December 13, 2013
Reference No. 08-1112-0062/5000
Mr. Bill Millar
Preston Sand and Gravel
669 Charles Street East
Kitchener Ontario
N2G 2R6
SILICA CONTENT OF HENNING PIT FEED MATERIAL,
NORTH DUMFRIES, ONTARIO
Dear Mr. Millar,
As requested, Golder Associates Ltd, (Golder) has undertaken evaluation of a sample of sand and gravel from
the vicinity of the proposed Henning Pit near Cambridge Ontario. The purpose of the analyses was to identify
quartz (SiO2) and silica (SiO) content in the sand and gravel.
The results of the testing are provided herein.
1.0
1.1
PROGRAM OF EVALUATION
Sample
Golder’s Materials Laboratory in Burnaby BC received a sample on November 13, 2013. It was contained in four
sealed containers, and consisted of sand and gravel of a maximum nominal size of approximately 20 cm (8”).
We understand that the sample was obtained from an active aggregate site located in the vicinity of the
Henning Pit from a site where the same geologic formation is exposed. These deposits consist of ice-contact
stratified deposits and sandy and gravelly deposits. The sand and gravel deposits underlie the surficial till
deposits and would represent the resource material that is currently being mined. As such, the sample collected
and submitted for analysis would be within the same sand and gravel deposit that is present at the proposed
Henning Pit.
This material was split into >19 mm and <19 mm sizes. A representative portion of the -19 mm material was
sieved in preparation for further testing, described below. The sample mass totalled approximately 240 kg.
1.2
Testing
Per Golder’s Proposal for evaluation of silica, the following test procedures comprise this program:

Sieve Analysis of the -19 mm portion
Golder Associates Ltd.
500 - 4260 Still Creek Drive, Burnaby, British Columbia, Canada V5C 6C6
Tel: +1 (604) 296 4200 Fax: +1 (604) 298 5253 www.golder.com
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Golder, Golder Associates and the GA globe design are trademarks of Golder Associates Corporation.
Mr. Bill Millar
Preston Sand and Gravel
08-1112-0062/5000
December 13, 2013

Petrographic Examination of three fractions (+19 mm; 4.75 x 19 mm; -4.75 mm)

