Article
Geochemistry & Geophysics
Jin-Sheng Zhou, Qiang Wang, Chang-Ming Xing, Lin Ma, Lu-Lu Hao, Qi-Wei Li, Zi-Long Wang, Tong-Yu Huang
Summary: Recent studies have identified a new crystal growth mechanism for clinopyroxene in mafic alkaline magmas, revealing that at low degrees of undercooling, all crystal faces grow concurrently, producing disequilibrium Al-Ti-rich {hk0} sectors; while at high degrees of undercooling, equilibrium sectors {hk0} initially form, followed by backfill of disequilibrium Al-rich {-111} sectors. These findings contribute to a better understanding of magma storage, ascent, and eruption based on clinopyroxene.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Qi-Wei Li, Jun-Hong Zhao, Mei-Fu Zhou, Jian-Feng Gao
Summary: Magmatic processes beneath the active continental margins have a significant impact on the structures and compositions of arc roots. Neoproterozoic igneous rocks are found extensively in the margins of the Tarim Block in northwest China. The Xingdier mafic-ultramafic intrusion, located at the northern margin of the Tarim Block, is composed of gabbro, pyroxenite, and peridotite units. The rocks in this intrusion exhibit varying compositions and contain elements characteristic of arc-affinity geochemistry. Their formation is likely influenced by crustal contamination and fractional crystallization processes in the arc root.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Chemistry, Physical
N. K. Libeesh, K. A. Naseer, S. Arivazhagan, A. F. Abd El-Rehim, K. A. Mahmoud, M. I. Sayyed, Mayeen Uddin Khandaker
Summary: The study based on Landsat 8 remote sensing data showed that the type of mafic and ultramafic rocks can be distinguished by different band combinations and analysis methods, further laying the technical foundation for rock radiation shielding.
RADIATION PHYSICS AND CHEMISTRY
(2021)
Article
Geochemistry & Geophysics
Seyed Ali Akbar Asadi, Habibollah Ghasemi, Fatemeh Sepidbar, Mohsen Mobasheri, Yuruo Shi, Richard M. Palin
Summary: The nature and formation of the Sikhoran ultramafic-mafic complex in southwest Iran is still debated. The complex is composed of various rocks and may have a polygenetic origin with different tectonic settings. The study suggests that the complex formed at different times and may have been influenced by processes such as mantle plume melting and oceanic subduction.
Article
Geochemistry & Geophysics
Jonathan K. Munnikhuis, Nathan R. Daczko, Antonio Langone
Summary: Tracking melt migration in the lower crust is essential for understanding the formation of Earth's crust. The Finero Mafic Complex in Italy provides evidence of metasomatism involving iron and titanium enrichment, resulting in the transformation of gabbroic rocks. The redistribution of rare earth elements and the presence of melt microstructures support the hypothesis that an externally derived hydrous mafic melt flowed along grain boundaries, modifying the mantle and crustal components of the Finero Mafic Complex. This interpretation provides valuable insights into the evolution of the lower crust.
Article
Geology
A. B. Laudadio, E. M. Schetselaar, J. E. Mungall, M. G. Houle
Summary: The 3D geological model of the Esker ultramafic-mafic intrusive complex in northwestern Ontario, Canada provides insights into the magmatic plumbing system and the formation of valuable Ni-Cu-(PGE) and chromitite deposits. It reveals a complex structure with shear zones and keel-shaped ultramafic promontories and suggests that the intrusion may have been guided by pre-existing normal faults. The model also shows that the distribution of chromitite ore is discontinuous and supports the idea of mechanical segregation.
ORE GEOLOGY REVIEWS
(2022)
Article
Geology
N. K. Libeesh, K. A. Naseer, S. Arivazhagan, A. F. Abd El-Rehim, Ghada ALMisned, H. O. Tekin
Summary: The Pakkanadu Ultramafic-Alkaline-Carbonatite complex in Salem district has been studied using geochemical and remote sensing methods. The study found that the dunite sample, with the highest Fe2O3 content, exhibited superior shielding properties. This suggests that the composition and density of the studied materials directly impact their properties, and that the superior shielding properties of dunite are worth investigating for other radiation types.
