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Lexicon of lithostratigraphic units for the Sudan
Published in J.R. Vail, Lexicon of Geological Terms for the Sudan, 2022
Intrusive into the lavas is a riebeckite granite, of irregular form, although in the west, centred on Sania well, arcuate outcrops of granite might indicate a ring-dyke about 8 km in diameter. Delany also reported the presence of gabbro on the western flank, but no details. The granite is intrusive into mica gneiss, and both granite and lava are cut by quartz porphyry and felsite, containing aegirine and iron-ores.
Comparison between conventional and multi-sensor geotechnical core logging methods
Published in Vladimir Litvinenko, EUROCK2018: Geomechanics and Geodynamics of Rock Masses, 2018
Mahadi Bhuiyan, Kamran Esmaieli
For this study, ~38 m of oriented core sample was obtained from six different geotechnical borehole intervals drilled in an open-pit mine. Four lithologies are present in the core. Granodiorite intrusives (GDI) consists of either: meta-intrusive diorite with a biotite foliation, or mafic metavolcanic basalt. Felsite (FVC) is a micro-crystalline quartz-feldspathic rock that preserves a strong phyllosilicate foliation in some sub-units. Banded iron magnetite (BIM) and metamorphosed greywacke and siltstone (SVC) are locally interbedded in the sample. The core is generally intact, i.e., un-weathered, and has high RQD and recovery.
Tunnels in Korea
Published in Xia-Ting Feng, Rock Mechanics and Engineering, 2017
S. Jeon, Y.H. Suh, S.P. Lee, S.B. Lee, K. Suh
Almost the entire length of the tunnel crosses Seoul granite as presented in Figure 15, which intruded Precambrian banded biotite gneiss. Seoul granite contains many xenoliths which were formed when the intrusion took place in Jurassic period. The predominant directions of discontinuities are N76E/86SE and N26W/81NE. Parallel to the joints, there are many intrusions of quartz or felsite veins of 20–300 cm in width.
Analytical and numerical assessment of a preliminary support design – a case study
Published in Cogent Engineering, 2021
Sylvanus Sebbeh-Newton, Shaib Abdulazeez Shehu, Prosper Ayawah, Azupuri A. Kaba, Hareyani Zabidi
The tunnel cuts through two major formations. The Karak Formation of Silurian-Devonian age extends from the inlet portal to chainage 3.82 km consist of metasediments such as hornfels, shale, metaschist, and phyllite. The Main Range granite is composed of coarse to very coarse-grained, porphyritic biotite granite cut by minor porphyritic differentiates and fine-grained variety of granite which represent a later phase of granite intrusion. Micro-granite, granodiorite, diorite, monzonite, granite porphyry, quartz porphyry, felsite, vein quartz, megacrysts biotite granite, megacrystic muscovite-biotite granite and equigranular tourmaline-muscovite granite are the other foundation rocks within the Main Range Granite.