Gene Ontology resource: enriching a GOld mine

The Gene Ontology Consortium (GOC) provides the most comprehensive resource currently available for computable knowledge regarding the functions of genes and gene products. Here, we report the advances of the consortium over the past two years. The new GO-CAM annotation framework was notably improved, and we formalized the model with a computational schema to check and validate the rapidly increasing repository of 2838 GO-CAMs. In addition, we describe the impacts of several collaborations to refine GO and report a 10% increase in the number of GO annotations, a 25% increase in annotated gene products, and over 9,400 new scientific articles annotated. As the project matures, we continue our efforts to review older annotations in light of newer findings, and, to maintain consistency with other ontologies. As a result, 20 000 annotations derived from experimental data were reviewed, corresponding to 2.5% of experimental GO annotations. The website (http://geneontology.org) was redesigned for quick access to documentation, downloads and tools. To maintain an accurate resource and support traceability and reproducibility, we have made available a historical archive covering the past 15 years of GO data with a consistent format and file structure for both the ontology and annotations

Chromium spinel in Late Quaternary volcanic rocks from Kamchatka: Implications for spatial compositional variability of subarc mantle and its oxidation state

Highlights • First comprehensive dataset of spinel inclusions in high-Mg olivine from Kamchatka • Oxidation state of parental magmas of Kamchatka ranging from ΔQFM+0.7 to +3.7 • ΔQFM correlates with Ba/La and La/Nb for back-arc magmas of Kamchatka • Decoupling of Cr# and TiO2 in primitive Cr-Spinel suggests slab melt contribution Abstract The Kamchatka volcanic arc (Russia) is one of well-studied but complex tectonic margins on Earth, with an extensive geologic history stretching as far back as the Late Cretaceous. Unlike many other subduction zones, primitive basalts with Mg# > 65 are abundant in Kamchatka, thereby allowing characterization of the mantle source through compositional analyses of near-liquidus minerals in the rocks. In this paper, we present a comprehensive dataset on the composition of Cr-spinel inclusions in olivine for all main Late Quaternary volcanic zones in Kamchatka, comprising of analyses of 1604 spinel inclusions and their host-olivine from 104 samples representing 30 volcanoes and volcanic fields. The studied rocks are basalts, basaltic andesites and high-Mg andesites, which cover the whole compositional range the Late Quaternary primitive volcanic rocks in Kamchatka. The composition of spinel shows large variability. Spinel inclusions with the lowest Cr# and Fe3+/Fe2+ ratios were found in basalts from Sredinny Range and Northern Kamchatka, whereas the most Cr-rich and oxidized spinel inclusions occur in basalts and high-Mg andesites from the Central Kamchatka Depression. Intermediate Cr-spinel compositions characterize the Eastern Volcanic Belt of Kamchatka. The compositions of olivine-spinel pairs were used to quantify the oxidation state of parental Kamchatka magmas and the degree of partial mantle melting. The redox conditions recorded in spinel compositions range from ΔQFM = +0.7 to +3.7. ΔQFM for samples from the Sredinny Range and Northern Kamchatka correlates with a number of proxies of the involvement of slab-derived components incorporated in the composition of their host-rocks (e.g., La/Nb and Ba/La), which suggests a coupling between the mantle oxidation and metasomatism by slab-derived fluids or melts. These correlations were not observed for frontal Kamchatka volcanoes with the highest estimated ΔQFM, which possibly indicates a buffering of the mantle oxidation state by sulfur. The estimated degrees of partial mantle melting range from 8 to >20% for Kamchatka volcanoes. Spinel from the Central Kamchatka Depression has the highest Cr# and could crystallize from magmas generated from the most depleted sources. In contrast to the Eastern Volcanic Belt, spinel Cr# and the inferred degrees of melting in the Central Kamchatka Depression do not correlate with spinel TiO2 content. The apparent decoupling between the proxies of mantle depletion in the CKD spinel is interpreted to reflect refertilization of the CKD mantle by oxidized Ti-rich slab- or mantle lithosphere-derived melts near the northern edge of the subducting Pacific Plate. This study demonstrates that the composition of Cr-spinel in volcanic rocks in combination with bulk-rock compositions can be a powerful tool to map regional variations of the mantle source depletion, oxidation state, and involvement of various slab derived components in island-arc magmatism