Keating Method
– a method of locating the magnetic
anomalies resembling the response of a modeled Kimberlite Pipe
based on the pattern recognition technique.
The model parameters of a vertically dipping cylinder are computed in a
grid form and adjusted for the assumed depth, radius and length of a cylinder as
well as for local Inclination, Declination and
areal extent of the particular anomaly, The
model grid is moved over Total Magnetic Intensity grid as Running Window.
The correlation between modeled and observed data is computed at each
grid node and anomalies with correlation coefficients that exceed a specific
threshold (i.e. 75%) are retained for comparison to other exploration data. [125
].
Kimberlite Pipe
– a
carrot- or mushroom-shaped, more or less vertical magmatic Intrusion body
originating very deep in the Earth (about 150 km), which sometimes contains
diamonds. K.P.
is often only several hundred meters in diameter and buried under a
cover of unconsolidated sediments. Because K.P.
composition is dominated by Mafic Rock
minerals, including Magnetite, its magnetic signature is often very distinctive. On Total
Magnetic Intensity or,
more clearly, on high-pass filtered magnetic maps, K.P.
is often expressed as a “bright dot” – a local high-intensity
circular-shaped anomaly. On a profile of the magnetic data displayed along a
survey line, K.P. is
presented as a short-wavelength, spike-like anomaly similar to that of Cultural
Noise (wellhead, for example), hence, careful Cultural Editing
is very important in K.P. exploration. In case of significant remanent magnetization,
the magnetic anomaly caused by K.P.
will be expressed as a “dim dot” – a local low-intensity (about 100 nT or
less) circular-shaped anomaly. Generally, estimates of location and depth of K.P. are
based on its model approximation as Monopole.
[13, 125]. See also Magma.
Koefoed Method
– a
two-dimensional (2-D) method of estimating a depth to the source of the magnetic
anomaly. K.M. is based on measuring horizontal distances between points on
the chosen flank of the regionally corrected anomaly that represent one-half and
three-quarter maximum slope values. Four measured distances (including the
opposite side of the same flank inflection point) are used to generate a set of
three depths: 1) for the contact; 2) thick plate (thickness-to-depth
ratio is about 1:1); and 3) thin plate (thickness-to-depth ratio is about
1:10) assumed source geometries. K.M.
also assumes that the strike length of a source body is at least four times its
depth below sensor. See Depth Rules and Magnetic Contact.
Koenigsberger Ratio (Q)
–
a ratio of Remanent
Magnetization to Induced
Magnetization:
Q
= “remanent magnetization / induced magnetization”,