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Advances in Applied Science Research, 2014, 5(3):146-151
ISSN: 0976-8610
CODEN (USA): AASRFC
146
Pelagia Research Library
Geochemistry and economic potential of marble from Obajana,
north central, Nigeria
1
Jimoh Onimisi Abdullateef,
2
A. A. Elueze and
1
J. B. Ahmed II
1
Department of Geology, Federal University Lokoja, Kogi State, Nigeria
2
Department of Geology, University of Ibadan, Oyo State, Nigeria
_____________________________________________________________________________________________
ABSTRACT
Nigeria is endowed with varieties of valuable solid minerals and rocks. These minerals/rocks are capable of
boosting the economic potentials of the country if fully exploited. Marble is one of such rocks that occur prominently
in Obajana area of Kogi State, North Central, Nigeria. Twenty five (25) marble samples were subjected to
geochemical, petrographic and physical analyses. Geochemical data show that the marble has variable geochemical
characteristics; low dolomite CaMg(C0
3
) (1.1-3.01%) and high calcite CaCO
3
(94-98%). Physical tests indicate
high compressive strength (93.46-95.77MPa), shear strength (13.84-13.34MPa) and low water absorption (0.30-
0.69%) respectively. Petrographical studies reveal that the marble contains calcite, dolomite, quartz, actinolite,
phlogopite and graphite. Based on these characteristics, the marble from Obajana is suitable as raw materials for
manufacture of lime, steel flux, drugs, toothpaste, lubricant, pesticide production, paper and paint. It is also
important in the production of livestock feed, electrical insulators, flooring tiles and terrazzo chips. The marble is
very suitable for cement production.
Keywords: marble, petrographical, geochemistry, variable characteristics, suitable raw materials.
_____________________________________________________________________________________________
INTRODUCTION
Marbles are generally metamorphic derivatives of sedimentary carbonates. They have been known to be relatively
impermeable during metamorphism (Nabelek, 1991). A review of the economic utilization of carbonates therefore to
some extent takes into consideration aspects of the mineralogy, physical and chemical properties of the marble
deposits. The marble occur as low-lying outcrops, scattered as lenses within quartz mica schist about 4km to
Obajana town. The marble in Obajana area occurs in large deposit, yet very little data are available on its chemistry.
This study therefore presents data on the marble chemistry with the purpose of appraising its economic potentials
and industrial applications.
MATERIALS AND METHODS
Field study
A reconnaissance survey and systematic field mapping of the marble deposits and other associated rock types was
undertaken between November 2010 and February 2011 when there was dry weather and outcrops were well
exposed. The marble in Obajana varies in colour from whitish, pinkish to grey while the texture ranges from fine,
medium to coarse. In places, the marble is associated with banded calc-gneiss within the schist rock unit.
Jimoh Onimisi Abdullateef et al Adv. Appl. Sci. Res., 2014, 5(3):146-151
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Petrology of Obajana area
Basement rock exposures in the Lokoja-Jakura schist belt are dominated by metasedimentary rocks, chiefly, quartz-
mica schist with small occurrences of quartzite, marble and silicate facies iron-formation. These metasedimentary
rocks are interbanded with meta-igneous rocks such as granite gneiss. Chemical data on major and trace elements of
the sheared and unsheared varieties of quartz – mica schist from the Obajana area, reveal a composition comparable
to that of semipelitic metasediment (Olobaniyi, 2003). The major rock types in Obajana area are gneisses, schists,
banded iron formation, quartzite and marble. Rocks in this area generally have a North-South trend and dip in a
western direction.
Sample collection
Forty five (25) representative marble samples of about 550g each were collected from the studied area (Figure-1) by
means of sledge hammer. Global positioning system (GPS) instrument was used to locate and determine the
elevations and co-ordinates of sampled points.
Fig.1: map of Northcentral Nigeria showing the location of the study area. (Adopted from Wikipedia)
Sample preparation
Thirteen (13) of the samples were pulverized into powder (180µm mesh) using Denver pulverize equipment. They
were sent to ACME laboratory in Vancouver, Canada for major and minor oxides geochemical analyses using the
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) method. X-ray Diffractometer (XRD) was also carried
out for three (3) pulverized marble sample in same laboratory. The whole rock CO
2
abundances were calculated
following duplicate determination of CaCO
2
using the Carbonate-bombe method of Birch, 1981.
