Results 91 to 100 of about 61,505 (248)

Paleoproterozic Icehouses and the Evolution of Oxygen Mediating Enzymes: The Case for a Late Origin of Photosystem -- II [PDF]

open access: yes, 2008
Two major geological problems regarding the origin of oxygenic photosynthesis are: (1) identifying a source of oxygen predating biological oxygen production and capable of driving the evolution of oxygen tolerance, and (2) determining when oxygenic ...
Kirschvink, Joseph L., Kopp, Robert E.
core  

A Comment on Tectonics and the Future of Life on Terrestrial Planets

open access: yes, 2003
It is argued that the tight interconnection between biological, climatological, and geophysical factors in the history of the terrestrial biosphere can teach us something of wider importance regarding the general astrobiological evolution of planets in ...
Adams   +10 more
core   +1 more source

Combustion and Pyrolysis EA‐IRMS Techniques to Determine the δ2H of Diamonds

open access: yesRapid Communications in Mass Spectrometry, Volume 40, Issue 10, 30 May 2026.
ABSTRACT Rationale Diamonds are generally considered to be metasomatic minerals originating from the Earth's mantle. They formed through the interaction of carbon‐bearing fluids or melts with the surrounding deep lithology. Most knowledge about the formation of diamonds comes from studying their mineral inclusions or stable isotopes.
François Fourel   +4 more
wiley   +1 more source

A palaeoecological approach to neotectonics : the geomorphic evolution of the Ntem River in and below its interior delta, SW Cameroon [PDF]

open access: yes, 2010
The Late Tertiary to Quaternary evolution of the Ntem interior delta in SW Cameroon shall be modelled. A step fault was formed along neotectonically remobilized Precambrian structures.
Eisenberg, Joachim
core  

Crustal Responses to the Destruction of Continental Lithosphere: Insights From Radial Anisotropy of the Tanlu Fault Zone, Eastern China

open access: yesGeophysical Research Letters, Volume 53, Issue 9, 16 May 2026.
Abstract Since the Mesozoic, much of the eastern China lithosphere was removed through thermo‐mechanical erosion and delamination, yet the effects on the overlying crust remain unclear. The Tanlu Fault Zone (TLFZ), the region's largest lithosphere‐scale weakness, offers a natural laboratory to assess crustal responses to lithospheric destruction.
Yuqi Zhu   +5 more
wiley   +1 more source

Sr-Nd Systematics and REE distribution in the type magnesite deposits in Lower Riphean of South Urals province

open access: yesЛитосфера, 2016
The geochemistry and REE of magnesite and host carbonate rocks of two Lower Riphean deposits of the South Urals province (Satka and Ismakaevo ore fields) confirm the metasomatic nature of the magnesite.
M. T. Krupenin   +2 more
doaj   +2 more sources

Geochemical characteristics of titanite and U-Pb age of garnet from mineral mines of the Southern Urals

open access: yesЗаписки Горного института
Mineralogical-geochemical (SIMS method) study of titanite and geochronological (ID-TIMS method) study of garnets from mineral mines of the Southern Urals has been carried out. The mineral associations containing titanite belong to four contrasting types:
Vladislav S. Stativko   +4 more
doaj  

Seismic Imaging Reveals Ongoing Modification of Craton Margins in Northeast Asia

open access: yesGeophysical Research Letters, Volume 53, Issue 9, 16 May 2026.
Abstract Cratonic margins are commonly modified, yet the processes responsible remain debated. The Korean Peninsula, situated between adjacent cratons, the Japan Trench, and a back‐arc system, provides a natural setting to investigate this problem. Using 4 years of dense seismic observations, we image upper‐mantle structure beneath the peninsula with P‐
Hwaju Lee   +3 more
wiley   +1 more source

Geochemical characterization of Gubanovskaya intrusion of rapakivi granites (Wiborg massif)

open access: yesVestnik MGTU
The paper presents new data on geology and composition of rapakivi granites of Gubanovskaya intrusion (Wiborg massif). Petrographic and geochemical characteristics of rapakivi granites of the second (ovoid) and third (trachytoid) phases of intrusion, as ...
Rogova I. V.   +3 more
doaj   +1 more source

Origin and evolution of the Amazonian craton [PDF]

open access: yes
The Amazonian craton appears to be formed and modifed by processes much like those of the better-known Precambrian cratons, but the major events did not always follow conventional sequences nor did they occur synchronously with those of other cratons ...
Gibbs, A. K., Wirth, K. R.
core   +1 more source

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