https://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&feed=atom&action=historyOR/12/032 Mineralogy - Revision history2024-03-28T17:47:28ZRevision history for this page on the wikiMediaWiki 1.41.0https://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=53395&oldid=prevAjhil at 08:54, 6 August 20212021-08-06T08:54:40Z<p></p>
<a href="https://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=53395&oldid=53223">Show changes</a>Ajhilhttps://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=53223&oldid=prevAjhil: /* Discussion */2021-08-03T12:20:14Z<p><span dir="auto"><span class="autocomment">Discussion</span></span></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en-GB">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 12:20, 3 August 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l872">Line 872:</td>
<td colspan="2" class="diff-lineno">Line 872:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This study has also highlighted an important difference in the swelling clay species present in the Lias Group rocks. The samples from Areas 5 and 4 (Wessex and Worcester Basins) contain discrete smectite whereas illite/smectite, I/S (90% illite) is present in the Areas 3 and 1 (East Midlands Shelf and Cleveland Basin) samples. Modelling suggests that all the clay minerals present in the Lias Group have small mean defect-free distances, typically <10 layers thick. Such small crystallite sizes indicate that all species will provide an input to the surface area of the rock. However, the difference in swelling clay species does help to explain the larger surface area values for the southern batch (mean 110 m<sup>2</sup>/g) compared with the northern batch (mean 85 m<sup>2</sup>/g) despite the presence of more coarse-grained siltstone samples in the south. The smaller surface area of I/S compared to smectite might therefore be expected to produce a greater degree of swell-shrink in the southern strata. However, the high concentration of calcite in the southern samples 'dilutes' the effect of the smectite surface area. In trying to relate the mineralogy and the engineering properties of the Lias Group, it is therefore imperative not only to determine the quantity and type of clay minerals present but also the quantity of calcite present. It is also necessary to know whether the calcite is present as a cement, which will influence engineering behaviour, and/or as shell fragments, which would have a reduced effect. The only previous petrographic study of the Lias Group mudstones (Pye & Krinsley, 1986<ref name="Pye 1986"></ref>) suggests that calcite and siderite are present as randomly dispersed rhombs, irregularly shape grains and patches of intergranular cement in the more silty sediments. No primary biogenic carbonate was observed as foraminifera, coccoliths or shell debris. Interestingly these authors also note that although the mudstones have a well-developed lamination and high degree of parallelism shown by micas and clay minerals, they are not notably fissile. During weathering they split into flaggy slabs rather than sheets. Such behaviour was attributed to the high proportion of authigenic minerals (carbonate, pyrite and kaolinite), which act as cements and bind adjacent laminae together.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This study has also highlighted an important difference in the swelling clay species present in the Lias Group rocks. The samples from Areas 5 and 4 (Wessex and Worcester Basins) contain discrete smectite whereas illite/smectite, I/S (90% illite) is present in the Areas 3 and 1 (East Midlands Shelf and Cleveland Basin) samples. Modelling suggests that all the clay minerals present in the Lias Group have small mean defect-free distances, typically <10 layers thick. Such small crystallite sizes indicate that all species will provide an input to the surface area of the rock. However, the difference in swelling clay species does help to explain the larger surface area values for the southern batch (mean 110 m<sup>2</sup>/g) compared with the northern batch (mean 85 m<sup>2</sup>/g) despite the presence of more coarse-grained siltstone samples in the south. The smaller surface area of I/S compared to smectite might therefore be expected to produce a greater degree of swell-shrink in the southern strata. However, the high concentration of calcite in the southern samples 'dilutes' the effect of the smectite surface area. In trying to relate the mineralogy and the engineering properties of the Lias