Supergenic Manganese in the Prospex Area – Bahia, Brazil

Confidential summary report

Guilherme M. Gonzaga
Geologist – CREA 2089/D-DF
061-8185 8757

Brasília- DF, June, 16th, 2011



In May, 2011, I had the opportunity and privilege to perform a consultancy work for Dr. Steffen Hagemann (Perth, Australia), aiming to evaluate the potential of the Prospex project together with other projects in the regions of Caetité and Calculé in Bahia, among others. My final report was sent exclusively to Dr. Hagemann. Besides that, I had to sign a confidentiality agreement with NWI (Perth), in which I am not allowed to provide any information to any person or company. However, since NWI themselves have forward my report (from now one referred to as report 1) to Prospex I feel I have the professional right to accept the invitation made to me by Prospex’s manager, Alexandre, to continue my observations and geological studies of the region.
This report, from now on referred to as report 2, concerns the practical issues, business and some geological aspects.

In report 1, besides other things, I showed that the manganese is of a supergenic nature and that it is preferentially associated to the slightly flat surfaces above the remaining rocks of a volcano-sedimentary sequence from the end of the Archean. I clearly suggested that Prospex purchase, as soon as possible, an auger in Belo Horizonte (MG), in order to make hundreds of trenches in the slightly flat surfaces, both in block 1 (Açoita Cavalo) and block 2 (Rio da Faca). It is not convenient that Prospex continue to do the preliminary evaluation directly from the manual wells that may or may not contain manganese. This kind of activities, besides being time consuming, may bring some difficulties with the local farmers. These manual wells should continue to be made, but only in the locals in which the auger trenches show the presence of manganese.

It is fundamental that some initial evaluation is made in block 2, which shows a much plainer surface than block 1 (fig. 2). This is more favourable to the supergenic enrichment of manganese. The beginning of the research activities in block 2 will add value to the project as a whole. I understand that besides the fact that nothing has been done in block 2, it has was not a target and that it was not discarded only because it is still valid with DNPM. As shown below and in photos 1 to 3, I am convinced that block 2 is an excellent target for supergenic manganese. Note that I am not suggesting that block 1 is of no importance.

Another topic in this report 2 is the study and sampling of coloured rocks (brown, green, yellow, white) in the region of Açoita Cavalo in block 1. This study (“exotic elements”) aimed for a sequence of samples for possible elements such as tantalum,niobium, thallium and uranium, among others, after the manager, Alexandre, identified concentrations of 0.35% Ta2O5 in sample PT504 (same location as samples E1B: photos 7 and 8). The samples will be sent to a lab and Prospex will be able to evaluate the issue after they receive the results.

The activities in this report 2 began with my trip to the region on Friday, 10th of June, returning to Brasília on Tuesday, 14th of June. Once more I had the collaboration of the manager of Prospex, Alexandre. He was very professional, competent and friendly, to which I thank him.



In report 1 I made clear the importance of the geomorphological control and that the manganese in the region is of a supergenic nature and, for that reason, directly related to the topography and geomorphology (fig. 1). I suggested that Prospex acquire at least one auger from the company Trado – Equipment and Services, in Belo Horizonte (MG). I had the opportunity to work with this equipment in many different  (No technical data, CONFIDENTIAL) projects in different regions. The results were excellent in all aspects as it is functional, resistant, trustworthy, easy to use and easy to transport. Trenches up to 15 m deep can be easily made, even in regions with some laterite.

Figure 2 shows both block 1 (Açoita Cavalo) and block 2 (Rio da Faca). The topographic map Caetité (SD.23-Z-B-II, scale 1:100,000) shows clearly that the slightly flat surfaces in both blocks are propitious to the prospection using an auger. These surfaces are more frequent and more extensive in block 2. Photo 1 shows an example of one slightly flat surface in block 2. Photo 2 shows the presence of manganese in a shallow trench (50 cm) in block 2. The auger will perform very well in this setting. Photo 3 (Pedreira dos Capixabas) shows, in block 2, the same basic group of volcanosedimentary rocks that occur in block 1 in the regions of Açoita Cavalo. These rocks with low rates of disperse manganese are responsible, through their supergenic enrichment, for the deposits of manganese in slightly flat surfaces in the region of the Bahia State (fig. 1).

Alexandre (the manager) and I had the opportunity to observer many of these surfaces, both in block 1 and (mainly) in block 2. These can be immediate target for teams with 1 or more augers, as chosen by Prospex or any other company that may join the project. In order to precisely delimitate these surfaces it will be necessary to perform a detailed study with satellite images and aerial photography, as suggested by me in report 1.



The regional geology and logistics information is presented in report 1. It is interesting to highlight once again that the logistics for the region, considering Brazilian standards, is very good.



In terms of operations in the field, we are calling this topic “exotic elements”.  Alexandre, the manager, identified 0.35% Ta2O5 in the same location as sample E1B (photos 7 and 8). These are small veins of greisen, which is very compatible with the presence of tantalum. Large bodies of greisen occur in Brazil; for example, Serra Branca in Goiás. Graisen can present economical concentrations, sometimes very import, of cassiterite, tantalite and other minerals. In the case of Prospex, nothing else can be said about it in scientific terms. Would there be large bodies of greisen in the area of Açoita Cavalo, block 1? Would they have good rates of tantalum and elements of interest? Nothing can be proven on the surface. There is no additional information. At this moment, this is speculation.

