The Hadean (/ h eɪ ˈ d iː ə n, ˈ h eɪ d i ə n / hay-DEE-ən, HAY-dee-ən) is a geologic eon of Earth history preceding the Archean.On Earth, the Hadean began with the planet's formation about 4.54 billion years ago (although the start of the Hadean is defined as the age of the oldest solid material in the Solar System, found in some meteorites, about 4.567 billion years old).

The Coniacian is an age or stage in the geologic timescale.It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by …

紀（き、英: period ）は、地質時代において代を細分する単位である。 この範囲において地層の境界を定めた接尾語は「系」（英: system ）である。 例えばデボン紀の岩石はデボン系と呼ばれる。 この表現は古生物学者達からは地質の年代というよりも古生物相の段階を指して発表の際に …

The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, Malm was also used to indicate the unit of geological time, but this usage is now discouraged …

African orogenies. Pan-African orogeny – Series of major mountain-forming events, Neoproterozoic Era (550 Ma); Damara orogeny – Mountain building event at the intersection of the Congo and the Kalahari cratons.; Kibaran orogeny – Mountain building event in what is now Africa; Eburnean orogeny – Mountain building event in what is now West Africa ...

The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic.It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian.. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age.

The Dorchester Pot was a metal vase-like object that was recovered in two pieces after an explosion used to break up rock at Meeting House Hill, in Dorchester, Massachusetts in 1851. According to text reprinted from the Boston Transcript, a local paper, in the June 5, 1852 Scientific American, the two pieces were found, loose among debris thrown out by the explosion.

Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (/ ˈ m ɒ l ə s k /).Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high.

The Santonian is an age in the geologic timescale or a chronostratigraphic stage.It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series.It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya.The Santonian is preceded by the Coniacian and is followed by the Campanian.

Puddingstone, also known as either pudding stone or plum-pudding stone, is a popular name applied to a conglomerate that consists of distinctly rounded pebbles whose colours contrast sharply with the colour of the finer-grained, often sandy, matrix or cement surrounding them. The rounded pebbles and the sharp contrast in colour gives this type of conglomerate the …

Distribución de ofiolitas. Las ofiolitas ocurren asociadas a zonas de orogénesis tanto antiguas como actuales. Por esto se encuentran frecuentemente tanto en zonas de subducción y colisión continental como en antiguos escudos donde estos sistemas se han preservado. Las ofiolitas más recientes se encuentran principalmente en el Cinturón Alpide y en el Cinturón de Fuego …

Rockfish Gap is a wind gap located in the Blue Ridge Mountains between Charlottesville and Waynesboro, Virginia, United States, through Afton Mountain, which is frequently used to refer to the gap.. Joining the Shenandoah Valley to the Piedmont region of the state, it is the site of the mountain crossing of Interstate 64, U.S. Route 250, and the former Blue Ridge Railroad which …

The Upper Cretaceous is the last geological epoch in the Cretaceous.It began 100.5 million years ago, and ended 66 million years ago.. The Cretaceous is traditionally divided into Lower Cretaceous (early), and Upper Cretaceous (late), because of the different rocks.The rocks reflect the conditions in which they were formed. From lowest to highest, it is subdivided into the …

Precambrian. The oldest rocks found on Skye are gneisses of the Lewisian complex that were formed about 2,800 million years ago during the Archaean. These gneisses outcrop on the southeastern coast of the Sleat peninsula and were originally granitic igneous rocks. Near Tarskavaig, Neoproterozoic metasediments of the Moine Supergroup are found above …