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Basalt Intrusion into Faulted Soft Sediment, Cape Bridgewater, Portland, Victoria



Roberto Weinberg, Monash University, Australia




This page records a faulted sandstone sequence into which basalt has intruded while it was still soft. This is at the west end of the beach at the village of Cape Bridgewater, This is part of Roberto Weinberg's Geosite.


Contact Relationships
contact basalt-sandstone
Figure 1a) Contact with basalt on the left, sandstone on the right, and a 4 metre long intrusion of basalt into the sediments.
intrusive basalt
Figure 1a)
intrusive basalt
Figure 1b) Elongated vesicles on the lobe on the right-hand-side define a broad circular pattern following the rounded lobe but discontinuous, interrupted by irregularities.
peperitic contact
Figure 1c) .
peperitic contact
Figure 1d) .
peperitic contact
Figure 1e) .
peperitic contact
Figure 1f) .

Sedimentary features and normal faults
Growth fault?
Figure 2a) Growth fault?
Figure 2b) Blocks.
noarmal faults
Figure 2c) .
normal faults
Figure 2d) .
Figure 2e) Normal fault.
Figure 2f) Detail.
Figure 2g) Normal fault.
Figure 2h) Detail.
Figure 2i) Normal fault through coarse sediments, diffuse plane.
Figure 2j) Normal fault through coarse sediments, diffuse plane.