sal ones/, 
i from this area 
)le geological 
)i geologicznej 
•6w Polski. 
m of the sate- 
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t. Warszawa, 
1 the Zechstein- 
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Lithological 
in Polish part 
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Geologioal Map 
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Danielska /in 
sat lineaments 
rotech. Polit. 
ij200 000: 
awa, A.Makowska 
awa, Inst.Geol. 
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
Analysis of lineaments and major fractures in Xichang-Dukou area, 
Sichuan province as interpreted from Landsat images 
Lu Defu, Zhang Wenhua & Liu Bingguang 
Institute of Geology, Academia Sínica, Beijing, China 
Xu Ruisong & Jang Baolin 
Institute of Geologic Technology, Academia Sínica, Guangzhou, China 
ABSTRACT; The Xichang-Dukou area in Sichuan province of China was studied using Landsat imagery and exist 
ing geological maps. 
A number of major and minor lineaments were identified which have been accounted for in available geologi 
cal maps. N-S and ENE fault and lineament systems are present in the area. Rose diagrams were analyzed to 
assess direction and frequency of lineaments. 
The fault zones are divided into two types: linear and arcuate. 
INFORMATION AND METHOD 
The area studied is located at the southern part 
of Sichuan province in China. Three Landsat images, 
scale 1 :500,000, cover about 60,000 ki? from north 
Minning-Yuexi in Sichuan province to south Yongren 
in Yinnan province. Geological maps of different 
type and scale are also available. Conventional 
visual interpretation methods were used, including 
modus of density slicing and local enhancement of 
lineaments for part of the area. 
ANALYSIS OF LINEAMENTS 
It is generally believed that fault zones and weak 
crustal zones are represented by lineaments on 
space imagery. 
The lineaments on Landsat were interpreted by 
considering those lineaments which could be clearly 
determined as fault zone, fractured structure, 
linear river valley, linear tonal anomely zone etc,» 
The lineaments larger than 5k™ length were only 
drawn on this map scale. 
On the basis of the directional distribution of 
the lineaments 4 groups have been distinguished, 
mainly in NS,NNW,EW,ENE direction, in which the NS 
(345°-5 ) and ENE(65°-75°) trends are the strongest 
and the most distinct on the imagery. The linea 
ments in NS direction are principally present in 
the Anninghe valley and towards the west. They are 
characterised by their continuity and greater leng 
th. The EW lineaments occur in two areas: one from 
Dukou to Huapin and another one from Xichang to 
Muli. Their length is less than that of the NS 
lineaments.(Figure 1) 
All linear features derived from the Landsat 
imagery and from existing geological maps were 
plotted in rose diagrams, as shown in Figure 2 and 
3 respeclively. 
The rose diagrams for length and frequency dis 
tribution are compiled in 5 interval classes.Fig.2 
indicates that the lineaments longer than 5 km in 
length account for the dominant NNW, NS and ENE 
trend. Fig.3 shows a preferred orientation of the 
near NS and ENE major faults. A difference was 
found in preferred orientations between the linea 
ments as interpreted from the Landsat imagery and 
geological maps. The lineaments show two length 
distributions in the direction 345 and £5 on the 
Landsat imagery and in the direction Q 355 0 and 5 
on the geological map. Directions 20 - 30 clearly 
present on the geological map are less exhibited on 
the Landsat»