OUR Archive
https://ourarchive.otago.ac.nz:443
The Otago University Research Archive digital repository system captures, stores, indexes, preserves, and distributes digital research material.2024-03-15T15:37:13ZProfiling free amino acid pool in the muscles of triplefin-fish after being fed with chitosan and zein-based films containing heavy metals to identify the potential changes in amino acid metabolism
http://hdl.handle.net/10523/16649
Profiling free amino acid pool in the muscles of triplefin-fish after being fed with chitosan and zein-based films containing heavy metals to identify the potential changes in amino acid metabolism
2024
Zhao, Chun
Previous studies have demonstrated that plastic particles (PLA), degraded from food packaging waste, have high affinity with heavy metals (HM) that result in a worse combined marine plastic pollution than plastic pollution alone. Chitosan and zein-based edible food film (CZF) is biodegradable and environmentally friendly which could be considered as an alternative material to reduce the plastic pollution. On the other hand, the heavy metals bound to PLA could induce oxidative stress disrupting the amino acid metabolism of fish, hence there is a need to evaluate whether CZF can reduce the heavy metal complex formation as well as the resulting oxidative stress that affects the amino acid metabolism of fish. The heavy metals came from the contaminants originally present in the ingredients used in the film making.
For this study, Triplefin-fish (Forsterygion capito, TPN-fish), a local species found in New Zealand waters was selected as our model organism due to its integral role within marine ecosystems, particularly in contributing to the lower levels of marine food chains. We exposed them to PLA and CZF at similar dosage and frequency for the same predefined feeding time (39 days). The profile of amino acid pool was measured only in the muscle portion of the fish. Based on the literature review, analysis of the free amino acid (FAA) pool was selected as a key biomarker to evaluate the effects of CZF and PLA exposure on TPN-fish muscle. The FAA pool profiling was conducted using gas chromatography with flame ionization detector (GC- FID) as an analytical approach. Multivariate and univariate statistical approaches, namely principal component analysis (PCA) and orthogonal partial least squares–discriminant analysis (OPLS-DA), and Mann–Whitney U test and one-way analysis of variance (ANOVA), were used to identify FAA discriminators associated with exposure to CZF and PLA. The identified discriminators were further evaluated by pathway analysis to identify potentially affected areas of amino acid metabolism.
The FAA pool in the white muscle of TPN-fish exposed to CZF was found to be altered, including a decreased level of branched chain amino acids (BCAAs), serine, methionine, phenylalanine, histidine, tyrosine, tryptophan, ornithine, and an increased level of alanine and glutamine. In addition, specific impacted pathways were identified in relation to the change in the FAA pool, namely phenylalanine, tyrosine and tryptophan biosynthesis; alanine, aspartate, glutamic acid and glutamine metabolism; valine, leucine and isoleucine biosynthesis. Overall, the altered amino acid metabolism was attributed to abnormal energy metabolism, reduction of weight gain and a disturbed immune system in TPN-fish. Moreover, the decreased levels of phenylalanine, tryptophan and histidine were found to be associated with changes in fish behaviour and swimming performance. The present study has demonstrated that FAA pool profiling can be a robust and effective approach in monitoring the biophysical effects of exposing TPN-fish to CZF.
This study was the first to use GC-FID based FAA pool profiling to investigate the effect of an alternative food packaging material (CZF) in a New Zealand aquatic ecosystem. Evaluation of the FAA data indicated that this approach could specifically contribute to the evaluation of the safety of CZF in the environment. The results of the present study also provide a preliminary framework in relation to the application of FAA profiling to evaluate metabolic changes in a model organism, on exposure to an alternative food packaging material, and its potential effect on the environment.
2024-03-15T02:43:46ZImmune cell activation and function in Crohn's disease
http://hdl.handle.net/10523/16648
Immune cell activation and function in Crohn's disease
2024
Laws, Gemma Ashleigh
Crohn’s disease (CD) is a chronic inflammatory bowel disease with many contributing factors: the immune response, genetic susceptibility, environmental factors, intestinal epithelium, and the host microbiome. Current treatments aim to control excessive inflammation but are not always effective. Human intestinal organoids can be grown from patient intestinal biopsy stem cells and can be used in in vitro experimental models to account for patient heterogeneity when investigating the pathogenesis of CD. I developed a two-dimensional (2D) intestinal organoid monolayer transwell model that corresponds to the lumen and lamina propria of the human gut. The monolayer model was used to manipulate apical (lumen) and basal (lamina propria) compartments with the addition of commensal bacteria and patient-matched peripheral blood mononuclear cells (PBMCs), respectively, and to study the contribution of the immune response on the epithelial integrity.
