Exploring the Geology of the Sychryd Gorge

!"#$%&'()*+,-*./0,&/1*2%&)-* * * 3*4&'-5*+%6&*7*7*7*7*7** 9:(19+%(-9*%5*+,-*>)??2&#/012&+@4)+0-%+,-.#>:?+,-.&7* 8,-*&'>-&*9'1-9*5:$$*4:0G*:(1*+,-*)&%6(1*'9*5%&;-1*4/*:(* !"#8,-*90&:;4$-*1%<(*5&%;*+,-*&%:1*+%*+,-*;%6+,*%5*+,-* :99%&+;-(+*%5*$%%9-*4%6$1-&9*:(1*9,'()$-*4:(G97** ./0,&/1*;͚ƚŚĞŽŶĨůƵĞŶĐĞ͛=*'9*%>-&*9+--#$/*+'$+-1*4-19*%5*+,-* * $%%&'#()*&+,-.&#/012&+*ʹ*:$+-&(:+'()*4-19*%5*$';-9+%(-* A"#L(*+,-*(%&+,-:9+*9'1-*%5*+,-*&'>-&*M+&6-*&'),+*4:(G=B*(-:&* :(1*;619+%(-?9,:$-7* +,-*:00-99*+&:0GB*:*<,'+-N)&-/*1-#%9'+*0:(*4-*9--(*'(*:* * >-)-+:+-1*4:(G7*8,'9*'9*:*;:(N;:1-*1-#%9'+H*<:9+-*2)*&* 1:+'()*5&%;*+,-*1:/9*<,-(*:*$';-G'$(*<:9*'(*%#-&:+'%(*:+* +,-*+%#*%5*+,-*4:(G7* *

!"#$%&'()*+,-*./0,&/1*2%&)-* * * 3*4&'-5*+%6&*7*7*7*7*7** 9:(19+%(-9*%5*+,-*>)??2&#/012&+@4)+0-%+,-.#>:?+,-.&7*

* 8,-*&'>-&*9'1-9*5:$$*4:0G*:(1*+,-*)&%6(1*'9*5%&;-1*4/*:(* !"#8,-*90&:;4$-*1%<(*5&%;*+,-*&%:1*+%*+,-*;%6+,*%5*+,-* Fig:99%&+;-(+*%5*$%%9-*4%6$1-&9*:(1*9,'()$-*4:(G97* A: Upper Limestone Shales at the confluence* # ./0,&/1*;͚ƚŚĞŽŶĨůƵĞŶĐĞ͛=*'9*%>-&*9+--#$/*+'$+-1*4-19*%5*+,-* * $%%&'#()*&+,-.&#/012&+!"#$%&'()*+,-**ʹ*:$+-&(:+'()*4-19*%5*$';-9+%(-*./0,&/1*2%&)-* A"#L(*+,-*(%&+,-:9+*9'1-*%5*+,-*&'>-&*M+&6-*&'),+*4:(G=B*(-:&* Fig C: Lime waste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;͚ƚŚĞŽŶĨůƵĞŶĐĞ͛=*'9*%>-&*9+--#$/*+'$+-1*4-19*%5*+,-* * &'>-&*:(1*'9*0$-:&$/*0%()$%;-&:+'0*'-*0%(+:'(9*#-44$-9B* ͚ZŽŽƚƐdƌĂǀĞƌƐĞ͛=B*:*+,'(*%6+0&%#*%5*9:(19+%(-*9+&-+0,-9* $%%&'#()*&+,-.&#/012&+*ʹ*:$+-&(:+'()*4-19*%5*$';-9+%(-* +,-*+%#*%5*+,-*4:(G7* Exploring the Geology of the Sychryd Gorge A Brief Tour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n the bed of the Mellte, '(*0%(+&:9+*+%*+,-*-:&$'-&*$';-9+%(-B*+,'9*9:(19+%(-*'9* if the water ﬂow is low, the 1'##'()*9%6+,<:&197* 1. The scramble down from the contact between the Upper * * ** road to the mouth of the Limestone Shales and the * Sychryd (‘the Conﬂuence’) is over Basal Grit can be seen. The steeply lted beds of the Upper Basal Grit here forms the Limestone Shales – alternang bed of the river and is

* beds of limestone and mudstone/ Fig A: Upper Limestone Shales at the clearly conglomerac ie confluence#

shale. * contains pebbles, almost all Fig A: Upper Limestone Shales at the confluence * # are quartz. * 3"#@(*+,-*4-1*%5*+,-*A-$$+-B*'5*+,-*<:+-&*5$%<*'9*$%-&*4-(1B*(-:&*+,-*+&--*<'+,*-"#%9-1*&%%+9*M!"#! 3*4&'-5*+%6&*7*7*7*7*7** 9:(19+%(-9*%5*+,-*>)??2&#/012&+@4)+0-%+,-.#>:?+,-.&7* B"#3+*+,-*&'>-&*4-(1B*(-:&*+,-*+&--*<'+,*-"#%9-1*&%%+9# *M!"#! 8,-*&'>-&*9'1-9*5:$&'>-&*:(1*'9*0$-:&$/*0%()$%;-&:+'0*'-*&'>-&*:(1*'9*0$-:&$/*0%()$%;-&:+'0*'-*$*4:0G*:(1*+,-*)&%6(1*'9*5%&;-1*4/*:(*0%(+:'(9*#-44$-9B*0%(+:'(9*#-44$-9B*͚ZŽŽƚƐdƌĂǀĞƌƐĞ͛=B*:*+,'(*%6+0&%#*%5*9:(19+%(-*9+&-+0,-9*͚ZŽŽƚƐdƌĂǀĞƌƐĞ͛=B*:*+,'(*%6+0&%#*%5*9:(19+%(-*9+&-+0,-9* !"#8,-*90&:;4$-*1%<(*5&%;*+,-*&%:1*+%*+,-*;%6+,*%5*+,-* :$;%9+*:$$*:&-*D6:&+E7* :99%&+;-(+*%5*$%%9-*4%6$1-&9*:(1*9,'()$-*4:(G97*:$;%9+*:$$*:&-*D6:&+E7* * :0&%99*+,-*&'>-&7*8,-9-*9:(19+%(-96":0&%99*+,-*&'>-&7*8,-9-*9:(19+%(-9#F-:1'()*6#*+,-*(:&&%<*)%&)-*%5*+,-*./0,&/1*/%6*:$;%9+**:&-*+/#'0:$*%5*+,-# *:&-*+/#'0:$*%5*+,-# %&#!",!/./,4$,)4!/4+*!;͚ůƵĞ^ƚĂůDŝŶĞ͛7!+,*$!*0)!'()(*!+,-.! ./0,&/1*;͚ƚŚĞŽŶĨůƵĞŶĐĞ͛=*'9*%>-&*9+--#$/*+'$+-1*4-19*%5*+,-*3. Heading up the narrow gorge of the Sychryd you almost immediately enter the * 4. Upstream of the high arch of the road bridge, the gorge quickly widens out. This is because it 4)+0-%+,-.