In the XRD method diffractograms were obtained with a Philip 1140 equipment using Cuk alpha radiation operated
at 40KV, 30MA and 1021 per minute. Ten (10) samples were tested for their physical strength properties while
another ten (10) samples were used for petrographic studies.
RESULTS AND DISCUSSION
Table-1 shows a variable geochemical characteristic of Obajana marble. SiO2 (silica) values are generally low to
high ranging from 0.58% to 7.99%. High content of silica has a positive impact on the economic use of marble for
cement production TiO
2
, MnO, FeO
3
values are all less than 0.4%. Similarly Na
2
O, K
2
O are less than 0.2% in the
marble.
Al
2
O
3
values ranges between 0.08 – 0.31% with an average value of 0.59%. These Al
2
O
3
values are comparable to
that of the Ososo and Igbeti marbles, (Emofurieta, 1995), Kwakuti marble (Mcleod, 1955) and Osara marble
(NSDA, 1986).
River Niger
Kabba Zongon Daji
Osara
Obajana
Choko choko
Okebunkun
Egbeda
Bako
Obele
Adugi
Kakuma
Okene Ilubusechi Takumena
Gbagede
LOKOJA
Geregu
Agbajo
Kara
Emiwoziri
Numai
Adana
Agbaja
Okoro
Mozum
Koji
Akpata
Agbado
Araromi Ape
Emeve
STUDY AREA
6 00
6 15 E
6 30 6 45 7 00
7 45 N
8 00 N
Major Road
River
Settlement
Jimoh Onimisi Abdullateef et al Adv. Appl. Sci. Res., 2014, 5(3):146-151
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CaO values ranges between 46.90 – 58.54% with an average value of 53.89% and this value is higher when
compared to the Burum marble (Okunlola, 2003), Ososo and Igbeti marbles, (Emofurieta, 1995) Igwe marble,
(Okoro, 2009).
MgO values ranges from 0.18% - 2.89% with an average value of 1.1% and this value is lower when compared to
the Igbeti and Ososo marbles, (Emofurieta, 1995), Ukpilla marble (GSNA Report number, 1192), Burum marble,
(Okunlola, 2003), Sharpfell marble (Dowrie et al, 1982) and Igwe marble (Okoro, 1982).
The Loss on ignition (LOI) varies between 38.10-42.60 % with the highest value of (42.60%). High LOI results
from loss of water from clay mineral, montmorillonite and loss of CO
2
from carbonate minerals. LOI in Obajana
marble is within range for cement production.
nterpretation of XRD reveals the presence of Calcite, dolomite and quartz (fig.2)
Fig: 2 X-ray diffractogram for Obajana marble sample G10 showing calcite (abundant) and quartz (very minor)
Trace elements content (Table 2) of the marble shows high Sr values which ranges from 1577 – 3673ppm with the
lowest values in some impure samples. Average value is 2853.5ppm. Of all the trace element Sr is the highest which
confirms its association with calcium.
Cu concentration in the samples ranges from 1.0ppm – 6.3ppm and have average value of 2.58ppm, higher values
are encountered in samples where marbles form intercalation with quartz mica schist
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Lead concentrations in the sample ranges from 0.3 – 1.8ppm and have an average value of 1.3ppm while zinc
amount to a range from 1.0 – 10ppm and average of 2.63ppm. Lead and zinc occur generally in close association.
Most lead and zinc occurrence are confined to marble, limestone, dolomite and other calc-magnesium rich rocks. In
Obajana they occur as associated element in the marble deposit.
