1. The continent of Gondwana formed between 570-510 million years ago through the collision of several continental fragments and microcontinents along orogenies in central Gondwana and East Africa. 2. Gondwana eventually amalgamated into the supercontinent Pangaea before beginning to break apart in the Early Jurassic period around 184 million years ago. 3. The breakup of Gondwana involved the drifting apart of East Gondwana (Antarctica, Australia, India, Madagascar), the opening of the South Atlantic between Africa and South America, and the separation of India from Madagascar during the Cretaceous period.

1. GONDWANALAND
AND
TECTONISM
Presented by –
Debasis Pal, Roll No. 414ER2020
Archchi Sarkar, Roll No. 414ER2024
M.Sc. Applied Gelogy, 3rd Semester
National Institute of Technology, Rourkela

2. INTRODUCTION
 The continent of Gondwana or Gondwanaland was named by Austrian
scientist Eduard Suess, after the Gondwana region of central northern India
(from Sanskrit gondavana - "forest of the Gonds“). The name had been used
in a geological context, first by H.B. Medlicott in 1872, from which the
Gondwana sedimentary sequences (Permian-Triassic) are also describe.
 Gondwana formed prior to Pangaea, then became part of Pangaea, and
finally drifted after the breakup of Pangaea.
 Gondwana is believed to have sutured between about 570 and 510 Mya,
thus joining East Gondwana to West Gondwana. It separated from
Laurasia 200-180 Mya (the mid-Mesozoic era) during the breakup of
Pangaea, drifting farther south after the split.

3. Span of
Gondwanaland
in GTS

4. Evidences that it existed…
1. Paleoclimatic evidence -
Ancient climatic zones match up when continents are moved back to their
past positions.
• Glacial tillites
• Glacial striations
• Carbonate deposits
• Evaporite deposits

5. 2. Late paleozoic glaciation -
Late Paleozoic glaciation patterns on southern continents are best explained
by their reconstruction into Gondwanaland

6. 3. Fossil Evidence Supporting Plate Tectonics -

7. 4. Paleomagnetism and Pole Locations
• Studies of rock magnetism allowed determination of magnetic pole locations
(close to geographic poles) through time.
• Paleomagnetism uses magnetic mineral alignment direction and dip angle to
determine the direction and distance to the magnetic pole. Steeper dip
angles indicate rocks formed closer to the north magnetic pole.
• Rocks with increasing age point to pole locations increasingly far from
today’s poles.

8. 5. Fit of rock units and boundaries
• Improved fit results in rock units (and glacial ice flow directions)
precisely matching up across continent margins.

9. Formation of Gondwanaland
The assembly of Gondwana was a protracted process. Several orogenies led
to its final amalgamation 550–500 Mya at the end of the Ediacaran, and into
the Cambrian. These include the Brasiliano Orogeny, the East African
Orogeny, the Malagasy Orogeny, and the Kuunga Orogeny. The final stages of
Gondwanan assembly overlapped with the opening of the Lapetus
Ocean between Laurentia and western Gondwana. During this interval,
the Cambrian explosion occurred.

10. Gondwana was formed from the following earlier continents and microcontinents,
among others, colliding in different orogenies:
•Azania: much of central Madagascar, the Horn of Africa and parts of Yemen and
Arabia (Named by Collins and Pisarevsky (2005): "Azania" was a Greek name for the
East African coast.)
•The Congo–Tanzania–Bangweulu Block of central Africa;
•Neoproterozoic India: India, the Antongil Block in far eastern Madagascar,
the Seychelles, and the Napier and Rayner Complexes in East Antarctica
•The Australia/Mawson continent: Australia, the west of Adelaide and a large
extension into East Antarctica
•Other blocks which helped to form Argentina and some surrounding regions,
including a piece transferred from Laurentia when the west edge of Gondwana
scraped against southeast Laurentia in the Ordovician. This is the Famatinian
block (named after Famatina in northwest Argentina) and it formerly continued the
line of the Appalachians southwards.
Reconstruction showing final stages of assembly of Gondwana, at 550 Mya.