Using these 2D human intestinal organoids, I modelled the gut immune responses in people with CD compared to healthy controls (HC), as well as the effect of bacteria and immune cells from the same patient on the epithelial integrity of the monolayers. Addition of PBMCs and heat killed bacteria to CD monolayers resulted in reduced epithelial resistance compared to monolayers derived from HC donors.
I developed a model of inflammation using HC monolayers and polyclonally active immune cells. The degree of immune cell activation was correlated with reduced epithelial integrity. Epithelial integrity was restored with the addition of anti-tumour necrosis factor (TNF) antibody in all HC derived monolayers and some CD derived monolayers (responders) and this response was associated with reduced abundance of CD4 and CD8 T cells and reduced inflammatory cytokine (TNF and interferon (IFN)-γ) production.
CD is associated with microbial dysbiosis and probiotic use has been an attractive therapeutic option to alter the microbiota in patients with CD. In this thesis, I developed a co-culture of human organoid monolayers, autologous immune cells and live probiotic bacteria. The influence of live probiotic bacteria on cytokine production, PBMCs phenotypes and epithelial integrity in the inflammation model was investigated. Addition of either the live probiotics Escherichia coli Nissle 1917 (EcN) or Vivomixx restored epithelial integrity in only some HC and CD derived monolayers, and affected the expression and localisation of tight junction proteins. Epithelial protection mediated by addition of probiotics was associated with reduced inflammatory immune cell phenotypes and reduced TNF and IFN-g cytokine production.
Taken together, activated immune cells caused inflammatory mediated epithelial damage to human organoid monolayers, and epithelial protection by anti-TNF or probiotic bacteria was associated with reduced abundance of T cells populations and decreased concentrations of TNF and IFN-γ, suggesting that epithelial damage in CD is the result of these inflammatory cytokines. Investigating the interaction of gut bacteria, immune cells and the intestinal epithelial cells will help in understanding the pathogenesis of CD. This organoid model, which is derived from individual patient tissues, accounts for patient heterogeneity and leads towards a personalised medicine approach.
2024-03-15T01:27:46ZFire & Ice Using ancient DNA to reconstruct the phylogeography of the extinct New Zealand Goose Cnemiornis spp. Te Ahi me te Hukapapa Te matai whenua ā-ira o te Tarepo
http://hdl.handle.net/10523/16647
Fire & Ice Using ancient DNA to reconstruct the phylogeography of the extinct New Zealand Goose Cnemiornis spp. Te Ahi me te Hukapapa Te matai whenua ā-ira o te Tarepo
2024
Greer, Liam
Changes in the physical environment over time has a sustained impact on the physical and genetic features of taxa and populations within a species. New Zealand has had a long and varied history in its 80-million-year existence which has shaped the endemic and native biota that call it home. The recent field of Palaeogenomics has shed light on the complex ways that the changes in the environment have impacted those species. The New Zealand goose Cnemiornis is a genus of recently extinct large and flightless waterfowl which was previously resident on both two main islands in the archipelago: Cnemiornis gracilis on the North Island, and Cnemiornis calcitrans on the South Island. In this thesis, palaeogenetic approaches were used to sample the DNA of Cnemiornis and construct the phylogeographic history and structure of the genus, examining whether the genus has been impacted by geologic events in patterns like those observed in cohabitant avifauna. Recovered partial mitogenomes confirmed the placement of Cnemiornis within the Anatidae family as the sister taxon to the extant Cape Barren goose Cereopsis novaehollandiae. Strong support for the existence of two species of Cnemiornis was shown through phylogenetic analysis, indicating that the two species diverged in the Mid Pleistocene as a result of the closure of the Manawatū strait. Within the South Island species C. calcitrans, phylogenetic analysis found strong support for two genetically distinct clades, called here C. calcitrans “northern” and C. calcitrans “southern”, with divergence attributed to the glacial-interglacial cycles of glacier expansion and contraction in the Southern Alps, and the Mid Pleistocene climate transition (MPCT). Within the North Island species, evidence thought limited was found to support two clades called here C. gracilis “eastern” and C. gracilis “western”, with divergence attributed to the intermittent volcanic events of the Taupō Volcanic Zone in central North Island. This study represents the first in-depth examination of a previously little known extinct New Zealand genus and furthers the evidence for palaeogenomics as a significant tool in the understanding of how a changing world impacts living organisms.
