<div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote">2015-05-12 14:49 GMT+02:00 pmailkeey . <span dir="ltr"><<a href="mailto:pmailkeey@googlemail.com" target="_blank">pmailkeey@googlemail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="gmail_extra">Now, we can start arguing about the definition of 'small' :)) - so I'll start, in this context, with any stone smaller than a <a href="http://en.wikipedia.org/wiki/Curling#Curling_stone" target="_blank">curling stone</a> !<br clear="all"><div><br></div><div><a href="http://en.wikipedia.org/wiki/Bowder_Stone" target="_blank">large ones</a> can be several feet in diameter and a couple of kT.</div></div></blockquote></div><br><br><br clear="all"></div><div class="gmail_extra">there are definitions for the sizes: <br>ISO 14688-1 which is basically DIN 4022.<br>in the US: <a href="http://upload.wikimedia.org/wikipedia/commons/e/e2/Wentworth-Grain-Size-Chart.pdf">http://upload.wikimedia.org/wikipedia/commons/e/e2/Wentworth-Grain-Size-Chart.pdf</a><br><br></div><div class="gmail_extra">the basic sequence clay, silt, sand, pebbles, cobbles, boulders is the same, there's nothing to argue about.<br><br></div><div class="gmail_extra">Cheers,<br></div><div class="gmail_extra">Martin<br></div></div>