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Shore platforms on the South Coast ofNew South WalesE. C. F. Bird a & O. F. Dent ba Reader in Geography , University of Melbourneb Research Student in the School of General Studies , AustralianNational UniversityPublished online: 25 Feb 2007.

To cite this article: E. C. F. Bird & O. F. Dent (1966) Shore platforms on the South Coast of NewSouth Wales, Australian Geographer, 10:2, 71-80, DOI: 10.1080/00049186608702463

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SHORE PLATFORMS ON THE SOUTH COAST OF NEW SOUTH WALES 71

SHORE PLATFORMS ON THE SOUTH COAST OFNEW SOUTH WALES

E. C. F. BIRD and O. F. DENT *

The origin of platforms at the foot ofcoastal cliffs has interested many geologistsand geomorphologists during the fifty yearssince Bartrum published his first paper onhigh-water rock platforms in New Zealand,and the literature on the subject is nowformidable.1 The term 'shore platform' hasbeen applied to a variety of shore forms,including horizontal and sloping benchesat various levels, and platforms that slopeseaward, passing beneath low tide level.Some of these have surfaces truncatinggeological structures in the shore zone,others show a correlation with surfaces ofresistant rock formations. Emphasis hasbeen given to the study of platforms at orslightly above mean high tide level, sub-merged by the sea only during the highesttides, or when strong onshore winds drivewaves across them. Some authors have at-tributed these to abrasion by storm waveswith the sea at its present level;2 othersconsider that they developed when the seastood slightly higher, relative to the land,and that emergence during Recent timeshas left them above their level of forma-tion.3 Some have given emphasis to weather-ing processes in evidence on the platformsand on the cliffs behind them, notably thesurface disintegration of many types of rockas the result of repeated wetting (by sea

*Dr. Bird is Reader in Geography in theUniversity of Melbourne; Mr. Dent is aResearch Student in the School of GeneralStudies, Australian National University.

spray and rainfall) and drying;4 others be-lieve that salt crystallization from sea spray,associated with wetting and drying, plays asignificant part in this.5 A distinction shouldbe made between the washing away ofweathered debris by the sea during oc-casional high tides or storm wave inunda-tion and the abrasion of unweathered rockoutcrops by waves, due either to thehydraulic action of water impact or to thescouring caused when debris (sand, shingleor cobbles) is moved to and fro across theshore zone. It is clear that no single ex-planation is adequate for all knownexamples of shore platforms at or slightlyabove mean high tide level: they can formin a variety of ways as the outcome of oneor more of these processes, and it is notpossible to deduce 'normal' modes of evo-lution from specific platforms studied indetail.

Any attempt to account for the develop-ment of shore platforms at or slightly abovemean high tide level should also explaintheir absence on adjacent sections of thecoast. The emphasis given in the literatureto shore platforms on the Australian coasttends to obscure the fact that high-tideplatforms are quite restricted in geo-graphical extent. They occur at scatteredlocalities on the coasts of Victoria, Tas-mania, New South Wales and southernQueensland, and have been reported fromAustralia's northern coast in the vicinity ofYampi Sound,6 but they are not found onthe coast that lies behind the Great BarrierReef. There are horizontal platforms dc-

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THE AUSTRALIAN GEOGRAPHER

veloped on calcarenite on the coasts ofWestern Australia, South Australia andwestern Victoria, but these are in a dif-ferent category, being typically developedat mean mid-tide level and therefore regu-larly submerged at high tide; solution ofcalcium carbonate has clearly played a partin their evolution.7 The present paperexamines high-tide shore platforms in thecontext of the variety of shore zonemorphology found on the South Coast ofNew South Wales between Sydney andCape Howe (Fig. 1), where neap tiderange is about four feet, and spring tiderange slightly more than six feet. Meanmid-tide level is a convenient datum formeasuring coastal forms, and is indicatedwithin the rocky shore zonation of plantand animal life8 by the horizontal upperlimit of the polychaete worm Galcolariacaespitosa, as observed on vertical rockwalls of crevices near the outer edge of arocky shore but protected from the directimpact of waves and surf.9