Table 1: Geochemical analytical results of the major oxides of Obajana marble samples
Oxide(wt %)
1
2
3
4
5
6
7
8
Range
Average
SiO
2
7.99
3.12
0.58
1.99
1.56
0.67
2.54
0.67
0.58
-
7.99
2.39
TiO
2
0.12 0.04 <0.01 0.03 0.02 <0.01 0.03 <0.01 <0.01-0.12 0.03
Al
2
O
3
2.31 0.81 0.08 0.43 0.34 0.10 0.52 0.11 0.10-2.31 0.59
Fe
2
O
3
0.88 0.35 0.06 0.24 0.19 0.09 0.25 0.08 0.06-0.88 0.33
Cr
2
O
3
0.003 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 -0.003 0.02
MnO 0.02 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.03 <0.01-0.03 0.01
MgO
2.37
0.85
0.18
2.89
0.73
0.31
1.06
0.41
0.18
-
2.89
1.1
CaO 46.90 52.90 57.97 51.66 54.28 58.54 53.43 55.51 46.90- 58.54 54.89
Na
2
O 0.33 0.15 0.07 0.12 0.10 0.07 0.11 0.07 0.07-0.33 0.13
K
2
O 0.47 0.21 0.02 0.04 0.06 0.01 0.09 0.02 0.01-0.47 0.12
P
2
O
5
0.09 0.06 0.03 0.05 0.05 0.08 0.05 0.12 0.03- 0.12 0.07
LOI 38.10 41.10 40.60 42.30 42.40 39.80 41.50 42.60 38.10-42.60 41.05
Total
99.54
99.60
99.56
99.76
99.69
99.68
99.59
99.60
99.54
-
99.76
99.67
Table 2: Geochemical results of the trace elements found in Obajana marble samples
Element (ppm) 1 2 3 4 5 6 7 8 Range Average
Ba 157 100 57 24 64 36 83 50 24-157 71.38
Cu 6.3 1.3 1.7 3.2 2.3 1.8 2.8 1.0 1.0-6.3 2.26
Co 1.5 0.6 <0.2 0.5 <0.2 0.4 0.4 <0.2 <0.2-1.5 0.5
Pb 4.0 1.5 0.5 1.5 0.7 0.3 1.8 0.9 0.3-4.0 1.38
Ce 13.4 3.5 1.2 3.0 1.9 0.8 3.3 3.4 0.8 -13.4 3.81
Nb
10.4
0.6
2.7
1.6
2.7
4.1
1.5
0.4
0.4
-
10.4
3.0
Rb 21.6 7.8 0.8 2.0 2.9 0.2 4.1 1.1 0.2-21.6 5.0
Sn 37 <1 16 5 15 9 5 <1 <1-37 11.13
Sr 3186 3058 3678 1577 2318 2586 3156 3269 1577-3678 2853.5
Ta 44.2 0.3 16.2 5.4 11.5 7.7 4.2 0.3 0.3-44.2 11.23
Th 2.5 0.7 0.3 0.4 0.5 0.2 0.5 0.3 0.2-2.5 0.68
Zr
28.6
8.7
2.2
7.7
5.9
1.9
5.4
3.4
1.9
-
28.6
7.98
Y 4.1 1.5 0.4 1.3 0.9 0.3 1.1 1.0 0.3-4.1 1.33
Economic potentials
The marble has high economic values classified by 6 broad categories namely: metallurgical, chemical,
environmental, construction, refractory and agriculture (Scott and Durham, 1984). Each of this group requires a
specification for the marble to be useful.
Metallurgical lime production
Most of the lime produced from marble is used as steel flux, in steel manufacture lime acts as a flux use in removing
of phosphorous, silica and sulphur, as calcium phosphates, silicates and sulphides in the slag which is tapped off as
molten metal. Requirements for metallurgical lime (steel flux) in blast furnaces, CaMgO is required with Silica
(SiO
2
) less than 5% less than 2% preferred. (Al
2
O
3
) less than 2%, (MgO) less than 4% . Phosphorus pentoxide
(P
2
O
5
) not more than a trace, i.e., .005ppm to .006ppm. While for steel flux (open hearth) Calcium carbonate content
preferably not less than 96% lower grades occasionally accepted. Phosphorus must not exceed trace amounts. The
Obajana marble meets this specification CaCO
3
>96% which means it can be used for both open hearth and blast
furnaces in steel fluxes.
