1. Australian Antarctic Data Centre
2. Discover and Manage Data
3. Records
4. ASAC_1150

Description

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 stratigraphically 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.

2008
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).

2009
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:

Site
Sample Number
Collector/Geologist
Date
Latitude
Longitude
Rock Type
Assemblage
Description (Desc)
Purpose
Foliation
Lineation (L)
Strike
Dip
Dip direction
Plunge
Plunge direction

The mineral assemblage code abbreviations are as follows:
Grt= garnet
Ksp= alkali feldspar
Pl (or plag)= plagioclase
Q= quartz
Cpx= clinopyroxene
Opx=orthopyroxene
Px=pyroxene
Bi= biotite
Sill=sillimanite
Musc= muscovite
Mag=magnetite
Cd=cordierite
Amph= amphibole
Hbl=hornblende

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.

Quality

The dates provided in temporal coverage are approximate only.

Access

Public use of data allowed, providing permission and citation of primary investigator.

Data are available for download from the provided URL.

The map produced from this dataset, The Geology of the Stillwell Hills, is also accessible via the provided URL.

Temporal Coverages

• Start date: 1996-09-30 - Stop date: 1999-03-31

Spatial Coverages

Science Keywords

• EARTH SCIENCE > SOLID EARTH > ROCKS/MINERALS/CRYSTALS > BEDROCK LITHOLOGY
• EARTH SCIENCE > SOLID EARTH > ROCKS/MINERALS/CRYSTALS > METAMORPHIC ROCKS
• EARTH SCIENCE > SOLID EARTH > ROCKS/MINERALS/CRYSTALS > MINERALS
• EARTH SCIENCE > SOLID EARTH > TECTONICS > PLATE TECTONICS > FAULT MOVEMENT
• EARTH SCIENCE > SOLID EARTH > TECTONICS > PLATE TECTONICS > FOLDS
• EARTH SCIENCE > SOLID EARTH > TECTONICS > PLATE TECTONICS > STRESS
• EARTH SCIENCE > SOLID EARTH > TECTONICS > PLATE TECTONICS
• EARTH SCIENCE > SOLID EARTH > TECTONICS > PLATE TECTONICS > LITHOSPHERIC PLATE MOTION

Use Constraints

This data set conforms to the CCBY Attribution License
(http://creativecommons.org/licenses/by/4.0/).

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.