10001 manuscripts in practice: Perl, XML, medieval chronicles, and why Unicode rocks‎

I work in the field of Armenian historiography. This means I get to play with medieval manuscripts. The things I'm doing with the manuscripts are theoretically interesting, but pretty boring in practice, so I'm using Perl to program away the most boring bits. I will talk about the problems of text criticism in general, what sorts of things can and can't be done by the computer, my initial aversion to XML, how I was shown (some of) the error of my ways, and how I'm combining a bunch of isolated pieces of technology that were mostly already in use to achieve fame and fortune in the world of Armenian studies.

Magmatic–hydrothermal molybdenum isotope fractionation and its relevance to the igneous crustal signature

We analysed the Mo isotope composition of a comprehensive series of molybdenite samples from the porphyry- type Questa deposit (NM, USA), as well as one rhyolite and one granite sample, directly associated with the Mo mineralization. The δ98Mo of the molybdenites ranges between −0.48‰ and +0.40‰, with a median at −0.05‰. The median Mo isotope composition increases from early magmatic (−0.29‰) to hydrothermal (−0.05‰) breccia mineralization (median bulk breccia = −0.17‰) to late stockwork veining (+0.22‰). Moreover, variations of up to 0.34‰ are found between different molybdenite crystals within an individual hand specimen. The rhyolite sample with 0.12 μg g−1 Mo has δ98Mo = −0.57‰ and is lighter than all molybde- nites from the Questa deposit, interpreted to represent the igneous leftover after aqueous ore fluid exsolution. We recognize three Mo isotope fractionation processes that occur between about 700 and 350 °C, affecting the Mo iso- tope composition of magmatic–hydrothermal molybdenites. Δ1Mo: Minerals preferentially incorporate light Mo isotopes during progressive fractional crystallization in subvolcanic magma reservoirs, leaving behind a melt enriched in heavy Mo isotopes. Δ2Mo: Magmatic–hydrothermal fluids preferentially incorporate heavy Mo iso- topes upon fluid exsolution. Δ3Mo: Light Mo isotopes get preferentially incorporated in molybdenite during crys- tallization from an aqueous fluid, leaving behind a hydrothermal fluid that gets heavier with progressive molybdenite crystallization. The sum of all three fractionation processes produces molybdenites that record heavier δ98Mo compositions than their source magmas. This implies that the mean δ98Mo of molybdenites published so far (~0.4‰) likely represents a maximum value for the Mo isotope composition of Phanerozoic igneous upper crust.

Episodic and long-lasting Paleozoic felsic magmatism in the pre-Alpine basement of the Suretta nappe (eastern Swiss Alps)

The Suretta nappe of eastern Switzerland contains a series of meta-igneous rocks, with the Rofna Porphyry Complex (RPC) being the most prominent member. We present LA-ICP-MS U–Pb zircon data from 12 samples representing a broad spectrum of meta-igneous rocks within the Suretta nappe, in order to unravel the pre-Alpine magmatic history of this basement unit. Fine-grained porphyries and coarse-grained augengneisses from the RPC give crystallization ages between 284 and 271 Ma, which either represent distinct magma pulses or long-lasting magmatic activity in a complex magma chamber. There is also evidence for an earlier Variscan magmatic event at ~320–310 Ma. Mylonites at the base of the Suretta nappe are probably derived from either the RPC augengneisses or another unknown Carboniferous–Permian magmatic protolith with a crystallization age between 320 and 290 Ma. Two polymetamorphic orthogneisses from the southern Suretta nappe yield crystallization ages of ~490 Ma. Inherited zircon cores are mainly of late Neoproterozoic age, with minor Neo- to Paleoproterozoic sources. We interpret the Suretta nappe as mainly representing a Gondwana-derived crustal unit, which was subsequently intruded by minor Cambrian–Ordovician and major Carboniferous–Permian magmatic rocks. Finally, the Suretta nappe was thrust into its present position during the Alpine orogeny, which hardly affected the U–Pb system in zircon.