#>:?+,-.&#=-'*1,)-.H*+,-*$:&)-&*#:&+*'9*5%&;-1* * * ';;-1':+-$/*-(+-&*+,-*;:'(*4%1/*%5*+,-*4)+0-%+,-.#>:?+,-.&#=-'*1,)-.H*+,-*$:&)-&*#:&+*'9*5%&;-1*71'8-.)9&'-:+# $%%&'#()*&+,-.&#/012&+*ʹ*:$+-&(:+'()*4-19*%5*$';-9+%(-*main body of the Carboniferous Limestone – a very hard rock but one which is crosses the 5&%;*;619+%(-9*46+*%00:9'%(:$*9:(19+%(-9*:##-:&7*8,-/*Dinas Fault beyond which are the easily eroded mudstones and thin sandstones of $,!*0)!($2*01*#2)!9)-*!./,&!+(!-9$$4)4:! A"#L(*+,-*(%&+,-:9+*9'1-*%5*+,-*&'>-&*M+&6-*&'),+*4:(G=B*(-:&* ()*&+,-.&5&%;*;619+%(-9*46+*%00:9'%(:$*9:(19+%(-9*:##-:&7*8,-/**ʹ*:*>-&/*,:&1*&%0G*46+*%(-*<,'0,*'9*9%$64$-*'(* :(1*;619+%(-?9,:$-7* soluble in even mildly acidic water. The Sychryd has cut a passage through this band the Middle Shales/Bishopston Mudstone&-9'9+*-&%9'%(*&:+,-&*4-++-&*+,:(*+,-*;619+%(-97*O%+-*+,:+B*%&#!",!/./,4$,)4!/4+*!. The river sides fall back and the ground is formed by ;͚ůƵĞ^ƚĂůDŝŶĞ͛7!+,*$!*0)!'()(*!+,-.! Fig! D: erosion resistant sandstone within mudstones# +,-*:00-99*+&:0GB*:*<,'+-N)&-/*1-#%9'+*0:(*4-*9--(*'(*:* '(*0%(+&:9+*+%*+,-*-:&$'-&*$';-9+%(-B*+,'9*9:(19+%(-*'9* * of limestone; its flow has moulded the shapes of the gorge sides with potholes and an assortment of loose boulders and shingle banks.$,!*0)!($2*01*#2)!9)-*!./,&!+(!-9$$4)4:->-(*;'$1$/*:0'1'0*<:+-&7*8,-*./0,&/1*,:9*06+*:*#:99:)-*&-9'9+*-&%9'%(*&:+,-&*4-++-&*+,:(*+,-*;619+%(-97*O%+-*+,:+B*! # >-)-+:+-1*4:(G7*8,'9*'9*:*;:(N;:1-*1-#%9'+H*<:9+-*2)*&* 1'##'()*9%6+,<:&197* +,&%6),*+,'9*4:(1*%5*$';-9+%(-H*'+9*5$%<*,:9*;%6$1-1*+,-*'(*0%(+&:9+*+%*+,-*-:&$'-&*$';-9+%(-B*+,'9*9:(19+%(-*'9* scallop markings. The thick beds of limestone dip northwards ie towards the Mellte 1:+'()*5&%;*+,-*1:/9*<,-(*:*$';-G'$(*<:9*'(*%#-&:+'%(*:+* * ! C"#C$:0G*0%$%6&-1*;619+%(-*0:(*4-*9--(*'(*#$:0-9*'(*+,-* * ** * 1'##'()*9%6+,<:&197* at around 30degrees. +,-*+%#*%5*+,-*4:(G7* 9,:#-9*%5*+,-*)%&)-*9'1-9*<'+,*#%+,%$-9*:(1*90:$$%#* 4:(G9*%5*+,-*&'>-&H*+,-*4$:0G-&*+,-*0%$%6&B*+,-*,'),-&*'+9* ;:&G'()97* *8,-*+,'0G*4-19*%5*$';-9+%(-*1'#*(%&+,<:&19*'-* * ** * * 0:&4%(*0%(+-(+7*8,%9-*<'+,*,'),-9+*0:&4%(*0%(+-(+*;'),+* 5. On the northeast side of the 6. At the river bend, near +%<:&19*+,-*A-$$+-*:+*:&%6(1*IJ1-)&--97* 4-*0%(9'1-&-1*1'&+/*0%:$97*8,-*0:&4%(*'9*:$$*+,:+*'9*$-5+*%5* river (true right bank), near the the tree with exposed roots * >-)-+:+'%(*<,'0,*1'-1*:(1*<:9*0%;#:0+-1*:(1*<,'0,B*%>-&* access track, a white-grey deposit (the ‘Roots Traverse’), a ;"#K#9+&-:;*%5*+,-*,'),*:&0,*%5*+,-*&%:1*4&'1)-B*+,-*)%&)-* ;'$$'%(9*%5*/-:&9B*+6&(-1*+%*9+%(-7*8,-&-*'9*9%;-*'&%(N can be seen in a vegetated bank. thin outcrop of sandstone This is a man-made deposit; Fig B: Basal Grit in the bed of the M ellte:# stretches across the river. D6'0G$/*<'1-(9*%6+7*8,'9*'9*4-0:69-*'+*0&%99-9*+,-*<).1+#=1:2,* 9+:'('()*M&69+N0%$%6&=*:(1*:*/-$$%<*0%$%&:+'%(*%(*9%;-*&%0G* waste lime dang from the days # These sandstones are 4-/%(1*<,'0,*:&-*+,-*-:9'$/*-&%1-1*;619+%(-9*:(1*+,'(** 96&5:0-9*<,'0,*'9*2)*-.),&#M5')*!=7#* when a limekiln was in operaon 6"#F-:1'()*6#*+,-*(:&&%<*)%&)-*%5*+,-*./0,&/1*/%6*:$;%9+*typical of the Bishopston Fig E: Iron within mudstones at the top of the bank. ';;-1':+-$/*-(+-&*+,-*;:'(*4%1/*%5*+,-*Fig E: Iron within mudstones! 71'8-.)9&'-:+# Mudstone Formaon ; the ! ()*&+,-.&! Fig B*ʹ:*:*>-&/*,:&1*&%0G*46+*%(-*<,'0,*'9*9%$64$-*'(* Basal Grit in the bed of the M ellte:larger part is formed from # Fig D: erosion resistant! sandstone within mudstones# ->-(*;'$1$/*:0'1'0*<:+-&7*8,-*./0,&/1*,:9*06+*:*#:99:)-* * # "#!"