Three-dimensional analysis of magnetotelluric data from the New Afton porphyry deposit, central British Columbia

Three-dimensional imaging of a Ag-Au-rich epithermal system in British Columbia, Canada, using airborne z-axis tipper electromagnetic and ground-based magnetotelluric data

Geophysics ◽

10.1190/geo2015-0230.1 ◽

2016 ◽

Vol 81 (1) ◽

pp. B1-B12 ◽

Cited By ~ 8

Author(s):

Juliane Hübert ◽

Benjamin M. Lee ◽

Lijuan Liu ◽

Martyn J. Unsworth ◽

Jeremy P. Richards ◽

...

Keyword(s):

British Columbia ◽

Volcanic Rocks ◽

Three Dimensional ◽

Data Sets ◽

Borehole Data ◽

Magnetotelluric Data ◽

Electric Field Amplitude ◽

Epithermal System ◽

Geologic Model ◽

Felsic Volcanic

We have evaluated results from a study combining airborne z-axis tipper electromagnetic (ZTEM) and ground-based magnetotelluric (MT) data to image an epithermal system in British Columbia. The spatially coincident use of these two methods allowed for a direct comparison of both data sets in the overlapping frequency band and showed that both measurements were consistent. Inversion of just the ZTEM data suffered from the lack of electric field amplitude information, which could be provided by the MT data. Three-dimensional inversion modeling of the two individual data sets was performed. Models of electrical resistivity derived from both data sets were consistent and could be correlated with the geological and structural setting of the mineralization. Gold is associated with disseminated pyrite and marcasite in quartz-sericite-altered felsic volcanic rocks and intrusions, especially near the contact with mafic volcanic rocks and a late diorite intrusion. The quartz-sericite alteration yields a conductivity anomaly, relative to the more resistive mafic country rocks. Although ZTEM and MT do not possess the resolution of the geologic model derived from borehole data, our model agrees well with a regional assessment of the deposit.

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In situ investigation of the primary recrystallization of alpha titanium in HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110313 ◽

1978 ◽

Vol 36 (1) ◽

pp. 634-635

Author(s):

S. Naka ◽

R. Penelle ◽

R. Valle

Keyword(s):

Dimensional Analysis ◽

Texture Evolution ◽

Cold Work ◽

Three Dimensional ◽

Primary Recrystallization ◽

Thin Foils ◽

In Situ Investigation ◽

Grain Growth Model ◽

Alpha Titanium

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.

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