ORE GEOLOGY REVIEWS
(2022)
Article
Geochemistry & Geophysics
Wyatt M. M. Bain, Pete Hollings, Lionnel M. M. Djon, Matthew J. J. Brzozowski, Daniel Layton-Matthews, Agatha Dobosz
Summary: The Archean Legris Lake mafic-ultramafic complex is associated with the world-class Lac des Iles palladium deposit. Modeling of the complex's composition suggests it is gabbronoritic, adding to the understanding of the link between the deposit and the complex. The study also found assimilation of metasedimentary country rock by the intruding magmas.
MINERALIUM DEPOSITA
(2023)
Article
Geochemistry & Geophysics
F. Bea, N. Bortnikov, A. Cambeses, S. Chakraborty, J. F. Molina, P. Montero, I. Morales, S. Silantiev, T. Zinger
Summary: The precipitation of zircon in mafic magmas may involve the formation of small zircon-saturated transient zones, explaining the abundance of syn-magmatic zircons in many mafic rocks.
Article
Geochemistry & Geophysics
C. Manikyamba, M. Santosh, K. S. Subramanyam, G. Harshitha Reddy, Jyotisankar Ray, Asima Kar, Arijit Pahari
Summary: The Simlipal complex in the Singhbhum Craton is an enigmatic geological formation that consists of a variety of rock types, including mafic volcanic rocks, quartzites, komatiites, and ultramafic rocks. These rocks exhibit different chemical compositions and element patterns, suggesting that they were formed in different geodynamic settings during the Neoarchean time. The complex is believed to have been formed in forearc and back-arc environments, and later juxtaposed with plume-derived volcanic sequences and passive margin sediments as the arc evolved towards the continent.
Article
Geochemistry & Geophysics
Arianna Secchiari, Alessandra Montanini, Dominique Cluzel
Summary: The discovery of amphibole-bearing intrusives in the New Caledonia forearc sequence highlights the compositional variability of magmas in the region, which may be related to the involvement of a heterogeneous mantle source during subduction initiation.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Geochemistry & Geophysics
Gultekin Topuz, Rainer Altherr, Osman Candan, Jia-Min Wang, Aral I. Okay, Fu-Yuan Wu, Ali Ergen, Thomas Zack, Wolfgang Siebel, Cosmas K. Shangh, Winfried H. Schwarz, Hans-Peter Meyer, Muharrem Satir
Summary: This study investigates the age and petrogenesis of mafic-ultramafic intrusions in the Pulur Complex. The intrusions consist of various rock types and were emplaced after the peak of high-grade metamorphism. The geochemical data suggests a genetic connection between the mafic-ultramafic intrusions and the high-K calc-alkaline granites in the region.
Article
Geochemistry & Geophysics
Alexander A. Iveson, Madeleine C. S. Humphreys, Ivan P. Savov, Jan C. M. de Hoog, Stephen J. Turner, Tatiana G. Churikova, Colin G. Macpherson, Tamsin A. Mather, Boris N. Gordeychik, Lubomira Tomanikova, Samuele Agostini, Keiji Hammond, David M. Pyle, George F. Cooper
Summary: The chemistry of primitive arc rocks provides insights into the compositional variability in the mantle wedge and slab-derived inputs to subduction-related magmatism. By analyzing olivine-hosted melt inclusions from the Kamchatka arc, systematic variations in element ratios are observed, which provide evidence for subduction-related metasomatism and mantle melting degrees. Across-arc variations in B isotopes reflect variable contributions of slab-derived components to depleted mantle compositions, with signals of compositional heterogeneity preserved during magma assembly and storage in the crust.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Yi Zhou, Hong Zhong, Wei-Guang Zhu, Zhong-Jie Bai, Chusi Li
Summary: Research in the Yuanbaoshan area of the Jiangnan Orogenic Belt in South China suggests that the mafic-ultramafic intrusions found there are more consistent with the subduction-related magmatism model rather than mantle plume activity. Geochemical features, isotopic compositions, and age data support the hypothesis of northward oceanic subduction beneath the southern margin of the Yangtze Block during the Neoproterozoic.
PRECAMBRIAN RESEARCH
(2022)
Article
Geochemistry & Geophysics
David A. Holwell, Daryl E. Blanks
Summary: Magmatic Ni-Cu-PGE sulfide mineralisation is commonly found in tholeiitic to komatiitic mafic-ultramafic intrusions, but has been increasingly discovered in alkaline-ultramafic, post-collisional magmatic systems. The Mordor Alkaline Igneous Complex in Australia shares similarities with other alkaline-hosted occurrences in terms of mineralisation characteristics.
MINERALIUM DEPOSITA
(2021)