In Situ 87Sr/86Sr of Scheelite and Calcite Reveals Proximal and Distal Fluid-Rock Interaction During Orogenic W-Au Mineralization, Otago Schist, New Zealand

2018 ◽  
Vol 113 (7) ◽  
pp. 1571-1586 ◽  
Author(s):  
Emma J. Scanlan ◽  
James M. Scott ◽  
Victoria J. Wilson ◽  
Claudine H. Stirling ◽  
Malcolm R. Reid ◽  
...  
Keyword(s):  
New Zealand ◽  
Rock Interaction ◽  
Otago Schist

A fossilFuchsia(Onagraceae) flower and an anther mass with in situ pollen from the early Miocene of New Zealand

2013 ◽  
Vol 100 (10) ◽  
pp. 2052-2065 ◽  
Author(s):  
Daphne E. Lee ◽  
John G. Conran ◽  
Jennifer M. Bannister ◽  
Uwe Kaulfuss ◽  
Dallas C. Mildenhall
Keyword(s):  
New Zealand ◽  
Early Miocene

Magmatic-Hydrothermal Mineralization Processes at the Yidong Tin Deposit, South China: Insights from In Situ Chemical and Boron Isotope Changes of Tourmaline

2021 ◽  
Author(s):  
He-Dong Zhao ◽  
Kui-Dong Zhao ◽  
Martin R. Palmer ◽  
Shao-Yong Jiang ◽  
Wei Chen
Keyword(s):  
South China ◽  
Hydrothermal Fluids ◽  
Boron Isotope ◽  
Granitic Magma ◽  
Gangue Mineral ◽  
Rock Interaction ◽  
Hydrothermal Mineralization ◽  
Mineralization Processes ◽  
Tin Deposit

Abstract Owing to the superimposition of water-rock interaction and external fluids, magmatic source signatures of ore-forming fluids for vein-type tin deposits are commonly overprinted. Hence, there is uncertainty regarding the involvement of magmatic fluids in mineralization processes within these deposits. Tourmaline is a common gangue mineral in Sn deposits and can crystallize from both the magmas and the hydrothermal fluids. We have therefore undertaken an in situ major, trace element, and B isotope study of tourmaline from the Yidong Sn deposit in South China to study the transition from late magmatic to hydrothermal mineralization. Six tourmaline types were identified: (1) early tourmaline (Tur-OE) and (2) late tourmaline (Tur-OL) in tourmaline-quartz orbicules from the Pingying granite, (3) early tourmaline (Tur-DE) and (4) late tourmaline (Tur-DL) in tourmaline-quartz dikelets in the granite, and (5 and 6) core (Tur-OC) and rim (Tur-OR), respectively of hydrothermal tourmaline from the Sn ores. Most of the tourmaline types belong to the alkali group and the schorl-dravite solid-solution series, but the different generations of magmatic and hydrothermal tourmaline are geochemically distinct. Key differences include the hundredfold enrichment of Sn in hydrothermal tourmaline compared to magmatic tourmaline, which indicates that hydrothermal fluids exsolving from the magma were highly enriched in Sn. Tourmaline from the Sn ores is enriched in Fe3+ compared to the hydrothermal tourmaline from the granite and displays trends of decreasing Al and increasing Fe content from core to rim, relating to the exchange vector Fe3+Al–1. This reflects oxidation of fluids during the interaction between hydrothermal fluids and the mafic-ultramafic wall rocks, which led to precipitation of cassiterite. The hydrothermal tourmaline has slightly higher δ11B values than the magmatic tourmaline (which reflects the metasedimentary source for the granite), but overall, the tourmaline from the ores has δ11B values similar to those from the granite, implying a magmatic origin for the ore-forming fluids. We identify five stages in the magmatic-hydrothermal evolution of the system that led to formation of the Sn ores in the Yidong deposit based on chemical and boron isotope changes of tourmaline: (1) emplacement of a B-rich, S-type granitic magma, (2) separation of an immiscible B-rich melt, (3) exsolution of an Sn-rich, reduced hydrothermal fluid, (4) migration of fluid into the country rocks, and (5) acid-consuming reactions with the surrounding mafic-ultramafic rocks and oxidation of the fluid, leading to cassiterite precipitation.

Developing an in situ, hydromechanical coupling, true triaxial rock compression tester and investigating the deformation patterns of reservoir bank slopes

2021 ◽  
pp. qjegh2021-043
Author(s):  
Lei Fan ◽  
Meiwan Yu ◽  
Aiqing Wu ◽  
Yihu Zhang
Keyword(s):  
Coupling Effect ◽  
Water Pressure ◽  
Pressure Coefficient ◽  
Hydromechanical Coupling ◽  
Rock Interaction ◽  
True Triaxial ◽  
Rock Structure ◽  
Deformation Patterns