11. One of the major sites of Gondwanan amalgamation was the East African Orogeny (Stern,
1994) at 650–630 Mya, where these two major orogenies are superimposed. This
orogeny affected a large part of Arabia, NE Africa, E Africa, and Madagascar. Collins and
Windley (2002) propose that in this orogeny, Azania collided with the Congo–Tanzania–
Bangweulu Block.
The later Malagasy orogeny at about 550–515 Mya
affected Madagascar, eastern East Africa and southern
India. In it, Neoproterozoic India collided with the
already combined Azania and Congo–Tanzania–
Bangweulu Block, suturing along the Mozambique Belt.
At the same time, in the Kuunga Orogeny
Neoproterozoic India collided with the
Australia/Mawson continent.

12. • Gondwana began to break up in the early Jurassic (about 184 Mya) accompanied by massive
eruptions of basalt lava, as East Gondwana, comprising Antarctica, Madagascar, India, and
Australia, began to separate from Africa. South America began to drift slowly westward from
Africa as the South Atlantic Ocean opened, beginning about 130 Mya during the Early
Cretaceous, and resulting in open marine conditions by 110 Mya. East Gondwana then began
to separate about 120 Mya when India began to move northward.
• The Madagascar block, and a narrow remnant microcontinent presently occupied by
the Seychelles Islands, were broken off India; elements of this breakup nearly coincide with
the Cretaceous–Paleogene extinction event. The India–Madagascar–Seychelles separations
appear to coincide with the eruption of the Deccan basalts, whose eruption site may survive
as the Réunion hotspot.
• Australia began to separate from Antarctica at 80 Mya (Late Cretaceous), but sea-floor
spreading between them became most active about 40 Mya during the Eocene epoch of
the Paleogene Period.
• New Zealand probably separated from Antarctica between 130 and 85 Mya.
The break-up of Gondwanaland involves two major time periods – the Jurassic and the Early
Cenozoic.
JURASSIC
Break-up and Drifting

13. • The continent of Australia-New Guinea began gradually to separate and move north at
55 Mya, rotating about its axis and thus retaining some connection with the remainder of
Gondwana for about 10 million years.
• At ~45 Mya, Indian Plate collided with Asia, buckling the crust and forming
the Himalayas. At about the same time, the southernmost part of Australia
(modern Tasmania) finally separated from Antarctica, letting ocean currents flow
between the two continents for the first time. Antarctica became cooler and Australia
became drier because ocean currents circling Antarctica were no longer directed around
northern Australia into the subtropics.
• The separation of South America from West Antarctica some time during the Oligocene,
perhaps 30 Mya, also caused climate changes. Immediately before this separation, South
America and East Antarctica were not connected directly.
• By about 15 Mya, the collision between New Guinea and the SW part of the Pacific Plate
pushed up the New Guinea Highlands, causing a rain shadow effect which drastically
changed weather patterns in Australia, drying it out.
• Later, South America was connected to North America via the Isthmus of Panama, cutting
off a circulation of warm water and thereby making the Arctic colder, as well as allowing
the Great American Faunal Interchange.
CENOZOIC

14. Dispersal of Gondwanaland
The relative positions of the continents at any time are determined by paleomagnetic measurements. Rocks formed at a certain time freeze in the
local magnetic field. The direction of the field tells the distance to the magnetic pole (paleolatitude). Magnetic anomalies on the sea floor also
provide a history of the opening of the ocean.

15. References
• Wikipedia and many other internet sources
• Weddell Sea tectonics and Gondwana break-up: an
introduction by E. C. KING, R. A. LIVERMORE & B. C.
STOREY, British Antarctic Survey, Natural
Environment Research Council, High Cross,
Madingley Road, Cambridge CB3 0ET, UK
• The Geological Society of America – Lyell Collection

16. That’s all, folks!