Group, it is therefore imperative not only to determine the quantity and type of clay minerals present but also the quantity of calcite present. It is also necessary to know whether the calcite is present as a cement, which will influence engineering behaviour, and/or as shell fragments, which would have a reduced effect. The only previous petrographic study of the Lias Group mudstones (Pye & Krinsley, 1986<ref name="Pye 1986"></ref>) suggests that calcite and siderite are present as randomly dispersed rhombs, irregularly shape grains and patches of intergranular cement in the more silty sediments. No primary biogenic carbonate was observed as foraminifera, coccoliths or shell debris. Interestingly these authors also note that although the mudstones have a well-developed lamination and high degree of parallelism shown by micas and clay minerals, they are not notably fissile. During weathering they split into flaggy slabs rather than sheets. Such behaviour was attributed to the high proportion of authigenic minerals (carbonate, pyrite and kaolinite), which act as cements and bind adjacent laminae together.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The difference between the type of swelling clay present in the northern and southern samples also suggests differences in their burial histories (Kemp, et al., 2005<ref name="Kemp 2005"></ref>). During burial of sedimentary sequences, the clay minerals contained in mudstones and shales undergo diagenetic reactions in response to increasing depth and temperature. Quantitatively, the most important change is the progressive reaction of smectite to form illite via a series of intermediate illite/smectite (I/S) mixed-layer minerals. In general, progressive changes are irreversible so that where basinal sequences have been inverted clay mineral evidence of the maximum burial depth is retained and can be used to estimate the amount of uplift. According to the Basin Maturity Chart of Merriman & Kemp (1996)<ref name="Merriman 1996">Merriman, R J, and Kemp, S J. 1996. Clay minerals and sedimentary basin maturity. ''Mineralogical Society Bulletin'', 111, 7–8.</ref>, the presence of I/S (90% illite) in the rocks from the Cleveland Basin suggests burial depths of 4&nbsp;km, assuming a 'normal' geothermal gradient of 25–30°C/km. The I/S (80% illite) in the sample from Area 3 (East Midlands Shelf), therefore, suggests shallower burial to perhaps 3&nbsp;km while the presence of smectite and kaolinite suggest that the mudstones from southern England are more immature and have only been buried to depths of less than c.&nbsp;3 km if the same geothermal gradient is assumed. These estimates are compared with those obtained independently from geological evidence in Table 3.4. See also <del style="font-weight: bold; text-decoration: none;">section 6.2.2</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The difference between the type of swelling clay present in the northern and southern samples also suggests differences in their burial histories (Kemp, et al., 2005<ref name="Kemp 2005"></ref>). During burial of sedimentary sequences, the clay minerals contained in mudstones and shales undergo diagenetic reactions in response to increasing depth and temperature. Quantitatively, the most important change is the progressive reaction of smectite to form illite via a series of intermediate illite/smectite (I/S) mixed-layer minerals. In general, progressive changes are irreversible so that where basinal sequences have been inverted clay mineral evidence of the maximum burial depth is retained and can be used to estimate the amount of uplift. According to the Basin Maturity Chart of Merriman & Kemp (1996)<ref name="Merriman 1996">Merriman, R J, and Kemp, S J. 1996. Clay minerals and sedimentary basin maturity. ''Mineralogical Society Bulletin'', 111, 7–8.</ref>, the presence of I/S (90% illite) in the rocks from the Cleveland Basin suggests burial depths of 4&nbsp;km, assuming a 'normal' geothermal gradient of 25–30°C/km. The I/S (80% illite) in the sample from Area 3 (East Midlands Shelf), therefore, suggests shallower burial to perhaps 3&nbsp;km while the presence of smectite and kaolinite suggest that the mudstones from southern England are more immature and have only been buried to depths of less than c.&nbsp;3 km if the same geothermal gradient is assumed. These estimates are compared with those obtained independently from geological evidence in Table 3.4. See also <ins style="font-weight: bold; text-decoration: none;">[[OR/12/032 Weathering#Lithology-based domains|Lithology-based domains]]</ins>.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><center></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><center></div></td></tr>