For refractory lime i.e. dead burned dolomite for open hearth lining. The requirements are Magnesium oxide (MgO)
not less than 18%. Silica (SiO
2
), ferric oxide (Fe
2
O
3
) and alumina (Al
2
O
3
) not to exceed 1% each, but lower grades
sometimes accepted. The Obajana marble is not useful because of its low MgO (1.1%) content.
Calcium carbide and Calcium cyanimide Production
In the manufacture of calcium carbide and calcium cyanimide, sodium alkalis such as sodium carbonate, bicarbonate
and hydroxide used in chemical manufacture. With the requirement of Calcium carbonate (CaC0
3
) content must
Jimoh Onimisi Abdullateef et al Adv. Appl. Sci. Res., 2014, 5(3):146-151
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exceed 95%. Magnesium oxide (MgO) should be less than 0.5%: alumina and ferric oxides (together) less than
0.5%; silica (Si0
2
) less than 1.2% and phosphorus less than 0.01%. Sulfur must not be present in greater than trace
amount. Obajana marble meets all this specifications with CaCO
3
content > 96% and therefore can be used.
In the use of marble in the manufacturing of calcium carbide- a product of the electric furnace formed when lime
and coke are mixed in 60% to 40% proportions respectively and heated to 2,000
0
C. For each ton of calcium carbide
manufactured, 2 tons of limestone or 1 ton of lime is required.
Paints and fillers
In the industries for the production of paints and fillers it is required that In general the calcium carbonate content
should exceed 96% but magnesian limestones containing as much as 8% magnesium oxide occasionally are
tolerated—the MgCO
3
content generally is 1%. Other maxima are; Fe203—0.25%, SiO
2
—2.0% and SO,—0.1%.
Quicklime for pulp and paper
While in the manufacturing of quicklime for pulp and paper the Calcium carbonate (CaCO
3
) contents must be more
than 96% for most manufacturers. In the paper industry, high calcium marble is required as it is suitable for making
soda pulp and sulfate pulp. The marble can be reacted with sulfur dioxide to produce cooking liquor. This acidic
liquor is then used to digest the constituents of the wood chips except cellulose. The Obajana marble meets these
specifications for both uses as fillers in paper and in the manufacturing of paints with CaCO
3
content of >96% and
MgO of less than 1.1%.
Lubricants
For the manufacturing of lubricants (greases) Calcium oxide not less than 72.6%, magnesium oxide not more than 1
%, maximum silica plus iron plus alumina, 1.5%, maximum carbon dioxide (at point of manufacture) 1%.The
Obajana marble meets this specifications due to its high calcium oxide and low magnesium oxide contents.
Textile dye
In production of lime for textile dyeing the Calcium carbonate (CaCO
3
) not less than 94%, alumina - iron not more
than 2%, silica not more than 2.5% and magnesia not more than 3%. Obajana marble meets these specification thus
it can be used in dye manufacture.
Pesticide production
In pesticide production, calcium arsenate, arsenic acid is reacted with a milk of lime forming calcium arsenate,
CaO> 60% is required, also for varnish the marble must be very low in iron and magnesium oxide. Obajana marble
can be used for both varnish and pesticide production.
Beet-sugar
For the manufacturing of beet-sugar the Silica (SiO
2
) content not more than 2%. Magnesia not more than 4% is
required. At some plants ferric oxide (Fe
2
0
3
) must not exceed 0.5%. The high calcium limes when finely powdered
can be employed in refining beet and cane sugar by carbonization. This is because the pure marble from Obajana
would not impart a sour taste to sugar. Since carbon-dioxide as well as lime is required in beet sugar refining, the
raw marble may be burned at the refinery. The lime precipitates impurities from the juices/syrup from impure
solutions. Obajana marble meets these specifications and thus can be useful in the beet sugar manufacturing.
Glass manufacturing
In glass manufacturing Ferric oxide (Fe
2
O
3
) not more than 0.05, preferably not more than 0.02% for colorless glass,
rock having up to 0.1 % Fe
2
O
3
is sometimes accepted for colored container glass. Calcium carbonate (CaCO
3
)
should exceed 96% in case of marble, or 96% calcium-magnesium carbonate in case of dolomite. Amounts of silica,
alumina, magnesia etc., must not vary from shipment to shipment. Obajana marble meets these specifications and
thus can be used in glass manufacturing.