2024-03-15T01:17:48ZOn the orientation of the soul toward grace or God: Simone Weil and Robert Bresson
http://hdl.handle.net/10523/16646
On the orientation of the soul toward grace or God: Simone Weil and Robert Bresson
2024
Voigt Hogg, Vida Virginia Gertrude
This thesis analyses and compares the religious and metaphysical philosophy of Simone Weil (1909-1943) with the cinema of auteur director, Robert Bresson (1901-1999), especially, in relation to their mutual concern regarding the soul in affliction. I argue that by understanding the contribution of Weil and Bresson, this knowledge may assist in learning that attention toward the soul will help to transcend the force of affliction experienced in one’s life. The methodological framework is based on Weil’s philosophical concepts, in particular, attachment, detachment, attention, affliction, decreation, necessity, and justice. I elucidate these concepts through the analysis of a select group of Bresson’s films. In my exploration, I show that in the cinematograph, Bresson’s approach converges with Weil’s philosophy as far as the natural (necessity) and the supernatural (divine grace) or God’s love are concerned. The analysis of specific scenes demonstrates Bresson’s emphasis on reality (the supernatural, as opposed to unreality or the natural), divination, and automatism, to reveal the force of affliction Weil asks us to transcend by way of attention. I suggest that Weil’s philosophy is a conscious practice which can be adapted to each individual soul. Here I draw on my experience of affliction, in addition to Bresson’s protagonists, Saint Augustine’s The Confessions, the BCE Hindu Scripture: The Bhagavad Gītā, and Homer’s Iliad or The Poem of Force; also, Plato’s “Allegory of the Cave” and the “Great Beast” in the Republic. This thesis argues that while the protagonists in Bresson’s films may be taken as figures for one or other of Weil’s concepts, the latter must be considered as “progressive,” namely: as each concept is first learned and then practiced, the soul only thus is reoriented to move closer toward its reunion with God, the creator.
2024-03-15T00:37:36ZInhaled dry powder to treat respiratory infections
http://hdl.handle.net/10523/16645
Inhaled dry powder to treat respiratory infections
2024
Saha, Tushar
Background: A number of viral and bacterial pathogens are responsible for multiple respiratory diseases in humans. The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the most recent example of the significant global health burden related to these infectious diseases. Although numerous antibacterial and antiviral treatments are available, not all of them are effective at rapidly achieving the desired therapeutic outcomes when administered in their conventional dosage forms such as tablets, capsules, or injections. The key limitations include numerous side effects due to the administration of high doses and insufficient drug concentration in the respiratory tract, the primary target site of many of these infections. Alternatively, inhaled treatment is considered an efficient approach for treating infections like SARS-CoV-2, by supporting the administration of lower doses and ensuring higher concentrations of the drug(s) in the lung. The inhaled treatment combining two or more anti-infective agents can increase potency and reduce the possibility of drug resistance. Repurposed drugs are often chosen against these respiratory pathogens and during pandemic situations as they are readily available and require less time to develop. Subsequently, this thesis aimed to develop both single and combinational inhalable dry powders containing suitable repurposed agents having anti-infective properties, mainly targeting viral respiratory pathogens, such as SARS-CoV-2, while also evaluating their effectiveness against selected bacterial respiratory pathogens (Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Klebsiella pneumoniae).
Methods: Early in the COVID-19 pandemic when limited options were available to target SARS-CoV-2, four commercially available and repurposed drugs having anti-infective properties, namely ivermectin, remdesivir, disulfiram, and ebselen were selected to develop as inhalable dry powders. Ivermectin and ebselen were developed as a single drug containing dry powder. On the other hand, remdesivir was developed as a combination with disulfiram or ebselen due to their reported synergistic activity. The inhalable dry powders were prepared by spray drying technique and in the presence/absence of different amino acids such as L-leucine, L-methionine, and L-tryptophan. The prepared dry powders were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy to assess the dry powder morphology and particle size, residual solvent amount, crystallinity, and drug-drug/drug-excipient interactions. The stability of ivermectin and remdesivir-disulfiram combinational dry powders was assessed at 25 °C/<15% RH and 25 °C/53% RH conditions for one month. The cytotoxicity and anti-SARS-CoV-2 activity of ivermectin dry powder and combinational dry powders of remdesivir with disulfiram/ebselen were assessed in vitro using cultured human airway epithelial cells (Calu-3 cells). In addition, the cytotoxicity and antimicrobial activity of ebselen dry powders were assessed using an alveolar epithelial cell line (A549 cells) and against Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae.
