Cretaceous
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The Cretaceous is a geological period that lasted from about 143.1 to 66 Ma. It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth
The impact of a meteorite or comet is today widely accepted as the main reason for the Cretaceous–Paleogene extinction event.
Drawing of fossil jaws of Mosasaurus hoffmanni, from the Maastrichtian of Dutch Limburg, by Dutch geologist Pieter Harting (1866)
Scipionyx, a theropod dinosaur from the Early Cretaceous of Italy
Facsimile of a fossil of Archaefructus from the Yixian Formation, China
Paleogene
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The Paleogene Period is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 Ma to the beginning of the Neogene Period 23.04 Ma. It is the first period of
Cretaceous
…Early Cretaceous Epoch (Albian Age) Chronology −140 — – −130 — – −120 — – −110 — – −100 — – −90 — – −80 — – −70 — – Mesozoic C Z Jurassic Cretaceous Paleogene Early Late Berriasian Valanginian Hauterivian Barremian Aptian Albian Cenomanian Turonian Coniacian Santonian Campanian Maastrichtian ← K-Pg mass…
A Paleogene-aged basaltic lava flow on the Isle of Staffa, Scotland (person standing on cliff top for scale). The bottom section of this cliff is volcaniclastic rock. The middle and top sections are two parts of a single basaltic lava flow; each part of the lava flow cooled differently, forming rock with different characteristics. The middle layer shows spectacular columnar jointing resulting from relatively slow cooling; the top layer has very irregular closely-spaced joints caused by more rapid cooling.
Paleogene flood basalts on the Ethiopian Plateau with the Afar Depression in the background.