East dipping sandstones (pale) and mudstones (dark) of the Tyee Formation.
Sandstones are massive and uniform, without much bedding or lamination.
Stop 1 & 2: 45 Ma Tyee Formation near Eddyville
Stop 3: 20 Ma Nye Formation in Newport
Stop 4: 17 Ma Astoria Formation at Wade Creek
Stop 5: 15.5 Ma Columbia River injections at Cape Foulweather
Stop 6: 15.5 Ma Columbia River basalt pillows and breccias at Depoe Bay
Stop 7: (off map), modern sand dunes and retaining walls at Neskowin
Stop 1 & 2: 45 Ma Tyee Formation near Eddyville
East dipping sandstones (pale) and mudstones (dark) of the Tyee Formation.
Sandstones are massive and uniform, without much bedding or lamination.
Large "rip-up" fragments of dark mudstone in pale sandstone.
Related to turbidity currents on ocean floor.
Sandstone dikes, injected downward into the mudstone while both were
still "liquid"/soupy.
The dikes are somewhat wavy and buckled, perhaps scrunched a bit during
compaction.
A fault runs through the outcrop from lower left to upper right.
Movement on the fault was probably left/west block down relative to
right block.
The pale creamy areas are actually the mineral calcite that grew on
the fault surface,
while movement on the fault was taking place. Crummy picture,
sorry!
Stop 3: 20 Ma Nye Formation
in Newport
Stop 4: 17 Ma Astoria Formation at Wade Creek
Stop 5: 15.5 Ma Columbia River injections
at Cape Foulweather
Stop 6: 15.5 Ma Columbia River basalt pillows
and breccias at Depoe Bay
Stop 7: (off map), modern sand dunes and retaining
walls at Neskowin