Department of Geology, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
Slump blocks, intraformational conglomerates and associated erosional structures in Pennsylvanian fluvial strata of eastern Canada
Article first published online: 14 JUN 2006
Volume 33, Issue 3, pages 387–399, June 1986
How to Cite
PLINT, A. G. (1986), Slump blocks, intraformational conglomerates and associated erosional structures in Pennsylvanian fluvial strata of eastern Canada. Sedimentology, 33: 387–399. doi: 10.1111/j.1365-3091.1986.tb00543.x
- Issue published online: 14 JUN 2006
- Article first published online: 14 JUN 2006
- received 24 December 1984 revision 20 July 1985
Pennsylvanian fluvial channel sandstones in New Brunswick and Nova Scotia contain numerous examples of eroded mudstone surfaces, including in situ mudstone beds, boulders and slumped blocks. The eroded surfaces bear a variety of structures including linear scours, flutes, longitudinal furrows and rill marks. A block of interchannel mudstone up to 40 m in extent, displays a basal slip-plane, slump-related deformation and evidence of intense corrasion on a channel floor. Mudstone clasts from small pebbles to boulders over 4 m long are common immediately above channel-base erosion surfaces and represent a lag. Clasts over 20 cm diameter are commonly fluted, occasionally on all sides, suggesting clast rotation. Rill marks occur on large mudclasts and in situ mudstone surfaces and indicate emergence and erosion by surging water or surface runoff. Preservation of the delicate erosional structures depended on a highly cohesive mud substrate and subsequent rapid burial. A previous interpretation of the mud blocks and their surficial features as the result of mud intrusion is inconsistent with the field evidence.