!#$%&'!()%*+$,!$-!./,&!$,!*0)!,$#*01*#2)!#+30*!(+4)!$-!# mudstones but occasional "#!"!#$%&'!()%*+$,!$-!./,&!$,!*0)!,$#*01*#2)!#+30*!(+4)!$-! Fig A: Upper Limestone Shales at the confluence# +,&%6),*+,'9*4:(1*%5*$';-9+%(-H*'+9*5$%<*,:9*;%6$1-1*+,-*"# C"#C$:0G*0%$%6&-1*;619+%(-*0:(*4-*9--(*'(*#$:0-9*'(*+,-* *0)!#+5)#!6!"#$! $%&$͚>ŽǁĞƌƌŝĚŐĞdƌĂǀĞƌƐĞ͛Žƌ͚%&'()*+,-$sandstones appear. They "# * 9,:#-9*%5*+,-*)%&)-*9'1-9*<'+,*#%+,%$-9*:(1*90:$$%#*6"#F-:1'()*6#*+,-*(:&&%<*)%&)-*%5*+,-*./0,&/1*/%6*:$;%9+*4:(G9*%5*+,-*&'>-&H*+,-*4$:0G-&*+,-*0%$%6&B*+,-*,'),-&*'+9**0)!#+5)#!6!"#$! $%&$͚>ŽǁĞƌƌŝĚŐĞdƌĂǀĞƌƐĞ͛Žƌ͚%&'()*+,-$ ;:&G'()97ŽƌŶĞƌ͛7!*4+(89/'(!/!3)$9$3+%/9!-/29*:!;0+(!+(!$,)!$-!/!(>?@AAB!/9+3,)4!-/29*(!<0+%0!#2,!*0#$230!*&--97* 0)!%$/9-+)94!/,4!than the mudstones. Note ŽƌŶĞƌ͛7!4+(89/'(!/!3)$9$3+%/9!-/29*:!;0+(!+(!$,)!$-!/!(-&/*,:&1*&%0G*46+*%(-*<,'0,*'9*9%$64$-*'(*4-*0%(9'1-&-1*1'&+/*0%:$97*8,-*0:&4%(*'9*:$$*+,:+*'9*$-5+*%5*Fig D: erosion resistant sandstone within mudstones# **0#$230!?/*)#-/99!C$2,*#':!A$9+4!(/,4(*$,)!/88)/#(!$,!$,)!that, in contrast to the >-)-+:+'%(*<,'0,*1'-1*:(1*<:9*0%;#:0+-1*:(1*<,'0,B*%>-&*>>?@AAB!/9+3,)4!-/29*(!<0+%0!#2,!*0#$230!*0)!%$/9-+)94!/,4! 5'),*0:(*4-*9--(7*8,-*C:9:$*2&'+*,-&-*5%&;9*+,-*4-1*%5*+,-* ->-(*;'$1$/*:0'1'0*<:+-&7*8,-*./0,&/1*,:9*06+*:*#:99:)-* B;"(+4)!$-!*0)!-/29*!6<)(*7!<0+9(*!./,4(!$-!=24(*$,)!/,4!"##K#9+&-:;*%5*+,-*,'),*:&0,*%5*+,-*&%:1*4&'1)-B*+,-*)%&)-*3+*+,-*&'>-&*4-(1B*(-:&*+,-*+&--*<'+,*-"#%9-1*&%%+9earlier limestone, this *M!"#! ;'$$'%(9*%5*/-:&9B*+6&(-1*+%*9+%(-7*0#$230!?/*)#-/99!C$2,*#':# *8,-&-*'9*9%;-*'&%(N !A$9+4!(/,4(*$,)!/88)/#(!$,!$,)! &'>-&*:(1*'9*0$-:&$/*0%()$%;-&:+'0*'-*0%(+:'(9*#-44$-9B* +,&%6),*+,'9*4:(1*%5*$';-9+%(-H*'+9*5$%<*,:9*;%6$1-1*+,-* ͚ZŽŽƚƐdƌĂǀĞƌƐĞ͛D6'0G$/*<'1-(9*%6+7*8,'9*9/')#)4!(+9*(*$,)!/88)/#!$,!*0)!$*0)#!6)/(*7:!"!./,4!$-!.9/%&!=B*:*+,'(*%6+0&%#*%5*9:(19+%(-*9+&-+0,-9*'9*4-0:69-*'+*0&%99-9*+,-*<).1+#=1:2,sandstone is dipping * 9+:'('()*M&69+N0%$%6&=*:(1*:*/-$$%<*0%$%&:+'%(*%(*9%;-*&%0G*(+4)!$-!*0)!-/29*!6<)(*7!<0+9(*!./,4(!$-!=24(*$,)!/,4!C"#C$:0G*0%$%6&-1*;619+%(-*0:(*4-*9--(*'(*#$:0-9*'(*+,-* :$;%9+*:$$*:&-*D6:&+E7* :0&%99*+,-*&'>-&7*8,-9-*9:(19+%(-94-/%(1*<,'0,*:&-*+,-*-:9'$/*-&%1-1*;619+%(-9*:(1*+,'(*9,:#-9*%5*+,-*)%&)-*9'1-9*<'+,*#%+,%$-9*:(1*90:$$%#**:&-*+/#'0:$*%5*+,-*# 96&5:0-9*<,'0,*'9*2)*-.),&#M5')*!=7#* %9/')'!=/*)#+/9!-+99(!*0)!-/29*!+*()9-:! southwards. 9/')#)4!(+9*(*$,)!/88)/#!$,!*0)!$*0)#!6)/(*7:!"!./,4!$-!.9/%&!4:(G9*%5*+,-*&'>-&H*+,-*4$:0G-&*+,-*0%$%6&B*+,-*,'),-&*'+9* * 4)+0-%+,-.#>:?+,-.&#=-'*1,)-.;:&G'()97*8,-*+,'0G*4-19*%5*$';-9+%(-*1'#*(%&+,<:&19*'-*H*+,-*$:&)-&*#:&+*'9*5%&;-1* Fig H: Blue Stal Mine! 5&%;*;619+%(-9*46+*%00:9'%(:$*9:(19+%(-9*:##-:&7*8,-/*! %9/')'!=/*)#+/9!-+99(!*0)!-/29*!+*()9-:0:&4%(*0%(+-(+7*8,%9-*<'+,*,'),-9+*0:&4%(*0%(+-(+*;'),+*! +%<:&19*+,-*A-$$+-*:+*:&%6(1*IJ1-)&--97* ! &-9'9+*-&%9'%(*&:+,-&*4-++-&*+,:(*+,-*;619+%(-97*O%+-*+,:+B* 4-*0%(9'1-&-1*1'&+/*0%:$97*8,-*0:&4%(*'9*:$$*+,:+*'9*$-5+*%5* Fig H: Blue Stal Mine! * %%#!;0)!,)E*!()%*+$,!$-!*0)!#+5)#!+(!/9+3,)4!<+*0!<0/*!+(!/!! 7. Black coloured mudstone can '(*0%(+&:9+*+%*+,-*-:&$'-&*$';-9+%(-B*+,'9*9:(19+%(-*'9*8. A rocky secon of bank %&#!",!/./,4$,)4!/4+*!>-)-+:+'%(*<,'0,*1'-1*:(1*<:9*0%;#:0+-1*:(1*<,'0,B*%>-&*;͚ůƵĞ^ƚĂůDŝŶĞ͛7!+,*$!*0)!'()(*!+,-.! ! be seen in places in the banks of 1'##'()*9;"#K#9+&-:;*%5*+,-*,'),*:&0,*%5*+,-*&%:1*4&'1)-B*+,-*)%&)-*%6+,<:&197* on the north/true right side $,!