Editing Permian rocks of south-central Yorkshire - 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 35: Line 35:
 
== Excursion details ==
 
== Excursion details ==
  
=== Locality 1 [SE 487 066], part of former Bilham Sand Quarry S.S.S.I. (25 mins) ===
+
=== Locality 1 [SE 487 066], part of former Bilham Sand Quarry S.S.S.I. (25 mins) ===
  
Park in the gateway [SE 4870 0672] opposite the sharp bend in the lane and walk 120  m to the southeast. This is a small conserved exposure straddling the contract of the Basal Permian (Yellow) Sands and the overlying Wetherby Member of the Cadeby Formation (Cycle EZ1). The Carboniferous/Permian unconformity was formerly exposed here but now lies 1–1.5 m below the quarry floor.
+
Park in the gateway [SE 4870 0672] opposite the sharp bend in the lane and walk 120 m to the southeast. This is a small conserved exposure straddling the contract of the Basal Permian (Yellow) Sands and the overlying Wetherby Member of the Cadeby Formation (Cycle EZ1). The Carboniferous/Permian unconformity was formerly exposed here but now lies 1–1.5 m below the quarry floor.
  
The Basal Permian Sands here are about 3.3 m thick (including the part now covered) and comprise almost level-bedded, yellow-brown, mainly medium-grained '''arkosic''' quartz sand with a patchy very weak carbonate cement; most of the grains are sub-angular to sub-rounded but some of the larger grains are rounded to well-rounded. The deposit is thought to have been a desert dune sand that was redistributed when the Zechstein Sea flooded the area.
+
The Basal Permian Sands here are about 3.3 m thick (including the part now covered) and comprise almost level-bedded, yellow-brown, mainly medium-grained arkosic quartz sand with a patchy very weak carbonate cement; most of the grains are sub-angular to sub-rounded but some of the larger grains are rounded to well-rounded. The deposit is thought to have been a desert dune sand that was redistributed when the Zechstein Sea flooded the area.
  
The contact with the Wetherby Member here is smooth, sharp and almost horizontal and the exposed basal part of the Wetherby Member comprises about 3.5 m of thin-bedded buff finely crystalline dolomite; the lowest 0.8 m of this may be an altered oolite. The dolomite contains several films and thin beds of brown dolomitic clay and scattered, poorly preserved casts of small '''bivalves'''; it is interpreted as a marine deposit, formed under relatively shallow water of low to moderate energy.
+
The contact with the Wetherby Member here is smooth, sharp and almost horizontal and the exposed basal part of the Wetherby Member comprises about 3.5 m of thin-bedded buff finely crystalline dolomite; the lowest 0.8 m of this may be an altered oolite. The dolomite contains several films and thin beds of brown dolomitic clay and scattered, poorly preserved casts of small bivalves; it is interpreted as a marine deposit, formed under relatively shallow water of low to moderate energy.
  
=== Locality 2 [SE 483 074], an old quarry in Second Plantation, Hooton Pagnell (20 mins) ===
+
=== Locality 2 [SE 483 074], an old quarry in Second Plantation, Hooton Pagnell (20 mins) ===
  
Park on the wide verge at the sharp corner of the lane and scramble 15 m to the north-northwest. This small quarry is cut into the escarpment of the Wetherby Member of the Cadeby Formation and supplied building stone. About 6 m of mainly thick-bedded buff shelly oolitic dolomite is exposed, the lowest beds lying an estimated 3–4 m above the unconformity (Basal Permian Sands being thin or absent). Some of the beds are so rich in shelly remains, mainly of the bivalves ''Bakevellia, Liebea, Permophorus ''and ''Schizodus, ''that they constitute coquinas and must have been shell-banks when they were formed. Where joints are widely spaced, these thick beds yielded blocks large enough to be used for window and door lintels and gate posts, all to be seen in and around nearby Hooton Pagnell village (Locality 3). Fully marine but very shallow-water and at least moderate energy conditions probably prevailed here when these sediments were accumulating.
+
Park on the wide verge at the sharp corner of the lane and scramble 15 m to the north-northwest. This small quarry is cut into the escarpment of the Wetherby Member of the Cadeby Formation and supplied building stone. About 6 m of mainly thick-bedded buff shelly oolitic dolomite is exposed, the lowest beds lying an estimated 3–4 m above the unconformity (Basal Permian Sands being thin or absent). Some of the beds are so rich in shelly remains, mainly of the bivalves ''Bakevellia, Liebea, Permophorus ''and ''Schizodus, ''that they constitute coquinas and must have been shell-banks when they were formed. Where joints are widely spaced, these thick beds yielded blocks large enough to be used for window and door lintels and gate posts, all to be seen in and around nearby Hooton Pagnell village (Locality 3). Fully marine but very shallow-water and at least moderate energy conditions probably prevailed here when these sediments were accumulating.
  
Fields immediately southeast of Locality 2 comprise a '''dip'''-slope, which is cut by a southwest–northeast fault that '''throws''' up Coal Measures to the southeast and brings in a second Permian escarpment at Bilham Sand Quarry (Locality 1).
+
Fields immediately southeast of Locality 2 comprise a dip-slope, which is cut by a southwest–northeast fault that throws up Coal Measures to the southeast and brings in a second Permian escarpment at Bilham Sand Quarry (Locality 1).
  
 
=== Locality 3 [SE 4808), Hooton Pagnell village (45 mins) ===
 
=== Locality 3 [SE 4808), Hooton Pagnell village (45 mins) ===

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>