Sangiran -- Home to fossils of prehistoric man

Sangiran -- Home to fossils of prehistoric man

By Nasruddin

SANGIRAN, Central Java (JP): Sangiran is just a hamlet on the
island of Java, but its name has resounded throughout the
scientific community since fossils of prehistoric man were
discovered in the vicinity. For more than 100 years, scientists
have tried to unveil the mystery of Sangiran's dark soil.

Thousands of pages have been written with competing theories
that attempt to unravel the secrets of these prehistoric
fragments. Conferences, seminars and publications about the
findings have added luster to the name of Sangiran in world of
archaeology, particularly in the field of paleoanthropology.

The geological layers of Sangiran form the most complete
paleoanthropological site in Indonesia. Fossils of hominids have
been found in a series of geological strata, which date from the
late Pliocene period until the Middle Plestocene (between 2
million and 200,000 years ago). Hominids are two-legged, upright
mammals, and include modern humans as well as the extinct
ancestors of humans. The Sangiran fossils are those of the
prehistoric Homo erectus, who evolved over a period of a million
years. The Sangiran fossils make up 65 percent of all the hominid
fossils found in Indonesia, and about 50 percent of the Homus
erectus fossils in the world.

The different geological layers were formed by the shallow
ocean (the Kalibeng layers), black clay (the Pucangan series),
volcanic sediment (fasies fluviatil of the Kabuh series), and the
muds of Notopuro which have sedimented above the Kabuh layers.
Between the Pucangan and Kabuh strata there is often found a
limestone layer, called grenz-bank.

The Sangiran site is located in a depression in Surakarta,
also called Solo, at the foot of Mount Lawu. The site was once
shaped like a dome, whose pinnacle was later eroded. The erosion
created the depression, reversing the shape of site. The erosion
has also uncovered the prehistoric ground layers in a natural
way, revealing layers of human fossils and other vertebrates.
These erosive processes are intensified by the action of the
Brangkal, Cemoro, and Pujajar rivers -- offshoots of the Bengawan
Solo which divides the Sangiran site in the north, center and
south.

In administrative terms, the Sangiran site belongs to the
Sragen district (Kalijambe, Gemolong and Plupuh regions), as well
as the Karanganyar district (Gondangrejo region) in Central Java.

In 1934, splinters of tools made from jasper and calcedon
stones were discovered by a Dutchman, G.H.R. von Koenigswald,
above the Kabuh series in the west of the Kubah Sangiran sea. He
believed that the gravel layer they were found in was formed at
the end of the Middle Plestocene period, because these tools are
associated with Trinil animals. Van Koenigswald's opinion was
criticized by other researchers, including De Terra, Heekeren,
and later Bartstra and Basoeki. They generally opposed the idea
that the remaining vertebrates had resulted from primary
sedimentation. They said the transformation of the sediment made
it difficult to identify the age of the tools in relation to the
gravel layers.

Two years later, another fossilized fragment of a hominid
jawbone was found in the upper Pucangan series. After that,
several skull fragments came to light in the Pucangan and Kabuh
series. They were named Pithecantrophis robustus (Sangiran 4),
Pithecantropis Dobius (Sangiran 5), Pithecantropis erectus
(Sangiran 2 and 3), and Megantropus paleojavanicus (Sangiran 6a).
The number of names reflects the diversity of the hominid fossils
of Sangiran. Pithecantropus in itself has become a classical and
historical term, and the species is usually described with by the
alternative name, Homo Erectus.

Indonesian researchers, like T. Jacob and S. Sartono, took
over paleoanthropological research in Java in 1960s. Research was
also conducted by the Geological Development and Research Center
in Bandung in cooperation with the Japan International
Cooperation Agency. The Center focussed on prehistoric humans in
Java, especially in Sangiran. Other cooperative works involving
the National Archeological Research Center (PPAN) and the Museum
National d'Histoire in Paris have been held since 1989 at the
excavation site in Ngebung, leading to the discovery of human
fossils in the Pucangan series. Massive tools and animal fossils
were also found on the bottom Kabuh layer.

In the 1980s, Suzuki attempted to date the Sangiran findings
using the fission-track method, while F. Semah and Yokohama tried
the paleomagnetic technique. Because of these attempts at direct
dating, the Sangiran site became increasingly well known.

Layers

The Sangiran dome in the Solo depression, is located at the
foot of Mount Lawu, on the western seaside. The Sangiran site is
considered the most complete in Java, because of its geological
layering and the hominid fossils.