*0)!($2*01*#2)!9)-*!./,&!+(!-9$$4)4:-/29*)4!.$2,4/#'!.)*<)),!9+=)(*$,)!*$!*0)!,$#*0!/,4!;'$$'%(9*%5*/-:&9B*+6&(-1*+%*9+%(-7! *8,-&-*'9*9%;-*'&%('()(*! N +,-.!*$!*0)!($2*0:!G)4(!$-!#$%&!()),!+,!*0)!#+5)#!(+4)(!/#)! the river; the blacker the colour, * D6'0G$/*<'1-(9*%6+7*8,'9*'9*4-0:69-*'+*0&%99-9*+,-*of the river (<).1+#=1:2,the ! 1st or * 9+:'('()*M&69+N0%$%6&=*:(1*:*/-$$%<*0%$%&:+'%(*%(*9%;-*&%0G* %%#!;0)!,)E*!()%*+$,!$-!*0)!#+5)#!+(!/9+3,)4!<+*0!<0/*!+(!/! * ** * %$,*$#*)4:!"!-2#*0)#!-/29*!%/,!.)!=/4)!$2*!$,!*0)! the higher its carbon content. 4-/%(1*<,'0,*:&-*+,-*-:9'$/*-&%1-1*;619+%(-9*:(1*+,'(*‘Lower Bridge Traverse’ * or 96&5:0-9*<,'0,*'9*2)*-.),&#M5')*!=7#* -/29*)4!.$2,4/#'!.)*<)),!9+=)(*$,)!*$!*0)!,$#*0!/,4!'()(*! 4$<,(*#)/=!(+4)!$-!*0)!,)E*!.#+43)!/.2*=),*:! Those with highest carbon ‘Cornflake Corner’) displays +,-.!*$!*0)!($2*0:!G)4(!$-!#$%&!()),!+,!*0)!#+5)#!(+4)(!/#)! content might be considered dirty a geological fault. This is %$,*$#*)4:!"!-2#*0)#!-/29*!%/,!.)!=/4)!$2*!$,!*0)! coals. The carbon is all that is le one of a swarm of NNW-SSE 4$<,(*#)/=!(+4)!$-!*0)!,)E*!.#+43)!/.2*=),*:! of vegetaon which died and was aligned faults which run compacted and which, over through the coalfield and millions of years, turned to stone. through Waterfall Country. Fig B: Basal Grit in the bed ofThere is some iron- staining (rust- the M ellte:# Solid sandstone appears on # Fig F: Fault with infill! colour) and a yellow coloraon on Fig E: Iron within mudstones! one side of the fault (west) 6"#F-:1'()*6#*+,-*(:&&%<*)%&)-*%5*+,-*./0,&/1*/%6*:$;%9+*some rock surfaces which is !! whilst bands of mudstone ';;-1':+-$/*-(+-&*+,-*;:'(*4%1/*%5*+,-*limonite (fig E).71'8-.)9&'-:+# and layered siltstone "$##!!"!#$%&'!()%*+$,!$-!./,&!$,!*0)!,$#*01*#2)!#+30*!(+4)!$-!D==)4+/*)9'!28(*#)/=!$-!*0)!$94!*#/=!.#+43)!/.2*=),*!+(! %&#!",!/./,4$,)4!/4+*!;͚ůƵĞ^ƚĂůDŝŶĞ͛7!+,*$!*0)!'()(*!+,-.! ()*&+,-.&*ʹ*:*>-&/*,:&1*&%0G*46+*%(-*<,'0,*'9*9%$64$-*'(* Fig*0)!#+5)#!/,!)E8$(2#)!+,!*0)!,$#*01*#2)!#+30*!./,&!$-!%0/,,)9!(/,4 D: erosion6!"#$!"# $resistant%&$͚>ŽǁĞƌƌŝĚŐĞdƌĂǀĞƌƐĞ͛ sandstone withinŽƌ͚ mudstones%&'()*+,-$appear on the other (east). # @ $,!*0)!($2*01*#2)!9)-*!./,&!+(!-9$$4)4:! ->-(*;'$1$/*:0'1'0*<:+-&7*8,-*./0,&/1*,:9*06+*:*#:99:)-* #ŽƌŶĞƌ͛(*$,)(F!$,)!(*/%&)4!/.$5)!/,$*0)#!/,4!()8/#/*)4!.'!7!4+(89/'(!/!3)$9$3+%/9!-/29*:!;0+(!+(!$,)!$-!/!(>?%/#.$,"#C$:0G*0%$%6&-1*;619+%(-*0:(*4-*9--(*'(*#$:0-9*'(*+,-*@AAB!/9+3,)4!-/29*(!<0+%0!#2,!*0#$230!*@#+%0!=24(*$,)(F!/9=$(*!%$/9(:! 0)!%$/9-+)94!/,4!material fills the fault itself. ! 9,:#-9*%5*+,-*)%&)-*9'1-9*<'+,*#%+,%$-9*:(1*90:$$%#* 4:(G9*%5*+,-*&'>-&H*+,-*4$:0G-&*+,-*0%$%6&B*+,-*,'),-&*'+9**0#$230!?/*)#-/99!C$2,*#':! !A$9+4!(/,4(*$,)!/88)/#(!$,!$,)! $#!D==)4+/*)9'!28(*#)/=!$-!*0)!$94!*#/=!.#+43)!/.2*=),*!+(! ;:&G'()97*8,-*+,'0G*4-19*%5*$';-9+%(-*1'#*(%&+,<:&19*'-*9. Immediately upstream of the 0:&4%(*0%(+-(+7*8,%9-*<'+,*,'),-9+*0:&4%(*0%(+-(+*;'),+*(+4)!$-!*0)!-/29*!6<)(*7!<0+9(*!./,4(!$-!=24(*$,)!/,4!10. An abandoned adit +%<:&19*+,-*A-$$+-*:+*:&%6(1*IJ1-)old tram bridge abutment is an &--97* 4-*0%(9'1-&-1*9/')#)4!(+9*(*$,)!/88)/#!$,!*0)!$*0)#!6)/(*7:!"!./,4!$-!.9/%&!1'&+/*0%:$97*8,-*0:&4%(*'9*:$$*+,:+*'9*$-5+*%5*(‘Blue Stal Mine’) into the /,!)E8$(2#)!+,!*0)!,$#*01*#2)!#+30*!./,&!$-!%0/,,)9!(/,4@ * exposure in the north/true right >-)-+:+'%(*<,'0,*1'-1*:(1*<:9*0%;#:0+-1*:(1*<,'0,B*%>-&*%9/')'!=/*)#+/9!