1 10 2 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/cd0887d0796095eddd0dc41b3db1e1dc.jpg 8e4939397352f33d03d66ea841e757b9 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/8299c6ff44bb9caa79c67702c74cb2c5.jpg 656cbb57478c378eff753a41a68050dd https://wserv3.esc.cam.ac.uk/p1acollections/files/original/6c4bb513fcf8f9af3b246a26e3b77ab6.jpg 4fcf5efddbe66c008e446fbb8eee5448 Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource <h2><strong>L361<br /></strong></h2> <h2>Oolitic ironstone</h2> Subject The topic of the resource <h3>Age</h3> <div class="element-text"> <p>Jurassic</p> <h3>Location</h3> <div class="element-text"> <p>Inferior oolite<br />Thrapston, Northamptonshire</p> </div> </div> Description An account of the resource <div class="element"> <h3>Hand Specimen</h3> <div class="element-text"> <p>This rock is made up of light grey sub-spherical<span> </span><a href="/p1acollections/items/show/230">ooids</a>.<span> </span><br />Fine to medium sand grain size.<span> </span><br />A few lithic/biogenic fragments.<span> </span><br />Dark grey cement.<span> </span><br />Small hair-line white veins run through this rock.</p> </div> </div> <div class="element"> <h3>Thin-section</h3> <div class="element-text"> <p>Ooids made up of a greenish sheet silicate mineral called<span> </span><span>chamosite</span>, partially altered to<span> </span><span>siderite</span><span> </span>and<span> </span><span>limonite</span>. Concentric structure. Central cores of fine-grained material.</p> <p>A layer formed of brown, transparent crystals, sometimes with rhombic cross-sections surrounds the peripheries of many ooids. This is<span> </span><span>siderite</span>.</p> <p>Some quartz grains.</p> <p>The cement is made up mainly of carbonate (<span>siderite</span>), with a small quantity of a green-brown material, which has anomalous interference colours.</p> <p>This rock is a grainstone (Dunham naming system) or oo-sparite (Folk naming system).</p> </div> </div> <div class="element"> <h3>Rock History</h3> <div class="element-text">Deposited in a moderate energy, marine energy.</div> </div> <div class="element"> <h3>Advanced Notes</h3> <div class="element-text"> <p><span>Chamosite</span><span> </span>is an Fe-rich chlorite, often greenish. It is a sheet silicate.</p> <p><span>Limonite</span><span> </span>is amorphous or cryptocrystalline, and yellow-brown to brownish-black in colour. It comprises hydrated iron (III) oxides with a range of compositions.</p> <p><span>Siderite</span><span> </span>is iron carbonate (FeCO₃). It is often difficult to distinguish siderite from calcite and dolomite optically.</p> </div> </div> <div class="element"></div> <div class="element"></div> <div class="element"> <h3>Rock Name</h3> <div class="element-text">oolitic ironstone<br />oolite</div> </div> marine moderate energy ooid https://wserv3.esc.cam.ac.uk/p1acollections/files/original/a8ebb735837d9956e575a80998326557.jpg fc76384c38e5cf0159e6f5d5cf29780a https://wserv3.esc.cam.ac.uk/p1acollections/files/original/095bede3faf77aba6437db18c5ea8c3d.jpg 081910d957d523c1ed6d58000288e9fd https://wserv3.esc.cam.ac.uk/p1acollections/files/original/264fccd8895162f27b1c45f528f49833.jpg 7c6514d9b3c13ca2538b98b74b1faae5 Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource <h2><strong>L353<br /></strong></h2> <h2>Limestone, oolitic, packstone</h2> Subject The topic of the resource <h3>Age</h3> <div class="element-text"> <p>Upper Jurasssic</p> <h3>Location</h3> <div class="element-text"> <p>Corallian, Weymouth</p> </div> </div> Description An account of the resource <div class="element"> <div class="element"> <h3>Hand Specimen</h3> <div class="element-text"> <p>Grey-buff colour rock made up of<span> </span><a href="/p1acollections/items/show/230">ooids</a>, mainly medium grained and spherical.<span> </span><br />Some shell and lithic fragments.<span> </span><br />Well compacted and cemented by calcite, which fizzes with acid.</p> </div> </div> <div class="element"> <h3>Thin-section</h3> <div class="element-text">The ooids look brown. They are made up of calcite grains much smaller than the thickness of the slide (which is 30μm). These small grains refract, diffract and reflect light travelling through the slide producing the brown appearance of the ooids. Most of the ooids were formed around a central nucleus (usually an angular quartz grain, sometimes a shell fragment).The calcite forming the ooids is mostly too fine-grained to distinguish individual crystals.<span> </span><br />Only some of the ooids appear to be touching in thin-section, but taking account of their 3D relationships, the rock is probably clast supported.<br />Rounded shell fragments including aragonite bivalve moulds and silicified brachiopods.<span> </span><br />Occasional quartz grains.<br />Clean, colourless calcite cement.<br /><br />This is a packstone (Dunham naming system) or oo-biosparite (Folk naming system).</div> </div> <div class="element"> <h3>Rock History</h3> <div class="element-text">Deposited in a moderate energy, marine environment.</div> </div> <div class="element"></div> <div class="element"></div> <div class="element"> <h3>Rock Name</h3> <div class="element-text">oolitic limestone<br />packstone<br />oo-biosparite<br />oolite</div> </div> </div> marine moderate energy