Results: All the prepared dry powders were within the size range of 1–5 μm indicating their suitability for inhalation. The used raw materials were crystalline in nature. However, the spray-dried ivermectin dry powder was amorphous whereas the other formulations such as ebselen dry powders, remdesivir-disulfiram, and remdesivir-ebselen combinational dry powders remained crystalline. The residual solvent amount was ~1% (w/w) for all the dry powders, and no drug-drug/drug-excipient interactions were observed. Different drugs showed distinct morphological features after spray drying. The optimized ivermectin and ebselen dry powders were wrinkled whereas remdesivir-disulfiram and remdesivir-ebselen combinational dry powders were spherical. The average fine particle fraction of optimized ivermectin, remdesivir-disulfiram combination, remdesivir-ebselen combination, and ebselen dry powders were 83%, 61%, 65%, and 68%, respectively. All these optimized dry powders contained L-leucine as an excipient. The stability study conducted for ivermectin and remdesivir-disulfiram combinational dry powders revealed no significant difference in the physicochemical and in vitro aerosolization properties of the respective dry powders. The 50% cytotoxic concentration (CC50) values of the optimized ivermectin, remdesivir-disulfiram combination, and remdesivir-ebselen combinational dry powders were 39.1 μM, 41.51 μM and >100 μM, respectively. The half maximal inhibitory concentration (IC50) of optimized ebselen dry powder was 225 μg/mL tested in A549 cells. All the dry powders showed comparable anti-infective and antimicrobial activity to the raw drugs. The half maximal effective concentration (EC50) of the ivermectin, remdesivir-disulfiram combination, and remdesivir-ebselen dry powders against SARS-CoV-2 were 15.8 μM, 4.43 μM, and 8.04 μM, respectively. In addition, the ebselen dry powders showed potent antimicrobial effects against Gram-positive bacteria Staphylococcus aureus and Streptococcus pneumoniae with a low minimum inhibitory concentration (MIC) of 0.31 μg/mL and 0.16 μg/mL, respectively. However, the dry powders lacked potent antimicrobial activity against the Gram-negative pathogens Pseudomonas aeruginosa and Klebsiella pneumoniae. It is important to highlight that all the cellular toxicity (CC50 and IC50) and anti-infective as well as the antimicrobial (EC50 and MIC) values for the dry inhalable formulations were comparable to those obtained with respective non-formulated drugs.
Conclusions: The stable inhalable dry powders containing single and combinational antimicrobial agents were successfully developed by spray drying technique. L-leucine-containing dry powders showed better aerosolization properties compared to the L-leucine-free formulations or other amino acids. More importantly, the potency of all the prepared dry powders remained comparable to the raw active agents, with the dry powders showing limited cell toxicity in the respiratory cell lines used in this study. Further preclinical studies in animal models (e.g., humanized mice, African green monkeys) will test the suitability of the prepared dry powders to inhibit SARS-CoV-2, Staphylococcus aureus and Streptococcus pneumoniae.
2024-03-14T00:25:51ZInvestigating ultradian rhythms in CRH neurons, CORT secretion, and animal movement
http://hdl.handle.net/10523/16643
Investigating ultradian rhythms in CRH neurons, CORT secretion, and animal movement
2024
Zheng, Shaojie
The hypothalamic-pituitary-adrenal (HPA) axis mediates the release of adrenal corticosteroids (CORT) under both basal conditions and in response to stress. The HPA axis is controlled by corticotropin-releasing hormone (CRH) neurons, which release CRH peptide to stimulate pituitary corticotrophs, leading to the secretion of adrenocorticotropic hormone (ACTH). Subsequently, ACTH is released into the bloodstream, where it triggers the adrenal cortex to synthesise and release CORT. In the absence of stress, CRH, ACTH, and CORT are secreted in a fluctuating pattern known as the ultradian rhythm (Henley et al., 2009; Windle et al., 1998; Ixart et al., 1993). In both humans (Henley et al., 2009) and rats (Windle et al., 1998), the ultradian rhythm in ACTH and CORT secretion is approximately one pulse per hour. Remarkably, the patterns of CRH neuron activity which control these ultradian rhythms remains unclear. In addition to controlling stress hormone release, CRH neurons have also been shown to control arousal and stress-associated behaviours (Fuzesi et al., 2016; Li et al., 2020). However, no studies to date have examined the relationship between CRH neuron activity and ultradian rhythms of arousal and stress hormone secretion. To investigate this, in vivo fibre photometry, automated blood sampling, and animal movement tracking were performed in a novel Crh-IRES-Cre rat.
