1 10 3 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/84c1834164497c8491f5db12efcef6d2.jpg c9a7faba04f5ca2d06682176ab35e8a8 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/b718221d8d279140605b8befd4e9d749.jpg 691b6ce9581e994fa11d953b4fd41bfb https://wserv3.esc.cam.ac.uk/p1acollections/files/original/c501e1086a63d3623e85cb1f1be70780.jpg b09c139b55148cacb06439964118c472 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>L200<br /></strong></h2> <h2>Volcanic Breccia</h2> Subject The topic of the resource <h3>Age</h3> <div class="element-text"> <p>Carboniferous</p> <h3>Location</h3> <div class="element-text"> <p>Melrose, Scotland</p> </div> </div> Description An account of the resource <div class="element-set"> <div class="element"> <div class="element-text"> <h3>Hand Specimen</h3> </div> </div> </div> <div class="element-set"> <div class="element"> <div class="element-text"> <p>Sedimentary textures, very poorly sorted.<span> </span><br />Sub-round to angular grains up to 20mm across.<span> </span><br />Wide variety of clasts: dark purple, cream, rusty orange, grey, several types of lava.<span> </span><br />Some black, shiny igneous crystals.<span> </span><br />Brown-grey matrix of<span> </span><a href="/p1acollections/items/show/266">volcanic</a><span> </span>ash.</p> </div> </div> <div class="element"> <h3>Thin section</h3> <div class="element-text">Wide range of clasts including<br />- Basalt<br />- Slate or phyllite<br />- Schist<br />- Chert<br />- Sandstone<br />- Carbonate<br />- Quartz<br /><br />Matrix of fine volcanic ash.</div> </div> <div class="element"> <h3>Rock History</h3> <div class="element-text">This is an example of the coarser type of material deposited by explosive volcanic action.<br /><br />NB,<br />This is not a typical volcanic breccia, as one usually sees a greater abundance of igneous clasts; other clasts could be wall-rock. Another name for this rock could be “lithic wacke”.</div> </div> <div class="element"></div> <div class="element"></div> <div class="element"> <h3>Rock Name</h3> <div class="element-text">volcanic breccia<br />lithic wacke</div> </div> </div> clastic extrusive lithic https://wserv3.esc.cam.ac.uk/p1acollections/files/original/852a77355d6e4e7f6cf8052de0bf7a9d.jpg 3418fba1e4453736b6dbd51d55fd9583 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/aab79550a27397bff8be8a5cb67ef43f.jpg f5f51d065ee3cc8e993e930077cbd5fc https://wserv3.esc.cam.ac.uk/p1acollections/files/original/1c200ce8cf23f154e881c3c62ad865c8.jpg 25a8c42f179836492f49a6fdb0bcbb5f https://wserv3.esc.cam.ac.uk/p1acollections/files/original/f3204ba875eb0b5fb7aaffafd6e91261.jpg 6a3a28ccf49c7653bc57780b5eacdd11 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/57c910796611238dbf565e32ca5fc702.jpg d53f7084c610e651bdaf2389f9297e28 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>L162<br /></strong></h2> <h2>Basalt, porphyritic</h2> Subject The topic of the resource <h3>Specimen Age</h3> <div class="element-text"> <p>Carboniferous</p> <h3>Location</h3> <div class="element-text"> <p>Volcanic neck, Lion's Haunch, Arthur's Seat, Edinburgh</p> </div> </div> Description An account of the resource <div class="element-set"> <div class="element"> <div class="element-text"> <div class="element"> <div class="element-text five columns omega"> <div class="element-text"> <div class="element-text"> <div class="element"> <div class="element-text five columns omega"> <div class="element"> <div class="element-text five columns omega"></div> </div> <div class="element"> <div class="element-text five columns omega"> <div class="element-set"> <div class="element"> <div class="element-text"> <h3>Hand Specimen</h3> </div> </div> </div> <div class="element-set"> <div class="element"> <div class="element-text"> <p>Black,<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/244">porphyritic</a><span> </span>rock comprising black clinopyroxene, grey feldspar and greenish olivine<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/236">phenocrysts</a>, in a fine-grained<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/205">groundmass</a>.</p> </div> </div> <div class="element"> <h3>Thin-section</h3> <div class="element-text"> <p>Plagioclase feldspar<span> </span><br />- Phenocrysts 1-4mm long, with a euhedral,<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/258">tabular</a><span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/206">form</a>. Randomly orientated. Characteristic<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/169">lamellar twinning</a>. Some are<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/267">zoned</a>.<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/210">Inclusions</a><span> </span>of magnetite, clinopyroxene and other minerals. Extensive<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/170">alteration</a><span> </span>along abundant cracks.</p> <p>Clinopyroxene (augite)<span> </span><br />-<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/189">Euhedral</a><span> </span>phenocrysts, 1-2 mm across. Moderate<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/247">relief</a>, inclined<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/190">extinction</a><span> </span>and first order pink to second order orange interference colours. Pale pink in thin-section. Some are<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/267">zoned</a>.