Geoscience Reference
In-Depth Information
human societies of the region. Our attention then turns to the physical
evidence for the megadroughts and the impacts they had on the ecosystems
and coastal populations of the West.
the ancestral pueblo collapse
An advanced agricultural society once l ourished in the American Southwest,
over a thousand years before air conditioning and massive public water works
made this region hospitable to our modern society. How could such a hot,
dry region have become a vibrant center for ancient societies without the
technological advantages we enjoy today? More curiously, why did this soci-
ety apparently collapse at its peak of sophistication and population? Since
i rst discovering the ruins of the Ancestral Pueblo—the collective name
given to the early people of this region formerly known as the Anasazi—
scientists have struggled to answer both questions.
Much of what archaeologists know about the Ancestral Pueblo comes from
pueblo and clif dwelling sites from the Four Corners region, including Chaco
Canyon in northwestern New Mexico, Mesa Verde in southwestern Colorado,
and Canyon de Chelly in northeastern Arizona. Archaeologists have used
the deteriorating remains of adobe pueblo walls, artifacts, pottery shards,
preserved food, soils, clothing, animals, and the skeletal remains of the people
themselves to reconstruct this culture and better understand its collapse.
Chaco Canyon in New Mexico was the site of one of the most extensive
Ancestral Pueblo settlements. By the ninth century, a warmer and wetter
climate allowed populations in this region of the Colorado plateau to expand.
At its peak, during the eleventh and early twelt h centuries, Chaco Canyon
was elegant, with great pueblos the size of modern apartment buildings hous-
ing hundreds of residents in large, high-ceilinged rooms. Enclosed within
these great houses were plazas and special circular sunken rooms, called kivas,
where people slept and worked. h e Ancestral Pueblo settlements were cities
in many respects, supported by agriculture, which had begun as early as the
second century and allowed people to settle in one place year-round. h ese
early farmers planted corn and a variety of vegetables, and, over the decades
and centuries, agriculture expanded onto the higher mesas to feed the growing
population. Most of this farming depended on annual rains, supplemented
by water from nearby streams and springs. Over time, however, the climate
became increasingly arid and unpredictable; the Ancestral Pueblo farmers