</table>Ajhilhttps://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=43696&oldid=prevDbk: /* Discussion */2019-11-27T15:24:56Z<p><span dir="auto"><span class="autocomment">Discussion</span></span></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en-GB">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:24, 27 November 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l860">Line 860:</td>
<td colspan="2" class="diff-lineno">Line 860:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Discussion==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Discussion==</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Mineralogical analysis of Lias Group samples from various sites representing a relatively large geographic and stratigraphic range have generally similar mineralogies to those described in previous studies (e.g. Kemp & Hards, 2000<ref name="Kemp & Hards 2000"></ref>; Mitchell, 1992<ref name="Mitchell 1992"></ref>; Bloodworth et al., 1987<ref name="Bloodworth 1987"><del style="font-weight: bold; text-decoration: none;">Bloodworth, A J, Kemp, S J, Inglethorpe, S D J, and Morgan, D J. 1987. Mineralogy and lithochemistry of strata beneath proposed low-level radioactive waste site at Fulbeck, Lincolnshire; Report to Sir Alexander Gibb and Partners, Site Investigation Consultants. ''British Geological Survey, Mineralogy and Petrology Technical Report'' No 87/15/C. </del></ref>; Pye & Krinsley, 1986<ref name="Pye 1986"></ref>; Cosgrove & Slater, 1966<ref name="Cosgrove 1966"></ref>). Non-clay mineral assemblages are typically composed of carbonates (calcite and dolomite), quartz, feldspar (albite and occasional Kfeldspar), ‘mica’, pyrite, gypsum and jarosite. Clay mineral assemblages are generally formed of illite, smectite or illite/smectite, kaolinite and chlorite.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Mineralogical analysis of Lias Group samples from various sites representing a relatively large geographic and stratigraphic range have generally similar mineralogies to those described in previous studies (e.g. Kemp & Hards, 2000<ref name="Kemp & Hards 2000"></ref>; Mitchell, 1992<ref name="Mitchell 1992"></ref>; Bloodworth et al., 1987<ref name="Bloodworth 1987"></ref>; Pye & Krinsley, 1986<ref name="Pye 1986"></ref>; Cosgrove & Slater, 1966<ref name="Cosgrove 1966"></ref>). Non-clay mineral assemblages are typically composed of carbonates (calcite and dolomite), quartz, feldspar (albite and occasional Kfeldspar), ‘mica’, pyrite, gypsum and jarosite. Clay mineral assemblages are generally formed of illite, smectite or illite/smectite, kaolinite and chlorite.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The relatively complex mineralogies of the Lias Group samples are difficult to quantify, even by employing state-of-the-art software modelling packages. For this reason the quoted mineral concentrations must be regarded with some caution. However, calculations using approximate values for %clay (from whole-rock XRD), the clay mineral concentrations from <2 µm XRD analysis and assuming theoretical surface area values for the individual clay minerals, reveal similar whole-rock surface area values to those determined empirically (Figure 3.3).</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The relatively complex mineralogies of the Lias Group samples are difficult to quantify, even by employing state-of-the-art software modelling packages. For this reason the quoted mineral concentrations must be regarded with some caution. However, calculations using approximate values for %clay (from whole-rock XRD), the clay mineral concentrations from <2 µm XRD analysis and assuming theoretical surface area values for the individual clay minerals, reveal similar whole-rock surface area values to those determined empirically (Figure 3.3).</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=43695&oldid=prevDbk: /* Discussion */2019-11-27T15:24:13Z<p><span dir="auto"><span class="autocomment">Discussion</span></span></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en-GB">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:24, 27 November 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l860">Line 860:</td>
