1.1 Briefing of Mine Area and Deposit Geology
Boloven Bauxite Mine area is located in Champasak Province in south of the Lao People’s
Democratic Republic, under the jurisdiction of Paksong District of Champasak, having a common
boundary with Attapu at the south. Its straight-line distances from the surrounding cities are: 90km
in the northwest from Pakse City, the capital of Champasak Province; 40km in the northwest from
Pakson City of Champasak; 45km in the north from Saigon City, the capital of Saigon Province;
and 36km in the east from Attapu City, the capital of Attapu Province. Its geographic coordinates
are 106°31′27.4″ ~ 106°41′31.7” E, 14°49′16.2″ ~ 14°59′01.4” N.
The mining right of such mine area is in the possession of SINO-LAOS ALUMINUM
CORPORATION LIMITED (SLACO). The mine area covers an area of 147.86km2 with 16
inflection points under mining concession .See Table 1-1 for details.
Table 1-1 Coordinates of Inflection Points under Mining Concession
The evaluation of regional resources potential, initial geological work in the mine area, is carried
out by the School of Geoscience and Environmental Engineering of Central South University with
the assistance from LSI. The evaluation began in November 2005. Evaluation on Bauxite
Resource Potential of Pakson District, Champasak Province, Laos was submitted in July 2006.
Italian-Thai Development Public Company Limited (ITD) has carried out geological investigation in
the mine area since February 2007 and then submitted Proposal for Development of Aluminum
Industry of Laos in September 2007. From October 2007 to October 2008, ITD has implemented
geological survey at some sections (PMA area, i.e. Primary mining block, 70 km2 approximately)
of the mine area. Geological Exploration & Research Institute of the Bureau of LNYS submitted
the Detailed Exploration Report on Bauxite of Boloven Plateau, Paksong District, Champasak
Province, Laos (hereinafter referred to as Phase I Detailed Exploration Report) in July, 2009. On
July 14, 2009, this Detailed Exploration report passed the review by Mineral Resources and
Reserves Evaluation Center of the Ministry of Land and Resources of the People’s Republic of
China. The review comment document is numbered as “GTZKPZ  No. 45”. From December
2008 to November 2009, ITD has implemented Phase II Detailed Exploration in the mine area
(NPMA area, i.e. Non Primary mining block, 80km2 approximately). In December 2009,
Italian-Thai Development (Public) Co., Ltd. (ITD) submitted the Phase II Survey and Resource
Evaluation Technical Report (Non PMA area) on Bauxite Project of Boloven Plateau, Paksong
District, Champasak Province, Laos of Sino-Laos Aluminium Co., Ltd. (hereinafter referred to as
Phase II Detailed Exploration Report).
The Phase I and Phase II Detailed Exploration Reports could be applied as the basis for the
Figure 1-1 Positional Relation among Mine area s and Ore Body Distribution
1.1.1 Geological Condition in Mine area
The mine area is located at the south of Bandon bulge. Strata in the area are simple. Magmation
mainly generates tertiary and quaternary volcanic rocks. No fault structure or metamorphism is
founded in the mine area. Slopes in the mine area are gentle, mostly covered by quaternary
weathered materials, with Mesozoic sandstones scattered in river valleys and gullies. Sandstones
are almost flat lying. Bauxites are distributed at flat ridges and hillsides.
Mesozoic strata and eluvium layer (Qel) & residual and slope sediment layer (Qedl) formed by
weathered quaternary plateau basalts (β) are sporadically exposed in the mine area. From top to
bottom, layers consist of:
1) Eluvium Layer (Qel)
Distributed above weathered basalts and sandstones, the layer could be classified as the first
layer (Qel1) and the second layer (Qel2) as per lithology and mineral association:
a. The first layer (Qel1)
It is the footwall of ore bodies and composed of claret-colored clays with sound color constancy,
high degree of purity and high plasticity. Limonite conglomerations and bauxite particles (1~5cm)
are scattered. Thickness is 0~15.9m. Some centralized bauxite particles in some sections may
form bauxites. Some parts of the layer are absent. There is no obvious boundary between the
layer and underlying weathered basalts, generating a gradual transition.
b. The second layer (Qel2)
The layer is regarded as the ore bed with upper part consisting of reddish-yellow clay-containing
bauxites and lower part consisting of claret-colored clay-containing bauxites. Bauxites in upper
part mainly exist in the state of gobbets or nodules; bauxites in lower part are in the state of
irregular flakes, nodules, gobbets, honeycombs, particles and dendrites. Thickness is 0.2~20m.
