Mariana Resources Ltd / Epic: MARL / Market: AIM / Sector: Gold
Mining
28 October 2009
Mariana Resources Ltd ('Mariana Resources' or 'the Company')
Confirms Gold-Silver Discovery at the Dos Calandrias Project
Argentina
Mariana Resources Ltd, the AIM quoted exploration and development
company focussed in Argentina and Chile, is pleased to announce a
significant new gold-silver discovery at its 100% owned Dos
Calandrias Project ('Dos Calandrias') located in the prospective
Deseado Massif region in southern Argentina. The discovery was
confirmed following results from the first eight holes of a 16 hole
diamond drilling programme at the Calandria Sur prospect.
Overview
* Best intersection from the Calandria Sur prospect of 91.5m
@ 1.6 g/t gold ('Au') and 17 g/t silver ('Ag') from 3.5m, including
21m @ 4.5 g/t Au and 39 g/t Ag from 40m
* Results from all holes demonstrate wide intersections of
gold and silver mineralisation open at depth and laterally
* Grades and nature of the orebody indicate bulk tonnage
potential
* Follow-up 3,000m drilling programme planned for early 2010
to define the project's economic potential
Mariana Resources Managing Director John Sutcliffe said, "These
exceptional results represent an exciting new gold-silver discovery
at Dos Calandrias, indicating its development into a major
mineralised system with bulk tonnage gold potential. This is the
first mineralisation of its type to be found in the Patagonia region,
and we believe it is comparable with a number of gold systems
worldwide. We are planning a major follow-up exploration programme,
which will include additional geochemistry, geophysics, step-out
drilling, deeper testing of the known mineralisation, and scout
drilling of the remaining prospective hydrothermally brecciated
rhyolite dome perimeter.
"The potential uplift in value that Dos Calandrias presents through
an economic discovery is significant. It is therefore the Company's
intention to fast track the project through resource definition
drilling."
Calandria Sur Drill Results
To date, the Company has undertaken a 16 hole diamond drilling
programme at Dos Calandrias targeting both the Calandria Sur and
Calandria Norte prospects of which eight holes were undertaken at the
Calandria Sur target totalling 883m. Preliminary results for hole
CSD13 at Calandria Sur together with the eight Calandria Norte drill
holes were released previously on 19 October 2009.
The table of results from Calandria Sur below demonstrates wide
intersections of gold and silver mineralisation in holes CSD 9, 12,
13, 15 and 16. Mineralisation is open at depth and laterally.
Hole From To Core length Gold Silver
(m) (m) (m) (g/t) (g/t)
CSD09* 22.5 77.3 54.8 0.8 10
Incl 67.3 75.3 8.0 1.9 13
CSD10** 38.9 99.9 61.0 0.2 4
Incl 38.9 44.9 6.0 1.1 10
CSD11 No significant results, hole remained in wallrock
CSD12* 19.3 24.9 5.6 1.9 25
And 45.5 89.5 44.0 0.6 6
CSD13** 7.0 109.0 102.0 1.2 17
Incl 89.0 109.0 20.0 2.6 39
CSD14 47.0 100.1 53.1 0.2 2
CSD15 3.5 95.0 91.5 1.6 17
Incl 49.0 70.0 21.0 4.5 39
Incl 51.0 53.0 2.0 28.4 154
CSD16 23.0 94.0 71.0 1.1 23
Incl 61.0 90.0 29.0 1.8 35
* Sampling commences and ends in mineralisation
** Sampling ends in mineralisation
Notes:
(1) Weighted average values are uncut
(2) A total of 145m of additional drill core sampling and assaying
spread over five holes is yet to be completed
(3) The above drill intercepts are considered to represent
approximate true widths
Consultant's on-site evaluation
Management and Directors recently accompanied leading geological
consultant and epithermal specialist Dr. Richard Sillitoe, on a
two-day site visit to appraise the significance of the Dos Calandrias
drilling results. Results conclude that the Calandria Sur prospect
is a low-sulphidation epithermal discovery located along the margin
of an extensively hydrothermally brecciated rhyolite dome ('HBD').
The mineralisation appears to possess bulk tonnage potential in being
disseminated and not reliant upon identifiable veins.
Dr. Sillitoe has provided the following summary of his preliminary
findings - illustrative material and his full report will be
available shortly at www.marianaresources.com
Calandria Sur
* Shallow level epithermal gold-silver mineralisation of
low-sulphidation at Calandria Sur occurs in a pervasively HBD
* The prospect is the first example of bulk tonnage gold-silver
mineralisation hosted in a dome-related hydrothermal breccia to
be discovered to date in the Jurassic epithermal precious metal
province of Patagonia.
* Drilling results to date strongly indicate that the gold-silver
mineralisation has a grossly annular, steeply inward dipping form
controlled by the contact between the HBD and country rocks.
There is a strong suggestion that the highest grade
mineralisation terminates upwards some 10m to 20m beneath the
current surface, thereby raising the possibility of concealed
mineralisation elsewhere around the HBD perimeter.
