Vredefort Dome

Vredefort Dome

Vredefort Dome, approximately 120 km south-west of Johannesburg, is a representative part of a larger meteorite impact structure, or astrobleme. Dating back 2,023 million years, it is the oldest astrobleme yet found on Earth. With a radius of 190 km, it is also the largest and the most deeply eroded. Vredefort Dome bears witness to the world’s greatest known single energy release event, which had devastating global effects including, according to some scientists, major evolutionary changes. It provides critical evidence of the Earth’s geological history and is crucial to understanding of the evolution of the planet. Despite the importance of impact sites to the planet’s history, geological activity on the Earth’s surface has led to the disappearance of evidence from most of them, and Vredefort is the only example to provide a full geological profile of an astrobleme below the crater floor.
Outstanding Universal Value

Brief synthesis

The Vredefort Dome is 120 km south west from Johannesburg. The property represents a unique geological phenomenon formed about 2 023 million years ago and is the oldest and largest known meteorite impact structure on earth. Within the area, geological strata comprising the middle to upper zones of the earth’s crust, developed over a period of more than 3 200 million years are exposed. All the classical related characteristics of a large astrobleme are found in the property. This multi-ring structure formed by the impact scar illustrates the effect of shock metamorphism of rocks, transformation of crystal structures and shatter cones of the immense force created by the impact.

Criterion (viii): Vredefort Dome is the oldest, largest, and most deeply eroded complex meteorite impact structure in the world. It is the site of the world’s greatest single, known energy release event. It contains high quality and accessible geological (outcrop) sites which demonstrate a range of geological evidences of a complex meteorite impact structure. The rural and natural landscapes of the serial property help portray the magnitude of the ring structures resulting from the impact. The serial nomination is considered to be a representative sample of a complex meteorite impact structure. A comprehensive comparative analysis with other complex meteorite impact structures demonstrated that it is the only example on earth providing a full geological profile of an astrobleme below the crater floor, thereby enabling research into the genesis and development of an astrobleme immediately post impact.

Integrity

The serial World Heritage property which is about 30,111 ha, is made up of a main component area of 30,108 ha and 3 satellite components of 1 ha each. The property of the Vredefort Dome includes key geological (outcrop) sites which demonstrate classic complex meteorite impact structure phenomena. A comprehensive comparative analysis with other complex meteorite impact structures demonstrated that it is the only example on earth providing a full geological profile of an astrobleme below the crater floor, thereby enabling research into the genesis and development of an astrobleme immediately post impact. This serial property is surrounded by a 5 km buffer zone that is designed to ensure the property’s long term protection against external development threats.

Protection and management requirements

Provision of legal protection and the establishment and maintenance of an effective management system involving all relevant stakeholders are essential requirements for this property.

The national World Heritage Convention Act of 1999 is to be applied to the World Heritage property following the completion of the national designation process. Various legal instruments are also applicable to ensure the protection of the property: These pieces of legislation include the Environmental Conservation Act(Act No. 73 of 1989), the National Environmental Management Act(Act No. 107 of 1998), the Physical Planning Act(Act No. 88 of 1967), the Subdivision of Agricultural Land Act(Act No 70 of 1970), the Free State Township Ordinance(Ord. No. 9 of 1969), National Environmental Management Biodiversity Act(Act No 10 of 2004) and the Free State Nature Conservation Ordinance(Ord. No. 8 of 1969). In terms of these laws, all development within or outside the property is subjected to an environmental impact assessment. Once the World Heritage Convention Act also applies to this property, it will automatically be recognized as a protected area in terms of the National Environmental Management: Protected Areas (Act 57 of 2003). Protection in terms of the latter legislation also implies that mining or prospecting will be completely prohibited within the property or its buffer zone.  The management of the property is to be guided by a multi-stakeholder Vredefort Dome Steering Committee and carried out on an interim basis by the Vredefort Dome Inter-Provincial Task Team. A framework defining roles and responsibilities is required. The future Management Authority is to oversee the implementation of the integrated management plan, taking into account the existing State Party’s action plan and draft management guidelines regarding the coordination of land-uses, development pressures, visual integrity, presentation and visitation of this World Heritage property.

An integrated management plan is required for the serial property so as to address the critical issues of the enforcement of the special land use planning requirements for the private property farmlands within the serial property, the preservation of the aesthetic rural/natural landscape and the protection, presentation of and public access to the clearly defined key satellite components. These conditions are essential to ensure that active conservation management is possible.
Long Description

Vredefort Dome, approximately 120 km south-west of Johannesburg, is a representative part of a larger meteorite impact structure (astrobleme). Dating back 2,023 million years, it is the oldest astrobleme found on Earth so far. With a radius of 190 km, it is also the largest and the most deeply eroded. Vredefort Dome bears witness to the world's greatest known single energy-release event, which caused devastating global change, including, according to some scientists, major evolutionary changes. It provides critical evidence of the Earth's geological history and is crucial to our understanding of the evolution of the planet. Despite this, geological activity on the Earth's surface has led to the disappearance of evidence from most impact sites and Vredefort is the only example to provide a full geological profile of an astrobleme below the crater floor, allowing research into the genesis and development of an astrobleme immediately post-impact.

The site contains high quality and accessible geological (outcrop) sites that demonstrate a range of geological evidences of a complex meteorite impact structure. The rural and natural landscapes of the serial property help to portray the magnitude of the ring structures resulting from the impact.

Source: UNESCO/CLT/WHC
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