The formation of spherical clay balls on the slopes of sandpit quarry, the Rudice-Sec (Czech Republic)

FAIMON, Jiří and Slavomír NEHYBA. The formation of spherical clay balls on the slopes of sandpit quarry, the Rudice-Sec (Czech Republic). Online. Catena. Elsevier, 2004, vol. 58, No 1, p. 23-40, 17 pp., [citováno 2024-04-23]

Basic information

• Original name: The formation of spherical clay balls on the slopes of sandpit quarry, the Rudice-Sec (Czech Republic)
• Name in Czech: Tvorba sférických závalků na svazích pískového lomu, Rudice-Seč (ČR)
• Authors: FAIMON, Jiří (203 Czech Republic, guarantor) and Slavomír NEHYBA (203 Czech Republic)
• Edition: Catena, Elsevier, 2004.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10500 1.5. Earth and related environmental sciences
• Country of publisher: Netherlands
• Confidentiality degree: is not subject to a state or trade secret
• Organization unit: Faculty of Science
• UT WoS: 000223391900002
• Keywords (in Czech): závalky; pukliny; roklinová eroze; děšťové srážky; tvarování; sfericita; transport
• Keywords in English: Clay balls; Cracks; Gully erosion; Rainfall; Shaping; Sphericity; Transport
• Tags: International impact, Reviewed

Abstract

Clays on the steep slopes of a small artificial sedimentary basin (sandpit quarry) alternately desiccate/crack and erode during hot dry and rainy seasons, respectively. Small irregular blocks of clay (IBC) predefined by cracks are released by gully erosion. The IBCs are quickly transported to the slope base and then rolled down the basin bottom by runoff. Due to rotation about a randomly changing axis and under an effect of deformation forces, the IBCs are transformed into spherical clay balls (SCB). The SCBs are transported, in general, towards the depositional base where they are buried by assorted sandy/clayey sediment. As soon as the kinetic energy of the runoff has decreased, the SCBs remain spread along transport path. From their distribution, the shaping process was evaluated. Based on data processing, the dependency, Psí = 1-{1-Psí(0)}x10^{-8.9E-5 lambda/d(ef)} relating the clay ball projection sphericity, Psí, to the effective diameter, d(ef), and to the distance from the steep slope base, lambda, was found. Based on this equation, the length of clay ball transport can be estimated if the projection sphericity and effective diameter are known.

Abstract (in Czech)

Clays on the steep slopes of a small artificial sedimentary basin (sandpit quarry) alternately desiccate/crack and erode during hot dry and rainy seasons, respectively. Small irregular blocks of clay (IBC) predefined by cracks are released by gully erosion. The IBCs are quickly transported to the slope base and then rolled down the basin bottom by runoff. Due to rotation about a randomly changing axis and under an effect of deformation forces, the IBCs are transformed into spherical clay balls (SCB). The SCBs are transported, in general, towards the depositional base where they are buried by assorted sandy/clayey sediment. As soon as the kinetic energy of the runoff has decreased, the SCBs remain spread along transport path. From their distribution, the shaping process was evaluated. Based on data processing, the dependency, Psí = 1-{1-Psí(0)}x10^{-8.9E-5 lambda/d(ef)} relating the clay ball projection sphericity, Psí, to the effective diameter, d(ef), and to the distance from the steep slope base, lambda, was found. Based on this equation, the length of clay ball transport can be estimated if the projection sphericity and effective diameter are known.

Links

• MSM 143100004, plan (intention): Name: Geologické procesy a jejich environmentální vyústění - styk variscid a alpid

Investor: Ministry of Education, Youth and Sports of the CR, Geological Processes and their Environmental Impact - Contact of the Variscides and Alpides