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	<id>http://earthwise-staging.bgs.ac.uk/index.php?action=history&amp;feed=atom&amp;title=Wales_%28Cymru%29_-_North_Wales_Coalfield</id>
	<title>Wales (Cymru) - North Wales Coalfield - Revision history</title>
	<link rel="self" type="application/atom+xml" href="http://earthwise-staging.bgs.ac.uk/index.php?action=history&amp;feed=atom&amp;title=Wales_%28Cymru%29_-_North_Wales_Coalfield"/>
	<link rel="alternate" type="text/html" href="http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;action=history"/>
	<updated>2026-04-17T15:00:32Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.42.3</generator>
	<entry>
		<id>http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=27546&amp;oldid=prev</id>
		<title>Dbk at 09:08, 19 April 2016</title>
		<link rel="alternate" type="text/html" href="http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=27546&amp;oldid=prev"/>
		<updated>2016-04-19T09:08:33Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 10:08, 19 April 2016&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l7&quot;&gt;Line 7:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 7:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;==Basement rocks==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;==Basement rocks==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the north-west Wales area.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the north-west Wales area.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Category:&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;18. &lt;/del&gt;Wales (Cymru) | 05]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Category:Wales (Cymru) &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;- summary &lt;/ins&gt;| 05]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Dbk</name></author>
	</entry>
	<entry>
		<id>http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=6615&amp;oldid=prev</id>
		<title>Jeth1 at 11:54, 4 November 2014</title>
		<link rel="alternate" type="text/html" href="http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=6615&amp;oldid=prev"/>
		<updated>2014-11-04T11:54:42Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 12:54, 4 November 2014&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The North Wales Coalfield is defined by a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;north - south &lt;/del&gt;surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;extend &lt;/del&gt;from Deeside south through Wrexham to Oswestry. The geography is dominated by a prominent ridge of Carboniferous Limestone in the west and falls gently eastwards toward the low ground of the Cheshire Plain of the Central England region in a series of low ridges.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The North Wales Coalfield is defined by a &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;north—south trending &lt;/ins&gt;surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;extends &lt;/ins&gt;from Deeside south through Wrexham to Oswestry. The geography is dominated by a prominent ridge of Carboniferous Limestone in the west and falls gently eastwards toward the low ground of the Cheshire Plain of the Central England region in a series of low ridges.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Image:P662426.jpg|thumb|300px|Carboniferous Limestone sedimentary rocks forming the escarpment of Mynydd Eglwysseg, Llangollen. P662426.]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Image:P662426.jpg|thumb|300px|Carboniferous Limestone sedimentary rocks forming the escarpment of Mynydd Eglwysseg, Llangollen. P662426.]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;=&lt;/del&gt;==Sedimentary &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Bedrock=&lt;/del&gt;==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;==Sedimentary &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;bedrock&lt;/ins&gt;==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The youngest &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Sedimentary Bedrock &lt;/del&gt;is the Coal Measures, comprising a thick, densely faulted sequence of alternating grey mudstones and sandstones with thin coal seams that together make up the formerly productive part of the North Wales Coalfield. These rocks formed from vast quantities of sediment being transported by large river deltas. Occasionally the tops of these deltas were exposed, which allowed massive swampy forests to develop. After burial the vegetation from these forests was compressed to produce layers of coal. The upper part of this sequence comprises red sandstone and mudstones without economic coal layers. The Coal Measures pass down into layers of sandstones and mudstone collectively known as the Millstone Grit. The lowest part of the succession comprises layers of Carboniferous Limestone (Plate P662426) that generally dip toward the east and &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;extends &lt;/del&gt;under the rest of the area at depth. As well as exploitation of coal seams, the limestone is host to mineral deposits of lead that were widely mined in the past. More recent interest in the Coal Measures has focused on their potential as a resource for gas. As well as its mineral potential, the presence of significant fractures in the Carboniferous Limestone means that it is a locally important minor aquifer that represents a significant source of public water supply.