Buldir Island (also sometimes written
Buldyr; ) is a small island in the western
Aleutian Islands of the
U.S. state of
Alaska. It lies midway between the
Near Islands in the West and the
Rat Islands in the East. It is the most westerly of the Aleutian Islands which formed as a result of volcanic activity in the late Quaternary or Recent times. The rocks from which the island formed are of two different ages with a considerable time gap. The rocks of the older dome are mainly
olivine basalts and the younger dome consists of
hornblende basalts and basaltic
andesites. That this island is younger than some of the neighboring islands is also suggested by the fact that there are fewer species of flowering plant on this island.