Geology of Lowland aquifersThe lowland basins commonly contain important groundwater resources. In the Willamette basin of NW Oregon, the Miocene Columbia River Basalt (CRB) is a significant ground water aquifer. In this area, ground water development has gone beyond the alluvial basins and into the CRB around the basin margins. However, water flow, recharge and water quality in the basalts is controlled by complex internal stratigraphy and structure.
Although monotonous at first glance, the CRB can be mapped on a flow by flow basis using subtle variations in appearance, chemical composition, and paleomagnetic direction. We are combining field mapping, subsurface data, aeromagnetic surveys, paleomagnetic, and geochemical studies to document flow by flow stratigraphy, crustal faulting, and their role in controlling ground water resources. Our objective is to provide a modern, three dimensional model of basalt structure and stratigraphy needed to manage sustainable ground water supplies in the CRB.
Geology of the Columbia River Basalt Group
- Geologic Map of Quaternary Units in the Willamette Valley, Oregon
- Mt Angel and vicinity
- Salem East and Turner
- Salem West and Sidney
- Chehalem Mountain