Geological and Geochemical Evolution... Part 6 of 10

THE GOLD POTENTIAL OF GUATEMALA
Summary
Most of the work reflected in this section is based on a geochemical and geological survey conducted by
the Korean International Cooperation Agency (KOICA) and the Korean Institute of Geology, Mining, and
Materials (KIGAM) in 1998. The main objective of the Korean surveys was to fulfill the geochemical
exploration for discriminating the characteristics of mineralization of the Motagua Basin and its vicinities.
The author also used the data from previous exploration studies (mainly pitting and assay results)
conducted by Transmetales Ltda. (Transmetales), Cominco Resources International Limited (Cominco),
and other companies.
The ore deposits in the east and east central Guatemala are generally divided into three types of deposits:
Vein type of gold-silver and lead-zinc deposits widely distributed in volcanic and granite intrusives
especially in the southern part of Motagua fault zone;
Nickel-chromium deposits associated with ultramafic serpentinite and peridotite rocks in the middle part
of Guatemala; and
Antimony and polymetallic ore deposits related with Tertiary rock which is exposed in the regions of mid-
Tertiary volcanic activity.
For the most part they form pods or narrow veins, which appear to be widely scattered throughout the
dissected volcanic plateau. From the Paleozoic to the Quaternary, tectonic and magmatic activity has
occurred in different occasions which have caused a diversity of ore deposits.
The present section compiles the existing information on the Izabal District and the La Unión Area, south
of the Izabal Lake. It shows the gold potential of several targets in the region.
Location
Guatemala (Fig. 80) lies between 17° 50′ and 13° 40′ N in latitude and 92° 20′ and 88° 15′ E in longitude in
Central America comprising seven nations such as Honduras, El Salvador, Nicaragua, Costa Rica, Panama,
and independent Belize. The area of Guatemala territory is 108,900 km².
Figure 1. Map of Guatemala showing the location of the studied area.

The La Unión Area is bounded on 14°53′47″ ~ 15°00′50″N latitude and 89°16′41″~ 89°25′37″E longitude
and belongs to Zacapa and Chiquimula Provinces. The area is located about 10km south of Gualán City,
which lies about 150km southeast of Guatemala City, and can be reached by the Central American
Highway No. 9 from Guatemala City to Gualán City in about three hours by car. The area is located in the
southern part of the Motagua River and belongs to Gualán and La Union 1: 50,000 scaled geographic
quadrangle.
The Izabal District is bounded on 15°21′20″ ~ 15°24′26″N latitude and 89°43′24″ ~ 88°47′54″E longitude
and belongs to Izabal Province. The area is located about 10km south of Morales City, which is located
about 200km southeast of Guatemala City, and can be reached by the Central American Highway No. 9
from Guatemala City to Gualán City in about six hours by car. The area is located in the eastern part of
the Motagua River and belongs to Morales and Cerro Caral 1: 50,000 scaled geographic quadrangle.
Climate
The climates of Guatemala are varied, such as tropical rain-forest climate on the Caribbean coast, a
savanna climate on the pacific coast and a high land climate in the interior uplands. The general climate
of Guatemala is commonly divided into three types similar with Central America according to the
elevation: hot region, generally extending from sea level to 800m; temperate region, extending from
800m to 2,000m; and cold region, extending from 2,000m to 4,000m. The tropical climate of the
Caribbean coastal belt especially in Puerto Barrios, Morales, and Gualán is characterized by a high annual
rainfall, which ranges from 203 to 754 cm. The rain is brought in by the trade winds from the Caribbean
Sea. The mean temperature of the tropical rainy belt is about 27°C depending on the elevation. The
desert climate of interior lowland such as Río Hondo, Chiquimula, Zacapa and Ipala area is characterized
by arid to sub-arid climate. The vegetation of the Caribbean coastal region of Guatemala is similar to that
of the many parts of the tropical rain-forest.
Local Resources and Infrastructure
There are several rivers and creeks crossing the area, so water sources should not be a problem. Electrical
power could be derived from any of the towns or smaller communities in the area. These towns are joined
by the 2-lane Central American Highway No. 9, so personnel for mining activities is easy to find, especially
in an area with previous mining history. Within the area of the properties, or very nearby, suitable places
for potential tailing storage and waste disposal areas can be found. Lake Izabal has enough depths for
marine transportation to the Caribbean Sea.

Non-Lateritic Deposit Types
Guatemala lies geotectonically on the triple junction part of the Caribbean plate, Cocos plate, and North
American plate. The Motagua fault is east-west extended and active now along the boundary between
the Caribbean plate, and the North American Plate. The structural pattern of Motagua basin is
characterized by NW and NE dissected plateau which structurally controls the site to develop ore deposits.
The ore deposits in the east and east central Guatemala are generally divided into three types of terms of
ore deposits:
1. Vein type of gold-silver and lead-zinc deposits widely distributed in volcanics and granitic intrusives
especially in the southern part of Motagua fault zone;
2. Nickel-chromium deposits associated with ultramafic serpentinite and peridotite rocks in the
middle part of Guatemala; and
3. Antimony and polymetallic ore deposits related with Tertiary rock which is exposed in the regions
of mid-Tertiary volcanic activity.
For the most part they form pods or narrow veins, which are appeared to be widely scattered throughout
the dissected volcanic plateau. From the Paleozoic to the Quaternary, tectonic and magmatic activity has
occurred in different occasions which have caused a diversity of ore deposits.
Areal distributions of the ore deposits could be defined by two main distinct areas according to their
occurrences; the metamorphic province and the volcanic province. On the other hand, not important
mineralization is found in the rest of the country.
In the metamorphic terrain, several phases of deformation since the Devonian, including rocks with
different grades of metamorphism as well as the igneous rocks associated and carbonates and clastics of
different ages, account for the diversity of ore minerals. Quartz veins containing gold have been poorly
studied, and alluvial deposits containing gold are mined from different riverbeds, at least 2,000g daily.
Antimony and ilmenite in Carboniferous deposits are exploited, as well as zinc and lead minerals in
Paleozoic carbonates.
In the volcanic province, gold-silver deposits are expected to be found in granites and in veinlets within
the tuffs. Exploration of gold has been oriented to small areas leaving the rest unexplored. A Cu-Ag
deposit 50kms east of Guatemala City was exploited from 1694, and a Zn-Cu-Ag deposit close to the
border with El Salvador is temporarily closed.
Antimony Deposits: Anabella and Los Liogos mines of Ixtahuacan district in the western border of
Guatemala produce the crude and concentrates of antimony ore. An antimony trioxide plant is in
Huehuetenango. The antimony mines which have been operated until now are Las Tablas deposits, El
Carrizal prospect and El Horno prospect. But most of them are small scale mines of the vein, lode and
disseminated type ore deposits in volcanic rocks except El Horno prospect is the vein type in granodiorite.
Chromite Deposits: The chromite deposits in Guatemala are associated with intrusive serpentinite and
peridotite, which form two discontinuous belts extending from the Mexico-Guatemala border to Puerto
Barrios. The peridotite and serpentinite cut sedimentary and metamorphic rocks of Paleozoic and pre-
Paleozoic age and were probably intruded at the beginning of the Tertiary Era. The peridotite, where
fresh, is generally dark green or black, where is altered to serpentinite, the color is light yellow or yellowish

green. Because of shearing, most of the serpentinite is highly slickenside and minutely fractured; locally
a schistosity trends eastward. Dikes of basalt, andesite, and diorite associated with later volcanism
intrude the serpentinite.
There are four typical chromite ore deposits in Guatemala such as Jalapa, Cabanas, Pasaguas, and El Retiro
district. The Jalapa district, about 15km north of Jalapa includes the Corona, La Gringa, and La Paz mines,
which were major producers and the La Esparanza, Loreto, Salvador and La Independencia deposit, which
were small mines. The chromite deposits are in serpentinite which forms the summit of the ranges lying
between the River Motagua valley on the north and a high volcanic plateau on the south. Most of them
are on the southern flank of the range and in the recent the mines are closed because of the less economy.
Pasasaguas District: The chromite outcrops are exposed in the low hill of River Motagua near Morazán in
the Pasaguas districts. In ancient time Australian mining companies worked for excavation of chromite
ore first in this area. But the most of ore deposits show the low grade. On the whole the serpentinite
area north of the River Motagua appears to contain few chromite pods.
Table 1. Known mines in the Jalapa District.
Mine Country Rock Ore Body Ore Mineral Grade (%)
La Gringa Serpentinite Lens, (20mx2m) Chromite 52-57 (Cr203)
Corona Serpentinite Small lens Chromite 52-56 (Cr203)
La Paz Serpentinite Small lens Chromite 58 (Cr203)
Table 2. Known mines in the Cabañas District.
Mine Country Rock Ore Body Ore Mineral Grade (%)
La Joya Serpentinite Lens, Disseminated Chromite 51%
La Corona Serpentinite Boulder Chromite -
Buenos Aires Sheared
Serpentinite
Fragments Chromite 53%
El Retiro District: El Retiro district is 10 miles north of Salama, in the hills west of the Salama-Cobán
highway. The deposits are in the middle of serpentinite belt, which is about 12 miles wide. Chromite is
exposed on the surface in the massive serpentinite in a few areas. The grades of ore show 48-51% Cr2O3
and a chromium-iron ratio of 2.75%.
Copper Deposits: Typical copper mineralized areas in Guatemala have been found in such mine areas as
San Mateo prospect, Mataquescuintla, Los Sandillales prospect, Zuhoi deposits, Cero Vivo prospect, and
a small-scale deposits in the volcanic rock belt. The types of ore are divided into several patterns as veins,
lenses and disseminated in structure systems of the Paleozoic metamorphic and Tertiary volcanic rocks.
According to the report of U.S. Geological Survey Bulletin-1034 (1948), in San Mateo prospect, copper
minerals are in schist that is exposed in stream beds of Cerro Bobi. However, in the southern part of
Guatemala the ore deposits are developed in silicified rhyolitic tuffs. Most of the ore veins are small scale

