MINERAL RESOURCES

Tasmania GEOLOGY OF TASMANIAN GEOLOGICAL SURVEY

485000mE 490000mE 495000mE 48E 54E 158 158

Elliot Reef

North Head LEGEND

Anchor Rock ALLUVIAL, LACUSTRINE AND SWAMP DEPOSITS

Alluvium, including deposits at the margin of lakes. 109 Wireless Hill Older alluvium of terraces. Handspike Pt Colluvium of wash slopes.

54 30S Hasselborough 54 30S Bogs, swamps and "featherbed" (includes significant areas of peat without bedrock ANARE STATION Bay outcrops ; on the north− west coast these peat deposits cover palaeo− beach deposits Buckles on an elevated wave− cut platform 6− 9m above sea level). Bay Palaeo− lake deposits of laminated mud, silt and organic material, extent inferred, Half Moon Bay usually concealed beneath younger alluvium (not shown). Exposed palaeo− lake deposits indicated (large dots). (Note: at grid reference 493000mE 3946200mN similar deposits 3960000mN 3960000mN have been deposited by a former marine inlet). Elizabeth and Mary Pt SLOPE DEPOSITS

Scree slopes. Eagle bay Halfway 286 Hill 113 Eagle Pt 219 North Scoble Mountain Alluvial fans, with slopes of less than 22 degrees. Unity Bay Lake Unity Pt Boot Hill Deposits of large (2− 20m) boulders along coasts, typically in bays on west coast.

241 N Middle Beach

u Island g BEACH AND AEOLIAN DEPOSITS g Langdon Bay Lake e ts Pebbly to cobbly beach deposits. C k k Nuggets Pt kery C Roo Beach deposits with sand. The Nuggets Langdon Pt 321 243 Coastal wind blown and dune sand.

308 371Mt Elder Aeolian silt and sand deposits, often with gravel lag; approximate thickness of deposit Douglas Bay in metres indicated where known.

Mt Power Palaeo− beach deposits of rounded and smoothed cobbles and pebbles, less commonly 326 with coarse sand; mostly on the plateau, but also on the isthmus (495750mE 219 347 3960750mN) at up to 9m above sea level, and below peat cover along the northern Tussock Pt Douglas Pt Mt Blair west coast (not indicated). GLACIOGENE DEPOSITS Boiler Rocks Deposits of grey clay with striated, facetted and polished cobbles and pebbles. 318

Lag deposits of striated, facetted and polished cobbles and boulders. 3955000mN 268 3955000mN Bauer Bay 277 SEDIMENTARY ROCKS

Stony Mawson Pt 236 Mudstone and siltstone, usually laminated and red (grey at 490400mE 3952900mN).

Sandstone and pebbly sandstone with muddy to silty matrix; usually grey, greenish− grey or red. Conglomerate, usually clast supported, consisting of sub− rounded to sub− angular cobble− to boulder− sized clasts of basalt and dolerite, in a mudstone to sandstone 178 210 C matrix. (Gabbro clasts in conglomerate at 490900mE 3956050mN). r eek Sandy Bay Square Lake VOLCANICLASTIC ROCKS 197 207 Hyaloclastite breccia consisting of angular to sub− rounded blocks of usually aphyric 195 Fla basalt in a glass matrix. Cormorant Pt t Cre ek Tulloch Lake 265 Volcaniclastic breccia, matrix− supported, with blocks of usually aphyric basalt.

292 178 Volcaniclastic breccia, clast− supported, with blocks of usually aphyric basalt. Mt Tulloch Brothers Pt 288 196 266 LAVAS Pillow basalt, aphyric to very sparsely phyric (<5% plagioclase phenocrysts), usually amygdaloidal. Mt Harrison 284 Pillow basalt, sparsely to moderately phyric (5− 30% plagioclase phenocrysts), usually 219 amygdaloidal.

Prion Pillow basalt, densely to very densely phyric (>30% plagioclase phenocrysts), usually Lake amygdaloidal. 249 Tabular basalt flows, medium− to fine− grained, usually aphyric; rarely sparsely 3950000mN 3950000mN plagioclase− phyric or densely plagioclase− phyric. Rarely with zones of pillows. 54 36S 54 36S Tabular basalt flows, medium− to coarse− grained with mesoscopically visible plagioclase laths, usually aphyric; rarely sparsely plagioclase− phyric. Rarely with zones of pillows. Autobrecciation locally present. 341 Aurora Pt Mt Eitel Hornblende− phyric massive tabular basalt flows, medium− grained. Rarely sparsely plagioclase− phyric. Rarely with mesoscopically visible plagioclase laths.