</p> <p>Olivine<span> </span><br />- Very few phenocrysts are fresh enough to be easily identifiable. These are colourless in plane polarised light, have moderate relief, and up to second order pink interference colours. No<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/180">cleavage</a>.</p> <p>- 1st phase of alteration along cracks: The majority of the phenocrysts have been completely altered to greenish serpentine.</p> <p>- 2nd phase of alteration: orange brown mineral – probably the amphibole<span> </span><span>cummingtonite</span>. Characteristic curving cracks and the<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/246">prismatic</a><span> </span>form of olivine are still visible.</p> <p>Groundmass<span> </span><br />- Fine-grained. Plagioclase feldspar needles, clinopyroxene, some olivine (mostly altered), and opaques, probably magnetite. Occasional calcite grain.</p> </div> </div> <div class="element"> <h3>Rock History</h3> <div class="element-text"> <p>Two stage cooling<span> </span><br />1. Phenocrysts grow slowly in a magma chamber.<span> </span><br />2. Fine-grained groundmass grew rapidly →<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/191">extrusive</a>.<span> </span><br />Hydrothermal alteration, possibly as part of the<span> </span><a href="https://wserv3.esc.cam.ac.uk/p1acollections/items/show/266">volcanic</a><span> </span>pile.</p> </div> </div> <div class="element"> <h3>Advanced Notes</h3> <div class="element-text"><span>Cummingtonite</span><span> </span>is an amphibole. It is colourless to pale green in thin-section, has moderate relief and two cleavages which intersect at 56°.</div> </div> <div class="element"> <h3>Rock Name</h3> <div class="element-text">porphyritic basalt</div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> alteration extrusive volcanic https://wserv3.esc.cam.ac.uk/p1acollections/files/original/6ee5b4daa895a80c4f5d1219f546fd1f.jpg ec992c8fa5fc180cef9aa183c5fccb0b https://wserv3.esc.cam.ac.uk/p1acollections/files/original/f04b282ccc316fc1d49d4170730b5892.jpg 7759e3afb21758ccf4ccadb89eb40ce9 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/d5a2b07e623f5f5b39a9506ee7ac050f.jpg 41972d8ec488fd6c039ae81709eaf2e3 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>L161<br /></strong></h2> <h2>Basalt, amygdaloidal</h2> Subject The topic of the resource <h3>Specimen Age</h3> <div class="element-text"> <p>Cenozoic</p> <h3>Location</h3> <div class="element-text"> <p>Lava, Skye</p> </div> </div> Description An account of the resource <div class="element-set"> <div class="element"> <div class="element-text"> <div class="element"> <div class="element-text five columns omega"> <div class="element-text"> <div class="element-text"> <div class="element"> <div class="element-text five columns omega"> <div class="element-text"> <div class="element-text"></div> </div> </div> </div> <div class="element"> <div class="element-text five columns omega"> <div class="element-set"> <div class="element"> <div class="element-text"> <h3>Hand Specimen</h3> </div> </div> </div> <div class="element-set"> <div class="element"> <div class="element-text"> <p>Fine-grained, greenish black rock comprising dark and white minerals.<span> </span><br />Contains<span> </span><a href="/p1acollections/items/show/172">amygdales</a>, mostly white, though some have black cores.</p> </div> </div> <div class="element"> <h3>Thin-section</h3> <div class="element-text"> <p>Fine-grained plagioclase<span> </span><a href="/p1acollections/items/show/215">laths</a><span> </span>and irregular clinopyroxene (augite) grains, replaced with calcite. Many of the plagioclase laths have been almost entirely altered.</p> <p>The amygdales are filled with<span> </span><span>zeolite</span>, growing in spherulitic and radiate patterns. Many have rims of calcite and fine-grained chlorite.</p> <p>Some vein material -<span> </span><a href="/p1acollections/items/show/203">granular</a><span> </span>quartz with<span> </span><a href="/p1acollections/items/show/257">sutured contacts</a>.</p> </div> </div> <div class="element"> <h3>Rock History</h3> <div class="element-text"> <p>Fine-grained → rapid,<span> </span><a href="/p1acollections/items/show/191">extrusive</a><span> </span>crystallisation.<span> </span><br />Gas bubbles trapped within lava produced<span> </span><a href="/p1acollections/items/show/264">vesicles</a>.<span> </span><br />Circulation of fluids → precipitation of zeolite within the vesicles.</p> </div> </div> <div class="element"> <h3>Advanced Notes</h3> <div class="element-text"> <p><span>Zeolites</span><span> </span>are produced at low temperatures. They are commonly precipitated in basaltic volcanic piles.</p> </div> </div> <div class="element"> <h3>Rock Name</h3> <div class="element-text">amygdaloidal basalt</div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> alteration extrusive mafic