نتایج جستجو برای: late neoproterozoic
تعداد نتایج: 196368 فیلتر نتایج به سال:
[1] The late Neoproterozoic era, 600–800 Myr ago, was marked by at least two intervals of widespread cold that left glacial deposits at low paleolatitudes. Both ‘‘Snowball’’ solutions with global ice cover and ‘‘Slushball’’ solutions with ice-free tropical oceans have been proposed to explain the paleomagnetic data. The Snowball model is best able to explain the auxiliary geological evidence, p...
BACKGROUND Photolyases and cryptochromes are evolutionarily related flavoproteins, which however perform distinct physiological functions. Photolyases (PHR) are evolutionarily ancient enzymes. They are activated by light and repair DNA damage caused by UV radiation. Although cryptochromes share structural similarity with DNA photolyases, they lack DNA repair activity. Cryptochrome (CRY) is one ...
the dalir phosphate horizon is located ~57 km southwest of chalous, mazandaran province. the horizon developed as stratiform within upper shale of soltanieh formation (late neoproterozoic - early cambrian). according to mineralogical data, the major minerals of the phosphate horizon are calcite, fluorapatite, dolomite, quartz, pyrite, muscovite, and illite. microscopic evidence such as existenc...
Early Paleozoic bottom waters were mainly ferruginous, like the Neoproterozoic, with a shift to increased euxinia in Devonian.
The supercontinent Rodinia is hypothesized to have been assembled and positioned in tropical latitudes by the early Neoproterozoic Era. Paleomagnetic data from limestones of Svalbard and basaltic dikes of South China have been interpreted to record rapid changes in paleogeography driven by true polar wander that may have rotated the supercontinent in association with the 800 Ma Bitter Springs c...
An unusual richness of biogeochemical events is recorded in Neoproterozoic– Cambrian strata of the Death Valley region, California, United States. Eight negative carbon isotope (d13C) excursions are found in carbonate units between 1.08 Ga and the Precambrian/Cambrian boundary; four of these excursions occur in carbonates that contain textural features similar to those found globally in postgla...
The integration of fossils, phylogeny, and geochronology has resulted in an increasingly well-resolved timetable of evolution. Life appears to have taken root before the earliest known minimally metamorphosed sedimentary rocks were deposited, but for a billion years or more, evolution played out beneath an essentially anoxic atmosphere. Oxygen concentrations in the atmosphere and surface oceans...
The Terra Nova Intrusive Complex (TNIC) in northern Victoria Land, Antarctica, results from widespread magmatism during the Early Paleozoic Ross Orogeny. According to field relationships, geochemistry, and geochronology data, part of TNIC comprises Browning Unit (BIU), which is associated with an arc crustal melting including migmatization Wilson Metamorphic Complex, later Campbell (CIU), attri...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید