Mapping & Petrography Appendices · appendix-16
Petrography — Sheet 16
The Pettijohn ternary diagram places the BL sample in the mudrock field because matrix overwhelmingly exceeds the arenite–wacke threshold. This is a classification translation of the modal estimate, not an independent line of evidence.
SOURCE-LED TECHNICAL READING
Geological interpretation and evidential boundary
The Pettijohn ternary diagram places the BL sample in the mudrock field because matrix overwhelmingly exceeds the arenite–wacke threshold. This is a classification translation of the modal estimate, not an independent line of evidence. The plotted proportions should be traceable to a point count, with lithic fragments and feldspar distinguished consistently and the matrix definition stated. Because the point lies deep within the mudrock domain, modest counting uncertainty is unlikely to change the name, but it still affects quantitative comparisons among samples. The diagram supplies controlled terminology; process interpretation must rely on sedimentary structures, grain-size distributions, stratigraphic position and the regional deep-water facies association.
- Source
- Private geological appendix archive · controlled source record
- Location in source
- Source-linked record
- Image quality
- HD
- Record ID
- appendix-16