up to 1-2m in width. The ore bodies of other areas are embedded in the fault and fissure zones at Zuhoi
deposits, and Cero Vivo prospect. Most of copper minerals in above mentioned areas are reported to
chalcopyrite and chalco-oxides associated with a little amount of lead and zinc.
Another copper target is Oxec (Fig. 69), located 17 km to the east of the Cahabón Township within the
Marichaj mining concession, in the Cahabón District, its centre being located approximately at Latitude:
15º34'00" North and Longitude: 89º41'00" West (Aceituno, et al., 1971a). These authors determined the
existence of 2 Mt grading 2% copper.
Figure 2. Copper stains from the Oxec deposit.
Lead-Zinc Deposits: The major lead-zinc deposits in Guatemala are known to be distributed in the
Departmento de Huehuetenango, and Alta Verapaz. The principal deposits are in three areas such as
Chiantla-San Sebastián, San Miguel, and Cobán districts. The above-mentioned typical lead-zinc deposits
are the replacement and vein type ore bodies embedded in the structural systems or contact zone with
generally granitic rocks. The ore minerals are pyrite, sphalerite, galena, and chalcopyrite.
Manganese Deposits: The reported manganese deposits are located in Perez manganese prospect,
Brenes, and La Cumbre deposit. The epigenetic manganese deposits enriched in the contact zone
between limestone and phyllite or in the quartz bearing manganese vein zones are distributed in the
Chiquimula and La Unión areas. The dimension of the ore bodies is more or less 50 feet with the shape
of lenses and nodules containing little amounts of nickel and cobalt.
Exploration
The project areas cover the provincial departments of Izabal, Zacapa and Chiquimula districts which are
belonged to the nineteen 1: 50,000 scaled quadrangles in the eastern part of Guatemala.
The Izabal-Zacapa Area
The geology of Izabal and La Unión Area are shown in Figs. 70-71. The rock formations occurred in
surveyed areas are as follows: East Western Extended Quaternary-Tertiary granite rocks intruding
randomly in the south-eastern boundary with Honduras and in the volcanic belts, Cretaceous to Tertiary
sedimentary rocks, undivided ultramafic rocks distributed along the Motagua fault zone and Paleozoic
metamorphic rocks developed as basement of the above mentioned formations.

Figure 3. Regional geological map of the Izabal District, Guatemala (IGN, 1970).
Figure 4. Regional geological map of the La Unión area, Guatemala (IGN, 1970).

Igneous Activity
Six granite bodies are identified in the Motagua Basin and Chiquimula district, four of which are distributed
around the Motagua fault zone and two of which occur in the districts of Chiquimula and La Union in this
survey areas (Fig. 72). According to the geological maps scaled 1:50,000 and 1: 250,000, the ages of
granite intrusions are reported to the late Cretaceous and Tertiary Periods. The two granite bodies among
them were named as Agua Fría Granodiorite and Chiquimula pluton by 1/50,000 scaled geological map
and in terms of the convenient descriptions.
The Korean report named the rest of them Santa Rosa pluton, Gualán pluton, Lampocoy pluton, and
Johnes pluton respectively. Especially the Santa Rosa pluton which have not been given the descriptions
on that body until now in the 1/500,000 quadrangle geological map is to be the same pluton with the
Agua Fría Granodiorite.
Figure 5. Simplified geological map of granitic rocks from the studied area in Guatemala (Tv- Tertiary
volcanics, A- Santa Rosa Pluton, B- Agua Fría Pluton, C- Gualán Pluton, D- Chiquimula Pluton, E-
Lampocoy Pluton, and F- Johnes Pluton).
Santa Rosa Pluton: This pluton is distributed in the southern side of Motagua fault. This could be defined
to a part of Buena Vista pluton in 1:50,000 Los Amates geologic map. This granite is composed of non-
foliated biotite granite and hornblende diorite. Ah, pues no sabía que estaba hablando con más de una
persona…
The biotite granite is medium to coarse grained and mainly consists of weakly recrystallized and anhedral
quartz, plagioclase, K-feldspar, and biotite. Accessory minerals are zircon, opaque, epidote, and
secondary chlorite.

The hornblende diorite is characterized by plagioclase, hornblende, and small amount of quartz and
sphene, and by the absence of biotite.
Agua Fría Granodiorite: Agua Fría Granodiorite, which is named by 1: 50,000 Los Amates geological map,
is distributed in the southern side of the Motagua fault and cover about 24.5km2
. The Agua Fría
Granodiorite is medium to coarse grained, foliated granodiorite with mafic enclave. The foliation is mainly
N20°E.
Agua Fría Granodiorite consists of quartz, plagioclase, K-feldspar, biotite, apatite, zircon, and opaque
minerals. Quartz is mostly recrystallized and biotite occurs as sub euhedral crystal or forms small flaky
grains along the boundary of other minerals.
Gualán Pluton: This pluton is the largest batholith in the investigated area as shown in 1:250,000 scaled
geologic map of Chiquimula. The granitic rocks distributed in the southern part of Motagua fault show
nearly north-south direction and cover about 270km2
.
Gualán pluton occurs in two varieties: hornblende-biotite granodiorite and hornblende diorite. The
granodiorite is medium grained rocks and consists of quartz, plagioclase, microcline, perthite, biotite,
hornblende, sphene, epidote, apatite, and opaque minerals. Poikilitic microcline contains inclusions of
biotite, quartz, and plagioclase. The Diorite is mainly composed of large crystals of hornblende and small
crystals of plagioclase, and biotite.
Lampocoy Pluton: Lampocoy pluton is distributed in the La Union and Lampocoy area with oval shape
and cover about 47km2
at 1:500,000 geologic maps. This pluton is characterized by foliated nature.
The Lampocoy pluton is medium to coarse grained, and consists of quartz, plagioclase, perthite, biotite,
sphene, apatite, epidote and hornblende in part. Quartz in Lampocoy granite shows mostly recrystallized
grains in small size and sub euhedral to anhedral in weakly foliated parts. Some aggregated grains have
undulated extinction, and they are interlocked or intergrown with each other. Plagioclases commonly
have albite twin and occur as large crystal. Biotite occurs as euhedral to sub euhedral forms, and
frequently contains apatite and zircon as inclusions.
Chiquimula Pluton: Chiquimula pluton with 242km2
area consists of several rock types such as gabbro,
diorite, granodiorite, granite, and minor aplite. The Chiquimula pluton was emplaced in Pennsylvanian
Santa Rosa group which is composed of phyllite and schist.
Granodiorite of Chiquimula pluton mainly consists of plagioclase, quartz, K-feldspar, hornblende, and
biotite. Accessory minerals are sphene, apatite, and zircon. Poikilitic plagioclases contain inclusions of
hornblende, and biotite. K-feldspars are mainly composed of perthite and sometimes microcline and
partly show poikilitic texture with inclusions of plagioclase and hornblende. Apilite is composed of quartz,
plagioclase, perthite, and biotite.
Johnes Pluton: The smallest pluton (2.75km2
) in the surveyed area occurs at the northern part of Motagua
fault. The Johnes pluton intrudes Paleozoic undivided metamorphic rocks composed of phyllite, schist,
gneiss, marble and migmatite.
Johnes pluton is medium grained and mainly consists of quartz, plagioclase, microcline, and biotite. And
minor amounts of hornblende, sphene, epidote, and allanite are found. Plagioclases occur as commonly
sub euhedral grains and usually shown albite and combined Albite-Carlsbad twinning. Epidote includes in
euhedral allanite cores.
Geochemistry and Chronology
Geochemical data for six plutons of Guatemala are shown in Table 3. Silica contents range widely from
about 50 wt% in the dioritic rock (Santa Rosa Pluton) to 74 wt% in the most of silicic Chiquimula pluton.

