Results 81 to 90 of about 59,128 (262)

Petrogenesis of Plagioclase Ultraphyric Basalts (PUB) From the Northeastern (NE) Pacific Ridge System: Evidence From Mineral Textures and Geochemical Characteristics

Geochemistry, Geophysics, Geosystems
Plagioclase crystals in plagioclase ultraphyric basalts (PUB) record changes in the major, trace, and isotopic compositions of evolving magmas. Those changes represent the record of specific processes in the crust and upper mantle that impart distinct ...
John B. Hewitt, Gokce K. Ustunisik, Roger L. Nielsen   +2 more
doaj   +1 more source

The Age and Origin of Block Deposits in the Victorian Alps, Australia

Permafrost and Periglacial Processes, EarlyView.
ABSTRACT Large periglacial block deposits are found in the mountains of southeastern Australia. Despite their widespread distribution, their mode of formation and age are poorly understood. These landforms hold considerable potential to shed light on the nature of cooling during glacial periods. In this paper we present a new study of block deposits in
Timothy T. Barrows, Michelle S. Worland, Julian Murton, Stephanie C. Mills, L. Keith Fifield   +4 more
wiley   +1 more source

Mineral associations in the rocks and metamorphism conditions of the Kandalaksha gabbro-anorthosite massif (Kola Peninsula)

Литосфера, 2016
The composition of mineral associations was studied in the main varieties of the rocks within the metamorphosed Kandalaksha gabbro-anorthosite massif in the southern part of the Kola Peninsula.
V. V. Chashchin, E. N. Steshenko, Ye. E. Savchenko, Ya. A. Pakhomovsky, A. V. Bazai   +4 more
doaj   +2 more sources

Testing the Recycled Gabbro Hypothesis for the Origin of “Ghost Plagioclase” Melt Signatures Using 87Sr/86Sr of Individual Olivine‐Hosted Melt Inclusions From Hawai'i

Geochemistry, Geophysics, Geosystems, 2021
Melt inclusions with large, positive Sr anomalies have been described in multiple tectonic settings, and the origins of this unusual geochemical feature are debated.
O. E. Anderson, M. G. Jackson, E. F. Rose‐Koga, J. P. Marske, M. E. Peterson, A. A. Price, B. L. Byerly, A. A. Reinhard   +7 more
doaj   +1 more source

Brittle Structural Control and Fluid Progress of the Jinqingding Gold Deposit: Implications for Epizonal Gold Mineralization

Acta Geologica Sinica - English Edition, EarlyView.
ABSTRACT The Jinqingding gold deposit in eastern Jiaodong is a significant gold mineralization within the Muping–Rushan metallogenic belt. This study integrates structural analysis and trace element geochemistry of sulphides to elucidate ore‐controlling mechanisms and metallogenic models.
Xiaohu Wang, Yuke Shen, Changshan Wei, Fengbin Han, Tao Guo, Huisheng Wang, Jiantao Yu, Yubo Song, Bo Wang, Longji Gong, Guijie Li   +10 more
wiley   +1 more source

Soil wetting and drying processes influence stone artefact distribution in clay‐rich soils: A case study from Middle Gidley Island in Murujuga, northwest Western Australia

Archaeometry, EarlyView.
Abstract Soils that contain swelling clay minerals (e.g., montmorillonite) expand and contract during wetting and drying, causing movement within the soil profile. This process, known as argilliturbation, can alter artefact distributions, destroy stratigraphy and complicate the interpretation of archaeological deposits.
Caroline Mather, Matthias Leopold, Kaitlin Sullivan, Kane Ditchfield, Tom Horrocks, Luke Gliganic, Emma Beckett, Diana Patalwala, Emielda Yusiharni, Michael Smirk, William Hiscock, Jo McDonald   +11 more
wiley   +1 more source

The Missing Magmas of MOR: Insights From Phase Equilibrium Experiments on Plagioclase Ultraphyric Basalts

Geochemistry, Geophysics, Geosystems, 2022
Plagioclase ultraphyric basalts (PUBs) are a class of mid‐ocean ridge (MOR) lavas found in a variety of ocean floor environments, are characterized by abundant (15–40 volume %) plagioclase megacrysts and a diverse trace element and isotopic signature ...
Gokce K. Ustunisik, Roger L. Nielsen, David Walker   +2 more
doaj   +1 more source

Rifting and arc-related early Paleozoic volcanism along the North Gondwana margin: geochemical and geological evidence from Sardinia (Italy) [PDF]

, 2012
Three series of volcanic rocks accumulated during the Cambrian to Silurian in the metasediment-dominated Variscan basement of Sardinia. They provide a record of the changing geodynamic setting of the North Gondwana margin between Upper Cambrian and ...
BUZZI L, FUNEDDA A., GAGGERO L, OGGIANO G   +3 more
core   +1 more source

Greek Commodities in Phoenicia: An Interdisciplinary Study of Imported Amphorae From Tell el‐Burak (Lebanon)

Archaeometry, EarlyView.
ABSTRACT This paper examines transport amphorae of Greek/Aegean types from the 7th–4th c. BCE imported to the Phoenician coastal settlement of Tell el‐Burak, Lebanon. We present a selection of 58 pieces analyzed by typological, chemical (NAA), and petrographic approaches.
Maximilian Rönnberg, Marcel Frenken, Johannes H. Sterba, Silvia Amicone   +3 more
wiley   +1 more source

The Mobility of Major and Trace Elements in EOC Minerals on Parent Chondrite Bodies

Geosciences
The combined EPMA and SIMS study of the geochemical features of olivine, low-Ca pyroxene and plagioclase in equilibrated ordinary chondrites (EOCs) has revealed the effect of thermal metamorphism on trace element concentrations in EOC silicate minerals ...
Kristina Sukhanova, Sergey Skublov
doaj   +1 more source