Intrusive relationships of granite and dolerite at Lagunta Creek, Freycinet Peninsula

Coastal exposures immediately south of the mouth of Lagunta Creek, Freycinet Peninsula, eastern Tasmania, illustrate the temporal and spatial relationships between various Devonian granites and a dolerite dyke. The oldest granite, an equigranular grey hornblende-biotite adamellite containing abundant mafic enclaves, was intruded by a more felsic, equigranular to variably porphyritic or seriate pink alkali feldspar granite, and associated aplite, leucogranite and pegmatite dykes. Field relationships indicate brittle fracture and stoping of the adamellite during dilational emplacement of the pink granite. Minor bodies of granite porphyry are also younger than the adamellite. A dolerite dyke, of hawaiitic composition and containing plagioclase megacrysts, intrudes the adamellite and also crosscuts the aplite and leucogranite dykes, and is the youngest phase. The granites are metaluminous to very weakly peraluminous, and are classified as I-types on both mineralogical and geochemical criteria. The adamellite is unfractionated and chemically reduced, and, together with similar rocks at Wineglass Bay and Cape Tourville, constitutes the Bluestone Bay Suite, which is geochemically distinct from, and younger than, other eastern Tasmanian granodiorite/adamellites. In contrast, both the pink granite and, to a lesser extent, the granite porphyry are fractionated and locally magnetite-bearing. Fractionation has resulted in high Rb, Y, Th and Pb and low P, Sr and Ba. The dolerite dyke, despite its alkalic major element chemistry, is depleted in Nb like some other granite-associated mafic rocks in the southern Lachlan Fold Belt

Pyroclastics in the Upper Parmeener Supergroup, near Bicheno, eastern Tasmania

Extensively altered, poorly welded ash-fall tuffs of rhyolitic to rhyodacitic composition occur both in situ within the Upper Parmeener Super-Group and as loose talus, at five localities up to twelve kilometres apart in the vicinity of Bicheno in eastern Tasmania. Three closely spaced tuff layers up to 0.7 m thick have been intersected in a drill hole. These and the four outcrops may represent the same stratigraphic interval. The rocks contain phenocrysts of embayed quartz, kaolinized feldspar and altered vermiculite in a devitrified matrix of quartz and kaolinite, in which may be discerned relict glass shard and bubble structures. In some localities, the vermiculite has been thermally exfoliated, suggesting heating to more than 3000 C during the intrusion of nearby Jurassic dolerite. Rhyolite, probably derived from unlocated Triassic flows, occurs as clasts within Triassic conglomerate float and as pebbles within Quaternary river gravels

The Tamar Trough revisited: correlations berween sedimentary beds, basalts, their ages and valley evolution, North Tasmania

The Tamar Trough, an Early Palaeogene fault structure, contains sedimentaty beds and interleaved basaltic flows that infill the structure along its 70 km length. These infills represent a complex interplay between sedimentation, channel erosion, eruptive dislocations, and even 'out of trough' diyersions of the ancestral Tamar drainage. Several areas of resistant basalt flows remain in the south, upper, middle and lower Tamar reaches. Although some palynological control was known, radiometric dating of previously untested basalts now allows close integration and age-pegging for observed palynological biozones. The K-Ar and Ar-Ar ages of the basalt bodies indicate eruptive events at 47, 33-37 and 25 Ma, correlating with Proteacidites asperopolus-Malvacipollis diversus, Nothofagites asperus and Proteacidites tuberculatus biozone age sedimentary beds respectively. Basanite, alkali basalt and hawaiite flows dominate basalt lithology with lesser olivine nephelinite, transitional olivine basalt, olivine tholeiite and quartz tholeiite. Basalt geochemistry suggests derivation from different degrees of partial mande melting (from 7 to 35%), with alkaline and tholeiitic basalts being derived from separate source regions. Most alkaline basalts have high-jl (HIMU) related trace element signatures, which are absent in the tholeiitic rocks. A basalt plug on the trough margin at Loira gave a Jurassic age and has Jurassic dolerite-like geochemistry. The Tamar sequence suggests that the initial fluvio-Iacustrine and later channel-fill sedimentation from 65(?) to 24(?) Ma was then punctuated in places by periods of alkaline volcanism between 47 to 33(?) Ma, and alkaline and tholeiitic volcanism between 33 to 24(?) Ma. No Neogene fossils are known, so this later period was probably one of net erosion. These contrasting quiet sedimentary and more volcanic intervals are related here to a tectonic model that involves northerly drift of Victorian and Tasmanian lithosphere over several former Tasman metasomatised mantle plume sources

A Cretaceous phonolite dyke from the Tomahawk River, northeast Tasmania

Field mapping and indicate that a phonolite which intrudes Devonian granite in the upper Tomahawk River area, Tasmania, is 3.2 km long and with a true thickness of 10-15 m. The rock contains of anorthoclase, sparse fayalitic olivine and low-Ti and rare biotite in a alkali feldspar laths, with interstitial clinopyroxene to amphibole or analcime and accessory apatite. It is peralkaline and evolved, even for phonolites, with very and CaO, and high and incompatible elements. However, relatively high Sr and Ba and the absence of a negative Eu anomaly suggest little feldspar fractionation in its petrogenesis. Its Late Cretaceous age 80.4 ± 1.6 Ma, 4oAr/39Ar plateau 75.8 ± 0.3 Ma, 4oAr/39Ar total fusion 76 ± 3.1 Ma) and geochemistry are unique for Tasmania and it represents a recognised, although very minor, igneous episode. It may be related to a change in dynamic regime following continental rifting, the opening of the Tasman Sea and the subsidence of Bass Basin

