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I've been looking at my specimens of Acrocoelites trisulculosus from the Toarcian Jet Rock (Mulgrave Shale Member = Falciferum Zone) of the north Yorkshire coast. This is an anoxic mudstone deposited during a prominent worldwide Ocean Anoxic Event (OAE) and, as might be expected, the preservation is very good. A number of them (7 so far) have a thin pyrite layer around the apex. This shows obvious lineation in all of them, mostly oblique to the axis of the rostrum. As pyrite is often associated with soft tissue decay, I strongly suspect that this is preserving muscle texture. The texture is similar to that preserved in some other coleoids (e.g. from Solnhofen). Has anyone else seen this? Comments welcome! EDIT: I may be wrong about the soft preservation - a few well preserved specimens from other localities (though not from here) show similar texture on the calcite. Most belemnites look smooth though. (Comments and photos further down this thread) Just two of the specimens here: No. 1: No. 2: left lateral (with divided dorso-lateral furrow - a little unusual) right lateral
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Big Diamonds Bring Scientists A Message From Superdeep Earth
Oxytropidoceras posted a topic in Geology
Big Diamonds Bring Scientists A Message From Superdeep Earth NPR, http://www.npr.org/sections/thetwo-way/2016/12/15/505386423/big-diamonds-bring-scientists-a-message-from-superdeep-earth Large, rare diamonds offer window into inner workings of Earth's mantle https://carnegiescience.edu/news/biggest-and-best-diamonds-formed-deep-mantle-metallic-liquid https://www.eurekalert.org/pub_releases/2016-12/gioa-lrd120716.php http://phys.org/news/2016-12-biggest-diamonds-deep-mantle-metallic.html http://www.livescience.com/57222-biggest-diamonds-form-in-liquid-metal-pools.html Diamonds: Huge, rare precious stones form 750km underground in Earth's mantle, International Business Times UK http://www.ibtimes.co.uk/huge-rare-diamonds-are-born-pools-liquid-metal-deep-below-earths-surface-1596725 the paper is: Smith, E. M., S. B. Shirey, F. Nestola, and others, 2016, Large gem diamonds from metallic liquid in Earth’s deep mantle. Science. Vol. 354, Issue 6318, pp. 1403-1405. DOI: 10.1126/science.aal1303 http://science.sciencemag.org/content/354/6318/1403 Yours, Paul H.