Tat Ali is a low Holocene shield volcano located in the northern part of the Afar Region of Ethiopia. This elevation is characterized as having an elongated summit depression that has produced a variety of rock types, ranging from basalts to pantellerites. NNW-SSE-trending fissures cutting the volcano have fed basaltic lava flows; those NE of Lake Afrera are of prehistoric date. Late-stage volcanism produced youthful basaltic lava flows on the floor of the summit depression, which is also the site of prominent fumarolic activity.