) and kaolinite (2% ~ 10%) in descending order, the three have the same change pattern, and the content of montmorillonite The study suggests that the montmorillonite-based clay minerals are the origin of terrigenous debris and most of them come from the rivers of New Guinea.The change of clay mineral content during glacial-interglacial cycles is similar to that of sea level At lower sea levels, New Guinea’s riverine material traverses more narrowly across the shelf, directly into the subsurface flow flowing westward, into the equatorial subflow and eventually into the core area of the western Pacific warm pool, The precession cycle of the stone content reflects the mechanical ablation intensity of the New Guinea Island in the provenance area as a function of the runoff size of the river and is controlled by the distribution of rainfall indicating the meridional direction of the equatorial convergence zone (ITCZ) migrate.