- Volatiles (make up 1 to 5% of magma)
- Stream ca. 70%
- Sulfur compounds ca. 15%
- Nitrogen ca. 5%
- CO, H, Cl, & Ar ca. 5%
- Stream ca. 70%
- Nuées Ardentes (glowing avalanche, firey cloud)
Figure 10.2 Schematic of ash flows.
Figure 10.3 Eruption of Mt. Pelee in 1902.
Figure 10.4 Ruins of St. Pierre, Martinique.
- Erupted Rocks
- Tephra (dust, ash, cinders, lapilli, blocks, bombs, etc.)
- Lava (Pahoehoe, Aa, Pillow)
Figure 10.5 Pahoehoe lava (Idaho).
Figure 10.6 Aa lava.
Figure 10.7 Tubular-shaped pillows of basalt potographed in the central rift of the east Pacific Rise
(from The Dynamic Earth - an introduction to physical geology, by Skinner and Porter, John Wiley & Sons, Inc., 1989).
- Tephra (dust, ash, cinders, lapilli, blocks, bombs, etc.)
- Shield Volcanoes (e.g., Hawaii)
Figure 10.8 Shield volcano (from The Earth - An Introduction to Physical Geology (2nd ed.), by Tarbuck & Lutgens, Merrill Publishing Co., 1984).
Figure 10.9 Kilauea Iki eruption (Hawaii).
Figure 10.10 Surtsey, Iceland (16 Nov. 1963).
Figure 10.11 Surtsey, Iceland (21 Nov. 1963).
Figure 10.12 Surtsey, Iceland (21 Apr. 1964).
- Cinder and Composite Cones
Figure 10.13 A. Cinder cone. B. Composite cone (from The Earth - An Introduction to Physical Geology (2nd ed.), by Tarbuck & Lutgens, Merrill Publishing Co., 1984).
- A) Cinder Cones
Figure 10.14 Snow covered cinder cone at Lassen Volcanic Nat'l Park, CA).
- B) Composite Volcanoes
Figure 10.15 Aerial view of Mt. St. Helens (R at ca. 35 miles) and Mt. Adams (L with height of 12,307 feet) in southern Washington.
- A) Cinder Cones
Figure 10.16 Shiprock, NM, with radiating dike.
Figure 10.17 Shiprock, NM (basaltic dike).
Figure 10.18 Church of the volcanic plug (Le Pay, France).
Figure 10.19 Devil's Tower Nat'l Monument, WY (Devil's Post Pile).
Figure 10.20 Devil's Post Pile.
Figure 10.21 Schematic of columnar jointing.
Figure 10.22 Tops of columnar jointing.
Figure 10.23 Schematic evolution of a caldera.
Figure 10.24 Wizard Island in crater lake of Mt. Mazama, OR.