The road to the Piton de La Fournaise continues from the Plaine des Cafres, crossing the drop of the Rempart des Sables, by some narrow hairpins cut in the flows of a small piton located 150 meters from the crest of the rampart . Close to the Ravine Germeuil, it took his name. Its age and that of the flows is between 500 and 1,000 years (older than the Piton Chisny).
The Pas des Sables: the zigzag road on the Plain of the Remparts before going down in the flows of the Piton Germeuil towards the Plaine des Sables - flight over ULM - photo © Bernard Duyck / June 2017
The Pas des Sables: the road descends in laces in the flows of Piton Germeuil towards the Plaine des Sables, and the forest road - photo © Bernard Duyck / June 2017
The plain of the Sands, covered with slag, is crossed by the forest road of the volcano. It is punctuated by some distant reliefs: the piton of the Cirque, the Half-piton and the Piton Chisny.
The formation of the Plaine des Sables is still subject to discussion: between collapse and sliding by gravitation, between 65,000 and 30,000 years ago.
The Plains des Sables is covered by the major lapilli emissions from Piton Chisny, dating from the year 910-1.030; the lava flows poured into the Langevin River and reached the sea by forming Pointe Langevin.
The rampart of Bellecombe constitutes the point of view overlooking the Enclos Fouqué and its access point, at the Pas de Bellecombe.
In the center of L'Enclos, which is a depression open towards the east, the terminal cone of Piton de La Fournaise. On its left is the Piton de Partage (Piton Sale), at its foot, the small cone of projections of Formica Leo, of which only the terminal part, where one distinguishes two craters, emerges from the lava flows of Piton de La Fournaise.
From the Pas de Bellecombe, the Piton de Partage and the Formica Leo in the Enclosure - photo © Bernard Duyck / June 2017
From Pas de Bellecombe, the Piton de La Fournaise and the Formica Leo - photo © Bernard Duyck / June 2017
The formation of the Piton de La Fournaise dates back approximately 530,000 years. This volcano-shield, 40 km in diameter, with low slopes, is marked in its summit by two great concentric collapses: the ramparts of the Plaine des Sables and Bellecombe, encircling part of the Enclos Fouque (of the French volcanologist / 19th century)
Its history is long and detailed on the site of the observatory, which distinguishes several phases of activity; I refer you to the page for details - link.
The Piton de la Fournaise massif. - The three caldeiras are indicated in red. The first dotted line is reconstructed by observations on the ground. The second can be observed at Pas des Sables. Its continuation is reconstituted to the East and the South. The third caldera corresponds to the Rampart of Bellecombe. From Mairine, 1998./ OVPF - and annotated model - click to enlarge
Trail on the Rampart / Path of Bert passes in the lava flows of Piton Chisny - photo © Bernard Duyck / June 2017
On the Rampart / Trail of the Piton of Bert : a burned area - photos © Bernard Duyck / June 2017 - recalls the eruption and the fire of the rampart the 23.10.2015 - with an archive view from the camera of the Piton de Bert, the closing of the trail and the intervention of the Dash 8 on the fire
- BRGM - Geological itinerary: the road to the volcano, discovery of ancient La Fournaise - link
- Cybergeo - Review of the typology of eruptions of Piton de La Fournaise, volcanic processes and associated risks - by N.Villeneuve and P.Bachèlery / 2006.
- IPGP / OVPF – Piton de La Fournaise - link