The following samples were collected:

E1A green – 14º 21’ 06.1” – 42º 29’ 12.3” Alt.: 930 m
E1B reddish brown (with tantalum) – same coordinates as E1A
E1C yellow – same coordinates as E1A
E2 yellow – 14º 21’ 08.9” – 42º 29’ 10.3” Alt.: 925 m
E3A white – 14º 21’ 10.5” – 42º 29’ 09.1” – Alt.: 915 m
E3B yellow – same coordinates as E3A
E4 brown – 14º 21’ 11.7” – 42º 29’ 09.4” – Alt.: 902 m
E5 yellow – 14º 21’ 14.0” – 42º 29’ 06.3” – Alt.: 905 m
E6A brown – 14º 21’ 16.7” – 42º 29’ 04.1” – Alt.: 898 m
E6B yellow – same coordinates as E6A
E7 yellow – 14º 21’ 18.1” – 42º 29’ 03.0” – Alt.: 892 m

The 11 samples collected in the region of Açoita Cavalo, block 1, will be sent to a lab in Belo Horizonte for the detection of minor elements (exotic elements). It is probable that there is no uranium associated to these samples or to other rock types in both blocks of the Prospex project.

The sixth largest uranium mine in the world (Lagoa Real) is located NE of Caetité. Although the regions of the Prospex project and of the Uranium Mine in Lagoa Real are practically identical, the Prospex area lacks the occurrence of a geological event directly responsible for the mineralisation of uranium (fig. 3). This fact is very convenient to Prospex as the presence of uranium is a negative factor to mining projects in Brazil as it can occur in serious problems with DNPM.
Prospex does not have a Geiger counter, but it is recommended that the next activities in the areas are performed using this kind of equipment. It is necessary to know the variation of natural radioactivity in the region.

The region of Açoita Cavalo, block 1, was subjected to much tectonic activity. It shows faulting, shearing, etc., which favours the hydrothermal activity that may transport tantalum, niobium, vanadium and other elements to surface.

Prior to collecting the samples above, two employees of Prospex received training regarding basic procedures and care for sampling. There can not be any contact with metallic objects as well as care must be taken for handling and storage of the samples (photos 4 and 5).



The manager from Prospex, Alexandre, sent some samples of manganese ore for analysis. Some of the rates are extremely interesting. More information is provided in the 2 attachments.



1. Observations regarding the geomorphological control, as suggested in report 1, confirm the importance of the issue to Prospex.

2. Both block 1 (Açoita Cavalo) and block 2 (Rio da Faca) show slightly flat surfaces that are favourable to the occurrence of supergenic manganese.

3. Block 2 (Rio da Faca) shows surfaces which are, overall, flatter and more extensive than those in block 1. This fact favours the supergenic mineralisation of manganese with lateral continuity.

4. Once again I recommend that Prospex buy and auger in Belo Horizonte.

5. As soon as Prospex acquires the auger it is recommended that the team that is going to be using this equipment be trained properly.

6. Prospex should await the results of the 11 samples that will be sent to Belo Horizonte for the analysis of minor elements.

7. If possible, a Geiger counter should be used in all the future activities because it is important to know the variation of the natural radioactivity in the region.

8. I do not believe that uranium may be a problem for Prospex.

9. There is a plenty available space to work with the auger immediately in both blocks. However, as mentioned in report 1, it will be necessary to acquire aerial photos and satellite images.

10. I am convinced of the importance of Prospex’ supergenic manganese project. It is possible to achieve an economical medium port mine. For that it is necessary to work on the area further. The first activities should be to acquire an auger and to start the trench activities.

11. The two attachments present some observations regarding the rates of manganese.

12. I recommend that Prospex and/or any other company that may join the project contact me if there is the need for any more information, which I will be happy to provide.

Brasília- DF, June, 16th, 2011
Guilherme M. Gonzaga
Geologist – CREA 2089/D–DF
61 – 8185 8757

Obs.: See accompanying two chemical analyses tables



Photo 7 – Collection of sample E1A (green material), metamorphic
orientation N45W deeping 50º SW. Açoita Cavalo, block 1. 14º 21’
06.1”  – 42º 29’ 12.3” – Alt.: 930m


Photo 8 -Location of sample E1C (yellow material) in Açoita Cavalo,
block 1. 14º 21’ 06.1” – 42º 29’ 12.3” – Alt.: 930m


Photo 9 – Location of sample E1B (reddish brown material).
objects. Prior chemical analysis of this material revealed 0.35%
Ta2O5. It is a typical greisen vein. Açoita Cavalo, block 1.
14º 21’ 06.1” – 42º 29’ 12.3” – Alt.: 930m


Photo 10 – Detail of previous photo (photo 9)


Photo 11 – General view of the behaviour of the volcano-sedimentary
sequence in Açoita Cavalo, block 1, where samples where collected for
the analysis of minor elements, which we refer to as exotic elements
for operational reasons. All the sequence was intensively affected by
many tectonic processes.


Photo 12 – Gnaiss from the volcano-sedimentary sequence in
Açoita Cavalo, block 1


Photo 13 – Banded Iron Formation (BIF) from the volcano-sedimentary
sequence in Açoita Cavalo, block 1


Photo 14 – General view of the area where the samples E1A, E1B e E1C
were collected in Açoita Cavalo, block 1. The rocks were affected by
intense tectonic activity.  14º 21’ 06.1” – 42º 29’ 12.3” – Alt.: 930