The Sangiran layers started with an oceanic layer (the
Kalibeng formation), dating back to the Pliocene period, but only
part of this layer has been exposed. The blue clay and ocean
limestone of Upper Kalibeng is covered by volcanic laver.

Other layers, formed from black clay sediment before the
Plestocene period, head towards the shoreline. Experts call this
the Pucangan formation, which is 1.8 to 0.7 million years old. In
this layer, scientists found the oldest fossil of Pithecantropus
as well as the remains of huge mammals.

Fossils from several animal species were found in the Pucangan
layers, along with several types of reptiles such as crocodiles
and turtles. Closer to the surface of the earlier layers were
cloven-footed herbivorous species such as deer and oxen. The
layers also contain the fossils of pigs (Cercopithecidae) and
monkeys (pongidae), and large animals like stegodon, hippos and
rhinos.

Another level was discovered in Sangiran, between the borders
of the Pucangan and Kabuh. Von Koenigswald introduced the
expression, grenz-bank in 1940 to describe one-meter thick
limestone strata which define the lower limits of the Kabuh
layers.

According to Sartono, the grenz-bank indicates the borderline
between the Kabuh series and the Pucangan layers below. The
grenz-bank is a layer of super limestone made from various pisoid
elements, like quartz minerals, fragments of frozen stones, clay,
bone fossils, mollusks and large foraminifera shellfish.

The grenz-bank was formed through a slow process of erosion,
through the action of the ebb and flow of the ocean tide. This
layer was formed when erosion caused large quantities of "relief"
material drift down the river, to eventually blend with other
material in the Solo depression, creating the grenz-bank. This
other material possibly originated from hills or from lagoons,
and formed a course mixture.

After the Pucangan formation limited by the grenz-bank, is the
Kabuh formation, which is about 500 to 600,000 years old. The
Kabuh layer consists of river sand deposits mixed with volcanic
material. Most human fossils of Sangiran were found in this
section. Examples include Pithecantropus II and III, discovered
by Von Koenigswald. Other scientists to locate Pithecantropus
fossils were T. Jacob (S.10, S.38) and S. Sartono. Sartono
discovered Pithecantropus VII and VIII, and the Sangiran fossil
17, the only one of its kind ever found.

Volcanic material from Notopuro was the last layer deposited
in Sangiran before the dome folded inwards. It is difficult to
date this layer, but it is estimated that huge volcanoes around
Solo violently erupted between 300 and 100,000 years ago. The
region was covered with volcanic material, containing large hunks
of stone, lava and alluvial sand.

Scientists are still debating the nature of the cultural
products of the prehistoric man known as Homo Erectus. There are
few clear clues to indicate the cultural context in which these
prehistoric humans lived.

Puech (1983) said that Homo Erectus from Java had no culture.
Heekeren (1972) and Bellwood (1985) believed that the hominids
made tools from materials, like wood and bamboo, which
deteriorated over time. Semah (1992) has claimed that no cultural
products have been found because of geological processes - the
human fossils traveled long distances before finally settling in
the alluvial deposits.

Recent research conducted on terraced deposits in Sangiran has
divulged some of the cultural history of the Plestocene era.
Ancient stone tools have been found in the lower layers of the
Kabuh deposits. PPAN's 1992 excavations in Ngebung strengthened
the interpretations about the presence of Homo erectus, with the
discovery of a fragment of a jaw fragment, with two teeth
attached, in river deposits dating back about 800,000 years.

The Nbebung site became important because of the discovery of
stone tools, known as the Sangiran flake-industry. Chopper
shards, cleavers, and faceted and un-faceted balls of andecit,
made from splinters of calcedon and jasper, were discovered.
Several researchers confirmed that the tools were cultural
products of Homo Erectus in Sangiran. Fossils of vertebrate
animals living in close proximity with prehistoric man suggest
that suggest that people lived there 1.5 million years ago.

The richness of the Sangiran site had led experts to describe
it as one of the human evolutionary centers of the world. It is
further used as a measuring device to examine evolutionary
processes in general.

The legacy of Java's Homo erectus from Java has no economic
value, but it offers a priceless historical understanding of life
in prehistoric times. The heritage does not glimmer with the
glitz of gem stones; it consists only of fragments basalt and
andesite rocks.

We may not realized that our present technology has arisen
from a long process, which began with the stone tools of Homo
erectus that have been found throughout Sangiran. These tools
appear simple and they are barely recognizable among river
stones, except to those who scrutinize the scene with
archeological glasses.