1.att. Smilšakmens
(www.resourcescommittee.house.gov/subcommittees/em)

2.att. Smilšakmens veidojums
(www.photo-mark.com/webpix/ds/Sandstone.jpg)

3.att. Kaļķakmens
(www.resourcescommittee.house.gov/subcommittees/em..)

4.att. Kaļķakmens veidojums
(www.lakepowell.net/navajo%20limestone%20layer.jpg)