-+99(!*0)!-/29*!+*()9-:! Basal Grit on the south/true (*$,)(F!$,)!(*/%&)4!/.$5)!/,$*0)#!/,4!()8/#/*)4!.'! ;"#K#9+&-:;*%5*+,-*,'),*:&0,*%5*+,-*&%:1*4&'1)-B*+,-*)%&)-*bank of channel sandstones, one ;'$$'%(9*%5*/-:&9B*+6&(-1*+%*9+%(-7! *8,-&-*'9*9%;-*'&%(le bank is flooded.N Fig H: Blue Stal Mine%/#.$,! @#+%0!=24(*$,)(F!/9=$(*!%$/9(:! D6'0G$/*<'1-(9*%6+7*8,'9*'9*4-0:69-*'+*0&%99-9*+,-*stacked above another and <).1+#=1:2,* 9+:'('()*M&69+N0%$%6&=*:(1*:*/-$$%<*0%$%&:+'%(*%(*9%;-*&%0G* ! 4-/%(1*<,'0,*:&-*+,-*-:9'$/*-&%1-1*;619+%(-9*:(1*+,'(*separated by carbon-rich * 96&5:0-9*<,'0,*'9*2)*-.),&#M5')*!=Fig7# *E: Iron within mudstones! %%#!;0)!,)E*!()%*+$,!$-!*0)!#+5)#!+(!/9+3,)4!<+*0!<0/*!+(!/!Fig I: Fault! with infill ! mudstones, almost coals. -/29*)4!.$2,4/#'!.)*<)),!9+=)(*$,)!*$!*0)!,$#*0!/,4! '()(*! "#!"!#$%&'!()%*+$,!$-!./,&!$,!*0)!,$#*01*#2)!#+30*!(+4)!$-!+,-.!*$!*0)!($2*0:!G)4(!$-!#$%&!()),!+,!*0)!#+5)#!(+4)(!/#)! *0)!#+5)#!6!"#$!"#$%&$͚>ŽǁĞƌƌŝĚŐĞdƌĂǀĞƌƐĞ͛Žƌ͚%&'()*+,-$%/#!G)'$,4!*0)!.#+43)!/.2*=),*!+(!/!8$$9!/*!/!(0/#8!.),4!+,! %$,*$#*)4:!"!-2#*0)#!-/29*!%/,!.)!=/4)!$2*!$,!*0)! ŽƌŶĞƌ͛7!4+(89/'(!/!3)$9$3+%/9!-/29*:!;0+(!+(!$,)!$-!/!(>?@AAB!/9+3,)4!-/29*(!<0+%0!#2,!*0#$230!*0)!%$/9-+)94!/,4!4$<,(*#)/=!(+4)!$-!*0)!,)E*!.#+43)!/.2*=),*:! *0#$230!?/*)#-/99!C$2,*#':!A$9+4!(/,4(*$,)!/88)/#(!$,!$,)!9+=)(*$,)!6-+3!J!@!͚dŝŵŽƚĞŝ͕͛ƌŵƉŝƚ^ŚŽǁĞƌ͕͚͛:ĂĐƵǌǌŝ͕͛ (+4)!$-!*0)!-/29*!6<)(*7!<0+9(*!./,4(!$-!=24(*$,)!/,4!͚tĂƐŚŝŶŐDĂĐŚŝŶĞ%&$!"#$tĂƚĞƌĨĂůů͛7:!D,!*0)!-/#!6+)!)/(*1*#2)! 9/')#)4!(+9*(*$,)!/88)/#!$,!*0)!$*0)#!6)/(*7:!"!./,4!$-!.9/%&!9)-*7!./,&F!.)'$,4!/,!$5)#0/,3+,3!*#))F!/!-/29*!%/,!.)!()),F! %9/')'!=/*)#+/9!-+99(!*0)!-/29*!+*()9-: ! Fig I: Fault with infill Fig G: Stacked channel sandstones! ! =/#&)4!.'!/!K$,)!$-!(0/**)#)4!#$%&:!;0+(!=/'!.)!*0)!(/=)!Fig H: Blue Stal Mine! ! -/29*!()),!/*!HH:! ! %%#!;0)!,)E*!()%*+$,!$-!*0)!#+5)#!+(!/9+3,)4!<+*0!<0/*!+(!/! %/#!G)'$,4!*0)!.#+43)!/.2*=),*!+(!/!8$$9!/*!/!(0/#8!.),4!+,! ! -/29*)4!.$2,4/#'!.)*<)),!9+=)(*$,)!*$!*0)!,$#*0!/,4!'()(*! *0)!#+5)#:!;0)!A'%0#'4!892,3)(!H:I=!4$<,!/!./,4!$-! Words and Photos - A Bowring.Fig F: Fault Formatted with infill! by T Partridge September 2012 +,-.!*$!*0)!($2*0:!G)4(!$-!#$%&!()),!+,!*0)!#+5)#!(+4)(!/#)! %$,*$#*)4:!"!-2#*0)#!-/29*!%/,!.)!=/4)!$2*!$,!*0)! 9+=)(*$,)!6-+3!J!@!͚dŝŵŽƚĞŝ͕͛ƌŵƉŝƚ^ŚŽǁĞƌ͕͚͛:ĂĐƵǌǌŝ͕͛ ! 4$<,(*#)/=!(+4)!$-!*0)!,)E*!.#+43)!/.2*=),*:! "# $#!D==)4+/*)9'!28(*#)/=!$-!*0)!$94!*#/=!.#+43)!/.2*=),*!+(! ͚tĂƐŚŝŶŐDĂĐŚŝŶĞ%&$! $tĂƚĞƌĨĂůů͛7:!D,!*0)!-/#!6+)!)/(*1*#2)! /,!)E8$(2#)!+,!*0)!,$#*01*#2)!#+30*!./,&!$-!%0/,,)9!(/,4@ 9)-*7!./,&F!.)'$,4!/,!$5)#0/,3+,3!*#))F!/!-/29*!%/,!.)!()),F! (*$,)(F!$,)!(*/%&)4!/.$5)!/,$*0)#!/,4!()8/#/*)4!.'! Fig G: Stacked channel sandstones! =/#&)4!.'!/!K$,)!$-!(0/**)#)4!#$%&:!;0+(!=/'!.)!*0)!(/=)! %/#.$,@#+%0!=24(*$,)(F!/9=$(*!%$/9(:! ! -/29*!()),!/*!HH:! ! Fig F: Fault with infill! ! ! $#!D==)4+/*)9'!28(*#)/=!$-!*0)!$94!*#/=!.#+43)!/.2*=),*!+(! /,!)E8$(2#)!+,!*0)!,$#*01*#2)!#+30*!./,&!$-!%0/,,)9!(/,4@ (*$,)(F!$,)!(*/%&)4!/.$5)!/,$*0)#!/,4!()8/#/*)4!.'! %/#.$,@#+%0!=24(*$,)(F!/9=$(*!%$/9(:! Fig I: Fault with infill ! %/#!G)'$,4!*0)!.#+43)!/.2*=),*!+(!/!8$$9!/*!/!(0/#8!.),4!+,! *0)!#+5)#:!;0)!A'%0#'4!892,3)(!H:I=!4$<,!/!./,4!$-! 9+=)(*$,)!6-+3!J!@!͚dŝŵŽƚĞŝ͕͛ƌŵƉŝƚ^ŚŽǁĞƌ͕͚͛:ĂĐƵǌǌŝ͕͛ ͚tĂƐŚŝŶŐDĂĐŚŝŶĞFig%& $I!: "#Fault$tĂƚĞƌĨĂůů͛ with infill7:!D,!*0)!-/#!6+)!)/(*1*#2)! 9)-*7!./,&F!.)'$,4!/,!$5)#0/,3+,3!*#))F!/!-/29*!%/,!.)!()),F! Fig G: Stacked channel sandstones! %/#!G)'$,4!*0)!.#+43)!/.2*=),*!+(!/!8$$9!/*!/!(0/#8!.),4!+,! =/#&)4!.'!/!K$,)!$-!(0/**)#)4!#$%&:!;0+(!=/'!.)!*0)!(/=)!*0)!#+5)#:!;0)!A'%0#'4!892,3)(!H:I=!4$<,!/!./,4!$-! ! -/29*!()),!/*!HH:! 9+=)(*$,)!6-+3!J!@!͚dŝŵŽƚĞŝ͕͛ƌŵƉŝƚ^ŚŽǁĞƌ͕͚͛:ĂĐƵǌǌŝ͕͛ ! ͚tĂƐŚŝŶŐDĂĐŚŝŶĞ%&$!"#$tĂƚĞƌĨĂůů͛7:!D,!*0)!-/#!6+)!)/(*1*#2)! 9)-*7!./,&F!.)'$,4!/,!$5)#0/,3+,3!*#))F!/!-/29*!%/,!.)!()),F! Fig G: Stacked channel sandstones! =/#&)4!.'!/!K$,)!$-!(0/**)#)4!#$%&:!;0+(!=/'!.)!*0)!(/=)! ! -/29*!()),!/*!HH:! ! >600$(9%93!21%3!@5!($*$6<)!)%9/+/)!?60$(!)+

