Task: Question Answering
Input (English): Context: A flood basalt is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava. Flood basalt provinces such as the Deccan Traps of India are often called traps, which derives from the characteristic stairstep geomorphology of many associated landscapes. Rampino and Stothers (1988) cite eleven distinct flood basalt episodes occurring in the past 250 million years, creating large volcanic provinces, plateaus, and mountain ranges. However, more have been recognized such as the large Ontong Java Plateau, and the Chilcotin Group, though the latter may be linked to the Columbia River Basalt Group. Large igneous provinces have been connected to five mass extinction events, and may be associated with bolide impacts., Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is also called "lava". The molten rock is formed in the interior of some planets, including Earth, and some of their satellites. The source of the heat that melts the rock within the earth is geothermal energy. When first erupted from a volcanic vent, lava is a liquid usually at temperatures from . , Earth, otherwise known as the world, is the third planet from the Sun and the only object in the Universe known to harbor life. It is the densest planet in the Solar System and the largest of the four terrestrial planets., In the Lunar geologic timescale , the Late Imbrian epoch occurred between 3800 million years ago to about 3200 million years ago . It was the epoch during which the mantle below the lunar basins partially melted and filled them with basalt . The melting is thought to have occurred because the impacts of the Early Imbrian thinned the overlying rock - either causing the mantle to rise because of the reduced pressure on it , bringing molten material closer to the surface ; or the top melting as heat flowed upwards through the mantle because of reduced overlying thermal insulation . The majority of lunar samples returned to earth for study come from this epoch . The Earth equivalent consists of half of the Archean eon . Millions of years before present, The pre-Nectarian period of the lunar geologic timescale runs from 4533 million years ago (the time of the initial formation of the Moon) to 3920 million years ago, when the Nectaris Basin was formed by a large impact. It is followed by the Nectarian period., The Eratosthenian period in the lunar geologic timescale runs from 3,200 million years ago to 1,100 million years ago. It is named after the crater Eratosthenes, whose formation marks the beginning of this period. The formation of the crater Copernicus marks its end, and the beginning of the subsequent Copernician Period. The massive basaltic volcanism of the Imbrian period tapered off and ceased during this long span of lunar time. The youngest lunar lava flows identified from orbital images are tentatively placed near the end of this period., Regolith is a layer of loose, heterogeneous superficial material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons., An impact event is a collision between astronomical objects causing measurable effects. Impact events have physical consequences and have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal impact. When large objects impact terrestrial planets like the Earth, there can be significant physical and biospheric consequences, though atmospheres mitigate many surface impacts through atmospheric entry. Impact craters and structures are dominant landforms on many of the Solar System's solid objects and present the strongest empirical evidence for their frequency and scale., The Moon is an astronomical body that orbits planet Earth, being Earth's only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, and the largest among planetary satellites relative to the size of the planet that it orbits (its primary). Following Jupiter's satellite Io, the Moon is second-densest satellite among those whose densities are known. , The lunar geological timescale (or selenological timescale) divides the history of Earth's Moon into five generally recognized periods: the Copernican, Eratosthenian, Imbrian (Late and Early epochs), Nectarian, and Pre-Nectarian. The boundaries of this time scale are related to large impact events that have modified the lunar surface, changes in crater form that occur through time, and the size-frequency distribution of craters superposed on geological units. The absolute ages for these periods have been constrained by radiometric dating of samples obtained from the lunar surface. However, there is still much debate concerning the ages of certain key events, because correlating lunar regolith samples with geological units on the Moon is difficult, and most lunar radiometric ages have been highly affected by an intense history of bombardment., Mare Imbrium (Latin for "Sea of Showers" or "Sea of Rains") is a vast lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the collision of a proto-planet during the Late Heavy Bombardment. Basaltic lava later flooded the giant crater to form the flat volcanic plain seen today. The basin's age has been estimated using U-Pb dating methods to 3938 ± 4 million years ago, the diameter of the impactor has been estimated to be 250 ± 25 km. The Moon's maria (plural of mare) have fewer features than other areas of the Moon because molten lava pooled in the craters and formed a relatively smooth surface. Mare Imbrium is not as flat as it was originally because later events have altered its surface., In the lunar geologic timescale, the Early Imbrian epoch occurred between 3850 million years ago to about 3800 million years ago. It overlaps the end of the Late Heavy Bombardment of the Inner Solar System. The impact that created the huge Mare Imbrium basin occurred at the start of the epoch. The other large basins that dominate the lunar nearside (such as Crisium, Tranquilitatis, Serenitatis, Fecunditatis, and Procellarum) were also formed in this period. These basins filled with basalt mostly during the subsequent Late Imbrian epoch. The Early Imbrian was preceded by the Nectarian., Basalt (, , , or ) is a common extrusive igneous (volcanic) rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of lava basalt flows., Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials., Subject: late imbrian, Relation: named_after, Options: (A) 1 (B) 100 (C) 3 (D) 4 (E) basalt (F) earth (G) india (H) io (I) isotope (J) java (K) mare imbrium (L) mars (M) moon (N) rock (O) sea (P) span (Q) technique (R) time
Output (English): mare imbrium