Sediment and Climate - Earth Sciences Laboratory

We recently obtained a five million-year record of climate change from the Atlantic Ocean off the coast of Portugal, and many of the deeper core sections making up this record were obtained by rotary drilling. The rotation of the outside of the sediment core (a pillar of clay about 7 cm in diameter, hundreds of meters long but cut into 1.5 m lengths) potentially affects the time-resolution of the climate record inside the deeper parts of the core. 

In this project, we will be using clay "trimmed" from the outside of the core sections to try to identify the extent of the disruption in the timing of the record that could be caused by the drilling technique. In addition, we will use some of the discarded "trimmed" clay to search for micrometeorites that may have fallen into the North Atlantic over the thousands of years that the clays in the cores were accumulating. We will use magnets to try to fish out micrometeorites from the sediments, and look for them under the microscope; this may or may not locate some micrometeorites, but will be an interesting side project, and we are sure to see some tiny fossils from the North Atlantic!

当研究室では、堆積コア（直径約7 cm、数百メートル長の粘土の柱を1.5 m長さに切断されたもの）に残されている気候変動の記録の研究を行っています。最近、ポルトガル沖の大西洋から500万年分の記録を含む堆積コアを手に入れることに成功しました。しかし、これらのコアを採取する際に使われた回転ドリル方は、コアの時間分解能を乱す（下げる）可能性があります。このプロジェクトでは、コアセクションの外側から採取された粘土を使用して、回転ドリルが引き起こす記録への混乱の程度を特定します。さらに、数千年の間北大西洋の海底に蓄積されていった微小隕石や化石を顕微鏡を使って粘土の一部から探しだしていきます。