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Magnetic airborne survey of the Osborne Mine, Australia#
This is a section of a survey acquired in 1990 by the Queensland Government, Australia. The line data have approximately 80 m terrain clearance and 200 m line spacing. The section contains the total field magnetic anomalies associated with the Osborne Mine, Lightning Creek sill complex, and the Brumby prospect.
Pre-processing: Source code for preparation of the original dataset for redistribution in Ensaio
import pandas as pd
import pygmt
import ensaio
Download and cache the data and return the path to it on disk
fname = ensaio.fetch_osborne_magnetic(version=1)
print(fname)
/home/runner/work/_temp/cache/ensaio/v1/osborne-magnetic.csv.xz
Load the CSV formatted data with pandas
data = pd.read_csv(fname)
data
Make a PyGMT map with the data points colored by the total field magnetic anomaly.
fig = pygmt.Figure()
fig.basemap(
projection="M15c",
region=[
data.longitude.min(),
data.longitude.max(),
data.latitude.min(),
data.latitude.max(),
],
frame="af",
)
scale = 1500
pygmt.makecpt(cmap="polar+h", series=[-scale, scale], background=True)
fig.plot(
x=data.longitude,
y=data.latitude,
fill=data.total_field_anomaly_nt,
style="c0.075c",
cmap=True,
)
fig.colorbar(
frame='af+l"total field magnetic anomaly [nT]"',
position="JBC+h+o0/1c+e",
)
fig.show()
The anomaly at the bottom left is the Osborne Mine. The ones on the top right are the Lightning Creek sill complex (the largest) and the Brumby prospect (one of the smaller anomalies).
Total running time of the script: (0 minutes 16.880 seconds)