Tectonic evolution of the Barberton greenstone belt

It characterizes one of the most well-preserved and oldest pieces of continental crust today by containing rocks in the Barberton Granite Greenstone Terrain (3.55–3.22 Ga).

The BGB is a small, cusp-shaped succession of volcanic and sedimentary rocks, surrounded on all sides by granitoid plutons which range in age from >3547 to <3225 Ma.

Greenstone belts are geologic regions generally composed of mafic to ultramafic volcanic sequences that have undergone metamorphism.

The volcanic layers deformed into synclines and the dome like TTG bodies created anticlines which is represented in the BGB today.

Thin interbedded sedimentary units that have silicified into impure chert mark breaks that have resulted from eruptive activity.

It is defined as a transitional unit of interlayered volcanic clasts and land derived sediments that were eroded from the underlying greenstone succession.

The Moodies Group, post-3225 Ma, is a combination of sandstone and conglomerate originating from the erosion of the underlying greenstone unit and the uplifted plutonic rocks.

[6] Granite-greenstone terrains are characterized by broad domiform TTG bodies underlying tight synclinal basalts and komatiites.

[9] Other interpretations involving accretion present tectonic amalgamation and suturing of pre-existing bodies to form a larger continental block.

Previously metamorphosed dense amphibolites at the base of the overlying greenstone layer sank down into a partially melted granitic middle crust.

These sinking greenstones forced the granitic partial melts sideways and upwards, emplacing them into the margins of the belt and later folding them.