There is an obvious boundary between the layer and underlayer.
2) Residual and Slope Sediment Layer (Qedl)
It is mainly distributed in hillsides and relatively low-lying areas. Protoliths of lower part are basalts
or sandstones, overlying bauxites. A small amount of residual deposits is found in bottom. Slope
deposits are in upper part. Part of deposits generates bauxite layer. The layer consists of
yellowish brown and maroon gravelly clays in loose accumulation. Gravels mainly are nodular and
massive ores. A humus layer (10~50cm) is generally close to the earth surface. The thickness of
caprock is 0~15.9m. In case that underlying bedrock is basalt, a clay layer or yellow, purple or
yellow-green earthy weathered basalts usually occur. In case that underlying bedrock is
sandstone, a thin clay layer and weathered sandstones usually occur. A large volume of quartzs
could be observed in weathered sandstones with naked eyes and magnifiers. There is an obvious
boundary between ore bed and underlayer which can be observed with naked eyes.
The structure is simple in the mine area, and the occurrence of the stratum is nearly horizontal as
a whole. No infold or rupture is found in such area.
188.8.131.52 Magmatic Rock
There are extensive plateau basalts (β) in the mine area, which are the native rocks of this
deposit. Rocks are of doleritic texture and massive structure in gray and dark gray. Minerals
consist of plagioclase (85~90%), pyroxene (10~15%) and iron clay montmorillonite (1~2%).
Generally, weathered basalts are widely distributed in the mine area, instead of unaltered basalts.
Weathered basalts are of earth and muddy texture in purple, yellow and yellow-green. Minerals
consist of kaolinite (65~70%), limonite (25~30%) and quartz (2~5%). In some rocks, primary
texture could be seen clearly, with white basic plagioclase phenocrysts distributed
1.1.2 Ore deposit geology
184.108.40.206 Deposit type
The ore deposit is a lateritic gibbsite bauxite mine area.
220.127.116.11 Characteristics of orebody
This deposit comprises 28 ore bodies of different sizes, which are numbered 1-10, 12, 13, 13_1,
14-21, 25, 27, 28, 30, 34, 35 and 66 respectively. They are distributed on two zones: Detailed
Exploration zone for phase I (PMA area), including 8 ore bodies numbered 1, 2, 7, 8, 10, 12
(12-N, 12-S and 12-E), 13, 15 and 28-E (Ore Body 28-E is incorporated into Ore Body 28 of the
Detailed Exploration zone for Phase II); and Detailed Exploration zone for Phase II (NPMA area),
including 20 ore bodies numbered 9, 13_1, 16-21, 14, 25, 27, 34, 35, 66, 3-6 and 30.
In this feasibility study, the mining right area can be further divided into four areas based on the
distribution characteristics of these ore bodies, including Block I, II, III and IV. Specifically, Block I
is at the middle south part of the mine area, including ore bodies numbered 8, 10, 12, 13, 13_1
and 15; Block II is at the west, including ore bodies numbered 9, 14, 27, 28, 34, 35 and 66; Block
III is at the east, including ore bodies numbered 16-21; and Block IV is at the north, including ore
bodies numbered 1-7, 25 and 30. Block I and II are the Primary mining block of this feasibility
All ore bodies occur in eluvium and el-dlQ of the quaternary system, present topographically
controlled morphology and occurrence and are mainly distributed along wide and gentle regions
of ridges or monadnock, with stratiform-like occurrence. Their surfaces are extremely irregular
oval. The largest ore body is 6.267km2
(Ore Body 12) in area, while the smallest one is
(Ore Body 13_1), averagely 1.15km2
; the maximum thickness is 6.41m, while the
minimum one is 2.54m, averagely 4.97m.There are 9 ore bodies with more than 5Mt of unit
reserve, including Ore Body 8, 12, 28, 66, 19, 1, 2, 7 and 25. They account for 72.78% of the total
The characteristics of ore bodies in both zones are shown in Table 1-2.