Interactions between water and rocks are the main factors affecting the deformation of rock masses on sloped banks by reservoir impoundment. The technology used in laboratory tests of water-rock interaction mechanisms cannot simulate the coupling of water, the rock structure and the initial stress environment. In this work, we develop an in situ hydromechanical true triaxial rock compression tester and apply it to investigate the coupling response of reservoir bank rocks to changing groundwater levels. The tester is composed of a sealed chamber, loader, reactor, and device for measuring deformation, which are all capable of withstanding high water pressures, and a high-precision servo controller. The maximum axial load, lateral load and water pressure are 12 000 kN, 3 000 kN and 3 MPa, respectively. The dimensions of the test specimens are 310 mm×310 mm×620 mm. The test specimens are grey-black basalts with well-developed cracks from the Xiluodu reservoir area. The results show that increasing water pressure promotes axial compression and lateral expansion, while decreasing water pressure causes axial expansion and lateral compression. A water pressure coefficient, K, is introduced as a measure of the hydromechanical coupling effect (expansion or compression) with changing groundwater level. A mechanical tester can be used to perform accurate field tests of the response of wet rocks to hydromechanical coupling. The test results provide new information about the deformation patterns of rock slopes in areas surrounding high dams and reservoirs.Thematic collection: This article is part of the Role of water in destabilizing slopes collection available at: https://www.lyellcollection.org/cc/Role-of-water-in-destabilizing-slopes

Comment and Reply on "Nd isotopic gradients in upper crustal magma chambers: Evidence for in situ magma-wall-rock interaction"

Geology ◽  
1991 ◽  
Vol 19 (2) ◽  
pp. 185
Author(s):  
Benjamin C. Schuraytz ◽  
Thomas A. Vogel ◽  
Leland W. Younker ◽  
G. Lang Farmer ◽  
Kathryn J. Tegtmeyer
Keyword(s):  
Wall Rock ◽  
Magma Chambers ◽  
Rock Interaction ◽  
Crustal Magma

scholarly journals Cancer care decision-making and treatment consent: An observational study of patients’ and clinicians’ rights

2020 ◽  
Author(s):  
Kevin Dew ◽  
L Signal ◽  
J Stairmand ◽  
A Simpson ◽  
D Sarfati
Keyword(s):  
Decision Making ◽  
New Zealand ◽  
Observational Study ◽  
Cancer Care ◽  
Shared Decision ◽  
Medical Specialists ◽  
Medical Oncologists ◽  
Audio Recordings ◽  
Care Decision

© The Author(s) 2018. This study identified ways in which patients and medical specialists negotiated decisions about cancer treatment by observing decision-making discussion in situ. Audio-recordings of cancer care consultations with 18 patients, their support people, and their medical specialists, including medical oncologists, radiation oncologists and surgeons were collected in different regions of New Zealand. Patients were followed up with interviews and specialists provided consultation debriefings. The interpretation of the data drew on the concepts of epistemic and deontic rights to argue that in complex consultations, such as occur in cancer care, we need to reconsider the simple dichotomy of preferred consultations styles as paternalistic or based on shared decision-making. Decision-making is a dynamic process with specialists and patients linked into networks that impact on decision-making and where rights to knowledge and rights to decision-making are interactionally negotiated. The level of information and understanding that patients desire to exercise rights needs to be reconsidered.

Trace element partitioning during high-P partial melting and melt-rock interaction; an example from northern Fiordland, New Zealand

2004 ◽  
Vol 22 (5) ◽  
pp. 443-457 ◽  
Author(s):  
F. C. Schröter ◽  
J. A. Stevenson ◽  
N. R. Daczko ◽  
G. L. Clarke ◽  
N. J. Pearson ◽  
...  
Keyword(s):  
New Zealand ◽  
Trace Element ◽  
Partial Melting ◽  
Rock Interaction ◽  
Trace Element Partitioning ◽  
Element Partitioning

scholarly journals Re-establishment of an endangered subspecies: the Norfolk Island Boobook Owl Ninox novaeseelandiae undulata

1996 ◽  
Vol 6 (1) ◽  
pp. 63-80 ◽  
Author(s):  
Penny D. Olsen
Keyword(s):  
New Zealand ◽  
Low Cost ◽  
Female Offspring ◽  
Nest Boxes ◽  
Large Trees ◽  
Island Group ◽  
Norfolk Island ◽  
In The Wild ◽  
Original Female

SummaryThe Norfolk Island Boobook Ninox novaeseelandiae undulata is confined to the small, isolated Norfolk Island group, an Australian territory. On morphological and biogeographical grounds, it is here classified as a large, distinctive subspecies of the New Zealand Morepork N. novaeseelandiae. In 1986 only one specimen, a female, survived. A shortage of large trees with suitable nesting holes appeared to be the immediate problem. The Australian Nature Conservation Agency, islanders and New Zealand wildlife authorities have cooperated in an attempt to re-establish an owl population in situ. Nest-boxes were erected in trees in the area frequented by the female and were used readily as roosts. In September 1987, two male New Zealand Moreporks were introduced. The female paired with one male and produced four hybrid F offspring (in 1989 and 1990). Two of these paired in mid-1991 and have since produced five F offspring (two in 1993 and three in 1994). The original female remains paired but now appears to be reproductively senile. At present there seems to be a shortage of mature males, since two female offspring are paired and both lay eggs and attempt to incubate them in the same nest; and a lone female has established a territory. In early 1995 all eleven owls appeared to be alive in the wild. The effort is low-cost, requires relatively little manpower, is carried out with minimal disturbance to the owls, and goes hand in hand with other conservation programmes.

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