South Coast Cliffs and Platforms

The coastline from Sydney Heads southto Cape Howe measures just over 400 miles,of which 57 per cent, is rocky shorelineand 43 per cent, bordered by sandybeaches. About one-third of the rockyshoreline has shore platforms, some ofwhich are smooth and horizontal, otherssloping, and others fragmentary, irregular,or dissected. Geologically, there are threemajor divisions: a northern sector domin-ated by gently-dipping Permian and Triassicformations, a central sector, extendingfrom south of Durras to Tathra, dominatedby strongly-folded Lower Palaeozoic meta-scdiments, and a southern sector dominatedby Devonian formations. In addition, thereare plutonic intrusions and interbeddedlavas which outcrop at the coast, as wellas scattered patches of Tertiary sands andgravels and Tertiary basalt in the coastalfringe.10 The pattern is shown on the geo-logical map of New South Wales publishedby the Geological Survey in 1962 at a scale

Fig. 1: Location map. Numerals indicate sites shownon Plates 1-10.

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SHORE PLATFORMS ON THE SOUTH COAST OF NEW SOUTH WALES 73

of 1:1,000,000 and on various more de-tailed maps of coastal sectors published bythe Mines Department of New South Wales.

South from Sydney Heads the TriassicHawkesbury Sandstone outcrops at thecoast, forming high, steep cliffs where thesandstones are massive, and stepped profileswhere ledges have been cut out by waveaction on outcrops of thinly-bedded sand-stone and intercalated shale (Plate 1).

Plate I: Structural benches on bed Jed sandstone atCape Solander.

These ledges are 'structural' in the sensethat they coincide with the upper surfacesof resistant sandstone strata; they are hori-zontal or gently sloping according to thedip of the rocks and they frequently extend10 to 20 feet above high tide level, wherethey are washed by occasional storm waves.These were the shore platforms describedby Jutson,11 and mentioned earlier byJohnson,12 who noted that it was possibleto follow a particular bench along the shore,down the dip of a resistant sandstone layeruntil it passed below sea level, when onecould clamber up on to another bench de-veloped on the next higher resistant out-crop. In detail the plan of the cliffs andplatforms reflects the pattern of verticaljointing which guides erosion in thesemassive sandstones.

South of Garie Beach the underlyingNarrabeen Group outcrops at the coast asa series of almost horizontal siltstones,

shales and sandstones, and beyond Coalcliffthese give place to Permian rocks of similarlithology comprising the Illawarra CoalMeasures. Horizontal shore platforms havedeveloped three to four feet above meanmid-tide level, backed by steep and activeh1-receding cliffs (Plate 2) . The platforms

Plate 2: Shore platforms on headlands at Coalcliff.

are prominent on the headlands betweenGarie Beach and Wollongong, at PortKembla, and at Shellharbour. Structural in-fluence is less in evidence than on theHawkesbury Sandstone coast, many plat-forms truncating local dip. Waves splashover them at high tide, but they are onlyreally awash at the highest spring tides, orwhen strong onshore winds drive wavesacross them. For most of the time they areabove the level of wave action, but therock surface is generally wet, and strewnwith shallow pools of water.

At Bass Point, south of Shellharbour, thecoast becomes more rugged on an outcropof well-jointed Permian lava (latite). Clefts,caves and blowholes have developed wherewaves have penetrated along lines of joint-ing, but there are no shore platforms.Underlying tuffaceous sandstones and silt-stones appear in the foreshore south ofBombo, and become dominant in the covesouth of Easts Beach at Kiama, where theyare marked by shore platforms up to 100feet wide developed just above mean hightide level, in contrast with the rugged latitc

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74 THE AUSTRALIAN GEOGRAPHER

shore (Plate 3) . These platforms are con-spicuous on the shore southward to Black

P/afe 3: Sfcore platform on tuffaceous sandstone (left)contrasts with rugged shore on latite (right), south

of Kiama.