Initially, RNAscope and immunohistochemistry (IHC) were used to characterise the Crh-IRES-Cre rat line. These experiments revealed a high level of co-localisation between Cre mRNA and Crh mRNA in the paraventricular nucleus (PVN) of Crh-IRES-Cre rats. IHC results also demonstrated Cre-recombinase protein labelling in the PVN.
I next performed GCaMP6s fibre photometry in order to record CRH neural activity in freely behaving Crh-IRES-Cre rats. These recording revealed a robust hourly rhythm (1.0 ± 0.09 pulses per hour) in CRH neuronal activity across the 24-hour day. Simultaneous animal movement tracking (as a measure of behavioural arousal) showed coordination between CRH neuronal activity and animal movement, suggesting a link between CRH neuron activity and arousal state. Causality analysis showed that there is a mathematical one-way influence of CRH neuronal activity on animal movement. Furthermore, CRH neuronal activity was consistently elevated when rats were exposed to a short white noise stressor.
In order to measure ultradian rhythms in CORT secretion, an automated blood sampling device was designed and optimised to collect consistent, small-volume, blood samples through a jugular vein catheter from freely moving rats. CORT levels showed robust ultradian rhythms of secretion, with 0.93 ± 0.12 pulses per hour. Simultaneous animal movement tracking showed a highly variable temporal coordination between CORT secretion and behaviour at an individual level.
Next, I performed simultaneous fibre photometry, blood sampling, and animal movement tracking to study the complex interplay between CRH neuronal activity, CORT secretion, and animal movement under both unstressed and stressed conditions. CRH neuronal activity exhibited an hourly rhythm of 1.14 ± 0.064 pulses per hour, whereas CORT secretion and animal movement showed ultradian rhythms of 0.90 ± 0.061 pulses per hour and 0.90 ± 0.041 pulses per hour, respectively. Cross-correlation analysis revealed a strong correlation between CRH neuronal activity, animal movement, and CORT levels under both unstressed and stressed conditions. This analysis showed that CRH neuronal activity preceded CORT secretion by approximately 15 minutes, which supports the hypothesis that pulsatile CRH neuronal activity drives ultradian CORT secretion. However, close examination of recordings revealed that not all pulses of CRH activity triggered pulses of CORT secretion. Likewise, not all pulses of CORT secretion occurred with a preceding pulse of CRH neuronal activity.
In summary, these data reveal the presences of ultradian rhythms in CRH neuronal activity, CORT secretion and animal movement in freely behaving rats. CRH neuronal activity was found to be highly correlated with animal movement and was shown to be a granger cause of animal movement using mathematical causality analysis. I have also shown CRH neuronal activity is correlated with CORT secretion with CRH neuronal activity preceding CORT by 15 mins. The mathematical modelling of the HPA axis also suggests that CRH neuronal activity determines the ultradian dynamics of CORT secretion. Overall, these results suggest that CRH neurons play an important role in coordinating ultradian rhythms of CORT secretion and behavioural arousal.
2024-03-13T22:59:01ZThe origins and future of the Burakumin
http://hdl.handle.net/10523/16642
The origins and future of the Burakumin
2001-05-12
Laidlaw, Ian Rutherford
The Burakumin ('Buraku' meaning 'hamlet', and 'min' meaning 'people') are a Japanese minority group that descends from the Tokugawa period outcasts. The Buraku people are currently involved in a struggle for liberation, which has been active for nearly 70 years, from their social position as objects of prejudice and conditions of socio-economic hardship. A great deal of research and interest has emerged in this group amongst both Japanese and non-Japanese researchers in recent years, and many theories and opinions as to their origins, their current situation, and their future conditions have emerged.
There has been considerable disagreement over the period and cause of their origins. Opinions as to the period of emergence of the ancestral groups of the Burakumin range from the 7th through to the 17th centuries, and theories to the cause range from social, to religious, to political reasons. The future of the Buraku liberation movement is also in doubt, and there is a general lack of research into their greatest current difficulties and future progression.
