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 TWO
The Science of Archaeology
Because archaeology is basically concerned with people, it forms
an important subdivision of the social science of anthropology.
Anthropology, the study of human culture, also includes three
related specialties—linguistics, the study of human speech
and language; physical anthropology, the study of the origins
and biological evolution of humans as well as the patterns of
human physical variation; and cultural anthropology, the study
of living peoples and the great variety of their customs,
adaptations, and achievements.
Native American Petroglyph at Columbia River Gorge.
In practice, archaeologists utilize theories and methods of
their colleagues in the other anthropological specialties and of
experts in other fields of scientific study as well. Linguists,
for example, can furnish useful checks on purely archaeological
information. One of their techniques measures the change that
has taken place between two related languages. Such change, say
many linguists, is apparent when one compares lists of
commonplace words, like "sky" or "mother," that nearly all
peoples have in their vocabularies. By finding the degree of
change in such word lists, the approximate time at which the two
languages split from a common ancestral tongue may be indicated.
Such data reinforce archaeological findings if they suggest a
cultural divergence during the same span.
Physical anthropologists provide special knowledge about
biological variation among modern humans and their ancestors.
This includes not only the study of ancient human fossil remains
in Africa, Asia, and other parts of the Old World but also
skeletal remains in the Americas, where no forms of humans
earlier than modern Homo sapiens are known. The study of
such remains provides information ranging from ancient diet and
disease to indications of intermarriage or the replacement of
one population by another. New breakthroughs in the realms of
genetics, blood chemistry, and dentition continue to open more
and more paths to our knowledge of the past.
Cultural anthropology furnishes a wealth of knowledge on how
living peoples use their environment, divide up labor, keep
track of time, and organize themselves in households or social
groups. If carefully applied, such information can provide
useful analogies to help interpret the meanings of the material
objects found in the ground.
Emerald Mound National Historic Landmark in Natchez
Trace Parkway.
Like modern settlements, the remains of past
settlements—that is, archaeological sites—are all
around us. Archaeologists are interested in knowing precisely
where these sites are so they can be preserved and protected for
study and for the benefit of future generations. The
geographical relationships among archaeological sites,
regardless of whether they were occupied at the same time or at
different times, can themselves provide clues to how their
inhabitants obtained food and other resources of the area.
Relationships among sites occupied at the same time can indicate
social, religious, and political links or conflicts that may
have characterized the region.
One such regional investigation, by archaeologist Donna Roper,
then of the University of Missouri at Columbia, concentrated on
the Sangamon River Valley in central Illinois. Her thorough
survey and sampling of the area brought two important periods of
occupation to light: one between about 150
B.C. and
A.D. 400, the other from around
A.D. 400 to 700—periods
that archaeologists, for convenient reference, have agreed to
label respectively Middle Woodland and Late Woodland. From her
work in the Sangamon Valley, Donna Roper found that during the
earlier period people tended to locate their settlements away
from the river, at the base of bluffs at the valley edge. These
bluff-base settlements were located near water sources and other
frequently used resources. During this early period, however,
additional temporary camps were set up in the valley bottomlands
to exploit aquatic resources and in locations farther afield to
hunt deer. Settlements of the later time span were built in the
bottomlands.
As Roper noted in her published report, these patterns were
apparently the result of seasonal food procurement in the
region—the reflection of a way of life similar to that of
the Kickapoo Indians, who occupied the area in early historical
times. According to eyewitness accounts in the historical
documents, the Kickapoo shifted settlements with the seasons,
practicing horticulture in one place during the summer, then
moving into the bottomlands during the colder months to hunt.
An archaeologist looks over the results of the
excavation.
Archaeologists often focus their investigations on a specific
site—any area of ground once used, and thus modified, by
human beings. There is no typical archaeological site. One may
be a 10,000-year-old campsite such as that found at Debert, Nova
Scotia, virtually indistinguishable on the surface from
surrounding meadows and forest. Others might hold the crumbling
buildings and refuse mounds of a great city like Chan Chan,
Peru, or Baalbek, Lebanon. Whether cave or field, cliff
dwelling or mound, or the stone foundations of a colonial house,
each site is a unique and fragile remnant of the past. It holds
not only artifacts but, more important, the sum total of
existing clues on the relationship of these objects to one
another. A site is a complicated package that, if carefully
opened and meticulously recorded, can lead to interpretations of
what happened at the place and provide information for
determining when, how, and why it happened.
Archaeologists in Jamestown, Virginia worked to locate
the site of James Fort.
