The strength of the lower continental crust; evidence from the Stillwell Hills-Oygarden Group Coastline.Entry ID: ASAC_1150
Abstract: The nature of the data were lithological and structural geological mapping, in addition to the collection of relevant geological specimens. The quality of the data collected ranges from detailed form surface mapping in the Oygarden Islands and locally in the Broka-Havstein and Stillwell Hills areas, to regional mapping in the majority of the latter two regions. The main episode of the high grade ... deformation preserved in the area occurred during the c.950Ma Rayner Structural Episode, a collisional event which affected large areas of Enderby, Kemp, MacRoberston Lands and the northern Prince Charles Mountains. In the Oygardens this deformation occurred in the middle to lower crustal levels, while the section through the Broka-Havstein, through to the Stillwell Hills, is thought to represent a continuation of this crustal section as a tilted crustal block, moving stratigraphicallly higher towards the Stillwell Hills. Work in the Oygarden Group has shown that at these deep crustal levels, lithology can be heterogeneous, and deformation varied, which opposes conventional ideas of lithological and rheological homogeneity, and a constant deformation style. With movement eastwards to the Stillwell Hills this work revealed differences in deformation style as one moves through the crustal levels, with deformation dominated by a more homogeneous deformation style of superposed penetrative deformation events. Geological samples will be used to constrain the nature of the mineral assemblages and fluid present during metamorphism, as well as study on the pressures and temperatures of metamorphism, and the phase relationships which developed throughout the metamorphic evolution of the belt.
In May of 2008, two new files were added to the dataset - a pdf copy of the original field notes taken in the Stillwell Hills during the project (SWHfieldbook2002_Halpin1.pdf), plus a new excel spreadsheet which is an attempt to bring together all the Stillwell Hills spreadsheets in the dataset (Halpin_StillwellHills_FieldData.xls).
In March of 2009, the excel spreadsheet, Halpin_StillwellHills_FieldData.xls, was replaced by a series of shapefiles (in the folder StillwellHills_FieldData).
The shapefile of the field sites data contains the following fields:
SITE: Individual site number/reference for location - corresponds to original hand-drawn maps and entries in the geologist's notebook.
OBS: Unique observation identification tag related to the SITE number - there may be several OBS entries for a single SITE, which may include several descriptions of rock types, measurements etc.
SAMPLE: Sample number if a sample was collected.
GEOLOGIST: The name of the geologist that recorded the observation/sample/measurement etc.
DATE_: The date of the recorded observation/sample/measurement etc.
ROCK_TYPE: Lithology type at the specified location
DESCR: Description of lithology type/mineralogy/sample/structural information etc.
FOLIATION: Inferred foliation type/generation (where S1=first generation foliation related to D1 deformation, S2=second generation foliation related to D2 deformation, S2/3= transposition of S2 foliation during D3 deformation etc, AP=axial plane.
STRIKE: Strike/trend of foliation (measured from north) in degrees.
DIP: Dip of foliation (measured from horizontal) in degrees.
DIP_DIR: Dip direction of foliation, allows DIP to be a unique direction.
LINEATION: Inferred lineation or fold axis generation (where L1=first generation lineation related to D1 deformation, L2=second generation lineation related to D2 deformation, L2/3= transposition of L2 lineation during D3 deformation etc, F1=first generation fold axis related to D1 deformation, F2=second generation fold axis related to D2 deformation, F2/3= transposition of F2 fold axis during D3 deformation etc.)
PLUNGE: Plunge of the lineation/fold axis (measured from horizontal) in degrees.
PLUNGE_DIR: Plunge/trend direction of the lineation/fold axis (measured from north) in degrees.
The data for this project is the same as that for ASAC_2214.
The fields in this dataset are:
The mineral assemblage code abbreviations are as follows:
Ksp= alkali feldspar
Pl (or plag)= plagioclase
The foliation codes begin with an 'S' which just means the measurement is a foliation, and then is followed by a number to indicate which deformation event the foliation records, hence S1, S2, S3 etc.
The lineation data are much the same however they begin with an 'L' followed by a number.