Harker diagrams of major elements generally exhibit linear trends for all plutonic rocks in the surveyed
area. In the diagrams, TiO2, Al2O3, MnO, total Fe2O3, MgO, CaO, and P2O5 show decreasing trends with
increasing SiO2. The total Fe2O3, MgO, and CaO diagrams show fairly good linear variation, but the K2O,
Na2O, and P2O5 diagrams shown scattered variation.
Most of plutonic rocks of the surveyed area at Guatemala belong to peraluminous granite as shown in
A/CNK (Molar Al2O3 / (CaO +K2O + Na2O) diagram, but four samples in Gualán, Chiquimula, and Santa Rosa
pluton indicate metaluminous character. Alumina saturation indices for most Guatemalan granites in
surveyed area are less than 1.1, which is typical of I-type granite proposed by White and Chappell (1983).
And most of granitoid in surveyed area also have compositions calc-alkaline magmatic character (Irvine
and Baragar, 1971; Miyashiro, 1974).
Concentrations of sixteen trace elements (Ba, Sr, Y, Nb, Ni, Cr, Co, Cu, Zn, Pb, Sc, V, La, Ce, Nd, and Th)
were measured by ICP-AAS. Data of major and trace elements are listed in Table 5. Trace element
variations show that the contents of Ba, Sr, Th, Zn, Pb, Sc, V, Ni, Co, and Cu in six granitic rocks vary
systematically with increase of SiO2 content. The content of Y, Nb, La, Ce, and Nd disperse in the granitic
rocks. In general, as the amount of SiO2 increases, that of Y, Sr, Nd, Th, Zn, Sc, V, Ni, Co, and Cu decreases,
while Ba and Pb show increasing trend.
Table 3. Major and trace composition of six granitic plutons in the area.
Tectonic discrimination using Y vs. SiO2 and Nb vs. Y diagrams of Pearce et al. (1984) is shown in Figs. 73-
76. Most of the samples, regardless of lithology, are plotted in the field of volcanic arc granite (VAG), and
syn-collisional granite (syn-COLG), suggesting tectonic setting in this area.
Sample Lampocoy Granite Johnes Granite
No. PB-40 PB-41 PB-42 PB-86-B PB-86-C PB-91-A PB-91-B PB-184 PB-178-1 PB-172-1 PB-172-2 PB-173 PB-73
SiO2 67.99 49.66 67.62 50.01 66.39 53.17 68.62 74.04 61.57 70.7 67.85 64.38 67.97
TiO2 0.48 1.62 0.51 1.04 0.61 1.53 0.45 0.17 0.79 0.43 0.48 0.69 0.45
Al2O3 15.83 16.65 15.75 12.87 16.42 17.66 16.06 13.34 16.34 14.19 15.39 17.26 14.37
Fe2O3 3.57 9.75 4.39 10.53 4.06 8.76 3.31 2.14 6.27 3.82 3.89 4.75 4.39
MnO 0.04 0.13 0.08 0.16 0.05 0.14 0.04 0.06 0.09 0.05 0.06 0.06 0.07
MgO 1.02 5.35 1.24 9.58 1.29 3.59 0.91 0.25 2.15 0.85 1.72 1.41 1.18
CaO 2.62 9.27 3.21 11.4 3.58 6.96 2.78 0.94 5.38 1.92 3.5 3.68 2.34
Na2O 4.74 3.99 3.99 1.78 4.37 3.94 4.89 3.88 3.47 3.2 3.17 4.52 2.36
K2O 2.66 1.12 2.07 0.78 2 2.41 1.94 4.36 2.35 4.07 2.79 1.97 5.68
P2O3 0.16 0.35 0.15 0.19 0.22 0.58 0.14 0.06 0.14 0.15 0.15 0.26 0.16
LOI 0.74 1.61 0.7 1.35 0.84 0.99 0.66 0.6 1.01 0.46 0.79 0.81 0.74
Total 99.85 99.8 99.71 99.69 99.83 99.73 99.8 99.84 99.59 99.84 99.79 99.79 99.71
Ba 758 244 233 63 628 395 674 656 616 618 706 532 1027
Sr 370 662 125 318 395 592 337 113 242 133 152 431 212
Y 8 15 22 23 10 18 14 14 46 18 20 17 22
Nb 4 18 13 5 7 13 5 11 10 13 8 13 11
Ni 23 84 46 98 36 51 21 22 19 49 30 29 17
Cr 65 107 50 326 43 65 50 37 47 55 58 39 47
Co 9 28 11 33 10 20 10 5 14 8 11 10 12
Cu 14 101 7 52 15 38 9 7 11 26 17 23 285
Zn 79 88 64 86 77 111 63 36 65 57 59 80 68
Pb 22 23 30 23 28 23 30 29 26 44 31 28 42
Sc 4 24 10 48 3 11 4 2 16 7 5 3 7
V 59 299 76 397 77 184 82 59 170 85 93 106 122
La 16 19 20 8 38 15 22 16 28 23 14 45 13
Ce 34 30 43 20 77 29 41 27 66 52 27 82 16
Nd 15 32 25 18 37 34 18 8 40 18 10 28 27
Th 3 12 6 16 6 12 5 4 10 11 4 8 12
Santa Rosa Granite Chiquimula GraniteAgua Fría Granite Gualán Granite

Figure 6. Alumina saturation diagram for granitic rocks within the studied area (molar ratio).
Figure 7. Discrimination diagram for volcanic arc granites (VAG), syn-collision granites (COLG), within
plate granites (WPG), and oceanic ridge granites (ORG).

Figure 8. Composition of the Guatemalan Granitic Rocks in weight percent of silica and total alkalis.
Figure 9. Nb-Y discrimination diagram for volcanic arc granites (VAG), syn-collision granites (COLG),
within plate granite (WPG), and ocean ridge granites (ORG).
The specimen analyzed for K-Ar age determinations were collected in Izabal and La Unión area. Five
samples collected in granite area are PB-40 (Santa Rosa granite), PB-172-2 (Lampocoy granite), PB-86R-C
(Gualán granite), PB-42R (Agua Fría granite), and PB-73R (Johnes granite). The sampling sites for K-Ar age
measurement are shown in Fig. 72.

Biotite was separated from the rock samples using magnetic separator and hand picking. The purities of
the separated samples are higher than 95% determined by using a microscopic observation. All samples
for K-Ar dating are analyzed for potassium (K) first, by ICP.
The isotopic compositions of argon (Ar) are analyzed by a NUCLIDE’S SGS 6”-60 Sector type mass
spectrometer at KIGAM.
The K-Ar isotopic analysis for the five granitic rocks is listed in Table 4. The age of four samples is 33-38Ma
belonging to Oligocene to Eocene Epoch. Only one sample of Johnes pluton shows 152Ma of Jurassic
Period.
Table 4. K-Ar ages for the rock forming minerals from Izabal and La Unión areas in Guatemala.
La Unión Area
The area is located in the northern part of the folded belt from the Sierra del Espíritu Santo, which
morphotectonically corresponds to the Cordillera Central with the oldest rocks of the region outcropping
extensively. This consists of Paleozoic, locally containing younger igneous intrusions or sedimentary
covers.
Structurally it is located between the Motagua Fault to the north and the Jocotán Fault to the south, both
parallel an NE-SW direction. They form the major structure to control the tectonic array of the area.
Locally, minor faults with an NW-SE direction, probably is related to the left lateral movement of the
Motagua Fault Zone.
The schematic geological map of the La Unión area is shown in Fig. 77.
Sample No. Mineral K (wt%) 40
Arx10-10
(mol/g) 40
Ar rad (%) Age (Ma)
PB-40R Biotite 6.55 4.413 75.45 38.44 ± 0.55
PB-172-2 Biotite 7.61 4.496 70.02 33.75 ± 0.55
PB-86R-C Biotite 7.41 4.32 67.66 33.31 ± 0.70
PB-42R Biotite 7.78 4.722 77.05 34.67 ± 0.63
PB-73R Biotite 6.28 1.728 94.21 152.06 ± 0.63

Figure 10. The geologic map of the La Union Area, Guatemala.
In the area, four lithologic units can be distinguished as described below.
Phyllite: Outcrops occur in the northern part and southeast corner of the area under study. Color ranges
from light brown to grayish brown with the perfect foliation due to the abundant presence of micas. In
the weathered zones, color turns to brick red forming clayish soils with considerable thickness.
Foliation ranges from N-S to N70°E. Dipping ranges from 30° to 50° to the south. These rocks probably
are originated from the metamorphism of politic rocks. Locally quartz vein with disseminated pyrite are
found, as in the locality of Las Viviendas.
Graphite Schist: The widely distributed outcrops are located mainly in the southern part of the project
area. A few small outcrops can be seen in northeastern part of Carozal between the Chichipate and
Colorada creek and northwestern part of La Yegua close to the junction of the el Pacayalito and the La
Yegua creeks. Another small outcrop is located close to La Union town.
The schist is black to grayish black, interbedded with quartzite or infiltrated with quartz vein and veinlets
discontinuously in its longitudinal extension, having a schistosity structure with a bondage appearance.
On the southeastern part, west of Peña Blanca, alternating lenses of white clay minerals of graphite schist
and concentrations of yellow to reddish iron oxides, were formed from the lixiviation of pyrite due to the
circulation of water within the lithologic unit. The schistosity has an N-S orientation with dipping 41° to
61° to the north.

