Around 190 million years ago, Pangaea began to break up. The breakup resulted in two landmasses: Laurasia, the northern group of continents, and Gondwanaland, the southern group of continents; Gondwanaland included South America, Antarctica, Australia, Africa, and India.
Breakups!
North America: 130 mya
Australia: 50 mya
India: 90 mya
Europe: 30 mya
Antarctica: 50 mya
The breakup of Pangaea continues until this day in the Great Rift Valley. However, the final major phase of the break-up of Pangaea occurred earlier, millions of years ago. Laurasia split when North America/Greenland freeing it from Eurasia; opening the Norwegian Sea. Finally, the Atlantic and Indian oceans continued to expand, closing the Tethys Ocean.
Convergent Boundary: Himalaya Mountains, Southern Asia
The Himalayas began to form during the late Cretaceous periods (The continental collision along the convergent boundary between the 70mya) making it one of the youngest mountain ranges on Earth and finished its major formation 50mya. Its formation occurred during the collision at the convergent boundary of the Indo-Australian Plate and the Eurasian Plate. It is mainly composed of metamorphic and sedimentary rocks and is referred to as a fold mountain.
The Alps, Europe
The Alps formed during the Alpine orogeny as a result of the collision of the African and European tectonic plates, in which the western part of the ancient Tethys Ocean. During the Mesozoic and early Cenozoic era ocean sediments pushed against the stable Eurasian landmass by the northward-moving African landmass. This created folds that elevated out of the ocean to create the beginnings of the Alps, which were later built up and re-elevated over millions of years.
If plates are moving away from each other, they create a divergent plate boundary. These divergent plate boundaries can occur between continental plates, oceanic plates or a combination of both. Divergent boundaries within continents initially produce rifts which produce rift valleys, whereas divergent boundaries between oceanic plates create mid-oceanic ridges. There are several hypotheses that attempt to explain these movements such as: Mantle convection, Ridge Push and Slab Pull. Famous examples of divergent plate boundaries include:
• The Mid-Atlantic Ridge
• Red Sea Rift
• Baikal Rift Zone
• East African Rift
• East Pacific Rise
• Gakkel Ridge
• Galapagos Rise
• Explorer Ridge
• Pacific-Antarctic Ridge
• West Antarctic Rift