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The youngest &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;sedimentary bedrock &lt;/ins&gt;is the Coal Measures, comprising a thick, densely faulted sequence of alternating grey mudstones and sandstones with thin coal seams that together make up the formerly productive part of the North Wales Coalfield. These rocks formed from vast quantities of sediment being transported by large river deltas. Occasionally the tops of these deltas were exposed, which allowed massive swampy forests to develop. After burial the vegetation from these forests was compressed to produce layers of coal. The upper part of this sequence comprises red sandstone and mudstones without economic coal layers. The Coal Measures pass down into layers of sandstones and mudstone collectively known as the Millstone Grit. The lowest part of the succession comprises layers of Carboniferous Limestone (&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&#039;&#039;&#039;&lt;/ins&gt;Plate P662426&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&#039;&#039;&#039;&lt;/ins&gt;) that generally dip toward the east and &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;extend &lt;/ins&gt;under the rest of the area at depth. As well as exploitation of coal seams, the limestone is host to mineral deposits of lead that were widely mined in the past. More recent interest in the Coal Measures has focused on their potential as a resource for gas. As well as its mineral potential, the presence of significant fractures in the Carboniferous Limestone means that it is a locally important minor aquifer that represents a significant source of public water supply.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;=&lt;/del&gt;==Basement rocks&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;=&lt;/del&gt;==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;==Basement rocks==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Northwest &lt;/del&gt;Wales area.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;north-west &lt;/ins&gt;Wales area.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Category:18. Wales (Cymru) | 05]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Category:18. Wales (Cymru) | 05]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Jeth1</name></author>
	</entry>
	<entry>
		<id>http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=6515&amp;oldid=prev</id>
		<title>Dbk at 15:16, 10 October 2014</title>
		<link rel="alternate" type="text/html" href="http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=6515&amp;oldid=prev"/>
		<updated>2014-10-10T15:16:06Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 16:16, 10 October 2014&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The North Wales Coalfield is defined by a north - south surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that extend from Deeside south through Wrexham to Oswestry. The geography is dominated by a prominent ridge of Carboniferous Limestone in the west and falls gently eastwards toward the low ground of the Cheshire Plain of the Central England region in a series of low ridges.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The North Wales Coalfield is defined by a north - south surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that extend from Deeside south through Wrexham to Oswestry. The geography is dominated by a prominent ridge of Carboniferous Limestone in the west and falls gently eastwards toward the low ground of the Cheshire Plain of the Central England region in a series of low ridges.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Image:P662426.jpg|thumb|300px|Carboniferous Limestone sedimentary rocks forming the escarpment of Mynydd Eglwysseg, Llangollen. P662426.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;===Sedimentary Bedrock===&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;===Sedimentary Bedrock===&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The youngest Sedimentary Bedrock is the Coal Measures, comprising a thick, densely faulted sequence of alternating grey mudstones and sandstones with thin coal seams that together make up the formerly productive part of the North Wales Coalfield. These rocks formed from vast quantities of sediment being transported by large river deltas. Occasionally the tops of these deltas were exposed, which allowed massive swampy forests to develop. After burial the vegetation from these forests was compressed to produce layers of coal. The upper part of this sequence comprises red sandstone and mudstones without economic coal layers. The Coal Measures pass down into layers of sandstones and mudstone collectively known as the Millstone Grit. The lowest part of the succession comprises layers of Carboniferous Limestone (&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Figure 8&lt;/del&gt;) that generally dip toward the east and extends under the rest of the area at depth. As well as exploitation of coal seams, the limestone is host to mineral deposits of lead that were widely mined in the past. More recent interest in the Coal Measures has focused on their potential as a resource for gas. As well as its mineral potential, the presence of significant fractures in the Carboniferous Limestone means that it is a locally important minor aquifer that represents a significant source of public water supply.