Defining Pangaea: Earth's Unified Landmass
Pangaea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, approximately 335 to 175 million years ago. It comprised almost all the landmasses on Earth, eventually breaking up to form the continents we know today. The name "Pangaea" comes from ancient Greek, meaning "all lands" or "all Earth."
Formation and Existence of Pangaea
The formation of Pangaea was a result of millions of years of continental collision, driven by plate tectonics. Continents slowly moved and merged, culminating in a single, massive landmass surrounded by a global ocean called Panthalassa. This supercontinent reached its maximum extent around 250 million years ago, during the Permian period.
The Breakup of Pangaea and Modern Continents
Pangaea began to rift apart around 175 million years ago, during the Jurassic period, initially splitting into two major landmasses: Laurasia to the north (which would become North America and Eurasia) and Gondwana to the south (which would become South America, Africa, Antarctica, Australia, and the Indian subcontinent). Over tens of millions of years, these smaller landmasses continued to fragment and drift to their current positions.
Impact on Climate, Geology, and Evolution
The existence and breakup of Pangaea had profound effects on Earth. Its vast size led to extreme continental climates, with arid interiors. Its fragmentation reshaped ocean currents, influencing global climate patterns. Geologically, the collisions that formed Pangaea created major mountain ranges. Biologically, the unified landmass allowed for widespread migration of species, while its breakup led to the isolation and subsequent divergence (speciation) of flora and fauna, profoundly influencing the course of evolution.