The Kalambo Falls on the Kalambo River is
a 772 ft (235m) single drop waterfall on the border of Zambia and Tanzania at the southeast end of Lake Tanganyika.
The falls are some of the tallest uninterrupted falls in Africa (after South Africa's Tugela
Falls, Ethiopia's Jin
Bahir Falls and others). Downstream of the falls, is the Kalambo Gorge which
has a width of about 1 km and a depth of up to 300m, running for about
5 km before opening out into the Lake Tanganyika rift
valley.
The falls were first seen by non-Africans in
approximately 1913. Initially it was assumed that the height of falls exceeded
300m, but measurements in the 1920s gave a more modest result, above 200m.
Later measurements, in 1956, gave a result of 221m. After this several more
measurements have been made, each with slightly different results. The width of
the falls is 3.6 – 18m.
Kalambo Falls is also considered one of the most
important archaeological sites in Africa, with occupation spanning over 250,000
years.
Archaeologically, Kalambo Falls is one
of the most important sites in Africa. It has produced a sequence of past human
activity stretching over more than two hundred and fifty thousand years, with
evidence of continuous habitation since the Late Early Stone Age until
modern times. It was first excavated in 1953 by John Desmond (J.D.) Clark who recognized archaeological activity around a small
basin lake upstream of the falls. Excavations in 1953, 1956, 1959, and 1963
allowed Clark to make conclusions about the multiple different cultures
inhabiting the area over thousands of years of time.
Pleistocene environmental
reconstruction
J.D. Clark's work incorporated both
questions of the cultures who lived at the Kalambo Falls site as well as what
their environment was like during times of occupation. Using plant
(floral) and pollen analyses, Clark was able to conduct the process of paleoenvironmental reconstruction. By studying pollen that settled on the
earth during different environmental settings, Clark was able to form a general
idea of what ecological factors affected the Kalambo Falls region at different
times. In order to do this, Clark used a tool for drawing out sediment
cores in order to
observe and analyse the different layers below the surface of the earth today.
He separated these layers into 6 different spectra, labeled zones U through Z.
The law of superposition is important to note when discussing
sedimentary layers; this law states that more recent layers of soil dispersal
will overlie older ones.
Zone U The bottom of Clark's core sample
is the oldest layer. Pollen samples collected indicate that swamp vegetation
and an abundance of grass grew on the Kalambo River. The tests also indicated
that the surrounding woodland grew during dry and hot climates. Clark concludes
that the ground-water levels must have been high in order for a swamp and
fringing, or riparian forest, to grow along the waters edge during a period of reduced
rainfall.
Zone V Pollen collected from the next
zone indicate an identical environment with the swamp and woodland vegetation
that was not affected by climate conditions, such as the drop of 3° Celsius (C) in the area.
Zone W Pollen of plants that grow in more open areas with more rainfall
were taken from Zone W. This indicates an increase in rainfall to about
75–100 cm and a woodland with an open canopy to allow that rainfall to
reach the ground below.
Zone X Clark indicates that the study of this zone was only on one sample
drawn from the soil below, so the conclusions are not finite in his study.
Plants indicated show a fringing forest that was poorly developed with a very
open woodland. Within these woodland conditions, there seems to be an influence
of evergreen elements that emerged.
Zone Y Clark was able to date this zone to approximately 27,000 to 30,000
years ago, because conditions were comparable to those dated in European soils
from this time. Evidence of an increase in rainfall and a temperature drop of
4.1 °C with a fringing forest that was well developed with the return of
swamp plants is indicated in the pollen collected.
Zone Z The final zone indicates a much poorer fringing forest and a
reduced shift of vegetation growth at the time.
Culture history of the site
Early Stone Age
The Early Stone Age is
described by Barham and Mitchell as the time period where the ancient ancestors
of Homo sapiens sapiens first emerged, branching from
the Australopithecus afarensis, evolving into Homo habilis and then Homo erectus 2.6 million years ago to 280,000 years ago. Archaeologists hypothesize that
the technological progression over time can be examined in the morphological
characteristics of tools that are associated with different eras of habitation.
The earliest identified stone tools, made by Homo habilis are known as Oldowan tools, and they consist of the
basic large pounding stones and small pebble flakes, known as Mode 1
technology. As time progressed and Homo habilis evolved into Homo erectus, so did the technology as more specialized stone tools
were being developed, even tools that were used for making other tools, Mode 2
and 3 technologies.
These Late Acheulean stone tools, along with hearths
and well-preserved organic objects were found at Kalambo Falls and documented
by JD Clark. These organic artifacts collected included a wooden club and digging sticks as
well as the dietary evidence for fruit consumption. Tools excavated from
Kalambo Gorge have been analyzed and OSL dating of quartzite within the soil
context to between 500,000 and 50,000 years ago, with amino acid racemization dating the oldest artifacts to
100,000 years ago.
Middle Stone Age
The Middle Stone age,
dated at 280,000 years ago to roughly 40,000 years ago, is the period
where the final stages of hominid evolution brought what is known today as
"modern human behavior."
During this time, the Acheulean industry
of Kalambo Falls was superseded by the Sangoan culture. This shift is considered
by Clark as a result to an ecological shift to a cooler and wetter climate. It
is at this time in the Archaeological record that the large, Acheulean handaxe
disappears and is replaced by the core axe and chopping tools characteristic of
Sangoan technologies. Heavy woodworking tools and small, notched and
denticulated tools, collected by Clark, were dated to have been made before
41,000 BC. This rapid change is predicted to be a result of population movement
during this time period, as the "Acheulean man" who lived in open
settlements were replaced by a culture associated with Homo rhodesiensis found at Broken Hill, the Sangoan culture. Evidence of Sangoan habitation
has been collected from less open Rock Shelters and Cave areas, possibly due to
the persisting, wetter climate.
