Discuss the archaeological determinants of palaeoenvironment.

According to Clark, J.D. (1970), Environment is something you are very familiar with. It is everything that makes up our surroundings and affects our ability to live on the earth-the air we breathe, the water that covers most of the earth’s surface, the plants and animals around us and much more.

Palaeo indicates early, archaic or something that deals or involves ancient forms or conditions. Palaeoenvironment is the determination of pre-historic environment of an archaeological site, using the methodologies of geology, botany, palynology and archaeozoology. Or means something that pertains to the changes in the environment through pre-history and history. In particular it deals with the environment changes that took place in the distant past. In general meaning, palaeoenvironment is an environment at a period in the geological past.

Today’s climate is different than that of earlier periods. In facts climate including vegetation, temperature and relatively humidity has varied considerably during the time of human habitation of planet earth. The palaeoenvironment can be determined by different proxies as follows.

Pollen analysis, this sometimes is called Palynology or the study of pollen grains. It was developed by a Norwegian geologist, Lennart Von Post at the beginning of the Century. It has proved invaluable to archaeology, since it can be applied to a wide range of site and provides information on archaeology as well as environment (Renfrew, C. & Bahan. 1996:224). Pollen grains are very resistant to decay. They are dispersed easily by wind. Plants produce them in a large numbers, and they will settle and accumulate on any undisturbed surface including for example in lake sediments or peat bogs. The low level of oxygen in such place helps to preserve them. Therefore by determination of the species of plants from which the pollen come it is possible to get an overall picture of vegetation represented and thus an idea of the kind of climate that must have prevailed. (Clark, J.D. 1970:30).

Phytoliths,  this comes from Greek words Phyto means “Plant” and lithos means “stone” these are minute particles of silica (Plant opal) delivered from the cell of plants and they survive after the rest of the organism has decomposed or been burned. They are common in herths and ash layers, but also to be found inside pottery, plaster and even on stone tools and the teeth of herbivorous animals. Phytoliths are useful in determining palaeoenviroment, like pollen grains they are produced in large number, they survive well in ancient sedments, and they have myriad shape and size that vary according to type. Through this it inform us primarily about the particular plants found in that areas also they give us a picture of palaeoenvironment (Renfrew, C. & Bahan. 1996:228).

Bone identification in the field, bones are usually only preserved in situation where they have been buried quickly, thus avoiding the effects of weathering and the activities of scavenging animals. After the collection, the first step is to identify as many fragments as possible, both part of the body and as a species. This is work of zoologist or one of the growing numbers of zoo archaeologists, although every archaeologist should be able to recognize a basic range of bones and species. Identification is made by comparison with a reference collection. The resulting and associations of species can also sometimes helps to date Paleolithic sites (Renfrew, C. & Bahan. 1996:235). Therefore through collection and identification of bones archaeologist will be able to determine types of animals existed as well as what kind of environment was there before.

 Diatom analysis, Diatoms are unicellular algae that have cell walls of silica instead of cellulose and this silica cell wall survived after the algae die. They accumulate in the great number at the bottom of any body of water in which the algae live; a few a found in peat, but more comes from lake and shore sediments. The process of identifying and counting them is much like that used in palynology, as is the collection of sample in the field and there after the samples are examined. For example the botanist J.P. Bradbury looked at diatoms from 9 lakes in Minnesota and Dakota and was able to show that the quality of their water had become eutrophic (more nutrient) since the onset of European settlement around lakes in the last century influx caused by deforestation and logging, soil erosion, permanent agriculture and the increase in human and human wastes (Renfrew, C. & Bahan. 1996:228).

Fossil cuticles, cuticles are the outermost protective layer of the skin or epidemis of leaves or blades of grass, made of cutin, a very resistant materials that retains the pattern of the underlying epidermal cell which have characteristics shapes. In fossil cuticles samples are collected and then are well examined by using the light microscope. Example the Scientist Patricia Palmer has found abundant charred cuticular fragments in core samples from lake sediments in East Africa the fragments were deposited there as a results of the recurrent natural grass fires at least 280000years. Many of fragments are large enough to present well- preserved diagnostic futures that under the light microscope on in Scanning Electronic Microscope (SEM) have enabled her to identify them to the level of sub-families or even genus and hence reconstruct changes in vegetation during this long period. (Renfrew, C. & Bahan. 1996:224-225).

Remains of woods, the study of charcoal (wood that has been burnt for some reasons) is making a growing contributuion to archaeological determination of environments ad of human use of timber.  Therefore charcoal usually found and extracted by archaeologist. Once the fragments have been sieved, sorted and dried, they can be examined by the specialist under the microscope, and identified normally at genus level, and sometimes to species. Since no chemical need to be used, charcoal has in addition proved the most reliable materials from which to take samples for radiocarbon dating. (Renfrew, C. & Bahan. 1996:230)

Sediments and soils, investigation of sediments (the global term for material deposited on the earth’s surface) and soil (the life supporting, biologically and physically weathered upper layer of those sediments) can reveal much about the condition that prevailed when they were formed. The sediments will be examined in subsequent sections on plants and animals (Renfrew, C. & Bahan. 1996:219),

Evidence from Ocean, the sediments of the ocean floor accumulate very slowly ( a few centimeters every thousand years) and in some areas consist primarily of ooze made up of microfossils such as the Shells of planktonic foraminifera-tiny one called marine organism that live in the surface water masses of the oceans and sink to the bottom when  they die are in archaeological stratigraphy, therefore through this one can able to trace changes in environmental condition through  time by studying core extracted from the sea bed and fluctuations in the species represented and the morphological (physical form) of single species through sequence (Renfrew, C. & Bahan. 1996:216) .

Generally, the environment governs human life, landforms and climates determine the vegetation which in turn determines animal’s life. The current environment differs from that of the pre-historic era since the current environment has changed due to advancement of technology. Therefore we can be able to determine the palaeoenvironment through different determinats like plant remains(Pollen, diatom analysis, phytoliths and fossil cuticles), also animal remains like(bones identification) and other determinants. Through this now we can distinguish palaeoenvironment and the current environment.

REFERENCE

Clark, J.D. (1970), the Pre-history of Africa. Thames & Hudson Ltd. London

Renfrew, C. & Bahan, (1996), Archaeology Theories, Methods and Practice. Thames & Hudson Ltd. London