Ok, did some searching on my own for archaeological info.
Ooparts & Ancient High Technology--Those Sophisticated Cave Men--Evidence of Noah's Flood? Page 10
"A trench created by a dynamite explosion about thirty years ago exposed a large number of floor layers formed of clam shells capped with a cement-like material made from burned shell and sand,"
"Constructed of cement-like floors, the mound, researchers say, is the oldest known platform intentionally built in Mesoamerica, the cultural region comprising Mexico, Belize, Honduras, Guatemala and El Salvador, and it could completely change our understanding of the prehistoric people who once inhabited this area.
The mound, built almost entirely from marsh clamshells, is 240 feet long, 90 feet wide and 21 feet tall. John Hodgson, a University of Wisconsin-Madison doctoral degree candidate in anthropology discovered it last October on a remote island in a swampy area along the Pacific coast of Chiapas in Southwestern Mexico."
"Based on the analysis, the very top floor layer dates to 2575 B.C. - almost 4,500 years ago. Each level below this layer increases in age with the lowest tested layer dating back more than 5,000 years ago to 3024 B.C."
In the most ancient primitive type cultures, archaeological sites mentioned on that page....shell beads, ornaments, burial mounds, then later a cement made of burned seashells and sand. I might add also, in North America, Native Americans used seashells like money,or a form of currency.