<td colspan="2" class="diff-lineno">Line 860:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Discussion==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Discussion==</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Mineralogical analysis of Lias Group samples from various sites representing a relatively large geographic and stratigraphic range have generally similar mineralogies to those described in previous studies (e.g. Kemp & Hards, 2000<ref name="Kemp & Hards 2000"></ref>; Mitchell, 1992<ref name="Mitchell 1992"></ref>; Bloodworth et al., 1987<ref name="Bloodworth 1987">Bloodworth, A J, Kemp, S J, Inglethorpe, S D J, and Morgan, D J. 1987. Mineralogy and lithochemistry of strata beneath proposed low-level radioactive waste site at Fulbeck, Lincolnshire; Report to Sir Alexander Gibb and Partners, Site Investigation Consultants. ''British Geological Survey, Mineralogy and Petrology Technical Report'' No 87/15/C. </ref>; Pye & Krinsley, 1986<ref name="Pye 1986"></ref>; Cosgrove & Slater, 1966<ref name="Cosgrove 1966"><del style="font-weight: bold; text-decoration: none;">Cosgrove, M E, and Slater, D L. 1966. The stratigraphical distribution of kaolinite in the post- Armorican formations of South-West England. ''Proceedings of the Ussher Society'', 1, 5, 249–252. </del></ref>). Non-clay mineral assemblages are typically composed of carbonates (calcite and dolomite), quartz, feldspar (albite and occasional Kfeldspar), ‘mica’, pyrite, gypsum and jarosite. Clay mineral assemblages are generally formed of illite, smectite or illite/smectite, kaolinite and chlorite.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Mineralogical analysis of Lias Group samples from various sites representing a relatively large geographic and stratigraphic range have generally similar mineralogies to those described in previous studies (e.g. Kemp & Hards, 2000<ref name="Kemp & Hards 2000"></ref>; Mitchell, 1992<ref name="Mitchell 1992"></ref>; Bloodworth et al., 1987<ref name="Bloodworth 1987">Bloodworth, A J, Kemp, S J, Inglethorpe, S D J, and Morgan, D J. 1987. Mineralogy and lithochemistry of strata beneath proposed low-level radioactive waste site at Fulbeck, Lincolnshire; Report to Sir Alexander Gibb and Partners, Site Investigation Consultants. ''British Geological Survey, Mineralogy and Petrology Technical Report'' No 87/15/C. </ref>; Pye & Krinsley, 1986<ref name="Pye 1986"></ref>; Cosgrove & Slater, 1966<ref name="Cosgrove 1966"></ref>). Non-clay mineral assemblages are typically composed of carbonates (calcite and dolomite), quartz, feldspar (albite and occasional Kfeldspar), ‘mica’, pyrite, gypsum and jarosite. Clay mineral assemblages are generally formed of illite, smectite or illite/smectite, kaolinite and chlorite.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The relatively complex mineralogies of the Lias Group samples are difficult to quantify, even by employing state-of-the-art software modelling packages. For this reason the quoted mineral concentrations must be regarded with some caution. However, calculations using approximate values for %clay (from whole-rock XRD), the clay mineral concentrations from <2 µm XRD analysis and assuming theoretical surface area values for the individual clay minerals, reveal similar whole-rock surface area values to those determined empirically (Figure 3.3).</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The relatively complex mineralogies of the Lias Group samples are difficult to quantify, even by employing state-of-the-art software modelling packages. For this reason the quoted mineral concentrations must be regarded with some caution. However, calculations using approximate values for %clay (from whole-rock XRD), the clay mineral concentrations from <2 µm XRD analysis and assuming theoretical surface area values for the individual clay minerals, reveal similar whole-rock surface area values to those determined empirically (Figure 3.3).</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=40993&oldid=prevDbk: 1 revision imported2019-05-28T14:30:06Z<p>1 revision imported</p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<tr class="diff-title" lang="en-GB">
<td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 14:30, 28 May 2019</td>
</tr><tr><td colspan="2" class="diff-notice" lang="en-GB"><div class="mw-diff-empty">(No difference)</div>
</td></tr></table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=40992&oldid=prevAjhil at 10:24, 9 May 20192019-05-09T10:24:00Z<p></p>
<a href="https://earthwise.bgs.ac.uk/index.php?title=OR/12/032_Mineralogy&diff=40992">Show changes</a>Ajhil