Results 1 to 10 of about 1,054 (150)
The object of research. At the top of the Upper Riphean-Vendian sedimentary sequence of the Bashkirian meganticlinorium (western and central parts of the named structure, corresponding to the stratotypical locality of Riphean) there is a series of fairly
А. V. Maslov
doaj +3 more sources
Proterozoic and early Cambrian protists: evidence for accelerating evolutionary tempo. [PDF]
In rocks of late Paleoproterozoic and Mesoproterozoic age (ca. 1700-1000 million years ago), probable eukaryotic microfossils are widespread and well preserved, but assemblage and global diversities are low and turnover is slow.
Knoll AH.
europepmc +3 more sources
Detailed petrographic, electron-microscopic, and paleomagnetic studies were conducted on flatbedded synsedimentary carbonate breccias from three blocks of rocks (one block from Minyar, two blocks from Katav-Ivanovsk) to verify the ideas about the time of
N. P. Parfiriev +3 more
doaj +2 more sources
Abstract Fine‐grained, siliciclastic units of the >1642 ± 3.9 Ma late Palaeoproterozoic Limbunya Group, Birrindudu Basin host rich, well‐preserved organic‐walled microfossil assemblages that include members of total‐group eukaryotes. These assemblages include taxa characteristic of this interval such as Tappania plana and Satka favosa, as well as less ...
Leigh Anne Riedman +4 more
wiley +1 more source
Abstract The sedimentary record of the Pahrump Group in Death Valley comprises well‐exposed successions of mixed carbonate and siliciclastic deposits. Despite the abundance of studies focussing on the depositional dynamics of mixed carbonate – siliciclastic deposition in the Phanerozoic, the record of similar Proterozoic examples is comparatively ...
Daniel Smrzka +7 more
wiley +1 more source
Constraints on the origins of iron silicide spherules in ultrahigh‐temperature distal impact ejecta
Abstract Terrestrially occurring iron silicide spherules, described in the geological literature for 160 years as cosmogenic and approved as “extraterrestrial” minerals by IMA CNMMN in 1984, so far have escaped any serious examination by meteoriticists.
Sergei Batovrin +5 more
wiley +1 more source
New data on oil and gas potential of the Vychegda Trough
This article is devoted to the problem of studying the petroleum potential of the underexplored territories of the European part of Russia, in particular, the Vychegda trough.
Tatyana V. Karaseva +3 more
doaj +1 more source
Initially, the age and stratigraphic position of the Tersk formation were determined with respect to the fact that this formation overlaps the Early Proterozoic granitoids.
N. B. Kuznetsov +10 more
doaj +1 more source
A Cryptic Alternative for the Evolution of Hyphae
The current view that hyphae evolved about 400 million years ago when plants and fungi colonized land is challenged. Recent recognition of a deep biosphere fossil record provides an alternative view on hyphae: one where the fundamental functions of hyphae developed in ancient cryptic habitats and already where adapted for a terrestrial life‐style when ...
Magnus Ivarsson +3 more
wiley +1 more source
Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating' [PDF]
The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use.
Aharon P. +55 more
core +1 more source

