Gts 1

• In 1669, Danish Scientist Nicolas Steno published the first laws of stratigraphy, a revolutionary idea that some believe the fossils had literally fallen from the sky.
• Giovanni Arduino, in the 1760s, continued the revolutionary work by defining the lowest layers of metamorphic and volcanic rocks as the 'Primary Layer', hard sedimentary rocks as the 'Secondary', and top layer softer alluvial deposits as the 'Tertiary & Quaternary'.
• In 1819, English Scientist William Smith figured out the solution by using fossils and comparing the remains of ancient organisms from different rock formations, allowing him to match the ages regardless of how far apart the areas were.
• The Geologic Time Scale is a chronological model that uses the stratigraphy of the earth, or the layers of rock, in relation to time.
• The Geologic Time Scale is studied by earth scientists, such as geologists and paleontologists, to study the events that occurred in our earth’s history.
• The earliest Eons are the Hadean (4.6 – 4 billion years ago), which is believed to have no fossils because it is the time of the fiery formation.
• The Paleozoic Era lasted from 541 to 252 million years ago.
• The Hadean Eon ends with the cooling of Earth’s crust, leading to the formation of continents.
• The Mesozoic Era is known as the Age of Reptiles due to the abundance of dinosaur species.
• Various events, including global warming, volcanism, and meteor impact, are to blame for The Great Dying.
• Amphibian evolved around 541 million years ago.
• During the Paleozoic Era, the formation of Pangea occurred, leaving a desert in the center and quickly populated by the ancestors of reptiles and mammals.
• The Mesozoic Era lasted from 252 to 66 million years ago.
• The Mesozoic Era ended with the Cretaceous-Paleogene (K-Pg) extinction event, which is believed to have been caused by a gigantic asteroid.
• The Paleozoic Era ended with a cataclysm, known as The Great Dying, where 70% of the population disappeared.
• The Paleozoic Era was divided into different periods of time.
• Land was first populated by plants and arthropods.
• The Cambrian Period, which occurred during the Paleozoic Era, marked the evolution of life.
• The next phase is the Archean (4 – 2.5 billion years ago), during which the planet's core shifted to a cold condition, leaving CO₂ and CH₄ in the atmosphere.
• Plants became widespread during the Paleozoic Era.
• The Phanerozoic Eon began 541 million years ago and is still ongoing.
• During the Proterozoic Eon, photosynthetic bacteria spewed oxygen to the atmosphere, wiping out most anaerobic life and creating a path for ancestral eukaryotes.
• During the Phanerozoic Eon, life became obvious and started with trees, amphibians, and different other life until now.
• The best way to explore the Phanerozoic Eon is through its Eras.
• During the rifting of Rodinia, a large piece called Pannotia broke off and moved to the south pole, affecting the Earth’s climate and triggering a massive ice age (Cryogenian period) as the glaciers formed over the south and extended to the north.
• The first Era of the Phanerozoic Eon is the Paleozoic Era, which spanned from 541 to 252 million years ago.
• The Proterozoic Eon saw the formation of the first supercontinents through a convergent called Nuna, which later broke apart.
• The Paleozoic Era began with the breakup of one supercontinent and the formation of another.
• Present of cyanobacterial have changed everything.
• During the Proterozoic Eon, another supercontinent called Rodinia formed and broke up.
• The first vertebrate animals colonized land during the Paleozoic Era.
• Life was exclusively unicellular during the Archean eon.
• Saturated oxygen in the ocean caused the formation of Banded Iron Formations (BIFs) during the Proterozoic Eon.
• Continents are forming and are the oldest terrestrial rocks.
• The Proterozoic Eon spanned from 2.5 billion to 541 million years ago.
• Ancestral eukaryotes appeared during the Proterozoic Eon.