Dear All:
The Geological Survey of Canada (GSC) has approved funding for a project
entitled "Characterization of diverse massive sulphide- and exhalite-forming
processes in the Finlayson Lake and Little Salmon Range areas, Yukon; and
their significance and application to mineral exploration". An integral part
of this project will be two graduate (Ph.D. and/or M.Sc.) student theses.
Fieldwork will start this coming field season (June or July, 2000). If you
know of students who may be interested, please encourage them to contact me
directly.
Sincerely, Jan Peter
DETAILS:
WHO:
Researchers involved are from the GSC (Jan Peter, Suzanne Paradis, Bruce
Taylor, Charlie Roots), together with colleagues from the Yukon Geology
Program (Don Murphy and Maurice Colpron), B.C. Geological Survey (Mitch
Mihalynuk, JoAnne Nelson), University of British Columbia (Stephen Piercey,
Stephen Rowins, Geoff Bradshaw), Carleton University (Brian Cousens),
University of Victoria (Scott Song), Expatriate Resources Ltd. (Harlan
Meade, Terry Tucker), Atna Resources Ltd. (Peter Holbek), Cominco (Paul
MacRobbie), and Pacific Ridge Explorations Ltd. (Wayne Roberts).
WHY:
oThe FLA is an emerging base metal camp in the Yukon, which itself is
experiencing markedly decreased mining activity and employment in recent
times. The area contains several recently discovered polymetallic massive
sulphide deposits in diverse geologic environments and which are of
sufficient tonnage and grade that one or several may be economically
exploitable in the next few years.
oThe FLA is the focus of an ongoing Yukon Geology Program (YGP) mapping
project and a new NATMAP project, the "Ancient Pacific Margin", which will
provide new geological maps, metallogenic studies, syntheses and exploration
models.
oGiven these significant monetary, logistical, and scientific efforts, there
is a timely need for a program to understand the processes which led to the
formation of the Devonian-Mississippian massive sulphide deposits, as
application of this knowledge may result in more effective exploration
methods here, elsewhere in Canada and abroad. Explorationists can use these
findings to initiate and refine exploration models and programs, which
target base metal sulphide deposits.
oIncreased geoscience knowledge for possible use in future resource
assessments for policy and land use decisions, resource and environmental
assessments and risk management of potential base-metal exploitation.
oComplements a current GSC NATMAP project (Paradis and Jonasson) to examine
the controls on Se and other trace element abundances in mineralization and
host rocks of the FLA; and a project by NATMAP and MDRU (Piercey, Mortensen
and Paradis) to unravel the tectonostratigraphic setting of the FLA and the
positions of the various deposits within it through the use of
lithogeochemistry and age-dating.
oMentor and educate young geoscientists involved with the project.
WHAT:
1) Research focused on the key massive sulphide deposits and occurrences and
their immediate host rocks in the FLA. The FLA hosts a wide variety of
massive sulphide deposit types: Kuroko-type and/or hybrid Kuroko-Sedex-type
(Kudz Ze Kayah, Wolverine); Cyprus-type (Ice, Money, Strike); and
Besshi-type (Fyre Lake).
2) Research targeting hydrothermal strata ("exhalites", including iron
formation, chert, barite) associated with massive sulphides.
Our goal is to understand the salient controls on the mineralizing processes
and their implications for exploration for concealed mineralization.
Specifically, what are the sources of metals, sulfur, carbon, and strontium
in the mineralization? Were magmatic volatiles or fluids important, or are
the fluids largely modified seawater? What were the physicochemical
characteristics of the mineralizing fluids, which influence how the metals
were dispersed at the paleoseafloor (e.g., temperature, salinity, metal,
sulfur, chloride, LIL contents)? Brines result in a sheet-like morphology,
and lack widespread, intense related hydrothermal alteration, whereas plumes
result in a mound-like morphology, with a well-developed underlying
alteration zone, which can be targeted by exploration. How were the metals
transported to their deposition site? Did the fluids undergo phase
separation or boiling, an important control on the precious metal tenor of
the sulphides? How were the metals precipitated? What were the redox
conditions at the sites of deposition, and did the mineralizing fluids carry
sulphur, or was it supplied from reduced seawater in, for example, an anoxic
basin? Did the mineralizing fluids evolve through time? Are there preserved
vertical and lateral variations in the isotopic signatures (O, H, C, S) of
the host rocks indicative of proximity to mineralization? Are their
mineralogical, bulk and isotopic compositional variations in the exhalites,
which may serve as vectors in the exploration for concealed massive
sulphides?
HOW:
oDocument the major sulphide deposits in the FLA (including form,
sedimentology, mineralogy, mineral chemistry, bulk composition, mineral
chemistry, and stable and radiogenic isotopic (S, C, O, H, Sr)
characteristics of sulphide and gangue (barite, carbonate, quartz, chlorite)
minerals and any associated hydrothermal alteration and exhalites) by XRD,
standard optical microscopy, electron microprobe, SEM, mass spectrometry.
oDocument changes in the composition, mineralogy, mineral chemistry, and
isotopic composition of exhalites along strike from known deposits and
evaluate their use as vectors toward concealed mineralization.
oDetermine physicochemical and isotopic characteristics of primary
mineralizing fluids (temperatures, salinity, metal and other species
contents, redox state, isotopic composition) through the use fluid inclusion
microthermometry, ion chromatography and possibly gas chromatography, PIXE
and SXRF.
oField work (sampling, mapping, core logging) will be done over the summer
months. Laboratory research will entail sample preparation (cutting,
crushing, pulverizing), polished thin and fluid inclusion section
preparation, x-ray diffractometry, bulk chemical analysis (in-house and
commercial labs), scanning electron microscopy, electron microprobing of
specific mineral phases, mineral separations, radiogenic and stable isotopic
analysis of specific mineral phases, fluid inclusions microthermometry,
PIXE, ion chromatography.
WHEN:
oProject funding commences April 1, 2000 and runs for three years.
FUNDING:
GSC, industry support, and NSERC matching funds are currently being sought.
FOR MORE INFORMATION:
oContact Jan Peter, Mineral Resources Division, Geological Survey of Canada,
601 Booth Street, Ottawa, Ontario, K1A 0E8. Phone (613) 992-2376; Fax (613)
996-9820; Email: [log in to unmask]
--
Jan M. Peter, Mineral Resources Division,
Geological Survey of Canada, 601 Booth Street,
Ottawa, Ontario, Canada K1A 0E8 ph (613) 992-2376
fax (613) 996-9820 email: [log in to unmask]
Mineral Deposits Subdivision homepage:
http://www.NRCan.gc.ca/gsc/mrd/mds/mdshome.html
EXTECH II homepage: http://extech2.gsc.nrcan.gc.ca/
personal homepage: http://www.NRCan.gc.ca/~jpeter/
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
