DEFINITION OF GONDWANA (GONDWANALAND)

The Late Proterozoic–Late Paleozoic supercontinent of the Southern Hemisphere, named

by Eduard Suess after the Gondwana System of southern

India. The name Gondwana means “land of the Gonds” (an

ancient tribe in southern India) so the more common rendition

of the name Gondwanaland for the southern supercontinent

is technically improper, meaning “land of the land of the

Gonds.” It includes the present continents of Africa, South

America, Australia, Arabia, India, Antarctica, and many

smaller fragments. Most of these continental masses amalgamated

in the latest Precambrian during closure of the Mozambique

and several other ocean basins and persisted as a

supercontinent until they joined with the northern continents

in the Carboniferous to form the supercontinent of Pangea.

The different fragments of Gondwana are matched with

others using alignment between belts of similar-aged deformation,

metamorphism, and mineralization, as well as common

faunal, floral, and paleoclimatic belts. The formation

and breakup of Gondwana is associated with one of the most

remarkable explosions of new life-forms in the history of the

planet, the change from simple single-celled organisms and

soft-bodied fauna to complex, multicelled organisms. The

formation and dispersal of supercontinents strongly influences

global climate and the availability of different environmental

niches for biological development, linking plate

tectonic and biological processes.

Since the early 1990s there has been an emerging consensus

that Gondwana formed near the end of the Neoproterozoic

from the fragmented pieces of an older supercontinent,

Rodinia, itself assembled near the end of the Grenville cycle

(~1100 Ma). The now standard model of Gondwana’s assembly

begins with the separation of East Gondwana (Australia,

Antarctica, India, and Madagascar) from the western margin

of Laurentia, and the fan-like aggregation of East and West

Gondwana. The proposed assembly closed several ocean

basins, including the very large Mozambique Ocean, and

turned the constituents of Rodinia inside out, such that the

external or “passive” margins in Madagascar and elsewhere

became collisional margins in latest Precambrian and earliest

Cambrian time.

The notion of a single, short-lived collision between East

and West Gondwana is an oversimplification, since geologic

relations suggest that at least three major ocean basins closed

during the assembly of Gondwana (Pharusian, Mozambique,

Adamastor), and published geochronology demonstrates that

assembly was a protracted affair. There is currently a large

amount of research being done to understand these relationships.

For example, an alternative two-stage model for closure

of the Mozambique Ocean has been recently advanced that

ascribes an older “East African” orogeny (~680 Ma) to collision

between Greater India (i.e., India–Tibet–Seychelles–Madagascar–

Enderby Land) and the cojoined Congo and Kalahari

Cratons. This was followed by a younger “Kuunga” event

(~550 Ma) that represents the collision of Australia–East

Antarctica with proto-Gondwana, thus completing Gondwana’s

assembly near the end of the Neoproterozoic.

See also NEOPROTEROZOIC; SUPERCONTINENT CYCLE.

GPS See GLOBAL POSITIONING SYSTEM.

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