The decision to excavate can be based on many factors. Usually a
particular problem—for example, when and why settled life
began in an area—determines the choice. For the historical
archaeologist, the reason for excavation may be to supplement or
verify the written record, which is often plagued by omissions,
biases, or vagueness. Excavations of settlements like Jamestown,
Virginia, or the recovery of the cargo of a Civil War-period
steamer provide glimpses of the past or, in the latter case, a
past instant. And while historical records are of immense help
in such cases, they may not address the specific archaeological
problem involved.
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Workers from the Interagency archaeological salvage
program race against time.
In other cases, reservoir flooding or disturbance of the ground
by highway construction, home building, or agriculture may
threaten sites with destruction. Such circumstances dictate a
program of conservation archaeology designed to protect as many
sites as possible and to recover information that would
otherwise be lost forever from sites that cannot be saved.
A good example of this is a site that once lay in an open pine
grove at the tip of Rose Island in eastern Tennessee, near where
the Tellico and Little Tennessee Rivers join. Knowing that Rose
Island would soon be drowned by the new Tellico Reservoir, the
Tennessee Valley Authority, in cooperation with the National
Park Service, arranged for archaeologist Jefferson Chapman of
the University of Tennessee at Knoxville to investigate Rose
Island. His preliminary exploration showed that there was far
more to Rose Island than first met the eye. Telltale bands of
dark soil indicating successive human occupation appeared about
six feet below the surface. The kinds of stone tools and the
absence of pottery in these deep layers suggested that the site
was quite old, occupied perhaps by wandering bands of
hunter-gatherers.
Like all archaeologists, Jeff Chapman knew that in excavating he
would necessarily destroy part of the site. Artifacts, of
course, could easily be taken back to the laboratory for further
study, but the all-important context of these remains could not
be removed. Here is where Chapman's professional training came
into play.
An archaeologist carefully screens dirt from excavation
units to locate artifacts.
Because the location of everything found would have to be
recorded in detail, he and his crew of students carefully laid a
reference grid of numbered wooden stakes through the pine grove
before removing the overburden of surface soil. For three months
they carefully troweled in selected grid squares, peeling away
the ancient deposits. As they progressed, layer by layer, they
were careful to leave all artifacts within a layer—stone
tools, chips, hearths, or whatever—in place until all
could be carefully inspected, drawn, and photographed. Then they
removed the artifacts to numbered bags before proceeding to the
layer below. Dirt from each layer, meanwhile, was carefully
screened to recover any artifacts or fragments that may have
been missed. In addition, samples of soil were washed in a
process known as flotation to separate out any seeds or plant
remains.
As the pits deepened, the buried layers they had carefully
removed could all be seen in cross section on the smooth walls
of the pit. These were plotted to precise scale on graph paper.
Archaeological storage at Anasazi Heritage Center.
By summer's end Chapman and his crew had recovered more than
40,000 items—including almost 30,000 tiny chips of stone,
the residue of tool manufacture and use. These, however, were
far less important than the thorough records the excavators
compiled, for the records could now serve as a substitute for
the excavated part of the site, telling people precisely where
each piece had been found.
Back in the laboratory, analysis of the material began. Whereas
it took Chapman only two summers to collect, record, and measure
the archaeological data, it took years to accomplish the
laboratory analysis, to formulate his conclusions, and to
prepare the results for publication.
Creating a map of the excavation site is essential due
to the destructive nature of archaeology.
By using computers and special software developed for the
purpose, thousands of stone lance points, other tools, and
fragments were sorted according to diagnostic characteristics,
or attributes. With the resulting classification, Chapman and
his team were able to compare their findings with those from
other sites and to estimate the time when Rose Island was first
occupied.
The stone chips and their locations suggested not only how the
tools were made but also where in the ancient camp the
manufacturing went on. And burned acorns and hickory nuts gave
valuable clues to the diet of the ancient Rose Islanders.
An archaeologist carefully unearths a prehistoric hearth
in Alaska.
In the course of his analysis Chapman received useful aid from
colleagues in other sciences. For example, technicians in
physics subjected his charred wood remains to radiocarbon tests.
Their dates—between 6100 and 7400
B.C., or early within the span
that archaeologists call the Archaic—reinforced his
preliminary dating of the main occupation of the site. This was
refined even more by other specialists who, by observing the
lineup of magnetic molecules in the Rose Island hearths, could
estimate fairly closely how much time had elapsed between the
use of successive fireplaces. A geologist well acquainted with
the mineralogy of the area showed that the people of Rose Island
had found flint nearby for their tools—one reason,
perhaps, for using the site—while a specialist in botany
used wood charcoal to identify oak, hickory, and other
vegetation, all crucial clues to the ancient environment.