Point, and are clearly visible from thePrinces Highway south of Kiama. At Crook-haven Head, sandstones of the upper partof the Shoalhaven Group outcrop to formledges which follow the bedding planes ofthe rocks, but close by, at Culburra, thereare shore platforms developed on thick silt-stone which are flat and stand three feetabove mean mid-tide level. Farther south,where the coarse, massive, indurated quartzsandstones of the Jervis Bay formationreach the shore at Currarong, an irregularramp of exposed rock follows the dip, andfrom Beecroft Head to St. George's Headthese hard rocks form precipitous, plungingcliffs, with only a local development ofstructural ledges where thinner horizontalbeds of sandstone have been differentiallyeroded by the waves. The pattern of verticaljointing influences the plan of these cliffs,with caves and clefts developed by waveattack along the more prominent joints.

Between Sussex Inlet and Bawley Point,sandstones, siltstones and conglomerates ofthe Conjola Formation13 outcrop at thecoast, the siltstones yielding broad hori-zontal platforms about three feet abovemean mid-tide level, the more massivesandstone outcrops forming structuralbenches. In addition, Tertiary basalt out-

crops in the headlands, north of Ulladullaproducing broad platforms where the basaltis weathering rapidly, but more irregulaishores, strewn with boulders, whereweathering has been more varied. At War-den Head, Ulladulla (Plate 4) , a hori

Plate 4: Shore platform at Warden Head, Ulladulla

zontal platform developed on mudstones irthe Conjola Formation stands about threefeet above mean mid-tide level, and i;readily accessible for detailed examina-tion.14 Towards the cliff base the flat platform gives way to a gently-sloping ramp ffew feet wide, backed by the vertical cliff.On the south side, facing waves generatedby the prevailing southerly winds andsouth-easterly swell, the cliffs are stillreceding, but on parts of the more shelterednorthern shore there are vegetated bluffs,evidently not being cut back' at the presenttime, though the platform fronting then-implies a phase of cliff recession here inthe past.

Farther south, to Bawley Point and againbetween Merry Beach and Flat Rock Headsouth of Durras, the coast is dominated b}coarse sandstones and conglomerates dip-ping 5° to 15° eastwards, and on these,structurally-controlled ledges and rampshave been formed. Locally, however, thereare flatter platforms, notably on the moresheltered northern sides of headlands, andwhere there are finer, thinly-bedded sand-stones or outcrops of siltstone, as at Depot

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SHORK PLATFORMS ON THK SOUTH COAST OF NEW SOUTH WALES

Beach. Between Bawlcy Point and MerryBeach there are no shore platforms; acoarse-grained basic igneous intrusion(Kioloa essexite) has proved extremely re-sistant to marine attack, and the coastalslopes merely pass beneath the sea, thewaves having achieved no more than theremoval of the thin soil and vegetationcover in the shore zone (Plate 5).

Plate 5: Slopes on essexite without shore plathrms,Bawley Point.

Permian rocks give place to LowerPalaeozoic formations a mile or so south ofDurras, and the nature of the shoretopography changes accordingly. The LowerPalaeozoic rocks include schists, phyllitcs,slates, sandstones, cherts and associatedvolcanics, and arc strongly folded alongmainly NNW-SSE axes. Part of the outcropis known as the Wagonga Series,15 believedto be of Cambrian age because it is moreintensively folded and crumpled than over-lying metasediments outcropping inland,which have yielded Ordovician graptolites.10

Lithological variations account for contrastsin shore topography and are more significantthan age from a geomorphological viewpoint.Between Bateman's Bay and BurrewarraPoint well-developed horizontal platformsthree to five feet above mean mid-tide leveland up tto 150 feet wide truncate thesteeply-dipping metasediments. On head-lands these platforms are backed by reced-ing cliffs, but as they pass along the flanksof embayments thev become lower and less

regular and pass locally into sloping inter-tidal platforms near bay-heads, where thecliff at the rear becomes a degraded andvegetated bluff. In the cinbayments waveabrasion is facilitated by the presence ofconsiderable beach debris, mainly sand andshingle, not found on the smoother andHatter headland platforms.

