Caves. Neil Morris. Niagara-on-the-Lake, ON: Crabtree, 1996. 32pp. Library bound, $21.95. ISBN: 0-86505-830-X. Paper, $9.95. ISBN: 0-86505-842-3. Grades 2 - 4 / Ages 7 - 9. Review by Alison Mews. ***/4

excerpt:

When a volcano erupts, hot molten rock, called lava, is thrown out and flows on the earth's surface. Sometimes, when a river of lava cools and hardens quickly on the outside, the lava inside remains hot and liquid, and flows on. Eventually the lava drains away, leaving a solid, hollow tube.

These volcanic caves, called lava tubes, can easily collapse. Their roof is usually thin, and earthquakes are common in volcanic areas. Lava tubes very rarely last long.

This informational book on caves is one the Crabapples series ``Wonders of our World." It provides an overview of the subject, with excellent visuals and simple text equally sharing the page, rather than an in-depth treatment of the subject. Each topic (for example, ice caves or sea caves), has a double-page spread, beginning with a definition and description of the formation of the specific cave type, and embellished with several colour photos and explanatory captions.