On March 5, 1904, the American archeologist Edward H. Thompson, began dredging the Cenote of Sacrifice at the ancient Maya city of Chichen I in Yucan, Mexico. Thompson hoped to substantiate legends describing this natural, water-filled, limestone well as a repository for the precious objects and human victims offered to the gods by the ancient Maya.
SOLUTION CAVERN - Naturally acidic groundwater seeping through cracks in the limestone bedrock dissolves areas of softer rock lying beneath the hard surface crust. Over time, this process creates large undergound caverns roofed with only a thin layer of surface limestone.
As erosion continues, this thin roof eventually collapses, leaving an open, water-filled hole.
Over thousands of years, erosion gradually fills the cenote with organic and mineral debris, reducing its depth. The Cenote of Sacrifice is currently in this stage.
As erosion continues, the cenote may completly fill, becoming a dry, shallow basin supporting trees and other vegetation.
Rain water absorbs a gas (carbon dioxide) from the air and forms a weak acid. As this trickles down through tiny cracks in the limestone, the weak acid dissolves a mineral in the limestone called calcite. Over time the limestone is dissolved and a cenote is formed.
1. Put three drops of water on the chalk. - What happens?
2. Put three drops of vinegar on the chalk. - What happens?
3. Chalk is made from limestone. Vinegar is a weak acid.
4. Try other liquids.- Did you find weak acids?
5. Number your rocks and print the logbook sheet.
6. Compare these rocks to the limestone. - Record your results.
7. Type the name of a weak acid that dissolved your limestone!
Puuc architecture is named for the hilly Puuc region of northwestern Yucatan where this style attained its ultimate refinment. Puuc buildings have rubble-filled concrete walls faced by a thin veneer of dressed stone. The exterior walls have plain lower facades supporting upper facades decorated with long-nosed Chac masks and geometric designs. Constructed of individually carved pieces fitted together to form a design, Puuc sculpture resembles a mosaic. In Chichen Itza the older, purely Maya buildings are in the Puuc style.
Toltec-Maya architecture combines Puuc construction methods with designs of Toltec or Central Mexican origin. Toltec elements at Chichen Itza include stepped-pyramid temples, long colonnades, atlantean figures used as structural supports, low detached platforms faced with carved panels, and doorways formed by twin descending feathered serpent columns.