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Lone Tree Point

USGS Topo Sheet: Anacortes South

Geographic coordinates: 48°24.43' N, 122°33.22' W

Paleoseismic record: Neither the Lone Tree site or a nearby site at Snee-oosh Point 1 km to the southeast, are likely to have recorded recognizable paleoseismic events.

Setting: Lone Tree Point is formed where a small tombolo is connected to Fidalgo Island by a 1-to-2-m-high, log-strewn beach berm on its north side and a 1-m-high sandy berm on its south side. A 100-m-wide pond between the berms is inundated during high tides. A slightly larger area of brackish-to-freshwater marsh lies behind a 1.5-m-high, log-gravel berm about 1 km to the southeast at Snee-oosh Point.

Stratigraphic description: Only a tiny area of thin (<0.2-m-thick) Salicornia marsh borders the southwest side of the pond at Lone Tree Point. Peaty sediment beneath the Scirpus/Typha marsh at Snee-oosh Point is probably thicker.

Paleontology/Paleoecology: No paleontologic work has been completed.

Geologic interpretation: Because most of the sediment at Lone Tree Point is sand and gravel, tidal marsh is almost nonexistent, and the berms are low, this site is very unlikely to have preserved changes in lithology that could be identified as resulting from coseismic land-level changes or tsunamis. The present marsh at Snee-oosh Point may have developed partly in response to the raising of its protecting berm during development of the area. Sediments beneath this marsh might record marine inundation events of the past few hundred to a thousand years. However, because the marsh is narrow and the berm low, stratigraphic evidence of coseismic land-level changes or tsunamis would be difficult to distinguish from evidence of storm tides.

Date of last work at site: September 1997

Status of work: No additional work is planned.

Published information on this site: None

Investigators: A. Nelson

Please use the following format in citing information from this page:

Nelson, A.R., Lone Tree Point, in Bucknam, R.C., compiler, 1999, Atlas of reconnaissance data from paleoseismic studies in the Puget Sound region, Washington: U.S. Geological Survey Web Page, http://earthquake.usgs.gov/regional/pacnw/paleo/atlas.html.

This URL is: http://earthquake.usgs.gov/regional/pacnw/paleo/reports/lonetree.htm
Modified July 29, 2002 by Susan Rhea