A fine horizontal platform two to threefeet above mean mid-tide level on Tertiarybasalt almost encircles Broulec Island.*On the eastern and northern sides it iswider and flatter and is submerged by thesea only at the highest spring tides, per-haps half a dozen times a year, and whenoccasional north-easterly gales drive wavesacross it. The platform surface is flat, ex-cept for residual knobs and ridges ofweathering basalt (Plate 6) . On the

Plate 6: Platform on basalt anJ degraded bluff,Broulee Island.

southern side it is narrow and more dis-sected, the waves having cut out clefts alongjoints, and locally the flat platform givesplace to an inclined ramp with a slope of5° to 8°. Beach material is not present onthe platform itself, but towards the rear isa beach of sand and shingle, backed b\degraded and vegetated bluffs which arenot at present receding. Similar features arefound on Broulee Point, and farther south,near Congo Point, a bench five to six feet

* For a sketch-map of Broulee Island see E. C. F. Bird(1964) Coastal I.anJforms, p.5-1.

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76 THE AUSTRALIAN GEOGRAPHER

above mean mid-tide level and up to 100feet wide on similar basalt follows the coast-line, backed by steep, thickly vegetatedbluffs which have evidently escaped waveattack for a long period. The platform hereis at an unusually high level and can rarelybe submerged by the sea. At Meringo, twomiles south, .a similar bluff is fronted byboulders of basalt rather than a platform,the basalt being more deeply and intricatelyweathered here.

At Binge Binge Point a gabbro-tonalitecomplex, related to the Moruya granodioriteintrusion, outcrops in a low coastal pro-montory, the rock surfaces passing beneaththe sea with little evidence of marine modi-fication except on the more exposed southernside, where storm waves have shifted largeboulders. Granodiorite reaches the coast atTuross, where again a rocky, block-strewnland surface passes beneath the sea, andadjacent to these intrusions the LowerPalaeozoic rocks at Mullimburra Point andTuross Head are strongly metamorphosedand exceptionally resistant to marineerosion, the foreshore showing ramps andridges related to structural detail. BetweenTuross and Tathra there is much variationin the Lower Palaeozoic rocks. Extremelytough, contorted black cherts form highstacks, such as Waramba Rocks,, just southof Narooma (Plate 7) , and steep, ruggedcliffs, with clefts cut out along weaker

zones, north of Boat Harbour. Flat shoreplatforms are restricted to outcrops ofrapidly-weathering schist and phyllite, oftenalong corridors following the geologicalstrike between ridges of harder sandstoneor slate, giving the ribbed and serrated ap-pearance shown in Plate 8. Sometimes there

Plate 7: Steep cliffs and no platforms on cherts south' of Narooma, looking towards Waramba Rocks.

Plats 8: Serrated shore topography with corridorplanation at Barraga Point.

is a broad accordance of ridge crests, sug-gesting that a platform previously de-veloped 8-12 feet above mean mid-tidelevel, and was subsequently dissected, withplanation along the weaker outcrops. Whereshingle is present, as at Narooma, there ismore evidence of abrasion by waves, withthe formation of an intertidal shore plat-form. Honeycomb, weathering, cavity for-mation and the disintegration of rock sur-faces are processes at work on cliff andforeshore outcrops of schist, phyllite, andfine-grained sandstone (Plate 9) , but noton the coarser and harder elements. In theTilba district the Mount Dromedary mon-zonite intrusion does not reach the coast,but associated intrusions influence the de-tails of shore topography, the reef at BoatHarbour Point being on a diorite intrusion,while ridges of pyroxenite run across theforeshore farther south.17 Montague Islandconsists of intrusive rocks related to theMount Dromedary complex18 and has srugged shore topography, without plat-

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SHORE PLATFORMS ON THE SOUTH COAST OF NEW SOUTH WALES 77

Plate 9: Weathering forms on schist near BarragaPoint.

forms; similar rocks produce similar fea-tures on the coast at Tilba Tilba Lake.

