Other Archaeological Sites / The Neolithic of the Levant (500 Page Book Online)
THE ENVIRONMENT OF THE LEVANT IN THE
Chapter 1 (Pages 6-11)
Excerpts and Definitions and Addendums:
The environment of the Levant at the close of the Pleistocene and early in the Holocene was until recently poorly understood. It had long been thought that changes in the environment at the end of the Pleistocene contributed to the evolution of the Neolithic way of life but the influence of these changes could not be properly assessed. Recent studies in geomorphology, palynology and palaeozoology have produced new evidence on which to base an outline reconstruction of the environment in the late Quaternary. I will begin this chapter by discussing certain general factors which affected the environment of the whole Levant. I will then consider the evidence for the climate, landscape and vegetation of each region of the Levant and how they were modified, first in the late Pleistocene and after in the early Holocene.
In northern latitudes the late Pleistocene is marked by the Wurm/Wisconsin glaciation. The Near East was not directly affected by the advance of the European ice sheets but its climate was significantly altered nonetheless. An indication of these climatic changes has been obtained from studies of the fauna and sediments in several deep-sea cores. Analyses of cores drilled in the Red Sea have determined that the climate was cooler and more humid there during the period of the last glaciation (See Page 345 in *1 Below). Two other deep-sea cores have been drilled in late Quaternary deposits in the eastern Mediterranean, one between Cyprus and Crete (#189) and the other west of Crete (V 10.67). Oxygen isotope analysis of these cores has shown that the temperature of the Mediterranean fell considerably during the period of the last glaciation (See Page 90 in *2 Below) and studies of the fauna of core V 10.67 have confirmed this conclusion. There is some doubt about how much the temperature actually decreased at this time but recent work suggests that the estimate of Vergnaud-Grazzini and Herman-Rosenberg of a fall of between 5 and 10 degress C is the more reasonable (See Page 534 in *3 Below).
This drop in temperature caused increased glacial activity in the mountainous regions of the Eastern Mediterranean. The present relict glaciers in the Taurus expanded considerably and it is estimated that the snowline lay about 1000 metres lower than today, that is at about 2650 metres. It is also believed that there were glaciers in the Mountains of Lebanon and on Mount Hermon but there is a divergence of opinion over how much the snowline was depressed in the Levant. Klaer claims that the permanent snowline today would lie between 3200 and 3400 metres but Messerli estimates that it would be as high as 3700 metres, that is above the summits of the highest mountains in the Lebanon. Both derive their different estimates from studies of present snowfall. Klaer and Messerli have also examined the evidence for glaciation in the mountains and almost agree on the level of the permanent snowline during the Wurm [Glacial Stage]. Klaer thinks that it lay between 2750 and 2850 metres and so fell about 500 metres; Messerli believes that the snowline was at about 2700 metres, a much greater fall of about 1000 metres. Messerli's estimate of a depression of about 1000 metres would agree better with the evidence from the Taurus [Mountains] and so may be the more likely. If a fall in the air temperature was the sole cause of this lowering of the snowline then it would need to have dropped about 6 or 7 degres C (See Page 550 ibid), an estimate which agrees broadly with the evidence of the deep-sea cores.
Studies of the sediments of some cave sites in the Levant have shown that these were deposited under the prevailing cooler climate of the last glaciation. This is most apparent at the inland sites of Jerf Ajla and Yabrud which were affected by continental conditions. Frost weathering could be detected throughout the Mousterian and Upper Palaeolothic sequence at Jerf Ajla (See Page 750 in *4 Below) although there were some fluctuations reflecting warmer climatic phases. It is also believed that the top five metres of deposit at Yabrud I, which includes the Mousterian layers, was laid down under cooler conditions (See Page 41ff in *5 Below). Although winters can be cold in these areas today they are rarely cool and moist enough to cause significant frost weathering.
Farrand has detected cryoturbation in the Levallois-Mousterian and Upper Palaeolithic layers at Jebel Qafzeh (See Page 553 in *3 and Page 233 in *6 Below) near Nazareth. This site lies on the edge of the Galilee hills at an elevation of 220 metres, sufficiently high apparently to have experienced frost weathering. The climate at coastal sites such as Tabun was also somewhat cooler during the last glaciation (See Page 177 in *7 Below) but not cold enough, apparently, to cause significant frost weathering (See Page 553 in *3 Below). The evidence from the caves thus supports that from other sources, indicating that during the last glaciation the temperature in the Levant fell by several degrees.
The advance of the ice sheets absorbed water from the oceans and markedly lowered sea-levels. During the later Wurm sea-levels throughout the world fell by perhaps 100 or 150 metres (See Page 152 in *8 and Page 217 in *14 and Page 1123 in *17 Below) which considerably altered the configuration of the coastline of the Levant. Taking the more modest estimate of a fall of 100 metres, the shoreline in Palestine would have lain 15 kilometres further west across a gradually sloping coastal plain. In Lebanon and southern Syria the coastal plain would have been about 5 kilometres wider than now, sloping down to the sea and dissected by wadis. North of Lattakia it would have been only 2 kilometres wider with a steep slope.
