Results 41 to 50 of about 188 (175)
Notes on the Permian to Recent Geology of the Kruger National Park
Permian to Recent rocks form narrow, roughly north- south and east-south-east trending belts in the north-eastern Transvaal. The rocks consist of a thin succession of Karoo sediments, a thick overlying succession of mafic and felsic volcanics referred to
J.W. Bristow, F.J. Venter
doaj +1 more source
Abstract The mechanisms by which new subduction zones form remain highly debated. Here we use Permo‐Triassic strata to evaluate potential mechanisms for initiation of the Talkeetna‐Bonanza Arc of the northern North American Cordillera. New mapping and analysis of Permian and Upper Triassic strata on the Alaska Peninsula suggest a period of uplift ...
Brandon M. Keough +2 more
wiley +1 more source
Origin of Picrite Blocks Near Wells [PDF]
Pieces of picrite found in 1904 in a field at Ebbor Rocks, near Wells, Somerset, western England, probably came from the Menheniot quarries which were the source of ballast used in the area. Comparison of thin sections supports this conclusion.
openaire +1 more source
ABSTRACT Reconstructing the pressure–temperature–time (P–T–t) evolution of (ultra)high‐pressure rocks is essential for constraining subduction and collisional dynamics. Subduction zones are often investigated using basic eclogites, whereas nonbasic high‐pressure rocks remain comparatively understudied, potentially hindering a comprehensive ...
Otavio S. G. Silva +7 more
wiley +1 more source
Vanadium Isotopic Compositions of the High‐3He/4He Baffin Island Lavas
Abstract The isotopic composition of vanadium (V) in hotspot lavas provides new insight into the source of deep mantle heterogeneities. We measured V isotopic compositions in Paleogene Baffin Island lavas, which erupted above the Iceland plume head, to constrain the mantle plume source. These lavas have V isotopic compositions that are lighter (−0.96 ±
Jonas Kaare‐Rasmussen +4 more
wiley +1 more source
Abstract The origin of the compositional dichotomy between high‐Ti and low‐Ti basalts in continental flood basalt provinces remains debated. Most existing studies attribute this dichotomy directly to variations in primitive magma composition to circumvent the complexities of significant evolutionary processes, such as multiphase fractional ...
Zongpeng Yang +6 more
wiley +1 more source
The Cape Verde archipelago is a long‐lived volcanic ocean island chain formed by a mantle plume in the Atlantic Ocean. The archipelago is characterized by ten subaerial islands with complex age relationships, abundant submarine volcanism and variable volcanic hazards.
Brian Oller +13 more
wiley +1 more source
Abstract Within the Danian Scaglia Rossa Formation appears a regionally correlatable horizon cutting across multiple sections and outcrops within the Umbria–Marche Basin of NE Italy, where it is intercalated with uniform pelagic carbonate successions. This horizon is called “ALE layer” and has tentatively been interpreted as a fine‐grained volcanic ash.
Toni Schulz +5 more
wiley +1 more source
Deep Origin and Shallow Launch for the Etna 122 B.C. Mafic Plinian Eruption
Abstract Basaltic Plinian eruptions challenge our understanding of explosive volcanism. The 122 B.C. Plinian eruption of Etna ranks among the most powerful mafic explosive events known. Here, we combine volatile barometry of 122 B.C. from olivine‐hosted melt and fluid inclusions with comparative data from the sub‐Plinian Fall Stratified eruption at ...
M. Gavrilenko +6 more
wiley +1 more source
Abstract Mafic continental large igneous provinces (LIPs) erupted rapidly and may have overwhelmed Earth's atmospheric and biospheric systems. However, the exact balance and interplay between short‐term climate warming caused by CO2 emissions and long‐term cooling due to LIP weathering remains poorly understood.
Kunyue Ling +5 more
wiley +1 more source

