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9 results for "Hirnantian glaciation"
E_5_02 — The Ordovician-Silurian Mass Extinction
The Late Ordovician mass extinction (c. 445–444 million years ago, at the Ordovician-Silurian boundary) was the second-most severe extinction event in Earth's history in terms of percentage of species lost — approximatel
ZF_1_10 — Meltwater Pulses and Rapid Sea-Level Events
Meltwater pulses — episodes of exceptionally rapid sea-level rise caused by the collapse or rapid melting of continental ice sheets — are the most dramatic events in post-glacial oceanography, with implications for under
E_2_12 — Great Oxygenation Event
The Great Oxygenation Event (GOE) — approximately 2.4–2.1 billion years ago — was one of the most transformative events in Earth's history: the first permanent rise of free molecular oxygen (O₂) in the atmosphere, from n
E_2_11 — Snowball Earth Hypothesis
The Snowball Earth hypothesis proposes that Earth's surface was entirely or nearly entirely covered by ice on at least two occasions during the Neoproterozoic era (c. 720–635 million years ago): the Sturtian glaciation (
E_4_24 — Quaternary Science: Integrating Ice Ages, Extinctions, and Migrations
Quaternary science is the interdisciplinary study of Earth's most recent geological period — the Quaternary (2.58 Ma to present), encompassing the Pleistocene (2.58 Ma to 11,700 BP) and the Holocene (11,700 BP to present
E_4_22 — Varve Chronology: Annual Lake Sediment Records
Varve chronology is a dating and paleoclimate method based on counting and analyzing varves — annually laminated sediment layers deposited in lakes (and occasionally in marine or estuarine settings). Each varve typically
R_1_09 — The Great Oxidation Event: Oxygen, Cyanobacteria, and Earth's Atmospheric Transformation
The Great Oxidation Event (GOE), occurring approximately 2.4–2.1 billion years ago during the Paleoproterozoic, was the most dramatic chemical transformation in Earth's history — atmospheric oxygen rose from trace levels
E_3_15 — Sea-Level Curves: Eustatic Change from LGM to Present
Sea-level curves — graphical reconstructions of how global mean sea level has changed through time — represent one of the most important datasets in Quaternary science, recording the waxing and waning of continental ice
O_5_05 — Ice Ages and Milankovitch Cycles: Orbital Forcing of Climate
Ice ages — periods when massive continental ice sheets expand to cover large portions of Earth's surface — are among the most dramatic climate events in the planet's history. The Quaternary glaciation (beginning ~2.6 mil
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