Evidence of fire technologies, such as
hearths, charred logs, reddened clay, and stone heat spalls were also collected
and found in association with charcoal remains. Radiocarbon dates of
the scattered charcoal indicate people were using fire systematically there
some 60,000 years ago.
The cool, wet climates of the region
were similar to that of the Congo, and similar cultural practices have been
identified at Kalambo Falls, known as Lupemban industries. Evidence suggests that the Sangoan tradition was replaced
by the Lupemban industry around 250,000 years ago and continued through to
117,000 years ago. It is characterized by two-sided, or bifacial, stone tools like core axes and
double-ended points that were possibly for hafting as spearheads. Geological
studies by J.D. Clark indicate that the frequency of these tools is possibly
due to factors that exemplified the amount of large pieces of breakable,
or knappable, raw materials.
Later Stone Age
The Later Stone Age is
the final age of the Paleolithic Era of Africa, and generally
refers to more recent hunter/gatherer sites. Around 10,000 years ago Kalambo
Falls was occupied by the Magosian culture which in turn gave way
to Wilton activity.
Iron Age and the Luangwa tradition
Around the fourth century AD, a more
industrialized Bantu speaking people began to farm and occupy the area. These
Bantu speaking people made ceramic vessels that have characteristics of East
African pottery, which suggests a population movement from the Rift
Valley. Burials from
this period are characterized by Clark as
shaft grave burials, which are similar to those of the earlier cultures of
the East African Rift as opposed to the Kalambo region.
The Iron
Age in Zambia is
split into an earlier, regionally categorized period and a later period of
materialistically differing traditions. Early assemblages of Iron tools and
pottery have been collected from the Kalambo Falls and are categorized as being
from the Kalambo Group tradition. At Kalambo falls, Early Iron Age
traditions are believed to have continued into the 11th century.
In 1971, Robert C. Soper studied
different assemblages of Iron Age Pottery in eastern and southern Africa and
consolidated them into two major groups, known as Urewe and Kwalewares. He indicated that Kalambo
and Mwabulambo pot traditions may also be included in these. David W.
Phillipson used these conclusions to form a north to south chronology of
artifacts and comprised many of the groups studied by Soper into one, Mwitu
tradition. This tradition is exhibited by pots that range from the first
millennium AD.
The Kalambo group was replaced by
the Luangwa tradition, whose pottery is similar to the Early Iron
Age Chondwe Group of the Central African
Copperbelt. Luangwa
Pottery is characteristic of necked pots and shallow bowls, with the most
common comb-stamped decoration pressed in a horizontal pattern of delineated
lines. There has yet to be found any evidence for an interface between this
Luangwa tradition and the Early Iron Age tradition at Kalambo Falls, whereas
sites at the Eastern Province of Zambia exhibit this interrelationship. Exact dates
for this transition in the Kalambo area are inconclusive, but the tradition has
continued through to the present.
Chronology of the site
Attempts to date artifacts from Kalambo
Falls have resulted in inconsistent results, ranging from 110,000 years ago
with racemization to 182,000 ±10,000 to 76,000 ±10,000 years ago with
applied uranium series dating. These studies underscore the
difficulty in establishing a chronology for human habitation at the falls,
which has lead many archaeologists to disregard its significance in the African archaeological record.
However, optically stimulated luminescence (OSL) on quartz artifacts has
recently improved understanding of the site's chronology. OSL works by sending
signals through a crystalline material and collects data on how long ago the
stone was exposed to light or heat.
OSL results have led to the creation of a new
chronology for the site, broken into six stages. Stage 1 ranges between
approximately 500,000 to 300,000 years ago. Stage 2 ranges from 300,000 to
50,000 years ago. Stage 3 dates range from 50,000 to 30,000 years ago. Stage 4
deposits date to 1,500 to 500 years ago and Stage 5 follows after 490 years
ago.
Acheulean stone tools (Mode 2 and 3
technologies) were collected from stratigraphic layers corresponding to the
first and second stages. More complex Mode 3 tools came from the first three
stages and are also found in Stage 4, whose corresponding layers contain a mix
of Stone and Iron Age artifacts.
Zambia and UNESCO significance
In 1964, the archaeological site was gazetted as a
national monument by Zambia's National Heritage Conservation Commission. It has
since been protected under Zambia's 1989 National Heritage Conservation Act.
In 2009, Kalambo Falls was included
on UNESCO list of tentative World Heritage Sites. Justifications for the inclusion are that the
Kalambo Falls are the 2nd highest waterfalls in Africa, the evidence of one of
the longest examples of human occupation in sub-Saharan Africa,
and the collected stone tools are from one of the world's earliest tool
industries, the Acheulean.
As of today, Kalambo Falls remains on the tentative
list for recognition as a protected World Heritage site.
Contemporary ecology
Today, both human and animal populations
traverse the Kalambo Falls area, which has a basin above the falls that
attracts many of both populations as an important stopping place. On the
Zambian border, the area is now a game preserve for the protection of many
animals. The falls' cliff-face ledges provide nesting places and breeding
sites for a marabou stork colony.