XRD and Rietveld analysis of the +19 and -4.75 mm portions

Thin section analysis of representative rock types selected from Petrographic Examination of the gravel
fractions
The results of the analyses that were undertaken are provided below.
2.0
2.1
RESULTS
Petrographic Examinations
The general approach outlined in CSA A23.2-15A, “Petrographic examination of aggregate” was used in these
analyses, except that an assessment of engineering characteristics was not included. The focus of the analyses
was to determine geologic/mineralogic composition of the materials, to support an assessment of the potential of
the material in the area of the proposed Henning Pit to generate airborne silica through the act of extraction.
That assessment is being carried out by others under separate cover.
In these examinations, the sample fractions were separated on the basis of their lithology into categories of
various rock types. Detailed results of each Petrographic examination are presented in the attached reports.
2.1.1
Gravel Fractions
The gravel fractions (+19 mm and -19 mm) were separately analyzed, but are summarized here for ease of
comparison.
The gravels were largely composed of sedimentary rocks, with carbonates being the dominant of these.
Carbonate rocks accounted for between 70% and 84% of these fractions, with sandstone, granite, gneiss, chert
and siltstone accounting for the balance of the samples.
The most common rock type was dolomite, which made up between 63% and 73% of these fractions. The
dolomite was subdivided into two subgroups on the basis of colour and texture. A lighter-coloured (white to light
grey) dolomite made up approximately 50% of the gravel fractions; this rock was dense and strong, and typically
contained minute voids. The second dolomite variant, “Dolomite 2”, was slightly darker in colour, being
characteristically medium to dark brown or brown-grey. This dolomite was usually fine- to very fine-grained,
dense and very strong. Dolomite 2 accounted for about 18% of the gravel fractions.
Limestone was the other carbonate rock type identified in the samples; this rock was typically fine-grained or
micritic, and often contained fossil fragments. Its colour ranged from light to medium grey to brown-grey, and it
was generally dense and strong material. The limestone content ranged from 8% to 11% by mass of the
samples.
2/7
Mr. Bill Millar
Preston Sand and Gravel
08-1112-0062/5000
December 13, 2013
Calcareous sandstone accounted for between 12% and 23% of the sample. This rock type varied somewhat in
terms of calcite content, from “slightly calcareous” to “calcareous”. Generally, this rock ranged in terms of its
composition, with many particles consisting largely of quartz grains in a matrix of calcite with some ferruginous
(i.e., iron-bearing) material, although some particles exhibited a more arkosic composition. The texture of these
rocks also ranged somewhat, from fine sandstone to siltstone textures. Finally, some of these rocks exhibited
annealed textures suggesting a degree of metamorphism in some examples.
A more ferruginous variety of sandstone was separately classified, accounting for about 1% of the sample.
Less than 1% of the sample comprised a rock type identified as quartzite/quartz siltstone, a dense, strong rock
type.
Granite, diorite and granitic gneiss made up about 2% to 3% of the sample. These rock types were typically
fresh, strong and dense.
A trace amount of chert (0.1%) was found in the +19 mm gravel fraction; this rock type was not found in the
-19 mm fraction. The chert was slightly leached, but otherwise strong.
Cementations of calcite-cemented sand grains accounted for 0.5% to 2.4% of the gravel fractions. The sand
grains contained in these rocks were of variable composition, but were often noted to consist of rounded grains
of limestone. The cementations were gauged to be of modest or low strength, since the bond between the
bound grains was of calcite, and generally brittle.
The following table details the geologic composition of the two gravel fractions:
Rock type
-19 mm gravel
+19 mm gravel
Dolomite 1
54.0
45.6
Dolomite 2
18.5
17.6
Limestone
11.1
7.6
Calcareous sandstone
12.2
22.8
Ferruginous sandstone
0.8
1.0
Quartzite/quartz siltstone
0.8
0.3
Chert
-
0.1
Granite-diorite, gneiss
2.1
2.6
Cementations
0.5
2.4
The +19 mm gravel was separately analyzed to evaluate its composition, since it is thought that this size fraction
would be likely to be crushed, at least in part, and then blended with material finer than 19 mm in order to
produce certain aggregate products such as road base, asphalt aggregate, drain rock and concrete aggregate.
Using quartz contents that were based upon microscopic examination, an estimated quartz and silica content of
about 15% was determined for the gravel fractions.
2.1.1.1
Thin-Section Samples
Representative specimens were selected from the rock type groups described above; these were submitted for
preparation of thin-section samples.
The thin-section samples were examined to develop in-depth
characterization if needed, of these rock types and to identify quartz and its proportion in each rock type. Details
on the results of this analysis are provided in a later section in this report.
3/7
Mr. Bill Millar
Preston Sand and Gravel
2.1.2
08-1112-0062/5000
December 13, 2013
Sand Fraction
Petrographic examination of the sand fraction was carried out on a fraction-by-fraction basis in accordance with
CSA A23.2-15A, after the sample had been sieved.
The identification of rock and mineral species was determined optically, augmented by standard physical tests
and characteristics. For each size fraction, the grains were identified and classified, and the proportion of each
rock type or mineral within that sieve fraction was calculated, based upon particle count.
Utilizing the sieve analysis data, the resulting weighted percentages of each mineral species identified optically
was determined.
The table which follows provide a summary of the weighted percentages of each rock and mineral species
identified in the sand fraction of the sample:
Contains SiO
Percent by count
Dolomite
Trace
34.6
Limestone
Trace to some
19.3
Sandstone / Quartzite
Yes (variable)
20.5
Granite-Diorite, Gneiss
Yes (variable)
3.5
Schist
Minor
0.9
Chert
Yes
0.5
Shale/Siltstone/Claystone
Minor
Quartz
Yes
12.5
Feldspar
No
4.2
Pyroxene
No
1.3
Garnet
No
0.3
Mica
No
0.3
2.1
The species listed above that contain or may contain quartz or another form of silica (SiO) are indicated as
noted. Some of these rock types may contain no SiO, while others are known to contain quartz. We provide the
following notes:

“Quartz” is all quartz (SiO2);

Dolomite may contain quartz or silica. This has not been determined and will require the examination of
thin section specimens;

Limestone may contain quartz or silica. Similar to dolomite, examination of thin sections is required to
assist in making this determination;

Sandstone and quartzite do contain quartz but it is variable. Some varieties may contain a significant
amount of quartz; others may contain only a modest amount of quartz;

