Le Secrétariat de l’UNESCO et le Centre du patrimoine mondial ne garantissent pas l’exactitude et la fiabilité des avis, opinions, déclarations et autres informations ou documentations fournis au Secrétariat de l’UNESCO et au Centre du patrimoine mondial par les États Parties à la Convention concernant la protection du patrimoine mondial, culturel et naturel.
La publication de tels avis, opinions, déclarations, informations ou documentations sur le site internet et/ou dans les documents de travail du Centre du patrimoine mondial n’implique nullement l’expression d’une quelconque opinion de la part du Secrétariat de l’UNESCO ou du Centre du patrimoine mondial concernant le statut juridique de tout pays, territoire, ville ou région, ou de leurs autorités, ou le tracé de leurs frontières.
Les noms des biens figurent dans la langue dans laquelle les États parties les ont soumis.
The Chirundu Fossil Forest National Monument site contains fossilised or petrified tree trunks of the Karoo age. It is situated in customary land of Chief Sikoongo of the Gwembe District in the Southern Province of Zambia and is 21 kilometres from the Chirundu border which forms a boundary with Zimbabwe.
The site has superb fossilised tree trunks measuring up to 1.2m in diameter assigned to Dadyoxlon sp. and Rhexoxylon africanum which are difficult to distinguish with naked eyes.
The main rock type here is sedimentary: red pebbly arkose (immature sandstones) formed during the Upper Karoo (Jurassic) times. These rocks show alternating coarse and fine sedimentary layers. The name Karoo is derived from the Karoo Basin of South Africa where similar rocks were surveyed.
It has unique palaeontological and geological resources. The fossils found in the site are of coniferous trees which flourished in the area some 150 million years ago. These are used as environmental indicators of the type of climate ecology that prevailed during that aeon and how it has changed to the current scenario.
The coniferous trees that grew then are no longer found; the current vegetation being mopane woodland which is characteristic of hot areas and valleys. The deduction therefore, is that the climate then was like that of temperate regions.
The Chirundu fossil-bearing sedimentary rocks have alternating bands of coarse and very coarse aggregates. That, coupled with annual growth, suggests that there were seasonal variations during the Karoo times.
The Chirundu fossil site lies within the Karroo super group of the coal-bearing Mid Zambezi Valley basin and partly in the Zambezi Mobile Belt of southern Zambia. Some of the fossils are still in their original environment and many of them are in a well -preserved state. There are those that are barely been moved and those that are scattered.
The barely moved fossils consist of the well preserved and unmoved fossil wood logs in the area. These logs appear to have maintained their position where they have been silicified after failing. Annular rings are also distinguished by colour. These logs range in size from short blocks of intact lengths of about 1-1.2m to long trunks of 10metres intact length.
The scattered wood logs appear to have been moved by water action and are mostly associated with low-lying areas such as streambeds. The fragmentation of fossils may have been caused by the smashing of the wood against each other. This implies that these are not in their original setting.
The area covered by both the barely moved and the scattered fossils is approximately 43square kilometres.
The fossils are formed from sandstones of the Escarpment Grit Formation of the Upper Karroo group.
Similar fossil wood exists in the Karroo rocks of Zimbabwe and South Africa, Arizona Petrified Fossil Forest National Monument in the United States of America.