* Highest gold grade intercepts to date abut the HBD contact and
are hosted by pervasively silicified breccia overprinted by a
marcasite-pyrite stockwork.
* Current first pass drilling has preliminarily tested
approximately 400m of the 1,500m mapped HBD perimeter.
* This drilling has shown that the highest grade gold-silver
mineralisation remains open below a vertical depth of
approximately 100m.
* Geological reconstruction of the HBD shows that the better drill
intercepts, ranging from 50m-100m, approximate the interpreted
true thicknesses (within 20%).
* Follow-up drilling will aim to undercut the current holes, which
are spaced 40m-100m apart, as well as test lag geochemical
anomalies around the remaining HBD perimeter. Lag sampling
around the perimeter will be in-filled and extended to better
define targets. A minimum 2,500m-3,000m drill programme is
recommended.
* Given the close observed association between the highest gold and
silver values and the marcasite-pyrite stockwork, consideration
is being given to conducting an Induced polarisation
chargeability-resistivity survey.
Calandria Norte
* Shallow drill testing of the two mapped veins did not intersect
high gold and silver values so at least one deeper hole needs to
be drilled to test for any downward changes that might indicate
approach to an ore-bearing epithermal environment.
Project Infrastructure
The Deseado Massif region in southern Argentina has excellent
infrastructure. Dos Calandrias has a paved national highway passing
within 20 km and is serviced by Caleta Olivia, located 150 km to the
north-east of the project and one of the most important ports in the
Santa Cruz province. Electric power is at a distance of
approximately 60 km and a national gas pipeline runs 15 km east of
the project.
**ENDS**
See website www.marianaresources.com for accompanying diagrams.
Ray Angus (UK) Mariana Resources Ltd Tel +61 4
00042630
John Horsburgh (Chairman) Mariana Resources Ltd Tel +61 2
94374588
John Sutcliffe (MD) Mariana Resources Ltd Tel +593 99
808080
Rob Adamson RFC Corporate Finance +61 2 9250
Limited (Nomad) 0041
Will Souter RFC Corporate Finance +61 2 9250
Limited (Nomad) 0050
Joe Lunn (Analyst) FinnCap (Broker) +44 20 7600
1658
Matthew Robinson FinnCap (Broker) +44 20 7600
1658
Felicity Edwards St Brides Media and +44 20 7236
Finance Ltd 1177
Hugo De Salis St Brides Media and +44 20 7236
Finance Ltd 1177
Additional Information
Drilling was undertaken by Boart Longyear Argentina. The drill
programme was managed by the Argentina Exploration Manager, Dr
Gustavo A. Rodriguez under supervision of Managing Director Mr John
Sutcliffe. Exploration information in this announcement has been
compiled by Mr Sutcliffe who is a Fellow of the Geological Society of
London, a Chartered Engineer and a Member of the Institute of Mining
and Metallurgy. Mr Sutcliffe has sufficient experience relevant to
the style of mineralisation and types of gold deposit under
consideration and to the activity that he is undertaking to qualify
as a Competent Person as defined in the JORC Code.
Sampling and Analytical Details
All diamond drill core samples are split on geological contacts with
minimum and maximum sample length of 0.4 and 2.1 metres respectively
and represent sawn half HQ-size core.
The programme consisted of 768 samples, (including certified control
standards, quarter core duplicates and blanks). All the samples are
collected under the supervision of the Company geologists. During the
sample handling procedure, the sample shipments are tracked. Core
samples were placed into uniquely labelled sample bags. A record of
the sample location and other specific details is documented in the
sample data base.
All samples were sent to ALS Chemex Labs with preparation facilities
in Mendoza and assayed in Chile for gold and multi element ICP
analyses. Rock sample preparation includes weighing, drying, fine
crushing of entire sample to better than 70%-2mm, split of 250g and
pulverise split to better than 85% passing 75 microns (PREP-31-
DRY-22). The 34 element ME ICP41 package analyses utilise an aqua
regia digestion. Gold analyses for all samples are fire assay and AAS
(Au-AA24, 50g nominal sample weight, range 0.005-10 ppm) with any
results over 10g/t checked using a gravimetric finish (Au-GRA22-50g ,
range 0.05- 1.000 g/t). Silver grades exceeding 100 g/t were assayed
by fire assay and gravimetric finish (Ag-GRA21, 30g nominal sample
weight, range 5-10,000 ppm).
ALS Cheme's quality system complies with the requirements for the
International Standards ISO 9001:2000 and ISO 17025: 1999
Quality Assurance/Quality Control
All technical information for the Company's Argentina projects is
obtained and reported under a quality assurance and quality control
(QA/QC) programme. Four different certified standards were inserted
at an average of one per 21 samples, blanks (in house) at one per 40
samples, while quarter-core duplicates were inserted at intervals of
approximately 45 samples. A total of 9% control samples have been
inserted. Assays that meet the QA/QC are incorporated in the Mariana
data base.
---END OF MESSAGE---
This announcement was originally distributed by Hugin. The issuer is
solely responsible for the content of this announcement.