Small plugs of picrite. Picritic pillow basalts at (490400mE 3945700mN). Olivine− bearing, matrix supported breccia at (490500mE 3945750mN). Soucek Bay INTRUSIVE ROCKS 273 Sheeted dolerite dykes, with screens of massive, coarse− grained gabbro absent, minor (<5%) or abundant (5− 30%). In Sandell Bay − Sellick Bay area, upper level sheeted dolerite dykes with rare screens of pillow basalt. Sheeted dolerite dykes with minor to abundant screens of massive fine− grained gabbro. Mt Ifould 374 Proportion of sheeted dolerite dykes typically 50− 80%.

Transition zone of subequal proportions of massive coarse− grained gabbro screens (30− 70%) and sheeted dolerite dykes (30− 70%). Skua Lake Gabbro and olivine gabbro, usually massive; may contain dolerite dykes (0− 30%) and rare ultramafic screens.

Sellick Bay Gabbro and olivine gabbro with compositional layering. (Handspike Point, 492250mE Green Gorge 3961250mN). ek re C Troctolite, usually with compositional layering; intruded by dolerite dykes.

Mt Law Dominantly plagioclase− bearing massive wehrlite and minor dunite, intruded by 347 r Gratitude e dolerite dykes. Mt Waite y 422 w Lake a S Massive wehrlite intrusion; plagioclase absent to very rare; without dolerite dykes (North Mountain, 494800mE 3958800mN). 3945000mN 3945000mN Flynn Dunite and plagioclase− bearing dunite; massive; partly or completely serpentinized. Lake

276 Dominantly harzburgite with subordinate dunite and plagioclase− bearing wehrlite, intruded by dolerite dykes. Double Pt Harzburgite; usually massive or occasionally with mineral layering; partly or completely serpentinized. Proportion of dolerite dykes typically <10% but locally up to 30%.

Mt Blake Pyramid Peak 283 Davis 371 Geological boundary − position approximate. Bay Pyramid Lake Geological boundary − position inferred.

245 Fault. Davis Pt

J Endeavour es Saddle Pt sie Lake N ic c 340 o l C re Sandell e k Bay Waterfall Bay

GN MN

340 Major Cape Toutcher Mt Gwynn 3940000mN Lake 260 3940000mN

Magnetic declination 29.6 deg (1991) 373 Tiobunga Rockhopper Pt Lake Mt Martin 54 42S 54 42S Scale 1:50,000 304 0 1 2 3 4 5km Mt Hamilton 433 Projection: Universal Transverse Mercator Horizontal datum − WGS 1984 Zone 57 Raine Pt Lusitania Bay

k e e Geology by B.D.Goscombe, BSc.(Hons), PhD and r

C J.L.Everard, BSc.(Hons)., December 1994 − May a

i 1995; September 1995 − January 1996. Project

n

a initiated and supervised by A.V.Brown, BSc.(Hons), t i s PhD, Director, Mineral Resources Tasmania, with u L Mt Aurora funds provided by the Australian Antarctic Foundation, 383 Mt Fletcher and logistical support provided by the Australian 428 Antarctic Division.

Precarious Pt 3935000mN 3935000mN

Mt Stibbs 340

Base map drawn from several sources; Mt Jeffryes The Spot multispectral satellite mosaic produced Waterfall 399 by the Australian Centre for Remote Sensing Lake (ACRES) 1994. While every care has been taken in the preparation of this data, no warranty is given as to the correctness of the information and Division of National Mapping Macquarie Island no liability is accepted for any statement or opinion or for any 1:50,000 topographic map (1971) warped to conform Cape Star error or omission. No reader should act or fail to act on the basis W with the satellite mosaic along coastline and lakes. of any material contained herein. Readers should consult professional hisky 382 C Incomplete aerial photography flown in 1976 advisers. As a result the Crown in Right of the State of Tasmania k and its employees, contractors and agents expressly disclaim all and Mt Kidson (mainly in the north of the island). GPS positions and field observations. any liability (including all liability from or attributable to any negligent or wrongful act or omission) to any persons whatsoever in respect of anything done or omitted to be done by any such person in Map produced by the Data Management Group, Mineral reliance whether in whole or in part upon any of the material in this data. Resources Tasmania, using GIS software. Original map produced March 1998. Crown copyright reserved. 363 Absolute position with respect to horizontal datum and topographic features is approximate. Caroline Pt

LOCATION DIAGRAM Mt Haswell 339 363 269 150 180 248 Mt Ainsworth Petrel Peak 40 South West Pt NEW ZEALAND Green Pt Windsor Bay Tasmania y a Macquarie B 60 t Island 3930000mN s 3930000mN a E South Reef th u Hurd Pt So 120

48E 54E 80 ANTARCTICA 40 60 80 158 158

485000mE 490000mE 495000mE

WARNING: INKS ARE LIGHT SENSITIVE Plotfile generated 26−SEP−2001