In the Bermagui district the LowerPalaeozoic rocks have been less intensivelymetamorphosed and • sections of platformhave developed slightly above mean hightide level. At Goalen Head doleritereaches the shore, and again the rock sur-faces pass into the sea with little marinemodification: there are no platforms andno cliffs or bluffs. At Bunga Head, a mileor so southward, Devonian rhyolite reachesthe coast in bold, steep headlands withrugged foreshores littered with rhyoliteboulders, and south from Tathra this for-mation produces steep "cliffs, with no shoreplatforms, but spectacular clefts and caveseroded along vertical joints. At MimosaRocks a sharp change in shore topographyoccurs Where the rhyolite gives place tofolded shales, which are truncated by a

broad platform three feet above mean mid-tide level, with a 4° ramp 20 feet wide atthe rear sloping up to a receding cliff ofshale. This marks the beginning of theDevonian Merimbula Formation, a seriesof shales and mudstones interbedded withmassive medium to fine-grained sandstones,which outcrop on 68 per cent, of thecoastline between Bournda Island and CapeHowe. Where sandstones outcrop, marineerosion has produced a stepped shore pro-file, with ledges developed on the hori-zontal or dipping surfaces of the sandstonebeds, but where the shales and mudstonespredominate, horizontal high-tide platformshave developed in front of receding cliffs.The response to lithological and structuralcontrol is well demonstrated at Toalla Point(Plate 10), where flat platforms truncate

Plate 70: Undulating platforms on sandstone and flatplatforms on mudstone at Toalla Points near Pambula.

broadly-folded mudstones, but undulatingsurfaces run parallel to the bedding onintervening sandstone strata. Similar fea-tures may be observed on the coast southof Twofold Bay, but the shores of this bayare marked by outcrops of rhyolite in steepcliffs at Eden and Edrom, and LowerPalaeozoic metasediments forming irregularcliff and shore profiles on headlands separat-ing sandy bays-. Beach gravels are alsopresent locally and, as in the Bateman'sBay district, there are sectors where aninter-tidal shore, platform has developed.

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7 8 THE AUSTRALIAN GEOGRAPHER

Discussion

• This summary of shore morphology alongthe South Coast prompts a number or

.generalizations. Broad horizontal shoreplatforms at or slightly above mean hightide level are best developed on fine-grainedrock formations subject to decomposition byweathering processes in coastal outcrops:shales, siltstones, mudstones, fine-grainedsandstones, schists, phyllites and homo-geneous basalts. Such platforms often trun-cate the local dip, their level of develop-ment being apparently related to the upperlevel of rock saturation. Repeated wettingand drying, possibly accentuated by saltcrystallization, disintegrates rock surfacesabove this level, releasing weathered debriswhich is washed away by the sea duringhigh spring tides and occasional storms.It is not necessary to invoke a higher sealevel stand in Recent times to account forthese platforms. On the other hand, theycannot be taken as evidence that there hasnot been a higher sea level and a subsequentemergence during Recent times. Proponentsof the hypothesis that the sea stood at ahigher level at the end of the Postglacialmarine transgression might suggest that thedegraded bluffs which back many of theplatforms were active, receding sea cliffswhen the sea stood at a higher level andthat degradation set in after Recent emer-gence lowered sea level relative to the land.Opponents of the hypothesis might arguethat the degraded bluffs are sectors of inter-mittently active cliff trimmed back at in-frequent intervals by exceptionally severestorms with the sea at its present level,and degraded during intervening phases ofrelative quiescence. The question remainsopen: clearly, any satisfactory explanationof shore planation must also account forassociated cliff forms, particularly wherewell-developed horizontal platforms frontdegraded and vegetated bluffs.

