Jurassic Museum of Asturias display in separate cabinets. In the Pre-Mesozoic hall, the exhibits relate to the time from the creation of the Earth 4500 million years ago to the Palaeozoic age, 251 million years ago with displays of first organisms on the Earth, evolution process of fossils and their dating, classification of the vertebrates and their inherited relations, deterioration and extinction of nearly 95% of these systems by end of the Palaeozoic period. In the hall representing the Cretaceous period, which is the last period of the Mesozoic era from 145 to 66 million years ago, the displays relate to the biological and
The Gap (Sydney) tablet. The Gap is formed from Sydney sandstone making it part of Sydney basin. The cliff was laid as sediment more than 200 million years ago in the Triassic period. During the Jurassic era, 40 million years later, a cataclysmic event resulted in an enormous crack forming within the strata. This fault allowed erosion from wave action to create the cliff line around Sydney. Tessellated basalt rock platforms lie at the base of the cliff because The Gap is bordered to the south and west by an older sequence of largely low-grade metamorphic and granitic rocks of the Lachlan Fold