Boundary Problems in Indian Stratigraphy

• Stratigraphic boundary problems are an important component of describing the geology and stratigraphy of India.
• Stratigraphic boundaries separate rocks of significantly different environments or lithology.
• Stratigraphic boundaries are ideally defined by distinct lithological, geochemical, and palaeobiological signatures, to which a chronological framework can be applied.
• Stratigraphic boundaries are determined by one or more of geological events such as 
  • volcanic activity, 
  • sedimentation, 
  • tectonism, 
  • paleo-environments & 
  • evolution of life. 

• Faunal records have played a major role in determining the boundaries of the Phanerozoic units. 
• The other geological events are dated on the evidence of fossil records. 
• Boundary problems refer to the process of demarcating stratigraphic boundaries and addressing the challenges that may arise.
• Marking sequence boundaries is not a straightforward exercise.

• Ther are four important boundary problems in Indian stratigraphy:
  1. Precambrian/Cambrian (Pc/P) 
  2. Permian/Triassic (P/T)
  3. Cretaceous/Tertiary (K/T)
  4. Neogene/Quaternary (Ng/Q)