EARTHQUAKE-INDUCED SUBSIDENCE AND BURIAL OF LATE HOLOCENE ARCHAEOLOGICAL SITES, NORTHERN OREGON COAST

Fire hearths associated with prehistoric Native American occupation li e within the youngest buried lowland soil oft he estuaries along the S almon and Nehalem rivets on the northern Oregon coast. This buried soi l is the result of sudden subsidence induced by a great earthquake abo ut 300 years agi along the Cascadia subduction tone, which extends off shore along the North Pacific Coast from Vancouver Island to northern California. The earthquake 300 years ago was the latest in a series of subsidence events along the Cascadia subduction zone over the last se veral thousand years. Over the long term, subsidence and burial of pre historic settlements as a result of Cascadia subduction zone earthquak es have almost certainly been an important factor contributing to the limited time depth of the archaeological record along this section of the North Pacific Coast.