Geo-Amble 24th July 17

A look at Trail 2 around Martley, HERE for a link to the guide.

Trail 2 is the shortest of the three circular geology walks in the parish.  Leaflets are available at the dispenser opposite the Crown.  In two and a half miles the route takes in a huge span of rock history, from the more recent deposits at the start and over the Nubbins to our most ancient (igneous) formations at Martley Rock.

What a glorious evening, so lucky were with the warm sunny weather and the fields in their golden cloths of barley, wheat and indeed oats, no rye tho, looked just beautiful.

Ian (Fairchild) explained the river deposits of fine sands interspersed with bulkier gravels and pebbles brought down in a storm lithified (turned into stone) from the early Triassic period approx. 250 million years ago.  Deposits from a large dry, desert like continent with monsoon rains, when the land was north of the equator (think the Sahara of today).  HERE is a note on cross bedding and HERE is an illustration of a braided river system.

We traversed up into the field above the village with terrific views all around, I never tire of this spot–East across the ancient, wide river valley (HERE is an illustrated guide on its formation) now occupied by the river Severn, to the Cotswolds (Jurassic limestones), NE to the Lickeys (largely Ordovician), the twin peaks of the Clent Hills (from the Permian), North to Penny and Rodge Hills with beyond, Woodbury and Abberley Hills (Silurian), NW to Clee Hills (the tops being a sill of hard, igneous rock forced up into the Carboniferous surrounds around 300 million years ago), West over the deep valley of the River Teme, to the Bromyard plateau, a dome of sandstone and mud/marl deposits from the Devonian period (think deserts formed south of the equator as today) and, in end on view South, the upstanding igneous front of the Malvern Hills.  What a panorama!  If you wish to see how the continents have moved over time, try EarthViewer a free app.  That helps to interprete the mystery of this slowly moving jigsaw and you can always look up weird names such as Ordovician to see where they came from and what they mean.

We followed a track along the edge of the steep river valley, above ancient orchards, skirting the line of the East Malvern fault, crossed the lane so meeting the Worcestershire Way and thence down to Martley Rock. Here Ian and I tried to explain how it was that five geological periods had ended up within 50m, sometimes with older deposits on top of younger ones and with great gaps in the sequence such that major eras were missing, for example no Ordovician, no Devonian.  To finish, having reached the allotted time of an hour and a half, we took the old sunken lane down to Martley and back to the cars at the hall.  Next week we plan to finish the trail by visiting the church and the Chantry geology garden then maybe venture to rocks near the Talbot at Knightwick.  Thanks to those who came along on Monday, hopefully a good turn out again next week–all welcome.

 So, time next week a little later, 6.15pm at Martley Memorial hall to complete the rest of today’s amble then assuming time, probably go down to the Talbot and up to local quarries on Ankerdine but Mike and I need to recce those first.
Links I promised from tonight:
Martley Rock on TVGS site HERE–lots to get your teeth into here
Plan of Martley Rock site temporary trenches HERE
Martley Rocks App notes on TVGS site HERE
Apps for the Geopark way HERE