(Click for Interactive Map)
Start Date: 1999-09-01
SOLID EARTH > ROCKS/MINERALS/CRYSTALS > BEDROCK LITHOLOGY
SOLID EARTH > ROCKS/MINERALS/CRYSTALS > METAMORPHIC ROCKS
SOLID EARTH > ROCKS/MINERALS/CRYSTALS > MINERALS
SOLID EARTH > TECTONICS > PLATE TECTONICS > FAULT MOVEMENT
SOLID EARTH > TECTONICS > PLATE TECTONICS > FOLDS
SOLID EARTH > TECTONICS > PLATE TECTONICS > STRESS
SOLID EARTH > TECTONICS > PLATE TECTONICS
SOLID EARTH > TECTONICS > PLATE TECTONICS > LITHOSPHERIC PLATE MOTION
ISO Topic Category
Quality The dates provided in temporal coverage are approximate only.
Access Constraints Public use of data allowed, providing permission and citation of primary investigator.
Data are available for download from the URL given below.
The map produced from this dataset, The Geology of the Stillwell Hills, is also accessible via the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1150 when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 138 MB
Distribution Format: excel, pdf, illustrator, text
Phone: +61 2 9351 2919
Fax: +61 2 9351 0184
Email: geoffc at mail.usyd.edu.au
University of Sydney School of Geosciences F05
Province or State: New South Wales
Postal Code: 2006
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: +61 3 6226 2406
Email: jahalpin at utas.edu.au
ARC Centre of Excellence in Ore Deposits School of Earth Sciences University of Tasmania Private Bag 79
Province or State: Tasmania
Postal Code: 7001
Kelly, N.M., Clarke, G.L., Carson, C.J., and White, R.W. (2000), Thrusting in the lower crust: evidence from the Oygraden Islands, Kemp Land, East Antarctica., Geological Magazine, 137, 219-234
Kelly, N.M., Clarke, G.L., Carson, C.J., and White, R.W. (1998), Ductile Thrusting near the Rayner Complex-Napier Complex Boundary, Oygraden Islands, east Antarctica., 14th Australian Geological Convention, Townsville, Australia.
Kelly, N.M., Clarke, G.L. and Klepies, K.A. (1998), Lower crustal thrusting in the Rayner Complex of East Antarctica., Tectonic Studies Group Annual Meeting, St. Andrews, Scotland
Kelly, N.M., Clarke, G.L., and Fanning, C.M. (1999), Proterozoic reworking of Archaen Crust: evidence from preliminary SHRIMP geochronolgy, Oygarden Group, Rayner Complex, East Antarctica., International Symposium on Antarctic Earth Sciences, Wellington, New Zealand
Kelly, N.M., Clarke, G.L., and Fanning, C.M. (2000), Proterozoic reworking of Archaen Crust in the Rayner Complex, east Antarctica., 15th Australian Geological Convention, Sydney, Australia
Halpin, J.A., Clarke, G.L., White, R.W., Kelsey, D.E. (2007), Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica., Journal of Metamorphic Geology, 25, 638-701
Halpin, J.A., White, R.W., Clarke, G.L., Kelsey, D.E. (2007), The Proterozoic P-T-t evolution of the Kemp Land coast, east Antarctica; constraints from Si-saturated and Si-undersaturated metapelites., Journal of Petrology, 48, 1321-1349
Halpin, J.A. (2007), Metamorphic and geochronological evolution of the Kemp and MacRobertson Land coast, east Antarctica., PhD thesis, 154, School of Geosciences, University of Sydney
Halpin, J.A., Gerakiteys, C.L., Clarke, G.L., Belousova, E.A., Griffin, W.L. (2005), In-situ U-Pb geochronology and Hf isotope analyses of the Rayner Complex, east Antarctica., Mineralogy and Petrology, 148, 689-706
Clarke G.L. (1988), Structural constraints on the Proterozoic reworking of Archaean crust in the Rayner Complex, MacRobertson and Kemp Land coast, East Antarctica., Precambrian Research, 40-41, 137-156
Creation and Review Dates
DIF Creation Date: 2000-12-15
Last DIF Revision Date: 2012-07-13