Whidbey Island is a great place to see deposits of several lowland Pleistocene glacial and interglacial sequences, combined with very pleasant beach walks. These field trips are ideal for winter. It is best to go near the start of an ebb tide- don’t get trapped against a steep cliff of sand and gravel by the flood tide! Use your head and consult tide charts. I’m including UTM grid coordinates for selected places, using the NAD 27 coordinate system. You don’t need them to find your way around, but a number of folks have asked for them on these field trips.
|Late-Pleistocene glacial sequence at Whidbey Island||Age: 14C or thermoluminescence||Whidbey field trip|
|Fraser Glaciation||Everson gmd||10,370-13,010||Blowers Bluff; West Beach*|
|Vashon till||~15,000||West Beach|
|Esperance sand (outwash)||18,000||Blowers Bluff|
|Olympia Interglacial||fluvial, lacustrine, peat deposits||22-28,000||Blower’s Bluff|
|Possession Glaciation||glaciomarine drift||70,000||Blower’s Bluff|
|Whidbey Interglacial||fluvial, lacustrine, peat deposits||~100-150,000||Double Bluff, Blowers Bluff|
|Double Bluff Glaciation||Double Bluff gmd||175- 200,000||Double Bluff|
|Double Bluff till|
* location not yet visited or written for Northwest Geology Field Trips website.
The trips that comprise this series of field trips will each have there own pages. Click the link to go to each trip.
The first trip visits the lowest sequence of Pleistocene glacial and interglacial sediments on Whidbey, the Double Bluff glaciation and the Whidbey interglacial period which followed.
Part 1: Useless Bay and Double Bluff- Pleistocene strata & earthquake-deformed interglacial sediment