An overstep is a

geological Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...

form that has a deposition of a

stratum In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

across inclined, progressively older rocks.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 The Market Weighton Axis is a geological feature which forms the south-eastern part of Yorkshire, England. The feature goes under a number of names such as 'block' or 'area' while the name of the town, Market Weighton is retained. 'Block' seems to ...

(figure 9). In

South East England South East England is one of the nine official regions of England at the ITL 1 statistical regions of England, first level of International Territorial Level, ITL for Statistics, statistical purposes. It consists of the counties of england, ...

, the Lower

Greensand Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called ''glauconies'' and co ...

is another very ..." The

Indira Gandhi National Open University Indira Gandhi National Open University, known as IGNOU, is a Central University located at Maidan Garhi, New Delhi, India. Named after former Prime Minister of India Indira Gandhi, the university was established in 1985 with a budget of 20& ...

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."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
An

onlap Onlap or ''overlap'' is the geological phenomenon of successively wedge-shaped younger rock strata extending progressively further across an erosion surface cut in older rocks. It is generally associated with a marine transgression. It is a more ge ...

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

References

Stratigraphy {{Geology-stub