Distribution of ocean and continents

Continental Drift Theory

A theory proposed by Alfred Wegener in 1912 that suggests all continents were once part of a single landmass called Pangaea.

Pangaea

The supercontinent that existed about 250 million years ago, from which all current continents were formed.

Panthalassa

The single vast ocean that surrounded the supercontinent Pangaea.

Laureasia

The northern landmass that resulted from the splitting of Pangaea.

Gondwanaland

The southern landmass that formed after the splitting of Pangaea, which included present-day Africa, South America, Antarctica, Australia, and India.

Glacial Tillite

Sedimentary rock formed from deposits of glaciers, providing evidence for past continental connections.

Fossils of Mesosaurus

Fossils of a small Permian reptile found only in Africa and Antarctica, supporting the idea of continental drift.

Sea Floor Spreading

The process proposed by Hess in 1961 that describes how new oceanic crust forms at mid-ocean ridges and pushes older crust away.

Plate Tectonics

The theory formulated in 1967 that describes the Earth's lithosphere as divided into tectonic plates that move over the asthenosphere.

Divergent Boundary

A tectonic plate boundary where two plates move away from each other, creating new crust.

Convergent Boundary

A tectonic plate boundary where two plates collide, leading to subduction zones and the formation of mountains.

Transform Boundary

A tectonic plate boundary where two plates slide past each other, with neither crust created nor destroyed.

Indian Tectonic Plate

The tectonic plate that includes Peninsular India and parts of Australia, marked by significant geological activity such as the uplift of the Himalayas.

Himalayas

A mountain range formed from the collision of the Indian Plate with the Eurasian Plate.

Abyssal Plains

Flat regions of the ocean floor lying between continental margins and mid-ocean ridges.

Mid-Oceanic Ridges

Underwater mountain ranges formed by tectonic plates moving apart and allowing magma to rise.

Subduction Zone

An area where one tectonic plate moves under another, often leading to the formation of deep ocean trenches.