Document of bibliographic reference 367422

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Threshold of motion and orientation of bivalve shells under current flow

Abstract

Disarticulated shells of three bivalve mollusk species (Anomalocardia brasiliana, Codakia orbicularis, and Divaricella quadrisulcata) were experimentally tested in laboratory flumes to determine the threshold of motion and final orientation of the valves. A total of 150 current flow experiments were conducted on single shells resting on a fixed sand bed. This study demonstrated that shells in the convex-up position are more resistant to flow when the umbo is pointing downstream rather than upstream. Moreover, species with higher frontal areas were more likely to be entrained at lower flow velocities. Results of dimensionless shear stress exhibited values far below the threshold of grains movement for beds of uniform roughness (Shields curve). It was observed that circular shells in convex-up positions were mostly orientated with the umbo pointing downstream. Conversely, elliptical shells in convex-up position tended to align their longer axis parallel to the flow with the posterior side of the valve pointing downstream. These results are not only directly applicable in interpretations of incipient shell motions and in paleocurrent analyses from field and sample data, but also support construction of accurate geological models.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:001055438900001

Bibliographic citation

da Silva, F.R.S.; Borges, A.L.O.; Toldo Jr., E.E.; Fick, C.; Puhl, E.; Oliveira, V.C.B. (2023). Threshold of motion and orientation of bivalve shells under current flow. Brazilian Journal of Geology 53(1): e20220080. https://dx.doi.org/10.1590/2317-4889202320220080

Topic

Marine

Is peer reviewed

true

Access rights

open access

Is accessible for free

true