The displacement of the coastline has important implications for the pattern of later prehistoric settlement as we see it today. All Terminal Palaeolithic and Mesolithic sites and some early Neolithic ones now situated near the sea would have lain well inland at the time they were inhabited. This includes the sites in the coastal dunes and around Mount Carmel in Palestine as well as many of the shelter sites in Lebanon. An open coastal plain would have lain to the west of these sites so their environments would have appeared much more favourable for settlement then than they do now. Almost certainly many more prehistoric sites were situated on the coastal plain which are now drowned. These would have included almost all the sites whose inhabitants might be expected to have supported themselves partly by fishing. Our present views about the economy and settlement pattern of sites on the seaward side of the coastal hills and mountains of the Levant will thus be distorted if we fail to allow for this evidence which we have lost.
Palaeo-temperature studies of deep-sea cores from the Atlantic, Caribbean and Pacific indicate that the temperature gradually began to rise worldwide between 20,000 and 15,000 BP (See Figures 3 and 4 in *18 Below). After 15,000 BP it rose sharply until it reached a maximum about 5000 BP. The palaeo-temperature curves derived from deep-sea cores mask almost all the minor fluctuations in temperature that occurred during this period but one temporary fall in temperature about 13,000 BP lasted long enough to be detected in the Caribbean cores (See Figure 3 in *19 Below). This has been equated with the Post-Allerod or Younger Dryas phase of cooler climate in northern Europe (See Page 40 in *10).
As the temperature increased so the glaciers melted and the level of the oceans around the world began to rise; this process had certainly begun by 12,000 BC (See Page 1123 in *17 Below) and perhaps earlier before 14,000 BC (See Page 396 in *11 and Page 46 in *12 Below). Thereafter, although interrupted by several short stages of retreat (See Page 1707ff in *13 and Page 154ff in *8 Below) the level of the oceans rose rapidly until about 5000 BC and then more slowly until it reached its present level about 4000 BC (See Figure 14 in *8 and Page 46 in *12 Below) or 3000 BC (See Page 530 of *14 Below). There is no general agreement on the actual levels of the sea worldwide at particular times during this period although one can gain some idea of the rapidity of the transgression by comparing estimates based on evidence from the continental shelves. Thus by 10,000 BC Fairbridge estimates that the sea had risen to about 40 or 50 metres below its present level (See Figure 14 in *8 Below) although Milliman and Emery believe it still to have been much lower (See Figures 1 and 2 in *17 Below): at 7000 BC perhaps 15 (See Figure 15 in *8 Below) or as much as 50 metres lower (See Figures 1 and 2 in *17 Below): at 5000 BC 10 to 30 metres below present levels.
The most recent curve of glacio-eustatic sea-level fluctuations during the Quaternary is that published by Shackleton and Opdyke (See Figure 7 in *12). This was derived from oxygen isotope analysis of foraminifera in a core, Vema 28-238, drilled in the sea bed of the Pacific. This new evidence also indicates that the level of the sea rose rapidly once the ice began to melt. The curve agrees better with that of Fairbridge than of Milliman and Emery; Shackleton and Opdyke estimate that at 10,000 BC the sea would have been about 30 to 40 metres below the present level.
These estimates may not correspond exactly with the Mediterranean rise in sea-level but as a recent study has shown that there was little tectonic movement along the Levant coastline during this period (Sanlaville quoted on Page 318 in *15 Below) they probably give a rough indication of the rate of change. They suggest that the coastal plain was sufficiently open to facilitate communications along the Levant coast until about 7000 or even as late as 5000 BC, that is during the later Neolithic. Thereafter, although the level of the sea rose further and there were additional minor fluctuations, this had no significant effect upon the pattern of settlement. Movement along the coast became more difficult, particularly at the foot of the Mountains of Lebanon between Beirut and Tripoli.
Studies of shorelines, sediments and pollen samples have shown that there were several marked oscillations in climate during the period of the last glaciation and after. Unfortunately these oscillations are not well dated and it is difficult anyway to correlate the evidence from these different sources. Thus there is no general agreement on the pattern of climatic change in the Levant during the late Pleistocene and Holocene. Some authorities believe they can detect a detailed sequence of climatic fluctuations which matches the well-documented record of northern Europe (See Page 274ff in *16) while others think that the evidence is insufficiently detailed for such a precise evaluation (See Page 559 in *3 and Page 389 and 404 in *9 Below). Nevertheless, there is now enough evidence from a variety of sources to attempt a reconstruction of the environment at the close of the Pleistocene and in the early Holocene, even if the absolute chronology is still uncertain ...
*1 Evidence of Climatic Changes in Red Sea Cores
*2 Pleistocene Temperature Variations in the Mediterranean
*3 Late Quaternary Paleo-Climates of
*4 Analysis of Sediments of Jerf Ajla and Yabrud Rockshelter
*5 Geology, Climate and Chronology of Yabrud Rockshelter I
*6 Geological Correlation of Pre-Historic Sites in the Levant
*7 New Excavations at the Tabun Cave .....
*8 Eustatic Changes in Sea Level (1961)
*9 Patterns of Environmental Change in the Near East
*10 Atmospheric Circulation During the Last Ice Age
*11 The Deglacial Hemicycle by W.R. Farrand (1965)
*12 Oxygen Isotope and Palaeomagnetic
*13 Late Quaternary Sea Level: A Discussion
*14 Environment and Archaeology: an Ecological
*15 The Middle and Upper Paleolithic
*16 Climatic and Vegetational Developments in North-
*17 Sea Levels During the Past 35,000 Years
*18 The Brunhes Epoch: Isotopic
*19 Quaternary Paleotemperatures and the