Had the excavation yielded other kinds of remains, the aid of
still more specialists might have been sought: Malacologists,
who study ancient and modern snail and other mollusk shells, and
palynologists, who identify pollen, can help detect
environmental changes through time; ichthyologists and
zoologists identify fish and animal remains.
Just as was the case with Roper's work in the Sangamon Valley,
the crucially important step of publishing the results of
Chapman's work at Rose Island, now covered by the reservoir
waters, was undertaken to ensure that the information would be
available to everyone concerned with the human past. Equally
important, following the recording and analysis, all the
excavated artifacts, samples, field notes, maps, and other
records were preserved so they will be available for future
scientists to reanalyze with the greater knowledge and improved
techniques and equipment of the future.
Jeff Chapman would be the first to acknowledge that Rose Island
was no Tut's tomb, but he didn't care. In the vast sweep of the
human past, the small Tennessee site is quite as essential a
chapter as that provided us by the golden trappings of Egypt's
pharaohs—and this is indeed what archaeology is all about.
Increasingly, archaeologists are turning not to sites but to the
analysis of existing collections of artifacts or records of past
surveys or excavations in order to gain information. With the
growing recognition that it is often best to keep ancient sites
intact for future generations, the study of collections, both
institutional and private, is likely to become more common.
Detailed information about each artifact is recorded and
preserved for future research or use in an exhibit.
During the late 1960s, James Judge, then of the University of
New Mexico, became interested in learning more about the life of
the Paleo-indians, the earliest recognizable culture of the
Americas—the Ice Age hunter-gatherers who lived in North
America before about 8000 B.C.
Judge was specifically interested in the Paleo-indians of the
Central Rio Grande Valley, New Mexico. His first step was a
survey of the area, much like that done by Donna Roper in
Illinois. After recording the locations of sites that could be
detected by surface evidence, Judge turned to existing
collections from the area. The use of such material ultimately
saved him an immense amount of time and effort in his analysis.
Using all these data, plus new information from sites he
investigated himself, Judge sought the relationships between
changes in Paleo-indian artifact forms, settlement location, and
the environment over time. The analysis revealed that the then
accepted view of Paleo-indian life in New Mexico as an
unchanging span devoted to the hunting of big game was wrong. In
its place emerged a picture of a long period in which patterns
of animal watering places and human settlement, as well as the
inventory of available animals, were in continuous change as the
climate fluctuated and gradually became drier and as humans
developed ways to organize themselves, to find and utilize
resources, and to make a place for themselves in their world.
Archaeologists often deal with periods of time much greater than
that embraced by Judge's work in New Mexico, for human or
human-like beings have lived on earth for some five million
years. However, far more than 99 percent of that enormous span
lies totally out of reach of the earliest written records. When
Columbus first set foot on what came to be called the Americas,
people had inhabited those two vast continents for more than
13,000 years, yet virtually no decipherable written records were
left. For any knowledge of our collective heritage, then,
archaeology is the sole source of information.
For those who choose it as a career, archaeology can be even
more intriguing than its popular image, and its personal rewards
can far outweigh what are often challenging working and thinking
conditions. There are many reasons that professional
archaeologists enjoy what they do. Perhaps the best is the
excitement of discovering some knowledge about ourselves that
would otherwise remain out of reach. Likewise, nonprofessional
avocational archaeologists can experience much the same
challenge and thrill in knowing that they too can contribute to
our knowledge of the human past. Neither can deny that there is
much yet to learn.
To learn more about topics covered in Chapter 2 visit these
National Park Service Features:
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Ancient Architects of the Mississippi:
Eight hundred years ago, the lower Mississippi
Delta was home to some of the most highly
organized civilizations in the world. This
feature tells you about life along the
Mississippi at that time, builders of great
mounds, and the activities of travelers and
traders. It also provides you with a myriad of
voices about the Delta's past.
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Submerged Archeology:
Learn about the underwater projects of the
Submerged Cultural Resources Unit, often in
partnership with other organizations, including
the U.S.S. Arizona and U.S.S. Utah at Pearl
Harbor, ships and planes in Palau and Guam, and
numerous historic shipwrecks in Dry Tortugas
National Park and off Isle Royale National Park.
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Archeological Research in the Parks:
Many national parks have active archeological
programs. Learn about the exciting results of
archeological projects in some of your favorite
parks by clicking on the state of your choice.
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Kennewick Man:
The human skeletal remains that have come to be
referred to as the "Kennewick Man," or the
"Ancient One," were found in July 1996, in
Kennewick, Washington. Almost immediately
controversy developed regarding who was
responsible for determining what would be done
with the remains. Claims were made by Indian
tribes, local officials, and some members of the
scientific community. The documents here provide
background information and detailed reports of
aspects of the work being done on Kennewick Man
by the Department of the Interior.
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