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