In this thesis I will be examining the various theories concerning the origins of the Burakumin and I will be linking the earliest outcast groups with the Tokugawa outcast class, which is known to be directly connected to the modem-day Buraku minority group, in order to discover how far the Burakumin can be traced back. This thesis will show that the origins of the Buraku people can be traced back as far as the Heian period and were primarily due to Shinto and Buddhist influences.
I will also conduct a case study of the origins of four of Japan's major performing arts (sarugaku, noh, kabuki and bunraku) and looking at the involvement of outcasts in their creation and development in order to provide a better picture of the social conditions of early outcast groups.
The second major topic that I will examine in this thesis is the future of the Buraku liberation movement. For this purpose I conducted three weeks ofresearch during a field trip to Japan in July and August 2000. I will be chiefly drawing on the interviews that I conducted in Japan with the people who are currently connected to the Buraku liberation movement, as well as recent research into modern Buraku conditions, in order to provide a picture of the current state of the movement, and a critical examination of its future.
Through this research I discovered that there is a current trend of change in direction with regard to the movement for Buraku liberation, but that there is a need for further critical examination from within the movement with regard to a number of issues such as education, internationalisation, legislation and combating discrimination. I also found that there is still a definite need for a representative organisation for the movement, and that claims that the primary liberation organisation, the Buraku Liberation League, is perpetuating a solution to the Buraku problem appear to be groundless.
2024-03-13T02:18:29ZDynamic metamorphism within the Rakeahua batholith, Mason and Doughboy Bay region, Stewart Island
http://hdl.handle.net/10523/16641
Dynamic metamorphism within the Rakeahua batholith, Mason and Doughboy Bay region, Stewart Island
1989-12-14
Peden, Ross
A reconnaissance geological map at 1: 25 000 is presented for a previously unmapped Mason-Doughboy Bay area on the west coast of Stewart Island. Five granitoid plutons with faulted and intrusive contacts within the Rakeahua Batholith have been identified.
The Walkers Hill Fault (new name) separates the Hellfire granitoid complex (Allibone, 1986) to the north from the Mason-Doughboy suite (this study) to the south.
The Mason-Doughboy suite consists of four plutons and the Gutter High Strain Zone (new name). The youngest pluton is the Adams Hill Leucogranite (new name) which intrudes the other three, Doughboy Bay Granodiorite (new name), Ernest Island Diorite (new name) and the oldest, Walkers Hill Diorite (new name).
The Mason Bay Granodiorite (Allibone, 1987 and this study) to the north of the Walkers Hill Fault is younger than the post-emplacement tectonism, overprinted in the Mason-Doughboy suite. The Mason Bay Granodiorite is in faulted contact with the Walkers Hill Diorite.
The Adams Hill Leucogranite forms an intrusion breccia with both the Walkers Hill Diorite and Doughboy Bay Granodiorite. Adams Hill Leucogranite dykes, also intrude the Doughboy Bay Granodiorite. Intrusive contacts between the Ernest Island Diorite and the Adams Hill Leucogranite are complex, and concurrently folded within the Gutter High Strain Zone. Major and trace element chemistry of the five plutons indicates I-type affinities, but suggests S-type character for granite tectonites from the Gutter High Strain Zone.
The Gutter High Strain Zone is a localised narrow zone of predominantly ductile deformation, 1-2km wide. Development of the zone was accompanied by dynamic metamorphism, associated with movement, to greenschist facies conditions.
A progressive sequence of granite - granite tectonites - mylonites, and calc-silicate metasediment, garnet quartzites and amphibolites are found within the Gutter High Strain Zone. The zone has regionally inferred significance.
Syn-posttectonic deformation of the Gutter High Strain Zone is synchronous with post-emplacement tectonism of the Mason-Doughboy suite, these events are older than the Walkers Hill Fault. It is unclear if the intrusion of the Adams Hill Leucogranite is cause or symptomatic of the Gutter High Strain Zone, but is syn-posttectonic.
Magmatic Cu-sulphide textures in globules from host Adams Hill Leucogranite dykes indicate immiscibile melts.
Possible meteorite impact crater features proposed by Bishop et al. (1987 an unpublished preliminary report) are equally explained by natural geological and geomorphological phenomena.
There were no 'potential' economic resources discovered in the field.
2024-03-13T01:57:36Z