PTBA Internship Report · internship-4-u36
Electrofacies — C–D interburden
The internship log panel brackets the C–D between core-constrained coal markers. Its serrated or irregular gamma expression is compatible with the alternation described in core—the c–d interburden is represented by very fine- to fine-grained sandstone and siltstone, locally coarser, with flaser, wavy and lenticular bedding.

SOURCE-LED TECHNICAL READING
Geological interpretation and evidential boundary
The internship log panel brackets the C–D between core-constrained coal markers. Its serrated or irregular gamma expression is compatible with the alternation described in core—the c–d interburden is represented by very fine- to fine-grained sandstone and siltstone, locally coarser, with flaser, wavy and lenticular bedding. That geometry reflects mineralogical contrast and vertical averaging, not an environment by itself; depth matching, density behaviour and core recovery must agree before the variability is assigned geological significance. The repeated thesis figure represents reuse of this source record, not a new measurement.
- Source
- Private internship source vault · Chapter IV record
- Location in source
- 4.5.2 Seam C
- Image quality
- Source scan
- Record ID
- internship-4-u36



