Editing Permian and Carboniferous rocks of Knaresborough - an excursion

Jump to navigation Jump to search

Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.

The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.

This page supports semantic in-text annotations (e.g. "[[Is specified as::World Heritage Site]]") to build structured and queryable content provided by Semantic MediaWiki. For a comprehensive description on how to use annotations or the #ask parser function, please have a look at the getting started, in-text annotation, or inline queries help pages.

Latest revision Your text
Line 3: Line 3:
 
[[File:YGS_YORKROCK_FIG_13_01.jpg|thumbnail|Figure 13.1 Geological map and cross-section of the Knaresborough area (with palaeocurrent information from Dr J. G. KaIdi).]]
 
[[File:YGS_YORKROCK_FIG_13_01.jpg|thumbnail|Figure 13.1 Geological map and cross-section of the Knaresborough area (with palaeocurrent information from Dr J. G. KaIdi).]]
 
[[File:YGS_YORKROCK_FIG_13_02.jpg|thumbnail|Figure 13.2 Carboniferous-Permian unconformity at Abbey Crags (Locality 4). Photo: B.G.S.]]
 
[[File:YGS_YORKROCK_FIG_13_02.jpg|thumbnail|Figure 13.2 Carboniferous-Permian unconformity at Abbey Crags (Locality 4). Photo: B.G.S.]]
 +
  
 
'''By Anthony Cooper''' British Geological Survey
 
'''By Anthony Cooper''' British Geological Survey
Line 88: Line 89:
 
=== Locality 14 [SE 3425 5742] ===
 
=== Locality 14 [SE 3425 5742] ===
  
Continue upstream past the High Bridge to Conyngham Hall Farm, where the track crosses the river again. About 50 m to the east, in the wooded area below Conyngham Hall, the attenuated Cadeby Formation (only 1.2 m thick) is seen resting on weathered purple-brown Carboniferous siltstones, and overlain by the Edlington Formation. The exposed Edlington Formation comprises 2.6 m of red-brown mudstone and sandstone. It includes sandy and micaceous detritus derived from Carboniferous sandstones similar to those exposed 100 m to the east, where the Edlington Formation rests directly on Carboniferous strata. The north–south cross-section through here is similar to the east–west cross-section shown in [[:File:YGS_YORKROCK_FIG_13_01.jpg|Figure 13.1]].
+
Continue upstream past the High Bridge to Conyngham Hall Farm, where the track crosses the river again. About 50 m to the east, in the wooded area below Conyngham Hall, the attenuated Cadeby Formation (only 1.2 m thick) is seen resting on weathered purple-brown Carboniferous siltstones, and overlain by the Edlington Formation. The exposed Edlington Formation comprises 2.6 m of red-brown mudstone and sandstone. It includes sandy and micaceous detritus derived from Carboniferous sandstones similar to those exposed 100 m to the east, where the Edlington Formation rests directly on Carboniferous strata. The north–south cross-section through here is similar to the east–west cross-section shown in [[:File:YGS_YORKROCK_FIG_13_01.jpg|Figure 13.1]].
  
 
=== Locality 15 [SE 342 575] ===
 
=== Locality 15 [SE 342 575] ===
  
Near Conyngham Hall Farm the Upper Follifoot Grit crosses the river, forming the foundations of the bridge. The sandstone dips to the east at 27° and comprises some 7 m of fine to medium-grained sandstone with subordinate siltstone partings and a thick bed of siliceous '''ganister''' with rootlets near the middle of the unit. The Carboniferous rocks here, and at Locality 16, dip steeply eastwards around the nose of the Harrogate Anticline. The resistant sandstone units form small escarpments projecting above the general level of the sub-Permian unconformity, and the basal Permian sedimentary rocks are banked against them.
+
Near Conyngham Hall Farm the Upper Follifoot Grit crosses the river, forming the foundations of the bridge. The sandstone dips to the east at 27° and comprises some 7 m of fine to medium-grained sandstone with subordinate siltstone partings and a thick bed of siliceous ganister with rootlets near the middle of the unit. The Carboniferous rocks here, and at Locality 16, dip steeply eastwards around the nose of the Harrogate Anticline. The resistant sandstone units form small escarpments projecting above the general level of the sub-Permian unconformity, and the basal Permian sedimentary rocks are banked against them.
  
 
=== Locality 16 [SE 3413 5722] ===
 
=== Locality 16 [SE 3413 5722] ===
  
Follow the river southwards to Foolish Wood where in an old, difficult to find, quarry the Upper Follifoot Grit dips southwest at 27°. At the back of the quarry, sub-horizontal dolomite, 0.5 m thick, of the Cadeby Formation rests with a basal '''conglomerate''' of local material on an irregular sandstone surface, and is overlain by red siltstone. The sandstone apparently formed a ridge on the sea-floor prior to the deposition of the Cadeby Formation. Only a few metres to the north of the quarry, where the dolomite rests on siltstones underlying the Upper Follifoot Grit it thickens to 3 m, forming an escarpment from which large blocks have slipped down to the river bank.
+
Follow the river southwards to Foolish Wood where in an old, difficult to find, quarry the Upper Follifoot Grit dips southwest at 27°. At the back of the quarry, sub-horizontal dolomite, 0.5 m thick, of the Cadeby Formation rests with a basal conglomerate of local material on an irregular sandstone surface, and is overlain by red siltstone. The sandstone apparently formed a ridge on the sea-floor prior to the deposition of the Cadeby Formation. Only a few metres to the north of the quarry, where the dolomite rests on siltstones underlying the Upper Follifoot Grit it thickens to 3 m, forming an escarpment from which large blocks have slipped down to the river bank.
  
 
Continue southwards on the west side of the River Nidd to Old Mother Shipton's car park; ensure that you arrive back before the car park closes.
 
Continue southwards on the west side of the River Nidd to Old Mother Shipton's car park; ensure that you arrive back before the car park closes.

Please note that all contributions to Earthwise may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Earthwise:Copyrights for details). Do not submit copyrighted work without permission!

Cancel Editing help (opens in new window)

  [] · [[]] · [[|]] · {{}} · · “” ‘’ «» ‹› „“ ‚‘ · ~ | °   · ± × ÷ ² ³ ½ · §
[[Category:]] · [[:File:]] · <code></code> · <syntaxhighlight></syntaxhighlight> · <includeonly></includeonly> · <noinclude></noinclude> · #REDIRECT[[]] · <translate></translate> · <languages/> · ==References== · {{reflist}} · ==Footnote== · {{reflist|group=note}} · <ref group=note> · __notoc__ · {{DEFAULTSORT:}} <div class="someclass noprint"></div> {{clear}} <br>