Inventory of Mine Openings Using Topographic Lidar State

Inventory of Mine Openings Using Topographic Lidar State of the Professions-Looking to the Future! Presented by: Clark Niewendorp, Industrial Minerals Geologist Oregon Department of Geology and Mineral Industries April 21 -23, 2015 1

North Santiam Mining District, Marion County Now part of the Opal Creek Wilderness & Opal Creek Scenic Recreation Area Lidar for this study is publicly available and was not flown specifically for an AML study Lidar data was collected by the Oregon Lidar Consortium; participating partners in 2009 2

North Santiam Mining District Little North Santiam River Whetstone Mtn. Gold Creek Site of original gold discovery Map Window Ruth Mine Jawbones Flats/ Amalgamated Mill Opal Creek Bornite deposit ~17 km (11 mi) long east-west; 8 km (5 mi) wide north-south • Rugged mountains • Steeply incised valleys • Densely forested Image from Quick Terrain Modeler 3

Abandoned Mine Land (AML) Surveys Traditional approach • USGS topographic maps • Ortho-photography • Historical mine records ü Reports ü Maps (claim, workings) ü Newspapers • Mineral surveys (County & BLM) Terrain analysis with lidar “FIELD SURVEY(S)” 4

What to look for in the lidar imagery? …looking for pixel shading patterns for… Adits Shaft(s) Open Cuts Abandoned Mines… STAY OUT and STAY ALIVE 5

Visualization Techniques CASCADE RANGE Bare. Earth DEM • Arc. GIS™ 10. 1 (Esri®): Lidar DEM (azimuth, 315; altitude, 45) Start with the most common ü Hillshade raster ü Slopeshade raster Ø A step further: Overlay (transparency) 6

Arc. GIS™ 10. 1 (Esri®) Hillshade & Slopeshade 50 % contrast 40 % transparency Prospect Pit 315° Adit & waste rock pile 45° 7

Relief Visualization Toolbox ver. 1. 1 (Zaksek and others, 2014)* Geo. TIFF of the Bare. Earth DEM • Analytical hillshading üHillshading from multiple directions • Principal Components Analysis (PCA) of hillshading • Slope gradient • Simple local relief model üSky-view Factor • Anisotropic Sky-View Factor • Openness – Positive • Openness – Negative * http: //iaps. zrc-sazu. si/en/rvt 8

Relief Visualization Toolbox ver. 1. 1 (Zaksek and others, 2014) Hillshade in multiple directions Hillshade 315° 45° 0 500 Feet 16 45° 9

Relief Visualization Toolbox ver. 1. 1 (Zaksek and others, 2014) Sky-View Factor High available sky Low available sky …proportion of available sky to DEM pixel through direct line of sight in all directions and at all angles without terrain obstructions… 10

Relief Visualization Toolbox ver. 1. 1 (Zaksek and others, 2014) 1 0 Clear distinction between protruding features and depressions 16 10 m (20 px) 11

Mining camps, mill sites, and trails/roads are AML features, too. Image from Quick Terrain Modeler 12

Cre ek Jawbone Flats mining camp Op al Ruth Mine Level 4 Mine road & haulage Battle Ax C Ruth Mine reek Level 5 Quick Terrain Modeler http: //www. opalcreek. org/history-ecology/ Ca. 1939 -40 13

Outcome… Lidar reconnaissance revealed 226 AML features in the district • mine entrances • exploration pits • waste rock areas Previous surveys showed only 58 AML features Able to show… Terrain analysis with lidar (DEM-bare earth) is an effective reconnaissance tool for generalization of AML features in advance of a ground survey Benefits… Increases efficiency and saves labor Can’t replace… Boots on the ground! 14