Direct optimization and multiple alignment of 28S D2-D3 rDNA sequences: problems with indels on the way to a molecular phylogeny of the cryptine ichneumon wasps (Insecta: Hymenoptera)

A molecular phylogeny of the Cryptinae based on the D2–D3 region of the 28S rDNA gene, including 176 cryptines representing 139 genera and an additional 77 outgroup genera, is presented. Direct optimization and multiple alignment each with a range of gap/substitution parameters were employed. The informal higher grouping of the ichneumonids were supported, but the relationship of the Ichneumoninae and Cryptinae was not resolved. Cryptinae tribes were supported but many genera formed constant groups that did not follow earlier subtribal divisions. We investigated artifactual placements of, e.g., Agriotypinae and Brachycyrtinae, and showed that they do not possess molecular synapomophies with the Ichenumoninae where direct optimization places them. The sequences of anomalous placed taxa were markedly longer (or in some cases shorter) than those of most other taxa, and this is explained by homoplastic indels at "hot spots" in the absence of large numbers of informative substitutions. We show that multiple alignment generally resulted in taxa with large insertions or deletions being placed in more plausible positions. The relationship of the genus Alomya is also explored

Orthomagmatic quartz and post-magmatic carbonate veins in a reported porphyry copper deposit, Andean Intrusive Suite, Livingston Island, South Shetland Islands

A previously reported porphyry Cu + Mo deposit in an Eocene pluton within the South Shetland Island magmatic arc has been re-interpreted as three distinct hydrothermal assemblages. The oldest assemblage (1) exsolved under confinement from the deep (∼6 km?) cooling magma whereas assemblages (2) and (3) formed during tectonic ± magmatic episodes at depths of < 1.5 km in the late Cenozoic. The three assemblages occur over the 5 × 11 km mapped in Barnard Point tonalite pluton. Assemblage (1) comprises shallowly dipping sheets of aplite, biotite + tourmaline pegmatite, massive ‘grey’ quartz, and quartz + tourmaline + bornite + chalcopyrite + molybdenite veins. Magnetite + tourmaline + chalcopyrite breccias have associated biotite, K-feldspar and muscovite alteration. Fluid inclusions indicate formation from hot (∼600°C), saline (40 equivalent weight % NaCl + CaCl2) aqueous-carbonic fluids that exsolved from the partly consolidated magma. The primary control on solution chemistry and nature of fracturing was the depth of pluton emplacement. Assemblage (2) consists of steep, vuggy veins and country-rock breccias, with thick propylitic alteration selvages, cemented by microcrystalline quartz, complex inter-growths of FeMg carbonate, bladed barite and trace amounts of bornite and chalcopyrite. These rocks, previously described as breccia (sensu ‘pebble’) dykes in the porphyry complex, are reinterpreted as an influx of moderately hot (175–330°C), weak to moderately saline (2–21 EWP NaCl), aqueous-carbonic fluids that underwent isobaric boiling at 0.8 to 1.3 km depth. Assemblage (3) consists of thin, hematitic fault infillings formed during a second episode of brittle faultin