![]() ![]() Results show the value of a combined modelling approach to automate the stochastic generation of facies distributions constrained by seismic interpretations. We introduce a workflow to demonstrate how these two methods can be applied in combination to predict fluvial meander-belt facies distributions, using a subsurface dataset on a Pleistocene succession from the Gulf of Thailand where abandoned channels are visible on seismic time slices, but for which bar-accretion geometries and the exact timing of channel abandonment are unclear. With reference to case-study examples, we review, discuss and employ two of these methods: (i) ChaRMigS generates possible scenarios for channel evolution and meander cutoffs by a reverse migration process (ii) PB-SAND is a forward stratigraphic model which simulates fluvial point-bar geometry and facies distributions from known palaeo-channel geometries. Different methods exist to model such accumulated successions present in the subsurface by integrating knowledge of system evolutionary behaviour and geometries visible on seismic time or stratal slices. One stone lost with Slimming World, though it's ta.The sedimentary record of meandering rivers contains a diverse and complex set of lithological heterogeneities, which impact natural resource management.The next cut off to come is probably in Tintern where there is only a small neck of land in the meander loop opposite the abbey - but we may have to wait until the next glaciation until the river has enough energy! Reply Delete This has been referred to as the 'Lost Lake' of Monmouth. One of the most recent meander cut-offs is in Monmouth and the former channel of Wye is still liable to flooding. This happened at different times so some of abandoned meanders are higher above the current river than others. As it did so some the meanders were eroded through at their narrowest points, leaving an abandoned loop of river channel high and dry, as at Newland. ![]() ![]() Then over the last 2 millions years, during several episodes of the glaciation, the Wye cut down over 200m through the limestones and sandstones to the current sea level. The meandering course of the river was superimposed on the complex geology below. ![]() Over millions of years all the soft chalks and clays were eroded and the meandering River Wye eventually began to cut into the hard rocks below. Around 65 million years ago the land began to rise (or the sea level fell) and meandering rivers developed on a flattish land surface draining into sea to the south. I think the idea is that this part of England and Wales was submerged beneath a shallow sea in the Cretaceous period when layers of chalks and clays were deposited on top of much older surface of folded rocks of sandstone and limestone. The ancient meanders of lower Wye are fascinating. Hi Angie, thanks very much for your blog and photos. Here's the promised photo of little me near Lodges Farm, where the track crosses Valley Brook. Take a look at the second comment to this post by someone who clearly knows their subject.Įnd of attempted geology lesson. If I've got that wrong then maybe some more learned soul * will enlighten us. Only the deep incision, where the ancient water flow cut through the carboniferous limestone remain. The tidal regime is semidiurnal and microtidal, with an average. Millions of years ago, long before the last ice age, the plateau on which the Forest of Dean stands was much higher, but over time the upper layers were eroded away, taking with them traces of Newland Meander north of Newland itself. 1A), located in the northwestern Adriatic Sea, is the largest Mediterranean shallow water body, with an area of about 550 km 2 (length and width of the tidal basin are about 50 km and 10 km, respectively see Fig. I'm little more that a fumbling amateur when it comes to geology, but if I'm interpreting a collection of scholarly articles correctly, it would seem that the Newland Meander is much older than the Ross and Bigsweir ones. It's logical to presume that it should rejoin the Wye somewhere near the top of the map, but where? There's a lot of high ground in the way. Zooming out, you can hopefully see that the meander scar can only be traced to a point near Newland. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |