Meteorological conditions improved remarkably in the Vallée de Joux during the Allerød Period. The landscape underwent a complete change compared to the preceding cold period. In the Jura, like in the valley, deep pine forests and silver birches replaced the grassland steppes which previously fed the mammoths and other big herbivores from the cold periods. These forested lands were progressively reconquered by man up to considerable altitudes – both in the Jura and in the Alps, but always on a small scale. There are clear indications of the existence of trade exchanges of silex and good quality rocks between the two sides of the Jura range. Epipaleolithic hunters occasionally went after stags, wild boar and deer in our regions, although the Jura per se was not home to any fixed populations. Henceforth, the countryside, fauna and flora in the vallée de Joux looked the way we know it today.
The rocks presented in this zone: the Mammoth Shrine, crushed fluvial glacier aggregate - Praz Rodet Gravel Pit
Plants presented in this zone: Festuca amethystine (Fescue), Aster alpinus (Alpine Aster), Dianthus superbus (Large Pink), Betula verrucosa (Birch), Pinus sylvestris (Scots pine).
Late Bølling-Allerød Period
The late Bølling-Allerød Period once again saw marked climate warming. Initially, the steppe landscapes of the Vallée de Joux were taken over by juniper bushes and shrubs. Following this, pines and silver birches grew once again on the upper slopes of the Jura. Generally speaking, the upper tree limit moved up to around 2000m above sea level. Willows and alders grew in the wet areas at lower altitudes. This climatic warming was fatal for the last remaining so-called glacial species, such as the famous woolly rhinoceros, the reindeer or the horse. But it allowed hunters to make a tentative return to our valley.
Rocks presented in this zone: Alluvial sediment from Lake Geneva
ts presented in this zone: Vaccinium myrtillus (European Blueberry), Betula verrucosa (Birch).
Mid Bølling-Allerød Period
Towards the middle of the Bølling-Allerød Period, the climate strongly deteriorated for a very short period. In the Jura, a clear reduction in the forests and the return of steppe-like landscapes is apparent, characterised by grasslands creating great open spaces. In the Alps, the glaciers once again regained land for a period. And while fauna from the cold steppes – bison, reindeer and prehistoric horses – made a short reappearance in the Vallée de Joux, the mammoths had already left the Jura for northern climes forever. Epipaleolithic hunters for their part had left their mountain lands. Into the bargain, they had never been more than very small groups who roamed the hills and valleys of the Jura. In fact, during the 13000 years that followed this era, no permanent human population inhabited our region, even when the most optimal conditions meant it was covered by fairly thick forests.
Rocks presented in this zone: Gravel - La Claie aux Moines - Savigny, round Granite ball
Plants presented in this zone: Helianthemum nummularium (Common Rockrose), Globularia cordifolia (heart-leaved globe daisy), Pulsatilla vulgaris (pasqueflower,), Hippophae rhamnoides (common sea-buckthorn).
Temperatures rapidly reached similar levels to those of the 20th century. The sudden melting of the ice which ensued caused sea levels to increase an incredible 14m in 350 years! Our regions once again became covered in forests, which completely overturned the division of animal and human populations. The last mammoths left our regions because of the lack of sufficiently large prairies to feed them. Simultaneously, the last hunters of large fauna from the Paleolithic Era were replaced by Epipaleolithic archers who adapted to hunting in the forest. The ground, stabilised by trees and a layer of duff, was no longer disrupted by landslides like the one that buried our mammoth from Le Brassus.
The Rhône Glacier retreated up to central Valais.
Rocks presented in this zone: Round gravel from LaCôte, boule Vallée de Joux, Ball of green granite from the southern Alps
Plants presented in this zone: Betula nana (Dwarf birch), Dianthus sylvestris (Woodland pink), Linaria alpina spp. petraea (Alpine Toadflax).
From this point on, the position of the continents has remained the same as we know it today. Since around -2 million years ago, cold periods resulted in the growth of enormous ice caps at high latitudes and on top of mountain ranges. Around 20000 BC, for example, the whole of Switzerland was completely covered in ice up to an altitude of between 1200 and 1500 metres above sea level. During the Older Dryas, around 17000 BC, the beginning of a retreat of the glaciers could be felt at low altitude, while the Vallée de Joux was still covered in ice. Some 2000 years later, men identical to us frequented the Lascaux Caves while mammoths, woolly rhinoceroses and reindeer strolled along the banks of Lake Geneva. In 14400 BC, or barely a few years after the swift retreat of the ice from the Vallée de Joux, Sapy the Mommoth from Le Brassus set off across the site that would become his tomb. Following the melting of the glaciers, a lake with a precarious wall formed above. When the moraine dike retaining the lake broke, a torrential flood of lava brutally buried our mammoth.
Rocks presented in this zone: Crushed fluvial glacier aggregate - Praz Rodet Gravel Pit
Plants presented in this zone: Salix helvetica (Swiss willow), Saxifraga paniculata (White Mountain saxifrage), Dryas octopetala (Eight petal Mountain Aven), Salix repens ssp. repens (Creeping willow).
Tertiary Period or Cenozoic Era
After the terrifying extinction that marked the Cretaceous-Tertiary boundary, life slowly resumed its normal course on our planet. The gap left by the dinosaurs was filled by mammals and big birds. Following the gentle collision of Italy, pushed by Africa, and the rest of Europe, the Alps became veritable mountains. Simultaneously, the land of the Jura rose up out of the water (-55 million years ago), and created folds ( -11 to -3 million years ago). The ridges and valleys so characteristic of the Jura have only existed since this time, as well as the Vallée de Joux itself. During the same period (-7 million years ago), the Sahelanthropus – a species very close to Homininae, lived in Africa, while mammoths also appeared on this continent (-5 million years ago).
Rocks presented in this zone: Molasse - Massonnens (FR)
Plants presented in this zone: Geranium sylvaticum (Woodland geranium), Epilobium angustifolium (Fireweed), Lythrum salicaria (Purple loosestrife), Digitalis grandi ora (Foxglove), Leucanthemum vulgare (Ox-eye daisy).
During the Cretaceous Period, the future Jura continued it migration towards the north and reached the same latitude as Greece today. The North Atlantic was then several hundred kilometres wide, but South America was still stuck to Africa. By slowly moving northwards 125 million years ago, Africa began to push the Iberian Peninsula, which was then an island, against the rest of Europe and then against the future Jura. These initial movements were responsible for the formation of the Alps but were not yet appreciable in the Jura which was located further north, and which was covered with a warm, not very deep sea. Modern looking sharks roamed all the seas across the globe. On land, the first flowering plants blossomed 110 million years ago, or nearly 120 million years after the oldest dinosaurs! And bees only appeared at the same time as the tyrannosaurus, 70 million years ago. The fall of a meteorite on the Yucatan 65.5 million years ago marks the end of the Secondary Period. This led to the extinction of ammonites and most of the dinosaurs, with the exception of the birds.
Rocks presented in this zone: Crushed gravel - La Sarraz.
Plants presented in this zone: Aconitum napellus (Monkshood), Caltha palustris (Marsh marigold).
Triassic and Jurassic Periods
At the very beginning of the Secondary Period, 251 million years ago, Le Brassus reached the Equator to the North. The future Jura was situated at the heart of an immense continent which brought together Africa, North America and Northern Asia. More than 225 million years ago, the first dinosaurs left their mark on the beaches by the sea which had started invading our region. When the supercontinent of the time split to make the current continents (220 million years ago), the centre and south of Europe formed a vast plain that was progressively invaded by the sea. The oldest layers of limestone and marl, of which the Jura consists, dates from this period. Further north, on solid ground, the first mammals cohabited with dinosaurs. 150 million years ago, the countryside of the future Jura looked like the Bahamas today – with a tropical climate and beaches, and the addition, however, of a great many dinosaurs and primitive birds with bills bristling with teeth.
Rocks presented in this zone: Chert and “blocs d’Enney” (blocks from Enney) (FR).
Plants presented in this zone: Pinus mugo (Mountain pine), Juniperus communis (Juniper), Juniperus sabina (Savin Juniper).
