Geologists stand on the narrow cobble beach at the NE base of Sumisujima. Vertical light-colored dikes cut intrusive rocks at the lower right alogn with oxidized tephra layers, breccias, and lava flows forming the pinnacle. The spire is an eroded remnant of the pre-caldera volcano on the outer southern flank of a large submarine caldera. A large segment of the eastern side of the pinnacle previously slumped into the sea.

Copyrighted photo by Kenichiro Tani, 2002 (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/).

Copyrighted image used with permission. All Rights Reserved. Contact photographer for any usage requests.

Keywords: dike | geology | stratigraphy | outcrop | erosion

Sumisujima