Gneissose Granite: Gneissose Granite is the largest unit of La Union area.: Gneissose Granite is white to
light brown in color and has a granoblastic texture and usually is moderate to intensively weathered.
Fresh outcrops can be found in Tajoral and surrounding drainages.
Dikes emplacements with aphanitic texture occur frequently in two directions. One group strikes N-S,
dips both north and south, has the thickness of 3 to 4 meters and is disseminated by pyrite.
The other group has an EW and E-NW direction, dipping north and south 40 to 60 degrees. Pyrite is less
common in these dikes.
Granite: Outcrops, is restricted between Riachuelito and Tajaral in the northwest corner of the project
area. One body of granite lain to north of Las Viviendas is estimated to an apophysis. This is a leucocratic
granite, holocrystalline texture. Emplacements of discontinuous quartz veins are common in an NW-SE
and NE-SW direction with dipping 70° to 80° both north and south. In these veins no mineralization can
be seen with the naked eye, except sample LR120 taken close to Guadalupe Village.
Sampling Preparation, Analyses, and Security
Systematic sampling of heavy concentrates from the stream sediments is carefully considered and all the
selected samples were dried without contamination. A total of 183 samples were collected in streams or
dried drainages. The collected samples were screened by a magnetic iron bar to segregate magnetic
minerals from the heavy concentrates. Final specimens involve heavy concentrates originating from the
surface various rocks and mineralized zone. Thirteen plutonic samples were collected from the
investigated area of Guatemala. Major element and trace element concentrations were determined by
XRF and ICP respectively at KIGAM.
For soil geochemical exploration, about 700 soil samples were taken. Sample depth was depending on
the condition of geology and topography. About 3 to 4 kg of soils from the dig hole with a depth of 50cm
to 1m (B1 horizon) were taken in the field. These samples should be dried before sieving to obtain 100 to
200g of – 80 mesh soils.
Also, for soil geochemical exploration, about 700 soil samples were taken. Sample depth was depending
on the condition of geology and topography. About 3 to 4 kg of soils from the dig hole with a depth of
50cm to 1m (B1 horizon) were taken in the field. These samples should be dried before sieving to obtain
100 to 200g of – 80 mesh soils.
Basic Statistic Interpretation
Average Values
Basic statistical values for each elements of Izabal and La Unión area are shown in Table 7. The mean
values of As, W, Sb, Rb, Au, and Th from La Unión area are higher than those in Izabal district. And the
mean values of Sc, Sn, La, Ce, Nd, Eu, Tb, Lu, U and Hf in both districts shown almost similar values.

Table 5. Statistical values for each elements of Izabal and La Unión area.
Correlation Coefficient
Correlation coefficients among elements are shown in Tables 8 - 9.
Table 6. Correlation analysis from heavy concentrates on the Izabal District, Guatemala.
Min Max Mean S.D. Mean + δ Mean + 2δ
As 0.00 37.20 6.30 8.30 14.60 22.90
Au 0.00 2670.00 63.70 339.10 402.80 741.90
W 0.00 397.00 12.30 46.60 58.90 105.60
Zn 0.00 666.00 100.00 94.50 194.50 289.10
Sb 0.00 4.70 0.50 1.00 1.50 2.40
Co 3.10 173.00 31.20 30.00 61.20 91.10
Cr 12.50 83200.00 3090.90 10238.90 13329.80 23568.60
I 0.00 86.80 7.10 12.20 19.30 31.50
Th 0.00 299.00 32.50 42.40 74.90 117.20
Ta 0.00 51.80 5.90 7.50 13.40 20.90
La 7.60 617.00 115.60 127.90 243.50 371.50
Ce 0.00 1100.00 188.80 213.30 402.10 615.40
Nd 0.00 514.00 74.30 102.60 176.80 279.50
Eu 0.40 9.10 2.60 1.80 4.40 6.10
Tb 0.00 12.00 1.40 1.60 3.00 4.50
Yb 0.00 523.00 12.20 59.60 71.80 131.40
Lu 0.00 5.60 0.90 0.80 1.70 2.50
Zr 0.00 7670.00 978.60 1544.70 2523.30 4068.10
Hf 1.70 131.00 22.60 26.00 48.60 74.70
Rb 0.00 198.00 29.40 42.30 71.70 113.90
Sc 2.30 35.30 15.90 7.80 23.70 31.40
Min Max Mean S.D. Mean + δ Mean + 2δ
As 0 228 20.4 35.9 56.3 92.2
Au 0 38400 336.9 3549.5 3886.4 7435.9
W 0 726 28.1 98.3 126.4 224.7
Zn 0 363 98.5 62.5 161 223.5
Sb 0 21.6 2.1 3.6 3.7 9.3
Co 2.7 95.4 18.5 14.6 33.1 47.7
Cr 6.9 5100 300 726.2 1026.2 1752.4
I 0 198 7 19.5 26.5 46
Th 1 885 46.4 94.9 141.3 236.1
Ta 0 59.2 3.2 6.2 9.4 15.7
La 7.6 820 120.4 152.9 273.3 426.2
Ce 0 1190 197.3 240.7 438 678.7
Nd 0 534 78.5 120.3 198.8 319.1
Eu 0.4 6.9 2.1 1.3 3.4 4.7
Tb 0 8.9 1.5 1.7 3.2 5
Yb 0 38.7 6 6.6 12.6 19.3
Lu 0 5.9 0.9 1 1.9 2.9
Zr 0 5460 659.7 909.8 1569.5 2479.2
Hf 1.7 492 20 47 67 113.8
Rb 0 227 63 49.4 110.4 159.7
Sc 2.2 50.3 14.6 9 23.6 32.6
La Union Area
Izabal District
U As Au W La Ce Yb Lu Th Cr Hf Nd Zr Tb Sc Rb Zn Ta Co Eu Sb
U 1.00
As 0.07 1.00
Au -0.04 -0.05 1.00
W 0.07 0.04 -0.02 1.00
La 0.16 -0.27 -0.04 0.04 1.00
Ce 0.18 -0.19 -0.02 0.06 0.96 1.00
Yb 0.04 -0.05 -0.02 0.17 0.10 0.09 1.00
Lu 0.34 -0.21 0.12 0.17 0.63 0.64 0.09 1.00
Th 0.31 -0.22 -0.02 0.11 0.88 0.89 0.10 0.83 1.00
Cr -0.13 0.02 0.01 -0.02 -0.21 -0.20 -0.05 -0.19 -0.18 1.00
Hf 0.12 -0.35 -0.01 0.04 0.45 0.36 0.08 0.55 0.41 -0.17 1.00
Nd 0.22 -0.18 -0.04 0.01 0.93 0.91 0.15 0.66 0.88 -0.20 0.40 1.00
Zr 0.06 -0.35 -0.08 0.03 0.38 0.29 0.10 0.46 0.33 -0.17 0.95 0.33 1.00
Tb 0.34 -0.21 0.08 0.14 0.76 0.79 0.09 0.86 0.92 -0.19 0.39 0.81 0.31 1.00
Sc -0.03 -0.07 0.36 0.01 0.08 0.04 -0.05 0.36 0.11 0.09 0.32 0.04 0.30 0.22 1.00
Rb 0.08 0.28 -0.11 0.08 -0.04 0.00 0.00 -0.23 -0.09 -0.17 -0.30 0.01 -0.29 -0.07 -0.41 1.00
Zn -0.06 0.32 0.05 0.06 -0.27 -0.22 -0.03 -0.09 -0.15 0.75 -0.14 -0.20 -0.13 -0.12 -0.04 -0.04 1.00
Ta -0.08 -0.17 -0.05 0.12 -0.02 -0.02 -0.05 0.07 0.01 0.69 0.10 -0.03 0.09 -0.01 -0.04 -0.18 0.58 1.00
Co -0.16 0.35 -0.01 -0.04 -0.29 -0.27 -0.10 -0.19 -0.27 0.66 -0.19 -0.26 -0.16 -0.24 0.29 0.20 0.62 0.31 1.00
Eu 0.04 -0.05 0.02 -0.06 0.59 0.56 -0.08 0.35 0.43 -0.25 0.49 0.36 0.49 0.49 0.35 -0.07 -0.21 -0.06 -0.09 1.00
Sb 0.14 0.64 -0.06 -0.07 -0.18 -0.13 -0.08 -0.22 -0.20 0.00 -0.15 -0.06 -0.13 -0.12 -0.16 0.40 0.33 0.00 0.08 0.13 1.00

