17
NANGGULAN PHOTOGRAPH MONTAGE
NP4.9. Uppermost Te1a beds show an alternating succession of muddy sandstone,
siltstone and carbonaceous mudstone/shale. Also noted from this interval
are laminae to thin interbeds of lignitic coal and debris of the mollusca
Axinaea dunkeri. A shallow delta plain environment is indicated with local
nearby brackish swampy mangrove conditions.
NP4.10. Close-up view of muddy sandstone strata (Te1b), showing an unusual local
concentration of siliceous meta-siltstone/ quartzite and milky metamorphic
quartz clasts within a multiply incised channel, Watupuru River, Nanggulan.
Lowest exposed channel cross-bedded layer of conglomeratic pebbly
sandstone is incised by a higher energy, sandy conglomerate void of
apparent layering. Shallow water, fluvio-deltaic/braided stream environment
is suggested.
NP4.11. View of Te1b Member, Axinaea zone at Watupuru River, Nanggulan.
Interbedded grey muddy sandstone, carbonaceous claystone and siltstone
show convex-up foreset cross-beds dipping 20º with a transport direction of
070º. Top-lapped beds dip more gently ENE at ±10º. Very shallow delta
plain environment indicated.
NP4.12. Close-up view of upper Te1b unit outcrop showing thin foraminifera rich
layers of Nummulites.
Shallow marine, inner neritic depositional
environments suggested.
NP4.13. Close-up view of Te2 outcrop showing a massive grain flow of calcareous
muddy sandstone containing transported Discocyclina debris. Shallow
marine, middle neritic depositional environment suggested.
NP4.14. Te2 stacked succession of 0.5-1.0 m thick beds of Discocyclina
interstratified with 1.0 m thick layers of medium grained, massive quartz
sandstone. Discocyclina and rare accompanying molluscan coquina textures
imply shallow marine water transport conditions with calcareous to sandy
clay acting as intra-debris matrix material. Clumprit River, Nanggulan.
NP4.15. Close-up view of uppermost Te3 Formation shows a thin bedded succession
of shale, mudstone, calcareous claystone and sandstone at Balak, Nanggulan.
Globergina-rich intra-layers are common throughout the outcrop. The close
spaced, steeply dipping fracture cleavage is a product of brittle deformation
associated with Nangullan fold development. No soft-sediment deformation
was observed. A deep marine, near bathyal (1-2,000 m water depth)
depositional environment is indicated.
NP4.16. Close-up view of uppermost Ton Formation at Balak, Nanggulan section of
Te3. This outcrop consists of light grey, varicolored Globigerina-rich chalky
marl and claystone. A deep marine, near bathyal (1-2,000 m water depth)
depositional environment is indicated.