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;The youngest Sedimentary Bedrock is the Coal Measures, comprising a thick, densely faulted sequence of alternating grey mudstones and sandstones with thin coal seams that together make up the formerly productive part of the North Wales Coalfield. These rocks formed from vast quantities of sediment being transported by large river deltas. Occasionally the tops of these deltas were exposed, which allowed massive swampy forests to develop. After burial the vegetation from these forests was compressed to produce layers of coal. The upper part of this sequence comprises red sandstone and mudstones without economic coal layers. The Coal Measures pass down into layers of sandstones and mudstone collectively known as the Millstone Grit. The lowest part of the succession comprises layers of Carboniferous Limestone (&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Plate P662426&lt;/ins&gt;) that generally dip toward the east and extends under the rest of the area at depth. As well as exploitation of coal seams, the limestone is host to mineral deposits of lead that were widely mined in the past. More recent interest in the Coal Measures has focused on their potential as a resource for gas. As well as its mineral potential, the presence of significant fractures in the Carboniferous Limestone means that it is a locally important minor aquifer that represents a significant source of public water supply.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;===Basement rocks===&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;===Basement rocks===&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the Northwest Wales area.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the Northwest Wales area.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Category:18. Wales (Cymru) | 05]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;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;&quot;&gt;&lt;div&gt;[[Category:18. Wales (Cymru) | 05]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Dbk</name></author>
	</entry>
	<entry>
		<id>http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=6153&amp;oldid=prev</id>
		<title>Dbk: Created page with &quot;The North Wales Coalfield is defined by a north - south surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that extend from Deeside south through Wr...&quot;</title>
		<link rel="alternate" type="text/html" href="http://earthwise-staging.bgs.ac.uk/index.php?title=Wales_(Cymru)_-_North_Wales_Coalfield&amp;diff=6153&amp;oldid=prev"/>
		<updated>2014-10-02T13:07:47Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;The North Wales Coalfield is defined by a north - south surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that extend from Deeside south through Wr...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;The North Wales Coalfield is defined by a north - south surface exposure of Carboniferous Limestone, Millstone Grit and Coal Measures that extend from Deeside south through Wrexham to Oswestry. The geography is dominated by a prominent ridge of Carboniferous Limestone in the west and falls gently eastwards toward the low ground of the Cheshire Plain of the Central England region in a series of low ridges.&lt;br /&gt;
&lt;br /&gt;
===Sedimentary Bedrock===&lt;br /&gt;
The youngest Sedimentary Bedrock is the Coal Measures, comprising a thick, densely faulted sequence of alternating grey mudstones and sandstones with thin coal seams that together make up the formerly productive part of the North Wales Coalfield. These rocks formed from vast quantities of sediment being transported by large river deltas. Occasionally the tops of these deltas were exposed, which allowed massive swampy forests to develop. After burial the vegetation from these forests was compressed to produce layers of coal. The upper part of this sequence comprises red sandstone and mudstones without economic coal layers. The Coal Measures pass down into layers of sandstones and mudstone collectively known as the Millstone Grit. The lowest part of the succession comprises layers of Carboniferous Limestone (Figure 8) that generally dip toward the east and extends under the rest of the area at depth. As well as exploitation of coal seams, the limestone is host to mineral deposits of lead that were widely mined in the past. More recent interest in the Coal Measures has focused on their potential as a resource for gas. As well as its mineral potential, the presence of significant fractures in the Carboniferous Limestone means that it is a locally important minor aquifer that represents a significant source of public water supply.&lt;br /&gt;
&lt;br /&gt;
===Basement rocks===&lt;br /&gt;
These rocks underlie the whole area at great depth. They comprise strongly folded and faulted mudstones and sandstones like those exposed in the east of the Northwest Wales area.&lt;br /&gt;
[[Category:18. Wales (Cymru) | 05]]&lt;/div&gt;</summary>
		<author><name>Dbk</name></author>
	</entry>
</feed>