The geological processes that form different types of caves is an ambitious and technical topic for a picture book. Though the explanations are adequate, the text is sometimes difficult, and there are numerous problems in the illustrations--including confusing perspectives, clutter, and the distracting use of circles overlaying the pictures as a highlighting device.

Again, by presenting the types of caves and how they are formed, Gibbons provides simple, straightforward science in picture-book format. Though sea, ice, and lava caves are mentioned, the focus here is on limestone caves. Several drawings show how rainwater containing carbonic acid erodes the limestone to form caverns filled with convoluted and beautiful spires, shards, and other shapes; one illustration defines the technical terms for these creations. The text is clear, but the drawings can be confusing—as when dripping water seems to create stalactites and stalagmites even in a cave filled with seawater. Cavils aside, a useful introduction. (Nonfiction. 7+)"

Gr 2-4-In straightforward, clear prose and colorful, text-related illustrations, Gibbons describes the formation and physical features of caves. Some of the pictures are labeled, and many depict people of varying ages exploring the different kinds of subterranean spaces. Plant and animal life found underground is briefly mentioned. The term spelunker'' is defined; oddly,cavern'' is not. Rules and supplies needed for spelunking are given, along with a short list of caves for enthusiasts to visit. Unfortunately, Gibbons's popular, child-friendly style is somewhat marred by unexplained circles (flashlights? spotlights?) that appear in each illustration. Young readers are likely to find them distracting. Both Jenny Wood's Caves (Gareth Stevens, 1991) and Lionel Bender's Cave (Watts, 1989) cover more ground and have excellent photos as well as cross-section illustrations. Nevertheless, this title will be enjoyed by budding scientists and explorers.-Kathleen McCabe, East Meadow Public Library, NY