Granite-diorite, gneiss. These rocks do contain some quartz; generally, it is judged that quartz contents will
be less than 25% for gneiss, less than 15% for granite, and less than 5% for diorite;

Chert was observed to contain some attached limestone; silica content would be estimated to be 90%;
4/7
Mr. Bill Millar
Preston Sand and Gravel
08-1112-0062/5000
December 13, 2013

Shale/siltstone/claystone is likely to contain some quartz; it is likely to represent less than 25% of these
rock types; and

Feldspar, pyroxene, garnet and mica do not contain quartz.
Thin-section examinations (reported below) provide further information on the quartz and silica content of the
rock types noted above.
2.2
Thin Section Analysis
As noted above, we selected several representative specimens from each rock type for preparation of
thin-section samples.
The thin sections were examined using a Nikon polarizing microscope to enable the identification of the
constituent minerals. In specific, we examined the samples to identify and estimate the proportion of quartz and
silica in the rocks.
The following table provides the data that was obtained in this way.
Rock type
Dolomite 1 (4 thin sections)
Dolomite 2 (3 thin sections)
Limestone (3 thin sections)
Granite gneiss (2 thin sections)
Ferruginous, calcareous sandstone (2
thin sections)
Chert (1 thin section)
Calcareous sandstone (4 thin
sections)
Metasiltstone (1 thin section)
Visually-estimated quartz
content (% by volume)
Weighted Average
0.1 – 0.5
0 – 0.1
0.1, 2, 15
10, 25
0.3
0.1
2.0
15.0
25 – 30
28.0
90
90.0
25, 40, 60, 40
50.0
60
60.0
These data were applied to the Petrographic information to determine overall quartz / silica contents for the
gravel fractions. They were also applied to the rock types identified in the sand fraction.
2.3
X-Ray Diffraction and Rietveld Analysis
The combination of X-ray Diffraction (XRD) with Rietveld analysis was selected as a means whereby chemistry
data could be analyzed to develop interpreted quantitative mineralogical information for bulk samples.
As such, samples of the +19 mm fraction and of the -4.75 mm fraction were submitted for these analyses.
The following table summarizes the interpreted data obtained for the sand and gravel fractions.
5/7
Mr. Bill Millar
Preston Sand and Gravel
Mineral
08-1112-0062/5000
December 13, 2013
Ideal Formula
Percent of Sand Fraction
Percent of Gravel Fraction
23.0
12.8
(Mg,Fe )5Al(Si3Al)O10(OH)8
2.0
1.2
Muscovite
KAl2AlSi3O10(OH)2
1.8
1.1
Actinolite
Ca2(Mg,Fe)5Si8O22(OH)2
0.8
0.8
Plagioclase
NaAlSi3O8 – CaAl2Si2O8
7.7
3.7
K-Feldspar
KAlSi3O8
3.9
2.2
Calcite
CaCO3
19.0
7.5
Dolomite
CaMg(CO3)2
41.8
70.7
100.0
100.0
Quartz
SiO2
Clinochlore
2+
Total
It may be noted that the Rietveld analysis utilizes software that determines a “best match” based upon
mathematical calculations and links the gross chemistry with interpreted mineral species. Although this method
provides an improved interpretation of the chemical data, Golder typically “calibrates” the mineral species
interpretation by means of optically-derived geologic and mineral identification, usually also including thin-section
interpretation.
3.0
SUMMARY OF RESULTS
Incorporating all of the data obtained from the analyses, the following quartz and silica content was calculated.
Quartz & Silica Content
Sample Fraction
by Petrography
24.6
7.3
12.7
Sand
4.75 x 19.0 mm
+19.0 mm
by XRD/Rietveld
23.0
12.8
Review of the data given above indicates close agreement between the XRD/Rietveld and Petrographic-based
quartz/silica contents.
Given the consistency of these results, and the close alignment of the two sets of data, we determined the
overall average quartz and silica content for the sample of sand and gravel, as shown below:
Gravel
Sand
Quartz content
Percentage of whole sample,
based on gradation
Weighted percent contribution
-19 mm
+19 mm
24.63
7.32
12.65
34.00
18.40
47.60
8.37
1.35
6.02
TOTAL
15.74%
6/7
ATTACHEMENT Petrographic Examinations