Flat Holm (Welsh: Ynys Echni) is a limestone island lying in the Bristol Channel approximately 6 km (4 mi) from Lavernock Point in Glamorgan. It includes the most southerly point of Wales. It is now managed by Cardiff Council's Flat Holm Project Team and designated as a Local Nature Reserve, Site of Special Scientific Interest and a Special Protection Area, because of the maritime grassland and rare plants such as Rock Sea-Lavender (Limonium binervosum) and Wild Leek (Allium ampeloprasum). During much of the most recent ice ages, from 1.8 million years ago, the sea level in the Severn Estuary was some 50 m (160 ft) below the current level and Flat Holm was joined to the Somerset coast as an extremity of the Mendip Hills. Sometime since the start of the Neolithic period, 15,000 years ago, the ice sheets retreated, and the flat plains surrounding the river estuary flooded; the hilltops of Mendip Hills became the islands of Flat Holm and Steep Holm. Flat Holm and Steep Holm form a link with the carboniferous limestones of the west of England, Sully Island and Barry, Wales. Part of the island is designated a Geological Conservation Review (GCR) Site and is a recognised Site of Special Scientific Interest (SSSI). The GCR and SSSI interest lies along the south-western shoreline from the north west point to Lighthouse Point where a wave cut portion of the limestone displays large fossil "ripple marks". There are argentiferous (i.e. silver-bearing) galena deposits on Flat Holm; the pits and mounds visible on the surface of the island are a result of trial borings. A dispute over lead mining rights in the 1780s ended with John Stuart, Lord Mount Stuart making an official complaint that the lighthouse keeper was using the coals intended for the light-house for processing lead. Mining for lead was not profitable, however, and the works were abandoned. From the Triassic period fills joints in the carboniferous limestone showing evidence of karstic (cave forming) processes during this period. Caves on the western and north-eastern sides of the island were used during the years of smuggling.
Source:Wikipedia
To Log this cache please go to the coordinations and make a photo with you and your GPS with the two Castle Rocks (just behind you) ,and adress it to your Log
Please anser me tow questions and sent it to me by mail via my profil And solve the following task.
Go to the Flat Holm Museum and look for Geologic information .
1. How many years ago start the evolution of Flat Holm ?
2. What will join from the the Triassicperiode in the Carboniferous Limestone?
Task :
Go to the fossil rippel marks, you will pass this during your Tour and send me the coordinations of the position.
Normally deviation is accepted