Table 7. Correlation coefficients for heavy concentrates from Zacapa district in Guatemala.
In the Izabal district, positive correlation coefficients higher than 0.5 are shown among the following
elements: As-Sb; La-Ce-Lu-Th-Nd-Tb-Eu-Hf-Zr; and Zn-Cr-Ta-Co. In La Unión area, positive correlation
coefficients higher than 0.5 are observed among the following elements: U-W-Yb-Lu-Th-Tb-La-Ce-Nd-Eu;
and Hf-Sc-Co.
Frequency
In the Izabal District and La Unión Area, frequency distribution patterns of As, Au, Zr, Hf, Nd, Sb, W, Tb U,
La, Ce, and Ta show left-skewed and frequency distribution patterns of Eu, Yb, Lu, Fe, Zn, Rb, and Sc show
left-skewed and nearly normal distribution.
Interpretation
The Elemental Distribution of Izabal District and La Unión areas
Chrome
Heavy minerals how a wide range of Cr contents from 83,200 ppm (8.3%) to 7 ppm. The isopleths of
strong Cr anomaly correspond to the area of the Ophiolitic Belt. Therefore, Cr anomalies are found in the
most of wide areas related with distribution of the ultramafic rocks. Particularly, the site of strong Cr
anomaly is distinctively consistent with the site of strong anomalies of Co and Zn.
Cobalt
Isopleths of anomalous higher values are drawn in 4 places in the Izabal district, while only one anomalous
site was drawn in the La Unión area. It is important that a distinct anomaly of Co is consistent with the
anomaly of Zn at the site of PB-23, which was 666 ppm of Zn.
Zinc
Results of chemical analyses show that a zinc sulfide was relatively collected in every sampling site. There
are many anomalous values above the mean values of zinc, but only one isopleth of 600 ppm is delineated
in the Izabal district.
Arsenic
The Korean report mentions the fact that there were no direct correlations between arsenic and gold
anomalies. In the opinion of the author, there is native gold mineralization within the ultramaphic rocks
with very low or none sulphides, as well as their sulphides gold mineralization associated to quartz veining.
If the gold deposit is represented by the arsenic anomaly instead of a gold anomaly, a new gold deposit
with the arsenic anomaly is found at the eastern area of the known Chiquimula area. Two anomalous
zones of arsenic values, 228 ppm in the known Chiquimula area and 189 ppm in southern area of La Union
U As Au W La Ce Yb Lu Th Cr Hf Nd Zr Tb Sc Rb Zn Ta Co Eu Sb
U 1.00
As 0.15 1.00
Au -0.03 -0.04 1.00
W 0.59 0.00 0.04 1.00
La 0.31 0.04 -0.06 0.19 1.00
Ce 0.31 0.04 -0.06 0.23 0.98 1.00
Yb 0.61 0.10 -0.02 0.51 0.46 0.48 1.00
Lu 0.59 0.10 -0.02 0.57 0.43 0.47 0.98 1.00
Th 0.90 0.09 -0.04 0.57 0.62 0.63 0.60 0.59 1.00
Cr -0.05 -0.06 0.05 0.05 -0.13 -0.11 -0.10 -0.06 -0.07 1.00
Hf 0.14 -0.01 -0.03 0.10 0.05 0.07 0.22 0.22 0.14 -0.05 1.00
Nd 0.34 0.03 -0.06 0.28 0.96 0.95 0.52 0.52 0.63 -0.14 0.05 1.00
Zr 0.33 0.01 -0.06 0.27 0.24 0.25 0.30 0.34 0.33 -0.13 0.26 0.31 1.00
Tb 0.53 0.06 -0.05 0.46 0.73 0.74 0.83 0.83 0.66 -0.09 0.03 0.79 0.25 1.00
Sc 0.17 -0.06 0.07 0.37 0.04 0.09 0.37 0.42 0.15 0.17 0.52 0.09 0.41 0.26 1.00
Rb 0.02 0.20 -0.12 -0.14 0.11 0.10 0.04 0.05 0.05 -0.16 -0.17 0.08 -0.19 0.10 -0.42 1.00
Zn 0.14 0.29 0.03 0.21 -0.12 -0.14 0.11 0.13 0.00 0.12 -0.07 -0.06 0.24 0.09 0.32 -0.05 1.00
Ta 0.30 0.01 0.00 0.35 0.26 0.25 0.28 0.36 0.33 0.19 0.09 0.26 0.17 0.34 0.25 -0.05 0.03 1.00
Co 0.10 0.13 0.06 0.19 0.10 0.14 0.09 0.13 0.13 0.45 0.14 0.13 0.15 0.16 0.53 -0.19 0.33 0.24 1.00
Eu 0.15 0.03 -0.04 0.12 0.58 0.59 0.37 0.39 0.31 -0.03 0.19 0.62 0.42 0.59 0.35 -0.12 0.07 0.17 0.29 1.00
Sb -0.01 0.39 -0.06 -0.08 -0.27 -0.28 -0.17 -0.18 -0.11 -0.10 -0.08 -0.28 -0.07 -0.20 -0.19 0.05 0.11 -0.15 -0.10 -0.24 1.00

(Fig. 78), are closely accompanied by zinc anomalies. Anomalous values of As, Zn, and Sb from the latter
may indicate polymetallic mineralization.
Figure 11. Anomaly map for arsenic from heavy concentrates on La Unión area, Guatemala.
Gold
It is one of the successful results to discover minute nuggets in the heavy sands collected from the site
PB-99. Results of chemical analyses show that most of samples contain little gold below detection limit
of INAA (Figs. 79-80).
Since the gold anomaly is not associated with the arsenic anomaly, the mode of anticipated gold
occurrence of two areas, the Zacapa and the Izabal, should be different.

Figure 12. The anomaly map for gold from heavy concentrates on Izabal district, Guatemala.
Figure 13. The anomaly map for gold from heavy concentrates on La Unión Area, Guatemala.
Uranium and Thorium
The distribution pattern of uranium is generally coincident with the thorium anomaly in the La Unión area.
It is significant that the highest anomalous value of uranium is accompanied by the anomalous values of
Th, W, Zr, at sampling site PB-119. These anomalies may be derived from monazite and zircon.
Zirconium and Hafnium
Three anomalous sites of Zr and Hf are found in the La Unión area. It is understood that the close chemical
affinity of hafnium and zirconium makes the separation of these elements very difficult. There are no
minerals containing hafnium independently of zirconium, so the sources of hafnium are the minerals
containing zirconium. It is estimated that Zr elements of samples may be derived from zircons and
baddeleyites, which are component minerals of granite or nepheline syenite. It is clearly found that the
anomalous values of Zr and Hf are located on an ultrabasic rock and a granitic rock as shown in geological
map of La Unión area. It may be proved that Zr and Hf contents of heavy sands re useful data for
interpretation to understand the geology in the vicinity of the sampling sites.
Scandium
Two anomalous zones are found in the La Unión area, which are the Chiquimula area and southern part
of Río Hondo. As mentioned above, distributions of scandium show two distinct geochemical patterns,
that is, a zone of ultramafic rocks and a zone of granitic rock in Chiquimula. Distribution of scandium in
Izabal district is less distinct that that of the La Unión area.
Antimony
Five anomalous zones are found in the La Unión area. The highest value of Sb, 21.6 ppm, was obtained
from PB-136 site. It is obviously noted that Sb mineralization seems not to be associated with other