FigJ: First waterfall! ! "#$!"#$!%&'($))%*$!(+,-!./00($))!+1!%&'!(')*!21%3!45!(%)$)! )#$$(!6.+*$!0#$!(%*$(7!80!%)!6!#/3$!69:!*$(;!0%3#0<;!1+<:$:! 690%,<%9$!%9!0#$!<%&$)0+9$7!=$*$(6$9?;<<0!@%&$)0+9$A!>$9:$(;9! B+<%0$!69:!C%

Fig E: Iron within mudstones! ! ! "#!"!#$%&'!()%*+$,!$-!./,&!$,!*0)!,$#*01*#2)!#+30*!(+4)!$-! *0)!#+5)#!6!"#$!"#$%&$͚>ŽǁĞƌƌŝĚŐĞdƌĂǀĞƌƐĞ͛Žƌ͚%&'()*+,-$ ŽƌŶĞƌ͛7!4+(89/'(!/!3)$9$3+%/9!-/29*:!;0+(!+(!$,)!$-!/!(>?@AAB!/9+3,)4!-/29*(!<0+%0!#2,!*0#$230!*0)!%$/9-+)94!/,4! *0#$230!?/*)#-/99!C$2,*#':!A$9+4!(/,4(*$,)!/88)/#(!$,!$,)! (+4)!$-!*0)!-/29*!6<)(*7!<0+9(*!./,4(!$-!=24(*$,)!/,4! 9/')#)4!(+9*(*$,)!/88)/#!$,!*0)!$*0)#!6)/(*7:!"!./,4!$-!.9/%&! %9/')'!=/*)#+/9!-+99(!*0)!-/29*!+*()9-:! ! Fig H: Blue Stal Mine! ! >600$(9%93!21%3!@5!($*$6<)!)%9/+/)!?60$(!)+600$(9%93!21%3!@5!($*$6<)!)%9/+/)!?60$(!)+

aligned with what is a faulted abutment is a pool at a 2%9,%'%$90!,6*$!);)0$&)5!69:A!+9!,<+)$!%9)'$,0%+9A!69! boundary between limestone to sharp bend in the river. The Fig K: Bwa M aen! the north and Basal Grit to the Sychryd plunges 1.5m down %90(%,60$!0(6,$(;!($*$6<%93!0#60!0#$!(+,-!#6)!.$$9!($D south. Beds of rock seen in the a band of limestone (fig J - ! ,(;)06<<%)$:!6:K6,$90!0+!0#%)!16/<07 Fig F: Fault with infillriver sides are contorted. A ! ‘Timotei’, Armpit Shower’, ! ! further fault can be made out on FigJ: First waterfall! ‘Jacuzzi’, ‘Washing "+$!E!)0$$'!?6<$9?;<<0!@%&$)0+9$A!>$9:$(;9!can be seen, marked by a '(+.6.<;!,+(($)'+9:)!0+!0#$!?%:0#!+1!0#$!96((+?!)<+0! B+<%0$!69:!C%-/4!*)4$600$(9%93!21%3!@5!Ɛ͘dŚĞ͚ŝŶŶĞƌŐŽƌŐĞ͛ŶĂƌƌŽǁƐĂŐĂŝŶ;ĂƐŝƚĚŝĚŶĞĂƌƚŚĞ($*$6<)!)%9/+/)!?60$(!)+͚/ǀǇWŽŽů͛!Žƌ͚ĞůůǇĨůŽƉWŽŽů͛=?! of Bwa Maen -/4!*)4$(fig K) rises sheer Ɛ͘dŚĞ͚ŝŶŶĞƌŐŽƌŐĞ͛ŶĂƌƌŽǁƐĂŐĂŝŶ;ĂƐŝƚĚŝĚŶĞĂƌƚŚĞ"# sinuous water soluon ! above the river. It is a huge and ͚tĂƐŚŝŶŐDĂĐŚŝŶĞ%&$! $tĂƚĞƌĨĂůů͛7:!D,!*0)!-/#!6+)!)/(*1*#2)!channels (incipient cave ",$!"#$!+*$(#693%93!,<%11!%)!,+&'+)$:!+1!&6))%*$!.$:)!+1!)#$$(!6.+*$!0#$!(%*$(7!80!%)!6!#/3$!69:!*$(;!0%3#0<;!1+<:$:! 5%/0(1$/5$!;)+#!+#$!<$((+$=!-*!+#$!')&$'!)*!0%'5$4!+%!51+!9)-*7!./,&F!.)'$,4!/,!$5)#0/,3+,3!*#))F!/!-/29*!%/,!.)!()),F! ! C6(.+9%1$(+/)!@%&$)0+9$A!0%<0%93!60!6!&+:$(60$!693<$!0+!0#$! Fig G: Stacked channelvery ghtly folded ancline in the sandstones+#'%17#!+#$!()3$*+%/$! !>͚/ǀǇWŽŽů͛=/#&)4!.'!/!K$,)!$-!(0/**)#)4!#$%&:!;0+(!=/'!.)!*0)!(/=)!!Žƌ͚ĞůůǇĨůŽƉWŽŽů͛=?! systems) and, on close 690%,<%9$!%9!0#$!<%&$)0+9$7!=$*$(6$9?;<<0!@%&$)0)!;+/!#$6:!$6)0!6<+93!0#$!'60#! +9$A!>$9:$(;9! are recognised including the ! tracery revealing that the .$)%:$!0#$!(%*$(7! B+<%0$!69:!C%$9?;<<0!@%&$)0+9$A!>$9:$(;9! ! B+<%0$!69:!C%600$(9%93!21%3!@5!($*$6<)!)%9/+/)!?60$(!)+$9?;<<0!@%&$)0+9$A!>$9:$(;9! .$0?$$9!G%96)!H+,-!69:!I?6!J6$9!0#(+/3#!?#%,#!0#$! pours (the ‘Main Waterfall’). =;,#(;:!'+/()!2ƚŚĞ͚DĂŝŶtĂƚĞƌĨĂůů͛57!! !-#!@6*+'$-3!-'$!-!*$')$*!%0!0-((*!51+!)/+%!*155$**)&$!.$4*!%0! ! B+<%0$!69:!C%)/!5%/+'-*+! !/#!F1'+#$'!16*+'$-3G!-!&$7$+-+$4!H1-''I!5-/!.$!*$$/!+%! tŽƌŵŚŽůĞ͛5!#6*$!1+(&$:!?