the matrix of igneous rocks, such as porphyry, in which larger crystals (phenocrysts) are embedded
groundmass in American English
(ˈgraʊndˌmæs)
noun
Geology
the small-grained matrix in which larger crystals are embedded
groundmass in American English
(ˈɡraundˌmæs)
noun
the crystalline, granular, or glassy base or matrix of a porphyritic or other igneous rock, in which the more prominent crystals are embedded
Word origin
[1875–80; ground1 + mass]This word is first recorded in the period 1875–80. Other words that entered Englishat around the same time include: fan-tan, knockabout, neoclassic, pressure point, weekender
Examples of 'groundmass' in a sentence
groundmass
Cr-spinel, rutile, ilmenite, and apatite occur as disseminated minute grains in the groundmass.
Tarun C. Khanna, V. V. Sesha Sai, S. H. Jaffri, A. Keshav Krishna, M. M. Korakoppa 2018, 'Boninites in the ~3.3 Ga Holenarsipur Greenstone Belt, Western Dharwar Craton, India',Geoscienceshttp://www.mdpi.com/2076-3263/8/7/248. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Their phenocryst shape and size and abundance of groundmass are also different.
Mohammad Arif, S. Wajid Hanif Bukhari, Noor Muhammad, Muhammad Sajid 2013, 'Petrography and Physicomechanical Properties of Rocks from the Ambela Granitic Complex,NW Pakistan', The Scientific World Journalhttp://dx.doi.org/10.1155/2013/349381. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Sample spots were selected from quartz phenocrysts and groundmass.
Kairi Ehrlich, Evelin Verš, Juho Kirs, Alvar Soesoo 2012, 'Using a titanium-in-quartz geothermometer for crystallization temperature estimationof the Palaeoproterozoic Suursaari quartz porphyry', Estonian Journal of Earth Scienceshttp://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2012/issue_4/earth-2012-4-195-204.pdf. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Grain assemblages of pyrite and chalcopyrite grains appear along cracks in the groundmass.
Masakazu Fujii, Hiroshi Sato, Eri Togawa, Kazuhiko Shimada, Jun-ichiro Ishibashi 2018, 'Seafloor hydrothermal alteration affecting magnetic properties of abyssal basalticrocks: insights from back-arc lavas of the Okinawa Trough', Earth, Planets and Spacehttp://link.springer.com/article/10.1186/s40623-018-0958-6. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Fluorine in particular mobilized only after extensive groundmass crystallization and incipient devitrification.
C Ian Schipper, Jonathan M Castro, Ben M Kennedy, Bruce W Christenson, AlessandroAiuppa, Brent Alloway, Pablo Forte, Gilles Seropian, Hugh Tuffen 2019, 'Halogen (Cl, F) release during explosive, effusive, and intrusive phases of the 2011rhyolitic eruption at Cordón Caulle volcano (Chile)', Volcanicahttps://www.jvolcanica.org/ojs/index.php/volcanica/article/view/26. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The basaltic fields consist of basalts and trachybasalts, with clinopyroxene and abundant olivine as phenocrysts and also in the groundmass.
Irene R Hernando, Eduardo J Llambías, Pablo D González, Kei Sato 2012, 'Volcanic stratigraphy and evidence of magma mixing in the Quaternary Payún Matrú volcano,andean backarc in western Argentina Estratigrafía volcánica y evidencia de mezclade magmas en el volcán Payún Matrú del Cuaternario, en el retroarco andino de Argentinaoccidental', Andean Geologyhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062012000100008. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
In most of this anorthosite, andesine megacrysts with bytownite inclusions are embedded in a fine-grained groundmass of bytownite or anorthite.
A. Hietanen 1986, 'Role of replacement in the genesis of anorthosite in the Boehls Butte area, Idaho',Bulletin of the Geological Society of Finlandhttp://www.geologinenseura.fi/bulletin/Volume58/sgs_bt_058_1_pages_071_079.pdf. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The results of engineering-geological surveys of groundmass artificially saturated with petroleum products (used oil, gasoline) are presented.
Prostov Sergey, Shabanov Eugene, Shadrin Alexandr 2017, 'The Study of Processes of Electrochemical Treatment of Soils at the Pilot Test Site',E3S Web of Conferenceshttps://doi.org/10.1051/e3sconf/20171501014. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Our results indicated that fine titanomagnetite grains in groundmass within back-arclava flows are altered due to hydrothermal processes.
Masakazu Fujii, Hiroshi Sato, Eri Togawa, Kazuhiko Shimada, Jun-ichiro Ishibashi 2018, 'Seafloor hydrothermal alteration affecting magnetic properties of abyssal basalticrocks: insights from back-arc lavas of the Okinawa Trough', Earth, Planets and Spacehttp://link.springer.com/article/10.1186/s40623-018-0958-6. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)