Results 131 to 140 of about 782,637 (367)

Geology, environment, and life in the deepest part of the world’s oceans

The Innovation, 2021
Summary: The hadal zone, mostly comprising of deep trenches and constituting of the deepest part of the world’s oceans, represents the least explored habitat but one of the last frontiers on our planet.
Mengran Du, Xiaotong Peng, Haibin Zhang, Cong Ye, Shamik Dasgupta, Jiwei Li, Jiangtao Li, Shuangquan Liu, Hengchao Xu, Chuanxu Chen, Hongmei Jing, Hongzhou Xu, Jun Liu, Shunping He, Lisheng He, Shanya Cai, Shun Chen, Kaiwen Ta   +17 more
doaj  

Unsolved problems in the lowermost mantle [PDF]

, 2006
Many characteristics of D '' layer may be attributed to the recently discovered MgSiO3 post-perovskite phase without chemical heterogeneities. They include a sharp discontinuity at the top of D '', regional variation in seismic anisotropy, and a steep ...
Brodholt, JP, Cormier, VF, Hirose, K, Karato, S, Yuen, DA   +4 more
core   +1 more source

Improved Precision and Reference Materials for Stable Carbon Isotope Measurement in Basaltic Glasses using Secondary Ion Mass Spectrometry

Geostandards and Geoanalytical Research, EarlyView.
Key Points High‐precision measurement results for δ13C in basaltic glasses were achieved down to 25 μg g‐1 CO2 using a refined measurement procedure via large‐geometry SIMS. Three new hydrous basaltic glasses (ETNA24, ETNA32, ETNA36) were established as reference materials.
Joshua Shea, Ery Hughes, Robert Balzer, Ilya Bindeman, Jon Blundy, Richard Brooker, Roman Botcharnikov, Pierre Cartigny, EIMF, Glenn Gaetani, Geoff Kilgour, John Maclennan, Brian Monteleone, David A. Neave, Oliver Shorttle   +14 more
wiley   +1 more source

Application of palynological data to the chronology of the Palaeogene lava fields of the British Province: implications for magmatic stratigraphy [PDF]

, 1997
New high-precision ages, determined from palynomorph assemblages within intercalated sedimentary deposits, are presented for the Palaeogene lava fields (Skye, Mull and Antrim) of the British Province. These data reveal very rapid averaged eruption rates (
Bell, B.R., Jolley, D.W.
core   +1 more source

Melt–Rock Interaction Experiments Reveal Rapid Microstructural and Chemical Changes at Lower Crustal Conditions

Journal of Metamorphic Geology, Volume 43, Issue 4, Page 341-358, May 2025.
ABSTRACT The reactive flow of melt through the mantle or crust triggers chemical disequilibrium, driving reactions that significantly alter the mineral assemblages and physical properties of host rocks. However, the degrees of chemical difference required to initiate these reactions and their timescale remain poorly understood.
Robyn L. Gardner, Nathan R. Daczko, Sandra Piazolo, John Adam, Uvana Meek   +4 more
wiley   +1 more source

New Indivisible Geoscience Paradigm [PDF]

arXiv, 2011
Earth's interior, I posit, is like one of the rare, oxygen-starved "enstatite chondrite" meteorites (and unlike a more-oxidized "ordinary chondrite" as has been believed for seventy years). Laboratory-analyzed enstatite-chondrite samples are comparable to having-in-hand impossibleto- gather deep-Earth samples.
arxiv  

The Effect of Lower Mantle Metallization on Magnetic Field Generation in Rocky Exoplanets [PDF]

, 2013
Recent theoretical and experimental evidence indicates that many of the materials that are thought to exist in the mantles of terrestrial exoplanets will metallize and become good conductors of electricity at mantle pressures. This allows for strong electromagnetic coupling of the core and the mantle in these planets. We use a numerical dynamo model to
arxiv   +1 more source

Extreme 18O-enrichment in majorite constrains a crustal origin of transition zone diamonds [PDF]

, 2015
The fate of subducted oceanic lithosphere and its role in the planet-scale geochemical cycle is a key problem in solid Earth studies. Asthenospheric and transition zone minerals included in diamond have been interpreted as representing subducted oceanic ...
Harris, J. W., Ickert, R. B., Stachel, T., Stern, R. A.   +3 more
core   +1 more source

A New UHP‐HP Tectono‐Metamorphic Architecture for the Southern Dora‐Maira Massif Nappe Stack (Western Alps) Based on Petrological and Microstructural Evidence

Journal of Metamorphic Geology, Volume 43, Issue 4, Page 359-383, May 2025.
ABSTRACT The southern Dora‐Maira Massif, where coesite was first discovered 40 years ago, is among the most studied and better known example of high/ultra‐high‐pressure (HP/UHP) terranes. Previous to this study, the Polymetamorphic Basement Complex of the southern Dora‐Maira Massif has been defined as a nappe stack consisting of three juxtaposed ...
Chiara Groppo, Simona Ferrando, Fabrizio Tursi, Franco Rolfo   +3 more
wiley   +1 more source

A ~60 Myr periodicity is common to marine-87Sr/86Sr, fossil biodiversity, and large-scale sedimentation: what does the periodicity reflect? [PDF]

Journal of Geology, 120, 217-226 (2012), 2012
We find that the marine 87Sr/86Sr record shows a significant periodicity of 59.3 \pm 3 Myr. The 87Sr/86Sr record is 171{\deg} \pm 12{\deg}out of phase with a 62 (\pm 3) Myr periodicity previously reported in the record of marine-animal diversity. These periodicities are close to 58 (\pm 4) Myr cycles found for the number of gap-bounded sedimentary ...
arxiv