Overstep

An overstep is a geological form that has a deposition of a stratum across inclined, progressively older rocks.^[1]

The Indira Gandhi National Open University syllabus definition is: "The term overstep is used to describe the relationship of beds in an unconformable sequence where the younger series rests upon progressively older members of the underlying series."^[2]

An onlap is a more general term than overstep, in which the younger beds overlap onto successively older beds.

References

^ Alistair F. Pitty Structure and Relief 1985 Page 28 "An overstep is a geological term describing the deposition of a stratum across inclined, progressively older rocks, as seen on both flanks of the Market Weighton axis (figure 9). In South East England, the Lower Greensand is another very ..."
^ Indira Gandhi National Open University (School of Sciences), (Undated). BGYCT-131 - Physical And Structural Geology, Block 3 - Structural Geology, Unit 12 - Joints And Unconformities. egyankosh.ac.in. Archived.

This article about stratigraphy is a stub. You can help Wikipedia by expanding it.

[1] Alistair F. Pitty Structure and Relief 1985 Page 28 "An overstep is a geological term describing the deposition of a stratum across inclined, progressively older rocks, as seen on both flanks of the Market Weighton axis (figure 9). In South East England, the Lower Greensand is another very ..."

[IGNOU-2] Indira Gandhi National Open University (School of Sciences), (Undated). BGYCT-131 - Physical And Structural Geology, Block 3 - Structural Geology, Unit 12 - Joints And Unconformities. egyankosh.ac.in. Archived.

[1]

[2]