Sediment core samples were collected from the continental shelf of the Chukchi Sea in July 1999 and rare earth elements (REEs) were measured by instrumental neurton activation analysis (INAA).

• 于 1 999年夏季我国首次北极科学考察期间在楚科奇海采集了三个沉积物岩芯 ,并采用中子活化法 (INAA)测定了沉积物样品中稀土元素的含量。