Upper Blue River geology clipped to the Andrews Experimental Forest

Geologic maps

Rock units of parts of the Blue River basin (including the Lookout Creek  watershed and upper Blue River above the junction with Lookout Creek), were described by several investigators who covered different portions of the basin at different scales.  A unit correlation table was developed (see below) and units were manuscripted using Priest .et .al (1988) for Lookout Creek and Walker and Duncan (1989) for upper Blue River.  Units were digitized and attributed using the investigators' descriptions.  The upper Blue River geology layer was clipped by the H.J. Andrews boundary to create this layer.  Rock unit strength was added as an attribute when the geology layer was used in a landslide hazard analysis.  Rock strength was determined by Swanson based on rock type and age. 
 
Rock Unit Correlation Table
Walker&   Priest*          Description                            Age
Duncan    et al                                                  (mybp)
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Tb        Tlava [Tmp,      ridge capping lava flows               4-8  
          Tmf not shown]

Tba       Tma, Tmb, Tml    some Tb lava flows, minor clastics     8-13

Tu        Tmt              clastics, especially ashflows           ~14
          Ttc              clastics                               18-25
          [Ta not shown]   as minor inclusions

Tmv                        Wolf Rock and other minor intrusive    Mio -
                           bodies                                 Olig
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* map unit boundaries are a mixture of Priest etal and Swanson and 
  James (1975) for their mapped areas

Dataset copied.

Dataset copied.