%0#%9!0#%)!./00($))!'6(0%,/<6(<;!!-#!@6*+'$-3!-'$!-!*$')$*!%0!0-((*!51+!)/+%!*155$**)&$!.$4*!%0! ! 6<+93!0#$!.+/9:6(%$)!?#$($!:%11$($90!.$:)!6($!%9!,+906,0! *)4$!%0!+#$!7%'7$!-+!+#$!/$:+!.$/4!-/4!-(*%!)/!+#$!')&$'!.$4! +%!+#$!8B!4)66)/7!()3$*+%/$!.$4*!%0!C)/-*!D%5E= ?!"#$!6#%+%! +#$!($0+J$-*+!%0!+#$!6-+#!*#%'+(I!.$0%'$!-/!-.-/4%/$4!.')5E! +#$!$%&%'()*+,?!9-5#!.$4!)*!*$$/!+%!4)6!+%!+#$!A9!>)/!5%/+'-*+!-/4!*)4$Ɛ͘dŚĞ͚ŝŶŶĞƌŐŽƌŐĞ͛ŶĂƌƌŽǁƐĂŐĂŝŶ;ĂƐŝƚĚŝĚŶĞĂƌƚŚĞ ?%0#!+9$!69+0#$(!69:!?#%,#!'(+.6.<;!)<%''$:!+*$(!$6,#! !/#!F1'+#$'!16*+'$-3G!-!&$7$+-+$4!H1-''I!5-/!.$!*$$/!+%!Fig N: Dinas Rock*#%;*!! !""#$%!%'!&'((#)$!""#?! +%!+#$!8B!4)66)/7!()3$*+%/$!.$4*!%0!C)/-*!D%5E=5%/0(1$/5$!;)+#!+#$!<$((+$=!-*!+#$!')&$'!)*!0%'5$4!+%!51+!?!"#$!6#%+%! .1)(4)/7?!K$I%/4!+#)*!+#$!K-*-(!L')+!'1/*!%1+!-/4!+#$!')&$'! +0#$(!?#$9!0#$)$!)0(606!?$($!1+<:$:7! +#'%17#!+#$!()3$*+%/$!>͚/ǀǇWŽŽů͛!Žƌ͚ĞůůǇĨůŽƉWŽŽů͛ =?! +#$!($0+J$-*+!%0!+#$!6-+#!*#%'+(I!.$0%'$!-/!-.-/4%/$4!.')5E!! ! Fig L: Limestone texture '1/*!+#'%17#!-!;)4$'!&-(($I!5#-'-5+$')*$4!.I!+#$!K)*#%6*+%/! ! *#%;*!!""#$%!%'!&'((#)$!""#!Fig?! M : Sychryd within Dinas Fault zone .1)(4)/7?!K$I%/4!+#)*!+#$!K-*-(!L')+!'1/*!%1+!-/4!+#$!')&$'!Fig N: Dinas Rock! ! !Fig K: Bwa M aen! <14*+%/$J!<)44($!A#-($*?!"#$!/$:+!;-+$'0-((!.$I%/4!)*! ! !!!!! Fig L: Limestone texture '1/*!+#'%17#!-!;)4$'!&-(($I!5#-'-5+$')*$4!.I!+#$!K)*#%6*+%/!! ĨŽƌŵĞĚďǇƚŚĞƌŝǀĞƌ͛ƐƉĂƐƐĂŐĞŽǀĞƌƚŚĞdǁĞ(&$!F%%+! 17. The Basal Grit overlies the ",$!"#$!+*$(#693%93!,<%11!%)!,+&'+)$:!+1!&6))%*$!.$:)!+1! 18. Upstream are a series of ! <14*+%/$J!<)44($!A#-($*?!"#$!/$:+!;-+$'0-((!.$I%/4!)*! A-/4*+%/$!ʹ!+#$!*-3$!.$4!%0!'%5E!-*!%551'*!-+!A7;4! Carboniferous Limestone and can C6(.+9%1$(+/)!@%&$)0+9$A!0%<0%93!60!6!&+:$(60$!693<$!0+!0#$!ĨŽƌŵĞĚďǇƚŚĞƌŝǀĞƌ͛ƐƉĂƐƐĂŐĞŽǀĞƌƚŚĞdǁĞfalls cut into successive "+$!E!)0$$'!?6<2!K%%E*!-/4!($-0($+*!-&-)(-.($!0'%3! Fig K: Bwa M aen! +#)*!-/4!%+#$'!5$/+'$*?! ! x 9:$;5<=6578>2!K%%E*!-/4!($-0($+*!-&-)(-.($!0'%3! x "+$!E!)0$$'!?6<2!B-+5#!%1+!0%'!+#$!-//1-(!F0%'$*+!F-;'! ,+9,($0$!'<601+(&!.$9$60#!0#$!=;,#(;:!,6),6:$7!"#$!?6<2!B-+5#!%1+!0%'!+#$!-//1-(!F0%'$*+!F-;'!Fig P: M iddle Pool( L$%6-'E!F$*+)&-(!>(-+$!<-IJ$-'(I!P1/$=! 6!16/<0!'<69$!ʹ!+9$!)%:$!+1!0#$!16/<0!F+9$!?#+)$!?%:0#! ! Figure 1Qa,b,c: Dinas Silica Rock M ine( x )@7:9>2!2%%E!16!+#$!A%1+#!B-($*!7'%16!%0!+#$! Fig P: M iddle Pool( !-#!@6*+'$-3!-'$!-!*$')$*!%0!0-((*!51+!)/+%!*155$**)&$!.$4*!%0! L$%6-'E!F$*+)&-(!>(-+$!<-IJ$-'(I!P1/$=( ! '(+.6.<;!,+(($)'+9:)!0+!0#$!?%:0#!+1!0#$!96((+?!)<+0!"#!"#$!$%&%'()*+,!%&$'()$*!+#$!,-'.%/)0$'%1*!2)3$*+%/$!! ! 19. Either side of the footbridge +#$!$%&%'()*+,?!9-5#!.$4!)*!*$$/!+%!4)6!+%!+#$!A9!>)/!5%/+'-*+! 20. Further upstream, a vegetated quarry can be seen to the le/east of the path shortly before 'ĞŽůŽŐŝƐƚƐ͛ƐƐŽĐŝĂƚŝŽŶ;;;;?*;7-?%'7?1E=!! .$0?$$9!G%96)!H+,-!69:!I?6!J6$9!0#(+/3#!?#%,#!0#$!-/4!5-/!.$!*$$/!+%!4%!*%!.%+#!%/!+#$!6-+#!-*5$/4)/7!+#$!89!( x )@7:9>2!/#!F1'+#$'!16*+'$-3G!-!&$7$+-+$4!H1-''I!5-/!.$!*$$/!+%!!2%%E!16!+#$!A%1+#!B-($*!7!.#(9)+#$'!*)4$!%0!+#$!0%%+.')47$!-'$!+1//$(*!4')&$/!)/+%!+#$!'%16!%0!+#$! are tunnels driven into the Basal +%!+#$!8B!4)66)/7!()3$*+%/$!.$4*!%0!C)/-*!D%5E=?!"#$!6#%+%! an abandoned brick building. Beyond this the Basal Grit runs out and the river runs through a =;,#(;:!'+/()*)4$!%0!+#$!7%'7$!-+!+#$!/$:+!.$/4!-/4!-(*%!)/!+#$!')&$'!.$4!!2ƚŚĞ͚DĂŝŶtĂƚĞƌĨĂůů͛57!! 'ĞŽůŽŐŝƐƚƐ͛ƐƐŽĐŝĂƚŝŽŶ;+#$!($0+J$-*+!%0!+#$!6-+#!*#%'+(I!.$0%'$!-/!-.-/4%/$4!.')5E!;;;?*;7-?%'7?1E$%&%'()*+,!;#$'$!+#$!=!! *-3$!4)6!5-/!.