Scientists believe that amber was deposited in a flat part of a prehistoric basin during the Upper Eocene and the Lower Oligocene in a delta of a naval river . Scientists believe that amber was deposited during the Upper Eocene and Lower Oligocene in a delta of a marine river , in a shallow part of a prehistoric basin .
Para saintis percaya bahawa ambar telah disimpan di bahagian rata lembangan prasejarah semasa Eosen Atas dan Oligosen Bawah di delta sungai tentera laut. Para saintis percaya bahawa ambar telah disimpan semasa Eosen Atas dan Oligosen Bawah di delta sungai laut, di bahagian cetek lembangan prasejarah.