elements such as gold, chromium, zinc, etc. Anomalous sites of Sb are located on a line, trending to N10º
W direction. It seems to indicate a mineralization trend along a structural line.
Thallium
Two anomalous areas are found in surveyed area. One anomalous zone is found in Izabal district. The
highest value of Ta in Izabal district, 51.8 ppm, was obtained from PB-23 site. And other zone in La Unión
area is located in sampling site, PB-27 (59.2 ppm).
Tungsten
Anomalous high values of tungsten are obtained from four sampling sites. Presence of tungsten minerals
represented by 776 ppm at the site PB-104 and 639 ppm at the site PB-119 is also confirmed by
mineralogical observation. The occurrence of tungsten minerals is predicted on granitic rocks in the
vicinity of sampling sites. According to the geological map, three anomalous sites are located on granitic
areas, but there is no granitoid in the vicinity of the sampling site PB-181.
Rare Earth Elements
Anomalies of LREE are closely related with distribution of the granitic bodies; meanwhile HREE anomalies
are associated with the distribution of the metamorphic rocks considered heavy REE fractionated garnet.
Rubidium
The distribution pattern of Rb in heavy sands does not reflect the underlying bedrock because K-rich
minerals (including K-feldspar and micas) containing Rb were eliminated in the heavy sands during
panning.
Multivariate Analysis
Factor analysis was carried out on the chemical data of the heavy concentrates by using the Varimax
rotation method. The eigenvalues of extraction were chosen over 1 of each variable and the numbers of
factor are 6. Eigenvalues and R-mode value are calculated into factor analysis against each sample points.
The cluster analysis was treated by using the correlation matrix. The variables are grouped into the several
related elements which can reflect the probably origin of the elements. The districts to be applied by
factor analysis are different in geologic setting, therefore divided into two districts same as those of the
application for other geochemical treatments in this project.
Factor analysis was carried out for presenting the spatial distribution of the correlated elements for the
mineralization by using the Varimax factor leadings. The factor anomalies in surveyed areas are
overlapped by the relating elements for the metallic mineralization. The factor leadings relating all the
elements are used for the performing their processes. The cumulative proportion of total variance of 6
factor ranges from 71.5 to 74.3. Factor loadings in Tables 8 and 9 are used for before and after rotations.
The lower side of these tables is the values of after Varimax rotation, which shows a remarkable
discrimination among factors.
Results of factor analysis showing the spatial distributions of factor anomalies represent the close
interrelationships among the factor loading groups of REE-Th-U, Zr-Hf, Co-Cr-Ta, Sc-Zn-Sb-As, and Au in
the both of Izabal district and La Unión area. The REE relating factors are discriminated by the relevant
associations of HREE (heavy rare earth elements) and LREE (Light rare earth elements) respectively
according to the sources of factor anomalies. In this survey, factor anomalies related with LREE are
derived from granite indicating the concentrates of heavy sand minerals, fractionating the lighter
lanthanides in such minerals; sphene, apatite, zircon, and monazite, meanwhile factors related with HREE
are originated from metamorphic rocks suggesting the concentrates of garnet fractionating the heavier

lanthanides. The above-mentioned REE patterns of factor anomalies are coincident with those on both
districts.
Table 8. Factor loadings of before and after rotation from Izabal District, Guatemala.
Before Varimax Rotation
Factor 1 2 3 4 5 6
Eigen Value 6.65 3.23 2.54 1.91 1.40 1.34
CPTV 28.90 43.00 54.00 62.30 68.40 74.30
As -0.38 0.14 0.59 0.46 -0.04 -0.10
Au 0.02 0.14 -0.13 0.20 -0.63 0.05
Ce 0.87 0.01 0.29 -0.17 -0.05 -0.22
Co -0.40 0.68 -0.02 -0.03 -0.11 -0.29
Cr -0.38 0.67 0.07 -0.53 0.03 -0.13
Eu 0.64 0.15 0.02 0.36 0.24 -0.38
Hf 0.65 0.27 -0.34 0.19 0.46 0.24
La 0.90 -0.01 0.19 -0.17 0.01 -0.22
Lu 0.81 0.28 0.06 0.02 -0.21 0.24
Nd 0.88 0.02 0.31 -0.13 0.01 0.22
Rb -0.16 -0.41 0.61 0.05 0.16 0.00
Sb -0.26 0.14 0.64 0.48 0.31 -0.06
Sc 0.25 0.45 -0.45 0.49 -0.36 -0.08
Ta -0.09 0.67 0.01 -0.50 0.22 0.06
Tb 0.86 0.16 0.25 -0.04 -0.23 0.03
Th 0.90 0.10 0.27 -0.19 -0.15 -0.01
U 0.26 0.03 0.36 0.18 -0.10 0.45
W 0.08 0.07 0.12 -0.13 -0.10 0.56
Yb 0.13 -0.09 0.01 -0.18 0.00 0.40
Zn -0.38 0.73 0.32 0 0.227 0.05 0.01
Zr 0.58 0.26 -0.38 0.20 0.54 0.22
Factor 1 2 3 4 5 6
As -0.14 0.05 -0.25 0.84 0.09 0.04
Au 0.01 -0.09 -0.29 -0.16 0.57 0.26
Ce 0.95 -0.08 0.07 -0.04 -0.08 -0.04
Co -0.18 0.67 -0.14 0.26 0.39 -0.31
Cr -0.12 0.92 -0.14 -0.07 -0.01 -0.06
Eu 0.59 -0.17 0.43 0.27 0.19 -0.27
Hf 0.32 -0.05 0.87 -0.17 0.14 0.07
La 0.93 -0.10 0.16 -0.02 -0.08 -0.08
Lu 0.72 -0.02 0.26 -0.18 0.31 0.33
Nd 0.95 -0.08 0.12 0.01 -0.09 -0.04
Rb 0.00 -0.21 -0.25 0.45 -0.52 0.13
Sb -0.09 0.07 0.05 0.86 -0.13 0.20
Sc 0.10 -0.06 0.21 -0.02 0.88 -0.14
Ta 0.02 0.83 0.18 -0.16 -0.07 0.07
Tb 0.89 -0.06 0.09 -0.07 0.17 0.23
Th 0.94 -0.03 0.08 -0.14 0.02 0.17
U 0.22 -0.12 0.08 0.11 0.01 0.68
W 0.05 0.05 0.00 0.01 0.02 0.14
Yb 0.07 -0.06 0.03 -0.04 -0.04 -0.10
Zn 0 0.118 0.85 -0.08 0.28 0.07 0.13
Zr 0.24 -0.05 0.92 -0.14 0.10 0.00
After Varimax Rotation

Table 9. Factor loadings of before and after rotation from La Union area, Guatemala.
Factors relating with U and Th in Izabal and La Unión areas represent the concentrates of HREE associated
with U partitioned heavier lanthanides or independent U minerals. But the origin of its related factor
anomaly should be traced to reveal the occurrences of that. The spatial distributions of factors related
with Co-Cr and Zr-Hf indicate the lithology and its related mineralization in both districts.
The descriptions of factor anomalies are presented below:
Izabal District
Factor 1: (related with REE and Th) indicates heavy mineral concentration from the various rocks,
especially granites distributed in the areas.
Factor 2: (related with Cr, Co, Ta and Zn) indicates the Cr-Co mineralization associated with
ultramafic rock.
Factor 3: (related with Hf and Zr) is originated from zircon in the heavy mineral concentration.
Before Varimax Rotation
Factor 1 2 3 4 5 6
Eigen Value 6.94 3.26 2.01 1.66 1.48 1.07
CPTV 30.20 44.40 53.10 60.40 66.80 71.50
As 0.00 0.23 0.61 0.34 0.32 0.06
Au -0.04 0.12 -0.12 -0.04 -0.19 0.29
Ce 0.77 -0.05 -0.14 0.28 0.09 0.08
Co 0.33 0.56 -241.00 0.47 -0.13 0.11
Cr -0.03 0.37 -0.22 0.37 -0.60 0.04
Eu 0.63 -0.05 -0.34 0.32 0.33 0.00
Hf 0.26 0.31 -0.30 -0.26 0.32 -0.51
La 0.74 -0.52 -0.12 0.28 0.10 0.11
Lu 0.84 0.06 0.16 -0.23 -0.10 -0.25
Nd 0.80 -0.46 -0.12 0.25 0.11 0.11
Rb -0.03 -0.36 0.54 0.27 -0.06 -0.34
Sb -0.25 0.20 0.58 0.03 0.29 0.15
Sc 0.47 0.66 -0.41 -0.10 0.11 -0.16
Ta 0.45 0.13 -0.06 0.03 -0.40 -0.01
Tb 0.89 -0.21 0.09 0.78 -0.07 -0.08
Th 0.08 -0.15 0.22 -0.21 -0.14 0.20
U 0.68 0.08 0.37 -0.38 -0.18 0.17
W 0.60 0.25 0.15 -0.37 -0.30 0.19
Yb 0.82 0.01 0.18 -0.23 -0.07 -0.26
Zn 0.16 0.60 0.25 0.20 0.18 0.29
Zr 0.48 0.20 -0.18 -0.22 0.43 0.24
Factor 1 2 3 4 5 6
As 0.08 0.03 -0.05 0.76 -0.05 -0.24
Au -0.05 0.00 0.07 0.02 0.00 0.06
Ce 0.93 0.23 -0.04 -0.09 0.01 -0.02
Co 0.19 0.00 0.26 0.28 0.73 0.14
Cr -0.14 -0.02 -0.07 -0.09 0.83 -0.02
Eu 0.76 -0.01 0.35 0.09 0.10 0.12
Hf 0.00 0.06 0.80 -0.09 -0.06 0.05
La 0.93 0.22 -0.08 -0.09 -0.01 -0.02
Lu 0.37 0.72 0.39 0.01 -0.03 -0.24
Nd 0.93 0.27 -0.03 -0.06 -0.01 -0.01
Rb 0.10 -0.01 -0.24 0.11 -0.19 -0.71
Sb -0.30 -0.03 -0.18 0.60 -0.18 -0.04
Sc 0.07 0.20 0.78 0.09 0.34 0.25
Ta 0.15 0.44 0.05 -0.11 0.45 0.00
Tb 0.70 0.56 0.14 0.01 0.02 -0.22
Th 0.45 0.79 -0.06 0.05 0.01 0.08
U 0.14 0.88 0.00 0.16 -0.02 0.07
W 0.04 0.79 0.10 0.06 0.16 0.16
Yb 0.38 0.71 0.37 0.01 -0.09 -0.26
Zn -0.05 0.10 0.13 0.67 0.23 0.12
Zr 0.30 0.26 0.36 0.22 -0.11 0.51
After Varimax Rotation

