Knowra Continental fragment Continental fragment A discrete block of continental crust separated from a larger continent, often transported by tectonic plate movement. Fragments range from small slivers to microcontinents.
Continental rifting : The stretching and thinning of continental lithosphere that can split a continent into separate plates. Rifting can detach crustal blocks that later become continental fragments.
Zealandia : A mostly submerged continent in the southwest Pacific, including New Zealand and New Caledonia. Zealandia is a large, relatively coherent example of continental crust separated from Gondwana.
Gondwana : An ancient southern supercontinent that included Africa, South America, Antarctica, Australia, India, and Madagascar. The breakup of Gondwana produced many present-day continental fragments.
Continental crust : The relatively thick, silica-rich outermost solid layer underlying continents and continental shelves. A continental fragment is defined by the continental crust it preserves.
Continental collision : The convergence and impact of continental lithosphere after intervening oceanic crust is consumed. A fragment can collide with a continent and become part of its crust.
Seafloor spreading : The creation of oceanic crust as magma rises at a mid-ocean ridge and plates move apart. New ocean floor can widen the gap between a fragment and its parent continent.
Seychelles microcontinent : A fragment of continental crust in the Indian Ocean, including the Seychelles islands. Its separation from India is associated with the breakup of Gondwana.
Pangaea : A supercontinent that assembled most of Earth's continental landmasses during the late Paleozoic and early Mesozoic eras. Its fragmentation began tectonic sequences that ultimately separated many crustal blocks.
Oceanic crust : The relatively thin, dense crust formed at mid-ocean ridges and underlying most ocean basins. Its properties distinguish ocean floor from the continental material in a fragment.
Accreted terrane : A crustal block attached to a continent through tectonic convergence, distinct in origin from surrounding rocks. Many fragments survive as terranes incorporated into continental margins.
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