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after a vertical movement if a surface has a complicated
form. In a like manner, a lineament indicating a thrust
will be revealed on the Kv map since thrusting also brings
into existence a scarp, as a rule.
However, lineaments indicating dip-slip, reverse and
thrust faults will not be recorded on the Kh map because
changes of the Kh sign along lines of these faults will be
random rather than systematic. At the same time, some
non-lineament changes on the Kh map will arise.
Suppose a strike-slip fault is formed within the surface
klmp. Kh and Kv values will also change in the
deformation zone. The Kh will take negative values along
all the fault line, while changes of the Kv sign will be
random rather than systematic. Consequently, the
following lineaments indicating horizontal movement
traces will be recorded on the Kh map: a) a black
lineament on a white background for a surface with
positive Kh value and for a plane surface, b) a white
lineament on a black background for a surface with
negative Kh values, and c) a lineament consisting of white
and black lines and spots for a complex surface. Some
non-lineament traces of horizontal movements will be
recorded on the Kv map.
After an oblique-slip and a gaping faults formation both Kh
and Kv ought to change sign systematically along fault
lines. Therefore, we can anticipate that lineaments
indicating these faults will be recorded on both the maps.
The method proposed has the following limitations:
1. It is impossible to determine and separate lineaments
of non-tectonic (i.e., erosion, eolian) origin without
ancillary geological, geophysical and geomorphic data.
2. Lineaments recorded on Kh and Kv maps can be
connected with flexures and folds. To determine and
separate these lineaments ancillary non-topographic data
have to be used too.
3. If a strike-slip fault is located along a surface strike a
lineament cannot be recorded by Kh mapping.
4. We also have to use ancillary geological data to
separate: a) a dip-slip, reverse and thrust faults equally
revealed on Kv maps and b) an oblique-slip and gaping
faults equally revealed on both Kh and Kv maps.
Kh and Kv digital models are obtained by DEMs
processing. To reveal topographically expressed faults
within a certain scale range DEM has to be compiled by
regular net and DEM resolution has to correspond to a
typical plan size of faults under study.
3. METHOD TESTING
To test the method developed we used the DEMs of an
abstract area with modelled faults and a DEM of a part of
the Crimean Peninsula and the adjacent sea bottom.
3.1 The Abstract Area
3.1.1 Study Site: The abstract area (Fig. 1 a) has sizes
of 60 m x 60 m. It includes a single near-east oriented
valley two watersheds. Elevation amplitude is 7.5 m.
3.1.2 Initial Data and Methods: The irregular DEM
of the abstract area was compiled (Fig. 1 a). Five simple
typical faults were modelled by deformation of the initial
irregular DEM: a vertical dip-slip fault with 1 m
253
displacement (Fig. 1 d), a left-lateral strike-slip fault with
3.5 m displacement (Fig. 1 g), an oblique-slip fault with
3.5 m left-lateral horizontal and 1 m vertical displacements
(Fig. 1 j), a overthrust with 15 m displacement (Fig. 1
m), a gaping fault with a trench of 1 m width and 0.2 m
depth (Fig. 1 p). Five irregular DEMs with indicated
modelled faults were obtained.
Regular DEMs of initial and deformed surfaces were
generated by the Delaunay triangulation and piecwise
polynomial smooth interpolation of corresponding irregular
DEMs. The matrix step 2 m was used. Kh and Kv digital
models (Fig. 1 b, c, e, f, h, i, k, I, n, o, q, r) for regular
DEMs were calculated by the algorithm of Evans (1980).
3.2 The Part of the Crimean Peninsula and the
Adjacent Sea Bottom
3.2.1 Study Site: The study site (between Latitudes
44°21' N - 45'30' N and Longitudes 33*13' E - 35*55' E)
has sizes of 210 km x 132 km. We chose this region to
test the method developed by two reasons. First, it is one
of the best studied areas in the world (Muratov, 1969;
Beloussov, Volvovsky, 1989). There are a lot of factual
geological, geophysical and remotely sensed data to test
fault revealing and morphology recognition. Second, a
diversity of relief and tectonic structures within the region
allow us to test the method in different topographic and
geological conditions.
The structure of the study site is complicated by a lot of
faults. The following main fault groups can be
distinguished — (Muratov, 1937; Shalimov, 1966;
Rastsvetaev, 1977; Borisenko, 1986):
1. Near-north-striking left-lateral strike-slip faults with
high-angle dips, 3-5 kilometres horizontal displacements
and tens of kilometres lengths. They most abundant in the
east, central and south-west parts of the study site.
2. Near-north-east and east-striking dip-slip faults with
north-west dips and tens of meters displacements. Some
researchers consider that these faults are trusts with 30°-
45° dips and several kilometres displacements.
3. Near-north-west-striking dip-slip and oblique-slip faults
with high-angle dips. Oblique-slip faults have right-lateral
10-100 meters horizontal displacements.
4. Near-north-striking dip-slip faults located in the west
part of the region.
3.2.2 Initial Data and Methods: To test the method
the irregular DEM of the part of the Crimean Peninsula
and the adjacent sea bottom was applied. This DEM was
compiled by digitising 1:300000 and 1:500000 scaled
topographic maps (Florinsky, 1992). The regular DEM
(Fig. 2 a) was generated by the irregular DEM
interpolation using the weighted average method. The
matrix step 500 m was used. Kh and Kv digital models
(Fig. 2 b, c) were obtained by the algorithm of Evans
(1980) using the matrix step 3000 m.
The map of revealed and morphologically classified faults
(Fig. 2 d) was obtained by a visual analysis of the Kh and
Kv maps (Fig. 2 b, c). To estimate efficiency of the
method we carried out a visual comparative analysis of the
obtained fault map (Fig. 2 d) and some factual geological
data (Moisejew, 1930, 1939; Muratov, 1937, 1969;
Lebedev, Orovetsky, 1966; Shalimov, 1966; Rozanov,
1970; Rastsvetaev, 1977; Sollogub, Sollogub, 1977;
Sidorenko, 1980; Kats et al, 1981; Kozlovsky, 1984;
Borisenko, 1986; Zaritsky, 1989).
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
