A HISTORY OF HEREFORDSHIRE TABLE OF STRATA {continued) lApproximate thickness in feet Dayia navkula ConchUium Knighti .... I Numerous graptolites, Scaphaspis ) ludensts, Hemiaspis Saltveyi, &c. (■Mocktree or Dayia Shales . . S f Aymestrey Stage . U Aymestrey or Conchidium Lime- 1 ^ U stone 3 (Dark grey argillaceous shale, with |J l.LowerLudlow .H calcareous concretions in places ( Wenlock j Grey subcrystalline, usually con- Limestone | cretionary limestone (■Fine-grained, grey and dark- l Wenlock Shales . coloured clayey shales, with lines of nodules in places 1 Bluish grey, usually massive lime- stone in the Woolhope dis- trict, but more shaly in the , Malvern and Ludlow districts I /Tarannon Shales. Shales and K I grey laminated sandstones pgi^^ia bina, Slricklandinia lens, II „,c=;r,o rinwn into ll Pentamcrus oblongus, Cteno- 40 to 150 75 to 250 Calymene Blumenbachi, Pkacops caudatus, Atrypa reticularis, Omphyma turbinatum, Favosites gothlandicus, Monograptus spp., Cyrtograptui spp., 8cc. ) passing down mto 1 v Upper Llandovery Kj^^y j^-U Sandstone. Sand- j stones and conglomerates of l Lower grey, yellow,and purple colours ^ 440 to 700 150 to 280 640 to
- 900
30 to 50 1,000 donta Eastnori, &c. I) Bala . .^ yLlandeilo V Llandovery "^ Arenig O ) o a V a cu u /Tremadoc J^inguk Flags .Absent from Herefordshire !' Upper Tremadoc. Absent from Herefordshire Lower Tremadoc. 'Grey Shales' with interstratified igneous , bands K CUpper Lingula Flags. ' Black ^ p^ji^ra, Jgnostus, Ctenopyge,
Shales' with interstratified - ■ - -
I igneous bands ^ ^ ' <-■■ Zone. gritty Kuictyonema sociak tj o T3 -d VMenevian t '? I Harlech fLongmyndian Uriconian . Malvernian 'Polymorphina - Lapivorthi Shales, black, with seams Hollybush Sandstone {a) Sandstones
- ^ {b) Sandstones,
Sphaerophthalmus, &c. cingulata Malvern Quarfii'^ Protospmgia, Kutorgina
var. pulsilla
. ^onthus fistula, H. malvemensis, - __M' lertainl^s-^^^fli.rwtf antiquissmm, Ku- ' 3fce hasl) torpna PhilRpsi, &c, 'H|P_^"gf|(r Phillipsi, Hyolithus frimaevus, OboUela (?) Groomi 1,000
5°o
( Not less than I 300 ) 900 to 1,100 I ( Several U hundreds of feet Not exposed at Rhyolites, andesi tuffs . . ■ Highly crystalline gneissic rocks ^RE-CAMBRIAN SYSTEM "^ belong to the Pre-Cambrian or Archaean The oldest rocks in ^^e co""ty ^^ ^.^^j^.g^ ,nd felsites, and gneissic, group, and comprise ^ 2^""%^^^ occur on the eastern side forming the fchisf^se, and vo came rocks^ S^ch ^^^^^^^^ .^ ^^^ .^^^^^^ l^'^r^ Malvern Hills j ^ut x^ xs som- ^^^ ^^^^^ ^^^ ^^^^^ ^^^^ ^^^ p^^^^,^^ ,here north-western side, composmg ^
