the contact surface between younger and older rocks representing a discontinuity in the geological record. Most commonly it represents an erosional surface
Examples of 'unconformities' in a sentence
unconformities
The bounding surfaces defining each allomember are transgressively modified subaerial unconformities.
Claudio Di Celma, Elisa Malinverno, Giulia Bosio, Karen Gariboldi, Alberto Collareta,Anna Gioncada, Walter Landini, Pietro Paolo Pierantoni, Giovanni Bianucci 2018, 'Intraformational unconformities as a record of late Miocene eustatic falls of sealevel in the Pisco Formation (southern Peru)', Journal of Mapshttp://dx.doi.org/10.1080/17445647.2018.1517701. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Levels of concretionary cementation with dolocrete features possibly mark the position of subaerial unconformities.
Kristjan Urtson, Kazbulat Shogenov, Alla Shogenova, Kalle Kirsimäe, Tõnu Martma, AnneKleesment 2012, 'Linkage of diagenesis to depositional environments and stratigraphy in the northernpart of the Baltic basin', Estonian Journal of Earth Scienceshttp://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2012/issue_1/earth-2012-1-15-32.pdf. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Both units have been subdivided into allomembers since they also present internal unconformities.
Sergio Marenssi, Sergio Santillana, Mauro Bauer 2012, 'Estratigrafía, petrografía sedimentaria y procedencia de las formaciones Sobral yCross Valley (Paleoceno), isla Marambio (Seymour), Antártica Stratigraphy, sedimentarypetrology and provenance of the Sobral and Cross Valley formations (Paleocene), Marambio(Seymour) Island, Antarctica', Andean Geologyhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062012000100004. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
At the base and/or within sorne of these units there are progressive unconformities.
Díaz Molina, M. 1987, 'Sedimentación sinectónica asociada a una subida relativa del nivel del mardurante el Cretácico superior (Fm. Tremp, provincia de Lérida)', Estudios Geologicoshttp://estudiosgeol.revistas.csic.es/index.php/estudiosgeol/article/view/626/648. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
This method, based on clustering models, detects unconformities, named outliers.
Henrique Gonçalves Salvador, Adilson Marques Da Cunha, Cleber Souza Corrêa 2009, 'Vedalogic: um método de Verificação de Dados Climatológicos Apoiado em Modelos MineradosVedalogic: a Method of Climatologic Data Verification based on Data Mining Models',Revista Brasileira de Meteorologiahttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-77862009000400007. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The play requires communication with faults or unconformities.
Cai-neng ZOU, Wen-zhi ZHAO, Cheng-zao JIA, Ru-kai ZHU, Guang-ya ZHANG, Xia ZHAO, Xuan-junYUAN 2008, 'Formation and distribution of volcanic hydrocarbon reservoirs in sedimentary basinsof China', Petroleum Exploration and Developmenthttp://www.sciencedirect.com/science/article/pii/S1876380408600713. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The exposed section has been divided into 21 lito-stratigraphic units defined by major unconformities.
Huguet, R., Pérez-González, A., Carbonell, E., Bermúdez de Castro, J. M., Vallverdú,J., van der Made, J., Allué, E., García, N., Martínez-Pérez, R., Rodríguez, J., Sala,R., Benito, A., Saladie, P., Martínez-Maza, C., Bastir, M., Sánchez, A., Parés, J.M., Rosas, A. 2006, 'The “Sima del Elefante” cave site at Atapuerca (Spain)', Estudios Geologicoshttp://estudiosgeol.revistas.csic.es/index.php/estudiosgeol/article/view/29/28. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The stratigraphic section allowed us to identify three main stratigraphic units differentiated through angular unconformities and sedimentary breaks.
Arribas, I., Ortiz, J. E., Torres, T. 2006, 'El anticlinal y las discordancias de Pareja (Guadalajara): definición de lasunidades cenozoicas de la Depresión Intermedia (provs. Cuenca y Guadalajara,España)', Estudios Geologicoshttp://estudiosgeol.revistas.csic.es/index.php/estudiosgeol/article/view/9/8. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The regional unconformities are marine or subaerial erosional surfaces, as well as non-depositional surfaces, locally marked by paleosoils.
Mauro Agate, Luca Basilone, Cipriano Di Maggio, Antonio Contino, Salvatore Pierini,Raimondo Catalano 2017, 'Quaternary marine and continental unconformity-bounded stratigraphic units of theNW Sicily coastal belt', Journal of Mapshttp://dx.doi.org/10.1080/17445647.2017.1314229. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The performed macro - and microscopic tests have shown the correct structure of the overlay weld without any welding unconformities.
Golański G., Lachowicz M., Słania J., Jasak J., Marszałek P. 2015, 'Research on 16Mo3 (16M) Steel Pipes Overlaid with Haynes Nicro625 Alloy Using MIG(131) Method / Badania Rur Ze Stali 16Mo3 (16M) Napawanych Metodą MIG (131) StopemHaynes Nicro625', Archives of Metallurgy and Materialshttp://www.degruyter.com/view/j/amm.2015.60.issue-4/amm-2015-0408/amm-2015-0408.xml?format=INT. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)