In the current state of research, the stratigraphy preserved at Menez-Dregan displays 17 individual levels of human occupation and 4 marine deposits, between ca. -500 000 and -150 000 years.
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The faunal remains are not well preserved because of the natural acidity of soils in Brittany, and only the stone tools allow us to understand the living style of the human groups which succeeded each other in this site, and who knew how to control fire at a very early date (around -465 000 years).
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The lithic industry found on the site is extremely abundant, and corresponds to a regional facies of the Acheulean. More than 153,000 stone tools in flint, quartz, quartzite, sandstone or microgranite have been recorded since the beginning of the excavation, as well as millions of knapping fragments. They are all studied in detail at the University of Rennes 1.
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Some examples of pollen and many different charcoals were also collected during the excavation. Very well preserved, the hundreds of charcoal and the few pollen examples that are preserved allow to reconstruct the landscapes and climates during the different occupations of the site in prehistory.
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Some of the oldest hearths in Europe: at the end of the 2014 excavation season, 12 hearths were clearly identified on the site of Menez-Dregan I. From 2015 to 2019, no new structures of combustion were discovered, nor in layer 8 or in layer 9.
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hat do we find in Menez-Dregan?
@ A.-L. Ravon
@ F. Eluard
@ J.-L. Monnier
@ A.-L. Ravon
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0
2a
2b
2c
3a
3b
4a
4b
4c
5
6
7
8b inf
9c
10
11
PF
5e-d
9b
9a
8b sup
8d
8c
8a
he Stratigraphy
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The stratigraphy preserved at Menez-Dregan I is very rich in information. With the exception of levels 0, 1, 2, 3 and 10-11, all stratigraphic units testify to the human presence on the site. They are presented here from the oldest to the most recent, and allow us to place the objects discovered in their context and their occupation.
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Just above the cave floor, the first geological level is the layer 10-11, a pebble layer deposited by the sea probably ca. 500 000 years ago. It does not contain any archaeological remains, since at that time the sea infilled the cave.
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On this pebble layer, the first human occupation is that of layer 9, which consists of levels 9a, 9b and 9c, and which occurred during a cold period. This is the oldest trace of the presence of humans in northwestern France. The hearth of layer 9a has been dated to ca. -465,000 years, placing it among the oldest hearths in Europe. Quite rare in Brittany for periods so old because of the natural acidity of the soil, some bone remains were collected during the search and analysed. Very degraded and reduced to the state of "dough", they are always associated with stone tools: it can therefore be said that they have been brought into the cave by humans, and that it is not a natural carnivore den, such as those used by hyenas for example. Bones found during excavations in 2017 and 2018 are still undergoing identification.
@ A.-L. Ravon
@ A.-L. Ravon
@ A.-L. Ravon
@ A.-L. Ravon
Following this occupation in cold period, the climate warms up, and the sea level rises: it even returns to the cave, and erodes the top of layer 9. The sea deposits again a pebble layer on the site, layer 8.
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The second human occupation takes place on this pebble layer. More than 5,300 stone tools were found, including a few handaxes. No hearths were identified during the excavation, despite the abundance of charcoals. The datings seem to place this occupation ca. 400 000 years ago.
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The third archaeological layer of the site is layer 7, during a colder phase. 16,383 stone tools were found there, with many traces of hearths. No dating could be done on this level, but it is estimated that it was occupied by hominins ca. 380,000 years ago. Palaeoparasitology analyses carried out in laboratory have led to the discovery of a Toxocara Canis cyst in the layer 7 sediment, which is a fossil intestinal parasite of hyena. The cave was probably occupied by groups of hyenas when it was abandoned by humans.
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Once again, after this occupation in cold weather, the climate warms up, the sea goes up in the cave, and erodes the top of layer 7. It deposits once again a pebble layer on the site, layer 6. On the top of this pebble layer, hominins return to settle at the beginning of a cooler period, probably 325 000 years ago. 20,516 stone tools were found, as well as a hearth, excavated in 2009.
The climate is getting colder, and around -320 000 years ago, several human groups take turns to settle in the cave. This is layer 5 and its numerous sub-levels, which in total comprise 91,770 stone tools, and 3 fireplaces: a circular hearth consisting of eight flat granite slabs, discovered in 1993, which contained in its centre a fragment of a molar of an Elephantid; a fireplace discovered in 1988 consisting of six large quartz pebbles arranged in an arc around a collapsed vault block; and a hearth discovered in layer 5d in 2005.
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The climate is getting colder again, and new human groups are coming into the cave, which at that time certainly looked more like a rockshelter at the foot of the cliff, following successive collapses. Layer 4 is the last human occupation of the site, and contains over 17,000 objects. This last human occupation on the site marks the beginning of the transition with the Middle Palaeolithic in the region, and the arrival of Neanderthal populations. A dating was performed on a heated flint of sub-level 4c, and gives an age of approximately 223,000 years.
@ J.-L. Monnier
@ P. Garcia-Medrano
@ A.-L. Ravon
@ J.-L. Monnier
Finally, a dune clogs the deposits (layer 3b), and has been dated to ca. -150 000 years ago. When it was discovered, the deposit was sealed by a sort of "embankment" covered with vegetation, obliquely eroding all the upper archaeological levels. The excavated layers are thus only partially preserved, which explains for example the absence of hearths in some of the levels where there are burnt artefacts.