The Precambrian and the Paleozoic eras
The estimated four billion years between the formation of the Earth and the appearance of the first abundant fossils with shells or a skeleton nearly 540 million years ago, is called Precambrian. It is followed by the Paleozoic era in which terrestrial plants appeared (-415 million years ago), followed by ferns and horsetails (-385 million years ago) and conifers (-350 million years). At that time, Le Brassus was situated at the heart of an island that was bigger than Madagascar, lost in the middle of a vast ocean between Africa and Northern Europe under the Tropic of Capricorn. The collision of this island with Europe created a long mountain range, now eroded, which extended from the centre of Spain to Bohemia via the Jura and the Black Forest. The Paleozoic era ended 251 million years ago with one of the biggest mass extinctions that the Earth has ever known – more than 95% of living creatures perished. The rocks from this far-off time still found in Switzerland are mainly granite and shale from the older periods and red and black sandstone from more recent times.
Rocks presented in this zone: Chert from Mörel and Susten (VS), Mont-Blanc granite, “bloc” (block) from Mörel and Susten (VS).
Plants presented in this zone: Dryopteris filix-mas (Male fern), Equisetum hyemale (Rough horsetail)
In 1969, an entire mammoth skeleton was found in the Vallée de Joux. It is displayed in the Musée de Paléontologie in Lausanne in the position in which he was found - recumbent in the moraine next to the retreating glacier. Only a few ribs are missing, probably torn off by predators shortly after his death.
It is exceptional to find a complete mammoth skull: the muscles of the neck and back are particularly developed in order to support the weight of the tusks and require a large anchoring area on the back. To lighten the gigantic cranium, the bone consists of thin walls about a millimetre thick, enclosing cavities of up to ten centimetres. One can understand why it is such a challenge to save a mammoth skull, if, with a stroke of luck, it has not been crushed prior to being discovered.
To safeguard the observations made at the time of discovery, a mould of the skeleton was required. The mould was made on the original, and only the missing ribs were reconstituted. The moulding technique created hollow bones which allow the supporting metal structure to be concealed.
We took the original skeleton “apart” in order to work with it in our St-Gallen laboratory. After creating a silicone negative, we dipped the bones in resin reinforced with fibreglass in order to create an identical reconstitution of the original skeleton.
The mould was bought by the Chenit municipality, for its 300th anniversary. It is now on display in a shelter designed to provide optimal viewing in the Jardin du Temps at Le Brassus.
Both the original skeleton and its copy exhibited at Le Brassus represent a veritable treasure studied by scientists from various institutes, especially the Niederweningen, ZH, «Mammutmuseum” (www.mammutmuseum.ch).
Urs and Sonia Oberli, Palaeontology Laboratory, St- Gallen
Plate on the façade of the former Le Brassus Station
The former Le Brassus Station received its first train on August 19, 1899. Steam was replaced by electrical traction on October 1, 1938.
On May 17, 2000, a TGV chartered by Audemars Piguet transported company employees to Paris, returning to Le Brassus the following day, on May 18.
The last train left the old station on June 8, 2008. On April 27, 2009, the first train entered the new station which was inaugurated on August 20, 2009, 110 years and one day after the first inauguration.
Photographs of the station’s demolition can be seen at :
The significance of the mammoth from Le Brassus
It is rare to find skeletons of woolly mammoths that are virtually complete. Thanks to the one found at Le Brassus, we have a better idea of what an adolescent mammoth looked like – with its hump-free back and small tusks.
We also know that mammoths had a period of rapid growth at the end of their adolescence with their vertebrae growing in spurts and certain joints, such as the elbows, only ossifying very late.
Our mammoth suffered from arthritis, a bone disease which only rarely affects known species. Judging by the marks on his tusks, the mammoth from Le Brassus made more head movement to the right than to the left.
A large herbivore, stiff competition for his peers
Above all, we can learn more about our mammoth’s feeding habits by observing his teeth. The molars of woolly mammoths present hard parallel enamel ridges, similar to elephants. Mammoths used their teeth to grind, with their lower jaws only moving from front to back, and not laterally, for example, in the same way as cows. With their enamel ridges, mammoths’ teeth were perfectly adapted to masticating steppe grasses, which were dry and very abrasive.