chronostratigraphic correlation charts

Downlap

Highstand Systems Tract (HST)

Lowstand Systems Tract (LST)

Maximum flooding surface

Onlap

Ravinement surfaces

Sequence Boundary

Shelf Margin Systems Tract (SMST)

Transgressive Surfaces

Trangressive Systems Tract (TST)

Unconformity

The establishment of the time significance of sedimentary units using biostratigraphy, radiometric methodologies and other time significant schemes.
Common bounding discontinuities used to subdivide the stratigraphic section can include:

• Unconformities or Sequence boundaries (SB1 and SB2)
• Ravinement and/or Trangressive surfaces TS),
• Maximum Flooding Surfaces (mfs)