Todd Morine
Miles Kreidler
Sam Saunders
Ryan Loux
GPH 492 – Magnetics
Table of Contents:
Page 1: Title, Table of Contents
Page 2: Method
Page 3: Interpretations
Page 4: Hidden Valley Transect 1- Gravity and Topography
Page 5: Hidden Valley Transect 1- Base Map
Page 6: Hidden Valley Anomoly- Geologic model
Page 7: Prater Transect- Gravity and Topography
Page 8: Prater Transect- Base Map
Page 9: Hidden Valley Transect 2, Whitewood Transect- Gravity and Topography
Method:
Survey Method 1:
Team members set up two magnetometers to take readings through the
course of the survey. A base station set at a certain location took readings
without moving, in order to correct for magnetic field drift. A field station
moved from point to point (every 10-40m) along the survey collected data along
transects. Students at both stations recorded magnetic field strength (nT), Time
(hour:min), noise (nT), and location (UTM NAD 84). This method was used for
the following transects: Hidden Valley 1, Hidden Valley 2, and Prater.
Survey Method 2:
Team members set up one magnetometer to take readings through the
course of the survey. No base station was set up. Drift correction was based on
the westernmost point along the transect at times 10:42am and 1:18pm. A field
station moved from point to point (every 10-40m) along the survey collected
data along transects. Students at the station recorded magnetic field strength
(nT), Time (hour:min), noise (nT), and location (utm NAD 84). This method was
used for the following the Whitewood transect.
Analysis:
After transferring the data into EXCEL format, the magnetics team
created graphs of distance (m) vs. magnetic field intensity and topography for
each transect as well as a base map with the field stations overlain. Significant
magnetic features were identified on both the maps and the graphs.
Interpretations:
Hidden Valley 1:
Three features were identified on the Hidden Valley 1 transect. At about
430m east of the base station, both forward and reverse surveys picked up an
extreme low in magnetism. This is interpreted to be a manmade anomaly,
possibly an engine block seen in the vicinity. At about 50m west of the base
station, magnetism rises by about 7000nT. This boundary coincides with the
mountain/valley interface, and is likely due to a transition from exposed bedrock
to valley sediments. At about 2800m west of the base station, there is a positive
magnetic anomaly. This anomaly was modeled as a block of magnetic material
below the surface. The model is attached.
Hidden Valley 2:
Due to the sporadic and inconsistent data for the Whitewood transect,
no interpretations were made.
Prater:
One feature was identified on the Prater transect. At approximately
2300m from the start of the transect, the data experienced a drop of
approximately 10000nT. This coincides quite will with the rangefront, and is
likely due to a transition from basin sediments to exposed volcanic bedrock.
Whitewood:
Due to the sporadic and inconsistent data for the Whitewood transect,
no interpretations were made.