Portland cement production
In Portland cement production, the major requirements are Magnesium oxide (MgO) not more than 3%, preferably
not more than 2%. Total alkalies not more than 0.5%. Minimum calcium carbonate (CaCO
3
) content varies from
plant to plant depending upon availability of other raw materials, but generally is more than 82%. Obajana marble
meets these specification thus it is suitable for the production of Portland cement.
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Water treatment
Environmental usage, especially in water treatment where a high pH of about 10-11 is needed for water softening.
The ability of Obajana marble to do this is not in doubt as it will kill most types of bacteria (Boynton, 1975) when
added to water retention tanks. Absence of Cobalt, mercury and lead is a major requirement and Obajana marble has
none of these earlier mention elements either in trace or minor amounts.
Sewage treatment
Their lime products will be useful in sewage treatment, neutralization of acid water, silica and phosphate removal
from sewage effluents. These specifications are quite similar to that for water softening and purification. If
processed quite well, the Obajana marble lime products should be useful in sewage water treatments.
Construction
For concrete aggregate, ballast, road metal, road base. General requirements are Concrete aggregate should be low
in alkalies and free from surface organic matter. Presence of opaline silica is highly undesirable in concrete
aggregate. Other aggregate suitability is based chiefly on durability, particularly toughness and of low porosity.
CaO, MgO of about 70%, CO
2
< 50% (ASTM, 1976). In terms of fitness, it must leave little or no residue.
Compressive strength of > 20Mpa, tensile strength > 2Mpa and shear strength > 7Mpa. Obajana marble meets these
specifications and could as well be used as road stabilizers, aggregates, ornamental stones and building blocks.
Agriculture
Soil liming is one of the oldest uses of raw and calcined marble (Ojo et al, 1998). The marble function as a
neutralizer of acids and soil enhancer, the requirements are pH>8 with low grittiness and Obajana marble having
(pH=8.3) meets this requirements and thus is useful as soil ameliorants and nutrients status enhancer.
CONCLUSION
Geochemical data of Obajana marble indicate variable characteristics; high calcite and low dolomite. An economic
appraisal of the marble and its associated minerals show that they serve as raw materials for a variety of products
such as fillers, glass, papers, lime, pesticide and sewage treatment. They also find applications in decorative
construction, monuments, paint making and most of all very suitable for cement production.
REFERENCES
[1] ASTM Standard method of physical testing of quicklime, hydrated lime and Limestone, C110-76A, 1976, 15pp
[2] Boynton, S; Chemistry and Technology of Limestone, John Wiley and Sons Inc, 1975.
[3] Dowrie, D. G and John, F, Modern lime burning plant at Sharpfell Quarry. Management and products report,
1982, pp 163-171
[4] Elueze, A .A and Okunlola O. A, Compositional features and industrial appraisal of The metamorphosed
carbonate rocks of Burum and Jakura area, central Nigeria, 2003
[5] Emofurieta, W.O and Ekuajemi V.O, Journal of Min. And Geol, 1995, Vol 31 No.1 pp89-97.
[6] Encyclopaedia Britannica, Online Search result for Marble deposits, 2010.
[7] Microsoft Encarta Dictionary/encyclopaedia search result for Marble deposits, 2009
[8] Nabelek, P. I ,Stable Isotope Monitors. Reviews in Mineralogy, 1991, 26, 395–435.
[9] Okunlola, O. A, Geological and compositional investigation of Precambrian marble Bodies and associated rocks
in the Burum and Jakura areas, Nigeria. Unpublished PhD Thesis, University of Ibadan, 2003, 250p
[10] Ojo, A. M, Agrogeological studies of limestone, phosphate and gypsum occurrences In Dahomey basin,
southwestern Nigeria. Unpublished M.Sc thesis, University of Ibadan 1998, 58p
[11] Scott, P.W and Dunham, A.C Problems in the evaluation of limestone for divers markets. 6
th
Indian MIN.Intl
Congress. Toronto, 1984, Pp 1-21.
