PTBA Internship Report · internship-4-u45
Electrofacies — A1–A2 interburden
The internship log panel brackets the A1–A2 between core-constrained coal markers. Its serrated or irregular gamma expression is compatible with the alternation described in core—the a1–a2 interburden is described as fine, locally tuffaceous sandstone with subordinate finer beds.

SOURCE-LED TECHNICAL READING
Geological interpretation and evidential boundary
The internship log panel brackets the A1–A2 between core-constrained coal markers. Its serrated or irregular gamma expression is compatible with the alternation described in core—the a1–a2 interburden is described as fine, locally tuffaceous sandstone with subordinate finer beds. 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
- 4.5.6 Seam A1
- Image quality
- Source scan
- Record ID
- internship-4-u45