$!*$$/?!WŚŽƚŽϭŝƐ͚*#+,-$ ! Grit where the same dip can be !.#(9)+#$'!*)4$!%0!+#$!0%%+.')47$!-'$!+1//$(*!4')&$/!)/+%!+#$!*#%;*!!""#$%!%'!&'((#)$!""#?! wider valley characterised by the Bishopston Mudstone/ Middle Shales. The next waterfall .1)(4)/7?!K$I%/4!+#)*!+#$!K-*-(!L')+!'1/*!%1+!-/4!+#$!')&$'! Fig N: Dinas Rock! !-/4!*)4$Ɛ͘dŚĞ͚ŝŶŶĞƌŐŽƌŐĞ͛ŶĂƌƌŽǁƐĂŐĂŝŶ;ĂƐŝƚĚŝĚŶĞĂƌƚŚĞ "#!$%&'()*!+!,-%'./0!,1&'!2.%31'4, BBNPA / 20 June 2011 $%&%'()*+,!;#$'$!+#$!*-3$!4)6!5-/!.$!*$$/?! !WŚŽƚŽϭŝƐ͚*#+,-$ ! '1/*!+#'%17#!-!;)4$'!&-(($I!5#-'-5+$')*$4!.I!+#$!K)*#%6*+%/!,ŽůĞDŝŶĞ͛!ǁŝƚŚŝŶǁŚŝĐŚŝƐĂƐŚĂĨƚŬŶŽǁŶĂƐ͚./)$*#+,-$ 5%/0(1$/5$!;)+#!+#$!<$((+$=!-*!+#$!')&$'!)*!0%'5$4!+%!51+!seen. Photo 1 is ‘Black Hole Mine’ beyond is formed by the river’s passage over the Twelve Foot Sandstone – the same bed of rock ,ŽůĞDŝŶĞ͛!ǁŝƚŚŝŶǁŚŝĐŚŝƐĂƐŚĂĨƚŬŶŽǁŶĂƐ͚./)$*#+,-$ "#!$%&'()*!+!,-%'./0!,1&'!2.%31'4<14*+%/$J!<)44($!A#-($*?!"#$!/$:+!;-+$'0-((!.$I%/4!)*!, ,ŽůĞ͛BBNPA?! / 20 June 2011 ! +#'%17#!+#$!()3$*+%/$!>within which is a sha known as ͚/ǀǇWŽŽů͛!Žƌ͚ĞůůǇĨůŽƉWŽŽů͛=?! as occurs at Sgwd Gwladus on the Afon Pyrddin.ĨŽƌŵĞĚďǇƚŚĞƌŝǀĞƌ͛ƐƉĂƐƐĂŐĞŽǀĞƌƚŚĞdǁĞFig(&$!F%%+! L: Limestone texture ! ‘the Black Hole’,ŽůĞ͛?! . A-/4*+%/$!ʹ!+#$!*-3$!.$4!%0!'%5E!-*!%551'*!-+!A7;4!! ! ! L;(-41*!%/!+#$!M0%/!NI'44)/?! ! K$I%/4!+#$!+%1'!?!?!?!! Fig N: Dinas Rock! B#$'$!+%!0)/4!01'+#$'!*%1'5$*!%0!)/0%'3-+)%/O! ! x 01$2! "-E$!-!(%%E!-+! Fig L: Limestone texture !!!!! ! !! ;;;?00%'$*+0-;'7$%6-'E?%'7?1E!! x 1345$565782!4'%6!)/+%!+#$!B-+$'0-((!,$/+'$G! N%/+/$440$5#-/! Beyond the tour . . . Where to find further sources of informaon: WEB: Take a look at www.fforesawrgeopark.org.ukx 9:$;5<=6578>2 EXHIBITION: !K%%E*!-/4!($-0($+*!-&-)(-.($!0'%3!drop into the Waterfall Centre, Pontneddfechan PUBLICATIONS: Books and leaflets available from this and other centres. EVENTS: Watch out for the annual Fforest Fawr Geopark Fesval (late May/early June) +#)*!-/4!%+#$'!5$/+'$*?GROUPS: Look up the South Wales group of the Geologists’ Associaon (! www.swga.org.uk) x 1?186>2!B-+5#!%1+!0%'!+#$!-//1-(!F0%'$*+!F-;'! Fig P: M iddle Pool( L$%6-'E!F$*+)&-(!>(-+$!<-IJ$-'(I!P1/$=! Words and Photos - A Bowring.( Formatted by T Partridge Septemberx )@7:9>2 !20122%%E!16!+#$!A%1+#!B-($*!7'%16!%0!+#$! !.#(9)+#$'!*)4$!%0!+#$!0%%+.')47$!-'$!+1//$(*!4')&$/!)/+%!+#$! 'ĞŽůŽŐŝƐƚƐ͛ƐƐŽĐŝĂƚŝŽŶ;;;;?*;7-?%'7?1E=!! $%&%'()*+,!;#$'$!+#$!*-3$!4)6!5-/!.$!*$$/?!WŚŽƚŽϭŝƐ͚*#+,-$ ! ,ŽůĞDŝŶĞ͛!ǁŝƚŚŝŶǁŚŝĐŚŝƐĂƐŚĂĨƚŬŶŽǁŶĂƐ͚./)$*#+,-$ "#!$%&'()*!+!,-%'./0!,1&'!2.%31'4, BBNPA / 20 June 2011 ,ŽůĞ͛?! !

Fig O: Upper gorge( ! Figure 1Qa,b,c: Dinas Silica Rock M ine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ĨŽƌŵĞĚďǇƚŚĞƌŝǀĞƌ͛ƐƉĂƐƐĂŐĞŽǀĞƌƚŚĞdǁĞ(&$!F%%+! A-/4*+%/$!ʹ!+#$!*-3$!.$4!%0!'%5E!-*!%551'*!-+!A7;4! L;(-41*!%/!+#$!M0%/!NI'44)/?! ! K$I%/4!+#$!+%1'!?!?!?!! B#$'$!+%!0)/4!01'+#$'!*%1'5$*!%0!)/0%'3-+)%/O! x 01$2!"-E$!-!(%%E!-+! ;;;?00%'$*+0-;'7$%6-'E?%'7?1E!! x 1345$565782!4'%6!)/+%!+#$!B-+$'0-((!,$/+'$G! N%/+/$440$5#-/! x 9:$;5<=6578>2!K%%E*!-/4!($-0($+*!-&-)(-.($!0'%3! +#)*!-/4!%+#$'!5$/+'$*?! x 1?186>2!B-+5#!%1+!0%'!+#$!-//1-(!F0%'$*+!F-;'! Fig P: M iddle Pool( L$%6-'E!F$*+)&-(!>(-+$!<-IJ$-'(I!P1/$=! ( x )@7:9>2!2%%E!16!+#$!A%1+#!B-($*!7'%16!%0!+#$! !.#(9)+#$'!*)4$!%0!+#$!0%%+.')47$!-'$!+1//$(*!4')&$/!)/+%!+#$! 'ĞŽůŽŐŝƐƚƐ͛ƐƐŽĐŝĂƚŝŽŶ;;;;?*;7-?%'7?1E=!! $%&%'()*+,!;#$'$!+#$!*-3$!4)6!5-/!.$!*$$/?!WŚŽƚŽϭŝƐ͚*#+,-$ ! ,ŽůĞDŝŶĞ͛!ǁŝƚŚŝŶǁŚŝĐŚŝƐĂƐŚĂĨƚŬŶŽǁŶĂƐ͚./)$*#+,-$ "#!$%&'()*!+!,-%'./0!,1&'!2.%31'4, BBNPA / 20 June 2011 ,ŽůĞ͛?! !