Unusual pegmatoid crystallisations in a nephelinite plug, near Round Lagoon, eastern Central Plateau, Tasmania

Pegmatoids in a Late Oligocene olivine nephelinite plug near Round Lagoon form a complex low-pressure fractionation suite. The host nephelinite contains meta-peridotite and meta-wehrlite mantle xenoliths and its composition (Mg# 0.63) may reflect both mantle and then limited fractionation. The pegmatoids range from ultramafic through mafic to feldspathic assemblages in a progressive, but discontinuous, fractionation sequence ~ olivine ~ sodalite ijolite, nepheline syenite ~ alkali syenite). Within this sequence, olivine and clinopyroxene compositions decrease in content, while clinopyroxene becomes increasingly Na- and Fe-rich to produce late stage aegirine-augite and aegirine. Nepheline is prominent in the sequence and crystallised over a wide temperature range from 10000 to <500°C. The presence of sodalite suggests volatile Cl-rich fluxing. Mg-rich spinel crystallised in assemblages, distinct from Fe- and Ti-rich oxides of the magnetite-ulvospinel series in later assemblages. The Round Lagoon low-pressure pegmatoids developed by fractionation in a narrow, vertical feeder rather than in broad lava ponds such as those noted in nephelinite flows at Inverell, New South Wales, and at La Madera, Argentina

Inhalation characteristics of asthma patients, COPD patients and healthy volunteers with the Spiromax® and Turbuhaler® devices: a randomised, cross-over study.

BACKGROUND: Spiromax® is a novel dry-powder inhaler containing formulations of budesonide plus formoterol (BF). The device is intended to provide dose equivalence with enhanced user-friendliness compared to BF Turbuhaler® in asthma and chronic obstructive pulmonary disease (COPD). The present study was performed to compare inhalation parameters with empty versions of the two devices, and to investigate the effects of enhanced training designed to encourage faster inhalation. METHODS: This randomised, open-label, cross-over study included children with asthma (n = 23), adolescents with asthma (n = 27), adults with asthma (n = 50), adults with COPD (n = 50) and healthy adult volunteers (n = 50). Inhalation manoeuvres were recorded with each device after training with the patient information leaflet (PIL) and after enhanced training using an In-Check Dial device. RESULTS: After PIL training, peak inspiratory flow (PIF), maximum change in pressure (∆P) and the inhalation volume (IV) were significantly higher with Spiromax than with the Turbuhaler device (p values were at least &lt;0.05 in all patient groups). After enhanced training, numerically or significantly higher values for PIF, ∆P, IV and acceleration remained with Spiromax versus Turbuhaler, except for ∆P in COPD patients. After PIL training, one adult asthma patient and one COPD patient inhaled &lt;30 L/min through the Spiromax compared to one adult asthma patient and five COPD patients with the Turbuhaler. All patients achieved PIF values of at least 30 L/min after enhanced training. CONCLUSIONS: The two inhalers have similar resistance so inhalation flows and pressure changes would be expected to be similar. The higher flow-related values noted for Spiromax versus Turbuhaler after PIL training suggest that Spiromax might have human factor advantages in real-world use. After enhanced training, the flow-related differences between devices persisted; increased flow rates were achieved with both devices, and all patients achieved the minimal flow required for adequate drug delivery. Enhanced training could be useful, especially in COPD patients

Hyperthyroidism and human chorionic gonadotrophin production in gestational trophoblastic disease

Background: Gestational trophoblastic disease (GTD) is a rare complication of pregnancy, ranging from molar pregnancy to choriocarcinoma. Patients with persistent disease require treatment with chemotherapy. For the vast majority, prognosis is excellent. Occasionally, GTD is complicated by hyperthyroidism, which may require treatment. This is thought to occur due to molecular mimicry between human chorionic gonadotrophin (HCG) and thyroid-stimulating hormone (TSH), and hence cross-reactivity with the TSH receptor. Hyperthyroidism usually resolves as the GTD is successfully treated and correspondingly HCG levels normalise. Methods: This paper reviews cases of GTD treated over a 5-year period at one of the three UK centres and identifies the prevalence of hyperthyroidism in this population. Four cases with clinical hyperthyroidism are discussed. Results: On review of the 196 patients with gestational trophoblastic neoplasia treated with chemotherapy in Sheffield since 2005, 14 (7%) had biochemical hyperthyroidism. Of these, four had evidence of clinical hyperthyroidism. Conclusion: Concomitant biochemical thyroid disease in patients with GTD is relatively common, and measurement of thyroid function in patients with persistent GTD is, therefore, important. The development of hyperthyroidism is largely influenced by the level of HCG and disease burden, and usually settles with treatment of the persistent GTD. However, rarely the thyroid stimulation can have potentially life-threatening consequences

Severe Respiratory Syncytial Virus Bronchiolitis in Infants Is Associated with Reduced Airway Interferon Gamma and Substance P

Severe human respiratory syncytial virus (hRSV) bronchiolitis in previously well infants may be due to differences in the innate immune response to hRSV infection. Aim: to determine if factors mediating proposed mechanisms for severe bronchiolitis differ with severity of disease