(1) The scoria has been expelled completely from the mercury

(2) It's always slightly warmer on Rangitoto thanks to the black scoria , but the 360 degree view of the gulf and the volcano-studded cityscape of Auckland is matchless.

(3) Chunks of black scoria

(4) Small vesicular pieces of volcanic material, scoria , collect around the vent to form a cinder cone.

(5) Alluvial, colluvial or chemically formed gravel, clayey gravel, sandstone, limestone, tuff, scoria are examples of marginal materials.

(6) Some of these cones are now barely recognisable, having been excavated for the volcanic cinder, scoria , used to build the roads of Auckland.

(7) Shoshonite nearest the contact with the overlying flow is scoriaceous and, being less weather resistant, has eroded back to form a conspicuous bench.

(8) They cut steps in the frozen snow and made good progress along a ridge of u2018rugged scoriae u2019 which took them to the summit.

(9) They can be traced for more than 40 miles, and for most of the strike length it is a thin, sandy or u2018 scoriaceous u2019 bed, ranging from a few inches to a few feet in thickness.

(10) The fine-grained ash groundmass contains equal proportions of scoriaceous tachylite and palagonite with basaltic lithic fragments.

(11) On the western side of the mesa, black hornblende xenocrysts several centimeters in size are also found in a scoriaceous , agglomeratic portion of the lava flow.

(12) Amygdaloidal cavities are located immediately below the uppermost scoriaceous part of the second flow, near its contact with the overlying flow.