Searching for Artifacts and Fossils 107soil mark A stain that shows up on the surface of recently
plowed fields that reveals an archaeological site.
middens A refuse or garbage disposal area in an archaeologi-
cal site.
grid system A system for recording data in three dimensions
for an archaeological excavation.
datum point The starting point, or reference, for a grid
system.
flotation An archaeological technique employed to recover
very tiny objects by immersion of soil samples in water to sepa-
rate heavy from light particles.
stratified Layered; term used to describe archaeological sites
where the remains lie in layers, one upon another.On the ground, sites can be spotted by soil marks, or
stains, showing up on the surface of recently plowed fields.
Soil marks led archaeologists to many of the Bronze Age
burial mounds in northern Hertfordshire and southwest-
ern Cambridgeshire, England. The mounds hardly rose
out of the ground, yet each was circled at its core by chalky
soil marks. Sometimes the very presence of a particular
chalky rock is significant.
Documents, maps, and folklore are also useful to the
archaeologist. Heinrich Schliemann, the famous and con-
troversial 19th-century German archaeologist, was led to
the discovery of Troy after a reading of Homer’s Iliad. He
assumed that the city described by Homer as Ilium was
really Troy. Place names and local lore often are an indica-
tion that an archaeological site is to be found in the area.
Archaeological surveys therefore often depend upon ama-
teur collectors and local people who are usually familiar
with the history of the land.
Sometimes natural processes, such as soil erosion or
droughts, expose sites or fossils. For example, in eastern
North America erosion along the coastlines and river banks
has exposed prehistoric refuse mounds known as shell
middens (the general term for a trash deposit), which are
filled with the remains of mussels and/or oysters, indicating
that shellfish consumption was common. Similarly, a whole
village of stone huts was exposed at Skara Brae in Scotland’s
Orkney Islands by the action of wind as it blew away sand.
Though natural forces sometimes expose fossils and
sites, human physical and cultural remains are more of-
ten accidentally discovered. In Chapter 2 we noted how
construction and quarrying work in Europe led to the dis-
covery of fossils of extinct animals, which then played a
role in the development of evolutionary theory. Similarly,
limestone quarrying at a variety of sites in South Africa
early in the 20th century led to the discovery of the earliest
humanlike fossils from millions of years ago (see Chapter
7). Disturbances of the earth on a smaller scale, such as
plowing, sometimes turn up bones, fragments of pots, and
other archaeological objects.
Because construction projects do uncover archaeologi-
cal remains so frequently, in many countries, including the
United States, construction projects require government
approval in order to ensure the identification and protec-
tion of archaeological remains. Cultural resource manage-
ment, introduced in Chapter 1, is routinely included in
the environmental review process for federally funded or
licensed construction projects in the United States, as it is
in Europe. This chapter’s Anthropology Applied feature
takes a closer look at cultural resource management.
Archaeological Excavation
Once a researcher identifies a site likely to contribute to
his or her research agenda, the next step is to plan and
carry out excavation. Obtaining permission to excavate
from a variety of local and national authorities is a critical
part of this planning. To begin, the land is cleared, and
the places to be excavated are plotted as a grid system
(Figure 5.1). The surface of the site is divided into squares
of equal size, and each square is numbered and marked
with stakes. Each object found may then be located pre-
cisely in the square from which it came. (Remember, con-
text is everything!) The starting point of a grid system,
which is located precisely in three dimensions, may be a
large rock, the edge of a stone wall, or an iron rod sunk
into the ground; this point is also known as the reference
or datum point.
At a large site covering several square miles, the plot-
ting may be done in terms of individual structures, num-
bered according to the square of a “giant grid” in which
they are found. In a gridded site, each square is dug sepa-
rately with great care. (In the photo on page 106, note how
the grid system is used even in underwater archaeology.)
Trowels are used to scrape the soil, and screens are used
to sift all the loose soil so that even the smallest artifacts,
such as flint chips or beads, are recovered.
A technique employed when looking for very fine
objects, such as fish scales or very small bones, is called
flotation. Flotation consists of immersing soil in water,
causing the particles to separate. Some will float, others will
sink to the bottom, and the remains can be easily retrieved.
If the site is stratified—that is, if the remains lie in lay-
ers one upon the other—each layer, or stratum, will be dug
separately. Each layer, having been settled during a particu-
lar span of time, will contain artifacts deposited at the same
time and belonging to the same culture (Figure 5.2). Cultural
change can be traced through the order in which artifacts
were deposited—deeper layers reveal older artifacts. But, ar-
chaeologists Frank Hole and Robert F. Heizer suggest,because of difficulties in analyzing stratigraphy,
archaeologists must use the greatest caution in
drawing conclusions. Almost all interpretations of
time, space, and culture contexts depend on stratig-
raphy. The refinements of laboratory techniques for