Factor 4: (related with As and Sb) is indicates the antimony and sulphides mineralization (Fig. 93).
Factor 5: (closely related with Au, Sc, and Co) suggests the gold and cobalt mineralization (Fig. 94).
Factor 6: (related with U) indicates U mineralization and the lithology composing the heavy REE
minerals partitioning U elements.
Figure 14. Distribution map of Factor 4 from heavy concentrates on Izabal district, Guatemala.

Figure 15. Distribution map of Factor 5 from heavy concentrates on Izabal district, Guatemala.
Heavy Concentrates
La Unión Area
Factor 1: (related with REE) indicates REE minerals from surrounded granite and metamorphic
rocks.
Factor 2: (closely related with W, W, and Th) reflects the W and U mineralization.
Factor 3: (related with Fe, Sc and Hf) suggests the mineralization of Fe-sulphides (Fig. 95).
Factor 4: (closely related with As, Sb and Zn) implies polymetallic mineralization (Fig. 96).
Factor 5: (related with Co, Cr, and Ta) indicates the lithology of ultramafic rock and its Cr
mineralization.
Factor 6: (related with Zr) suggests the lithology of the anomalous areas.
Figure 16. Distribution map of Factor 3 from heavy concentrates on La Union area, Guatemala.

Figure 17. Distribution map of Factor 4 from heavy concentrates on La Union area, Guatemala.

Detailed Soil sampling at La Unión Area
Average values
The average contents of Co and Cr in soils over the metasedimentary formation are similar to those of
soils over the granite. The average contents of Mn, Mo, Ni, Pb, Ti, and Zn, in soils over the
metasedimentary formation are slightly higher than those of soils over the granite. The average content
of Cu in soils over the metasedimentary formation is twice as much as that of soils over the granite.
Correlation Analysis
The groups which have high correlation coefficient over 0.5 are As-Mo, As-Pb, Co-Mn, Co-Ti, and Mo-Pb.
In soils over the granite, and are As-Pb, Co-Mn, Co-Ti, Co-Zn, Cr-Ni, Mn-Ti, and Mo-Pb in soils over the
metasedimentary formation.
The Elemental Distribution
As: Arsenic was detected in only six soil samples over the granite, and in thirty-four samples over the
metasedimentary formation (Fig. 97). The content of arsenic reaches a maximum of 238 ppm. The arsenic
anomalies are spatially related to lead and molybdenum anomalies. The anomalous zones of arsenic over
the granite are distributed in the west side of the road passing to la Union at the contact between the
granite and the metasedimentary formation.
Figure 18. Arsenic soil anomalies on La Unión area, Guatemala.
Co: The average of cobalt contents in soil samples over the granite and metasedimentary formation are
256 ppm and 25.1 ppm respectively. Cobalt anomalous zones over the granite are distributed in six areas
and nine sampling sites. The cobalt anomalies are spatially related to titanium, chrome, copper and
Manganese anomalous zones.
Cobalt anomalous zones over the metasedimentary formation overlap with the chrome, nickel,
manganese and titanium anomalous zones.
Cr: The content of chrome ranges from 5 ppm to 161 ppm in the studied area. The chrome anomalies
partially overlap the cobalt, copper, nickel, and titanium anomalous zones.
Cu: The content of copper ranges from 2 ppm to 127 ppm with average content of 22.5 ppm in soils over
the granite and of 49.6 ppm in soils over the metasedimentary formation.

Mn: The content of manganese ranges from 60 ppm to 3,090 ppm with average content of 514 ppm in
soils over the granite and of 635.2 ppm in soils over the metasedimentary formation.
Mo: The content of molybdenite ranges from 13 ppm to 41 ppm with average content of 23.9 ppm in
soils over the granite and of 30.6 ppm in soils over the metasedimentary formation. These molybdenum
anomalies overlap with anomalies of arsenic, lead, zinc, and copper.
Ni: The content of nickel ranges from 2 ppm to 95 ppm with average content of 19.3 ppm in soils over
the granite and of 26.6 ppm in soils over the metasedimentary formation.
Pb: The content of lead ranges from 12 ppm to 45 ppm with average content of 21.3 ppm in soils over
the granite and 30 ppm in soils over the metasedimentary formation.
Ti: The content of titanium ranges from 2,100 to 22,600 ppm (2.26%) and average content of 6,237.2 ppm
in soils over the granite and 6,817.5 ppm in soils over the metasedimentary formation. The titanium
anomalies overlap with the copper, cobalt, chrome, and manganese anomalies.
Ti: The content of titanium ranges from 2,100 to 22,600 ppm (2.26%) and average content of 6,237.2 ppm
in soils over the granite and 6,817.5 ppm in soils over the metasedimentary formation.
Zn: the content of zinc ranges from 28 ppm to 670 ppm with average content of 138.3 ppm in soils over
the granite and 240.7 ppm in soils over the granite. The anomalies are not overlapped with other
elements.
Multivariate Analysis
The following factors were determined for the soil samples in the area
Factor 1 is related to As-Co-Cu-Mo-Pb-Ti (Fig. 98).
Factor 2 is related to Co-Cr-Ti (Fig. 99).
Factor 3 is related to Cr-Ti.
Factor 4 is related to Zn.

Figure 19. Factor 1 for the soil sampling of La Unión, Guatemala.
Figure 20. Factor 2 for soil samples from La Unión, Guatemala.
The high value areas in factor 1 distribution are found at Pena Blanca, on the road to La Union, and Corozo
area. Especially distribution of greater values over threshold values of all analyzed elements is
concentrated in the southern Lampocoy. The anomalies of Co, Cu and Ti related with factor 1 are
distributed in the Corozo area. The anomalies of Co, Cr and Ti associated with factor 2 are located in the
Lampocoy area. Most area of La Union show a close association with factor 3 related to Cr-Ni. Factor 4 is
only related to Zn. The high score of factor 4 related to Zn is coincident with spatial distribution of Zn.
Geochemical Characteristics
As described elsewhere, the geology of the La Union area is composed of granite and metasedimentary
formations with graphite schist and phyllite.
At the La Union area, three geochemically anomalous areas are recommended as the potential area of
concealed mineralization, the area of which is required of more detailed and systematic exploration.
Possible type of ore deposit in La Union may be related to contact metamorphism rather than vein type.
1. Lampocoy area: As-Cu-Mo-Pb-Zn.
2. Northern La Unión area: As-Zn.
Cluster Analysis
Cluster analysis by using the correlation coefficient of the variables in Izabal district (Fig. 25) is grouped
into five such as Ce-La-Nd-Th-Lu, Se-Eu-Hf-Zr, Co-Zn-Cr-Ta, As-Sb-Rb and W-Yb-Au. REE group including
of Ce, La, Nd, Th and Lu is connected with the lithophile elements of Na, Fe, Sc and Eu with closely
associated Hf and Zr in Izabal district. U is related to the before mentioned groups. The Co, Zn, Cr, and
Ta are correlated with chalcophile elements such as As, Sb and Rb which are associates with W, Yb and
Au.

Cluster analyses for the most of the variables in La Unión area (Fig. 100) are grouped into four such as Ce-
La-Nd-Lu-Tb-Th-U, Sc-Zn-Co-Zr-Rb, Ta-W and Au-Hf-As-Sb-Cr. The REE group including Ce, La, Nd, Lu, Tb
and Th, U is related with Sc, Zn, Co, Na, Zr and Rb which are associated with Ta, W in La Unión area. Au is
associated with Hf, As, Sb and Cr which are related with Sc, Zn, Co, Na, Zr and Rb group.
Figure 21. Dendogram of cluster analysis for Izabal District and La Unión area.

