The Neoproterozoic Era, from approximately 1 billion to 541 million years ago, is a period within the Proterozoic Eon marked by significant geological and biological changes, including the emergence of complex multicellular life forms and dramatic shifts in Earth’s climate.
Breakup of Rodinia Supercontinent
The Neoproterozoic witnessed the breakup of the supercontinent Rodinia, leading to the formation of new ocean basins and the dispersion of land masses.
Formation of Gondwana Supercontinent
Towards the end of the Neoproterozoic, the supercontinent Gondwana began to form as some continental fragments coalesced. Gondwana would play a significant role in shaping Earth’s geography in the subsequent eras.
Ediacaran Biota and Early Animals
The Neoproterozoic is known for the Ediacaran Biota, a diverse group of soft-bodied organisms that provide insights into the early evolution of complex multicellular life forms.
Acritarchs and Microfossils
Microscopic fossilized organisms known as acritarchs became more prevalent during the Neoproterozoic. These microfossils offer valuable clues about the evolution of microscopic life.
Glacial Events and “Snowball Earth”
The Neoproterozoic is marked by multiple severe glaciations, often referred to as “Snowball Earth” events. These glaciations resulted in the widespread covering of Earth’s surface by ice and impacted global climates.
Sturtian and Marinoan Glaciations
Two major glaciations, the Sturtian and Marinoan glaciations, occurred during the Neoproterozoic. These events had a profound impact on ocean chemistry, sea levels, and life.
Following glaciations, the deposition of cap carbonates over glacial deposits is a distinctive geological feature. Isotopic records within the Neoproterozoic rocks provide insights into changing oceanic conditions.
The Pan-African Orogeny
The Pan-African orogeny was a major tectonic event that resulted in the collision of several continents. This event contributed to the assembly of Gondwana.
Rise of Complex Eukaryotic Life
The Neoproterozoic witnessed the emergence of more complex eukaryotic life forms, including multicellular animals with hard shells and skeletons.
Climatic Shifts and the End of the Era
Towards the end of the Neoproterozoic, there was a transition from extreme glaciations to a relatively warmer climate. This transition set the stage for the Cambrian explosion and the diversification of life in the subsequent Phanerozoic Eon.
Here are the periods that are part of the Neoproterozoic Era
- Tonian Period: The Tonian is the earliest period of the Neoproterozoic Era and lasted from approximately 1 billion to 720 million years ago. It is characterized by the emergence of various eukaryotic life forms, including potential early animals.
- Cryogenian Period: The Cryogenian is the middle period of the Neoproterozoic Era and lasted from approximately 720 to 635 million years ago. It is known for its extreme climatic conditions, including the occurrence of at least two major glaciation events (Sturtian and Marinoan glaciations) that led to near-global ice coverage.
- Ediacaran Period: The Ediacaran is the latest period of the Neoproterozoic Era and lasted from approximately 635 to 541 million years ago. It is known for the Ediacaran biota, which represents some of the earliest complex multicellular organisms. The period also marks the transition to the Cambrian Period of the Paleozoic Era and the emergence of the Cambrian Explosion, a rapid diversification of life forms.