Ordovisium Awal

Ordovisium Awal merupakan kala pertama dari periode Ordovisium, yang dimulai pada 485.4 juta tahun lalu, hingga 470 juta tahun lalu^[1]. Suhu Bumi pada kala ini perlahan menurun.^[2]

^ "Geologic TimeScale Foundation - Stratigraphic Information". timescalefoundation.org. Diakses tanggal 2021-12-27.
^ Munnecke, Axel; Calner, Mikael; Harper, David A.T.; Servais, Thomas (1 October 2010). "Ordovician and Silurian sea–water chemistry, sea level, and climate: A synopsis". Palaeogeography, Palaeoclimatology, Palaeoecology. 296 (3–4): 389–413. doi:10.1016/j.palaeo.2010.08.001.

[1] "Geologic TimeScale Foundation - Stratigraphic Information". timescalefoundation.org. Diakses tanggal 2021-12-27.

[Munnecke_2010-2] Munnecke, Axel; Calner, Mikael; Harper, David A.T.; Servais, Thomas (1 October 2010). "Ordovician and Silurian sea–water chemistry, sea level, and climate: A synopsis". Palaeogeography, Palaeoclimatology, Palaeoecology. 296 (3–4): 389–413. doi:10.1016/j.palaeo.2010.08.001.

[1]

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