base surge depositの例文

• The pyroclastic rock and the base surge deposits form an ash volcanic cone, while the ash covers a large surrounding area.
• Other eruption deposits are the Ngozi Tuff ( less than thousand years ago ) and the Ituwa Surge base surge deposits of uncertain age, but intermediary to the Kitulo pumice and Ngozi Tuff.
• The fourth, and last, major phase ( BO 4 / Minoan D ) was marked by varied activity : lithic-rich base surge deposits, lahars, debris flows, and co-ignimbrite ash-fall deposits.