Conclusions
The Geochemical Anomalies
The typical ore deposits in survey areas known up to the present are reported as Managua polymetallic
mineral deposit, Canaan gold-copper-lead-zinc deposits, El Pato-El Poxte gold deposit, and Quebradas
placer gold deposit. The descriptions on those ore deposits will be presented in term of interpreting and
filtering the geochemical anomalies.
Quebradas, Canaan, Dona Maria areas in the Izabal district have factor anomalies for the most of
elements. The factor anomaly in the Quebradas suggests that there is a close relationship between the
primary gold deposit and its placer deposit. The factor anomalies associated with Au and Pb-Zn
mineralization are factors 2, 4, and 5, which are coincided with the surrounding geologic features in
Canaan and Dona Maria areas of Izabal district.
The factors related with gold mineralization in La Unión area are factor 3 and 4. The above mentioned
factors have a tendency to coincide with the distribution patterns of geochemical elements and geologic
settings respectively.
The statistical processing of distributed chemical elements, factor and cluster analysis were carried out
for interpretation of the anomalous zones. The Quebradas, Canaan, and Dona Maria areas in Izabal
district and La Union area were recommended as the anomalous zones. The standards for the selection
of the anomalous zones are based on the above mentioned three analyses and geological settings which
are coincided with each other. The bases for the extraction of anomalous zones are as follows: (1) the
anomalous zone overlapping the factors over 3, (2) distributive patterns of the anomalous zone of
chemical elements related with the observed mineral showings, (3) the zones of the high potentials for
the mineralization in terms of the alteration and geologic settings.
First Phase – Korean Geochemical Survey
The first phase exploration was conducted by the regionally geochemical exploration on volcanic and
metamorphic belts of Motagua basin and its vicinity in order to select the promising areas for the detailed
geochemical exploration of the next phase.
The geochemical survey was accomplished by sampling the heavy concentrates of stream sediments in
the tributaries of second and third order. The geochemical atlas covering the Izabal, Zacapa and
Chiquimula administrative departments were elaborated and their information was integrated to the
anomalous maps.
According to basic statistics, the mean values of Na, As, W, Sb, Rb, Au and Th from the La Unión area are
higher than those of the Izabal district, and the mean values of Sc, Zn, La, Ce, Nd, Eu, Tb, Lu, U and Hf in
both districts show almost the same values. In Izabal District and La Unión area, frequency patterns of As,
Au, Zr, Hf, Nd, Sb, W, Tb, U, La, Ce, Ta and Th shown left-skewed tendency and those of other elements
show the tendency of left-skewed and nearly normal distribution. Such elemental groups as (As-Sb), REE-
Th), (Cr-Zn, Ta, Co), (Hf-Zr), and (Zn-Ta, co) in Izabal district (U-W, Yb, Lu, Th, Tb), (W-Tb, Lu, Th, REE), (Hf-
Sc), and in the La Unión area have positive correlation.
The distribution patterns of 21 elements reflect the lithologic and geologic characteristics in the districts
and the inter-relationship of elements. For example, chromium anomalies are closely related with
distribution of ultramafic rocks such as serpentinite and peridotite, especially in the Izabal district. The
distribution of REE is related to the emplacement of granitic rocks. And the distribution patterns of U, Zr
and REE are generally coincident with the Th and Hf, respectively. And they reflect the closely chemical
affinities of these elements.

The anomalous zones for the elemental distribution pattern are as follows: In the Izabal district,
anomalous patterns of REE-Th-Au, REE-Zr and Co-Cr are found in Quebradas, Canaan and Los Amates,
respectively. In the La Unión area, anomalous patterns of As are found in the Los Tablones area south of
Río Hondo, San Jacinto area south of Chiquimula and the La Libertad area south of La Union. Anomalous
zones of Sb are found in the San Jacinto area, and Esquipulas area. Anomalous zone of W is found in the
El Lobo area and the San Nicolas, western part of Zacapa.
Factor anomalies in Izabal are found in three concentrated areas where have the factors over three related
with polymetallic mineralization. In the La Unión area, also factors related with polymetallic
mineralization are detected which will be the guide for the mineralization in three mineralized areas. The
mineralized areas which deserve more detailed exploration could be recommended by the analysis in
respects of overlapping over 3 factors, chemical distribution patterns and geologic settlings for suitable
mineralization. The recommended areas for second phase of the Korean included the primary gold
mineralized area of Quebradas, the base metal mineralization of Dona Maria, the southern part of La
Union area, and the Jocotán mineralized area.
Second Phase – Korean Geochemical Survey
The second phase of the Korean exploration project was performed on the basis of soil sampling to
delineate occurrences of possibly mineralized areas selected at the first phase exploration such as La
Union and Las Quebradas areas. The exploration of this phase is concentrated on the detailed soil
geochemical surveys to select the promising area of possible ore deposits. These areas aggregate to about
240 km2
including the La Union area of 200 km2
, and the Quebradas area of 40 km2
.
In La Union, three geochemically anomalous areas were recommended as promising areas for the
concealed mineralization:
(1) Lampocoy area: As-Cu-Mo-Pb-Zn
(2) The northern La Union area: As-Zn
(3) Corozo area: Co-Ni-Cu
At the Quebradas area two geochemically anomalous areas were presented as the possible mineralized
areas. But the anomalies could be originated from contaminations with many agricultural fields at
mountain slopes and pre-existing mining operations.
(1) San Juancito area: Co-Cu-Ti-Mn
The northeastern part of San Juancito area: Co-Cu-Mn-Ni-Ti.

Recommendations
According to the above-mentioned basis for the selection of anomalous zones, they could be selected as
follows:
UPPER BEACH ZONE OF RÍO QUEBRADAS: The known placer gold deposit is located in mouths of
tributaries creeks in the anomalous zone, which reflects the primary gold deposit to be formed in upper
reach zone of creeks. The factor 1, and 3 related with each REE and Hf, Zr are overlapping in the upper
creeks of Quebradas placer gold mine area. Factor 3 before rotation closely related with Sb, As may be a
pathfinder for gold mineralization. The distribution pattern of As and above-mentioned factors are
coincided with the mineral showing of sulfides and gold in the anomalous zone. This zone is selected as
a promising area (“A” anomaly area in Fig. 101) for detailed survey.
CANAAN AREA: Factors 1, 4 and 5 closely related with each REE, As-Sb, and Au-Sc-Co are overlapping not
only in Canaan project area but also in the east extended part of the area. The distribution patterns of
geochemical elements are coincided with this anomalous zone. The Tertiary granite which intruded the
Paleozoic metamorphic rocks occupied the most of this area. This anomalous zone is not considered to
be selected as the detailed surveyed area because the anomalous zone is in the known ore deposit and
the previous explorations areas (“B” anomaly area in Fig. 101).
DONA MARIA AREA: The Dona Maria area is overlapping the factor 1 and 6 related with the each REE-
Th, U-W and factor 2, 4 related with Co-Cr-Ta-Zn and As-Sb-Sc. The chemical distribution patterns of most
of the above mentioned elements are coincided with the factor anomalies on these sites. These anomalies
indicate the base metallic mineralization. The area includes the promising zone for further detailed survey
(“C” anomaly area in Fig. 101). The geology of the anomalous zone consists of Cretaceous to Eocene
Subinal formation, and Paleozoic undivided metamorphic rocks.

Figure 22. Promising areas in the Izabal District according to the Korean study.
LA UNIÓN AREA: Most of factor anomalies (factor, 2,3,4 and 5) related with each W-U-Th, Sc-Hf, As-Sb-
Zn, and Cr-Co-Ta are concentrated in the southern part of the La Union area (“D” anomaly area in Fig.
102). These reflect the mineralization related with polymetallic and its associated gold deposits. As-Sb
are pathfinders for Au especially coexisting with the elements of Bi and Sc. The geology of this area is
composed of Paleozoic undivided metamorphic rocks and Lampocoy granite dated to 33.75±0.55 Ma by
K/Ar method in this survey. The La Union anomalous zone have a potential for the mineralization with
regards to the interpretation of the geochemical analysis and geologic settings. This zone deserves to be
selected for the detailed survey in next stage exploration.
JOCOTÁN AREA: Factor 2, 3 and 6 relating the W-U-Th, Sc-Hf, and Zr-Na are distributed in the anomalous
zone of Jocotán area. The distribution patterns of U and Th show the high level and the distribution
patterns of W, Ta, Fe, and REE are also detected to the moderate level, which indicate W and Ta
mineralization and the distributions of REE bearing minerals (“E” anomaly area in Fig. 102). This area is
occupied by Tertiary felsic tuffs and Quaternary basalt. The coincidence with 3 factors and the chemical
distribution patterns for the elements of U-Th-REE, W and Ta could be due to the association with U, Th,
and REE and the separated source of W and Ta mineralization. This anomalous zone is recommended as
a promising area for the more detailed survey on the basis of the above-mentioned analysis.

Figure 23. Promising areas in La Unión (Zacapa District) according to the Korean study.

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