Recent from talks
All channels
Be the first to start a discussion here.
Be the first to start a discussion here.
Be the first to start a discussion here.
Be the first to start a discussion here.
Welcome to the community hub built to collect knowledge and have discussions related to Middle Miocene.
Nothing was collected or created yet.
Middle Miocene
View on Wikipediafrom Wikipedia
| System/ Period |
Series/ Epoch |
Stage/ Age |
Age (Ma) | |
|---|---|---|---|---|
| Quaternary | Pleistocene | Gelasian | younger | |
| Neogene | Pliocene | Piacenzian | 2.58 | 3.600 |
| Zanclean | 3.600 | 5.333 | ||
| Miocene | Messinian | 5.333 | 7.246 | |
| Tortonian | 7.246 | 11.63 | ||
| Serravallian | 11.63 | 13.82 | ||
| Langhian | 13.82 | 15.97 | ||
| Burdigalian | 15.97 | 20.44 | ||
| Aquitanian | 20.44 | 23.03 | ||
| Paleogene | Oligocene | Chattian | older | |
| Subdivision of the Neogene Period according to the ICS, as of 2017[1] | ||||
The Middle Miocene is a sub-epoch of the Miocene epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene, and followed by the Late Miocene.
The sub-epoch lasted from 15.97 ± 0.05 Ma (million years ago) to 11.608 ± 0.005 Ma. During this period, a sharp drop in global temperatures took place. This event is known as the Middle Miocene Climatic Transition.
For the purpose of establishing European land mammal ages, this sub-epoch is equivalent to the Astaracian age.
References
[edit]- ^ "ICS Timescale Chart". stratigraphy.org.
External links
[edit]Middle Miocene
View on Grokipediafrom Grokipedia
The Middle Miocene is a sub-epoch of the Miocene within the Neogene period of the Cenozoic era, spanning approximately 15.97 to 11.63 million years ago and defined by the first common occurrence of the planktonic foraminifer Praeorbulina glomerosa at its base and the last common occurrence of the calcareous nannofossil Discoaster kugleri at its top.[1] This interval encompasses the Langhian (15.97–13.82 Ma) and Serravallian (13.82–11.63 Ma) stages and is marked by dynamic geological, climatic, and biological changes that shaped modern ecosystems.[2]
Climatically, the Middle Miocene featured the Miocene Climatic Optimum (MCO), a prolonged warm phase from about 17 to 14.5 Ma during which global temperatures were approximately 3–6°C higher than present, with reduced polar ice volumes, elevated sea surface temperatures (up to 11–20°C warmer at high latitudes), and atmospheric CO₂ levels around 500 ppm.[3][4] This warmth supported expanded tropical and subtropical biomes, including forests reaching high latitudes like the Arctic and Antarctic regions, and high precipitation in many areas. Following the MCO, the Middle Miocene Climate Transition (MMCT) around 14.7–13 Ma initiated global cooling of about 1.5–3°C, driven by Antarctic ice sheet expansion, a sea-level drop of approximately 50 m, and increased ocean circulation changes, leading to greater seasonality, aridity, and the retreat of tropical ecosystems in favor of northern coniferous forests.[5]
Geologically, the period saw intense tectonic activity, including the uplift of major mountain ranges such as the Himalayas, Andes, Sierra Nevada, and Cascades, which influenced regional climates through enhanced weathering and monsoon intensification in South Asia.[3] Volcanic events were prominent, exemplified by the massive Columbia River Basalt eruptions around 17–16 Ma in western North America, while oceanographic shifts included the initial restriction of the Panama Isthmus and Central American Seaway beginning around 15 Ma, altering global currents and contributing to the eventual isolation of the Atlantic and Pacific Oceans.[3][6] These processes, combined with the Antarctic Circumpolar Current, facilitated the long-term cooling trend and spread of aridity across continents.[3]
Biologically, the Middle Miocene witnessed the diversification and adaptation of terrestrial and marine life to changing environments, with the expansion of C₃ grasslands (and precursors to later C₄ dominance) replacing woodlands and promoting the evolution of grazing mammals such as hypsodont horses and other perissodactyls and artiodactyls around 18 Ma.[3] Forests extended poleward, supporting diverse avian groups like parrots and mammalian radiations, including early kangaroo bipedalism in Australia, while marine realms saw the proliferation of diatoms, kelp forests, reef-building corals, and the extinction of desmostylians.[3] These developments, driven by climatic optima and transitions, laid foundational patterns for modern biodiversity, including the rise of open habitats and herbivore adaptations.
