Proxima b, an Earth-size planet right outside our solar system in the habitable zone of its star, may not be able to keep a grip on its atmosphere, leaving the surface exposed to harmful stellar radiation and reducing its potential…
The week in science: 21–27 July 2017.
Acidified water draining from abandoned mines, studied primarily as a modern environmental hazard, may offer insight into the oxygenation of Earth’s early atmosphere and development of life on other planets, according to a new study.
U–Pb detrital zircon data from the Jurassic strata in the western Ordos Basin (WOB) show significant age differences between formations, from lower to upper including the Yan’an, Zhiluo, Anding, and Fenfanghe formations. The main peaks in the detrital zircon age spectra of the Yan’an Formation are at ca. 245, 444, 1813, and 2,387 Ma, which resemble those of the underlying Triassic strata in the WOB. Combined with the occurrence of reworked sporopollen and carbonate debris, the sediments of the Yan’an Formation are interpreted to be potentially recycled from the residual Triassic highlands. The overlying Zhiluo Formation contains detrital zircons mostly in the 260–290 Ma age range with only one peak at 269 Ma, reflecting primary derivations from the Permian granites in the Yinshan Belt to the north and/or the Alxa Block to the northwest. The detrital zircon age compositions of the Anding Formation, however, are most varied, with one prominent age peak at 274 Ma and several other minor peaks at 348 Ma, 447, 932, 1641, 2143, and 2514 Ma, reflecting complex origins. The uppermost syntectonic Fenfanghe Formation, contains detrital zircons with similar age compositions with the Yan’an Formation, once again interpreted as the result of recycled sedimentation. These two phases of multicycle sedimentation in the WOB reveals two intense tectonic events in the Late Triassic and Late Jurassic, whereas the provenance transition between the Yan’an and Zhiluo formations implies a less intense but extensive event in the Middle Jurassic. The complex age composition of the Anding Formation, however, are possibly as the result of climate change corresponding to the change of petrology and sediment colour. These Early‐Middle Mesozoic tectonic events evidenced by the U–Pb ages record the tectonic transition of the North China Block from the Tethys to the paleo‐Pacific tectonic domains.
Origin date/time: Sat, 29 Jul 17 20:51:52 GMT; Location: ; Lat/long: 52.242,-3.873; Depth: NA; Magnitude: 2.9
Origin date/time: Sat, 29 Jul 17 20:51:52 GMT; Location: TREGARON,CEREDIGION ; Lat/long: 52.274,-3.919; Depth: 7km; Magnitude: 1.5
Was this the earliest TV mention of “astrobiology”? A scene from the original Star Trek episode “Return To Tomorrow” which first aired on 9 February 1968: KIRK: “Who are you?” MULHALL: “Doctor Ann Mulhall, Astrobiology”…
Origin date/time: Sat, 29 Jul 17 03:54:05 GMT; Location: KAMES,ARGYLLANDBUTE ; Lat/long: 55.883,-5.242; Depth: 10km; Magnitude: 1.1
Every day, enough sunlight hits the Earth to power the planet many times over — if only we could more efficiently capture all the energy….
NASA scientists have definitively detected the chemical acrylonitrile in the atmosphere of Saturn’s moon Titan, a place that has long intrigued scientists investigating the chemical precursors of life….