geode - bubble-filling geode - large hand/display specimen in part because of the

in part because of the varied clasts

each covering a section of the work as it was completed

Transparent in thin sheets

The marsh was left high and dry about a century ago when the creek was incised during a flood

geode - bubble-filling geode - large hand/display specimen in part because of theGeodes are bubble fillings that weather out of a vesicular lava. As the flow cools, unescaped gases form voids in the otherwise solid flow. Subsequent hydrothermal activity fills these voids with mineral rich hot water and as it cools, crystals grow on the surface of the roughly spherical opening. In the lava flow, the immediate zone around the now crystal lined bubble is altered and becomes more resistant than the surrounding rock and subsequently