Horizontal platforms are also encoun-tered at various levels on cliffs wheremarine erosion has worked upon weakerelements, shales or thinlv-bcdded sand-

stones interbedded with layers of horizont-ally-bedded massive sandstone. Structurally-guided marine erosion also produces plat-forms and ledges that slope or undulatewith the dipping or folded surfaces of re-sistant strata. On the steeply-dipping LowerPalaeozoic formations, variations in re-sponse to weathering are marked by aserrated topography, with tracts of platformdeveloped on the rapidly weathering out-crops of schist and phyllite, while inter-vening harder rocks stand up in ridgesacross the shore. Many of the intrusiverocks exposed at intervals along the coast—the Kioloa essexite, the gabbros and grano-diorites south of Moruya, and the GoalenHead intrusion—have proved extremely re-sistant to marine erosion, and the shoresare marked by rock surfaces that slopedown below sea level, with no developmentof cliffs and platforms. Inter-tidal shoreplatforms are rare on the South Coast, butwhere they are found they appear to becorrelated with the presence of abrasivematerial, particularly shingle, which ismoved across the shore zone by waveaction. Shingle is of restricted occurrence,being derived locally from denudation ofconglomerates, hard bands in coastal out-crops, and Tertiary gravels. South Coastbeaches consist predominantly of sand'"with very little beach material on the shoreplatform sectors*

Lithological ' and structural factors aretherefore of prime importance in the de-velopment of high-tide shore platforms, andon the South Coast these features are clearlyrelated to weathering processes that decom-pose and disintegrate fine-grained rock for-mations, in particular to the process thathas been described as 'water-layer weather-ing'.4 Wave action removes the productsof decomposition from time to time butregularly strong wave attack destroys, ratherthan creates, high-tide shore platforms. Onthe South Coast they attain their best de-velopment on sectors of coastline that aresheltered by headlands and islands fromwaves generated by the prevailing southerlywinds and south-easterlv swell. On the

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SHORE PLATFORMS ON THE SOUTH COAST OF NEW SOUTH WALES 79

more exposed shores they are narrower ormore dissected, and where the waves arearmed with shingle there is a sloping, intcr-tidal platform rather than a high-tide plat-form in the shore zone. Structurally-guidedplatforms on resistant sandstone formationsare in a different category: their develop-ment is often better on more exposed sec-tions of the coast, where the lithologicalvariations have been thoroughly exploitedby storm wave activity.

It is almost certainly misleading toattempt to explain the formation of shoreplatforms entirely in terms of processesvisibly at work on them at the present time.There have been many changes in therelative levels of land and sea; sea levelswere relatively high at certain stages in latePleistocene times, and present sea level be-came established, following the Holocencmarine transgression, only within the past6,000 years20; there have also been climaticchanges towards warmer, cooler, wetter anddrier conditions, which are likely to havemodified the mode and tempo of weather-ing processes during Pleistocene times.With the possible exception of the weakestrocks, the morphology of cliff, bluff, plat-form, and foreshore is unlikely to be en-tirely the work of marine denudation duringthe past 6,000 years. The recession of cliffsand the formation of shore platforms aregenerally the outcome of several episodes ofcoastal denudation during Pleistocene times.Headland profiles retain traces of a benchrelated to a sea level 40-50 feet above thepresent, and there are relics of terraces at20-30 feet, notably in the Bithry area,and at 5-10 feet, preserved locally alongthe coast, particularly around the shores ofestuaries and inlets, indicating at least threeepisodes of marine denudation at highersea levels preceding the present stillstand.The evolution of coastal profiles is likelyto be the outcome of successive episodes ofcliff recession and shore planation, asshown in Figure 2. On rapidly-weatheringfine-grained formations the coastal profilespreserve no trace of earlier stages of de-velopment, the present platform- havingformed during the present stillstand. It isE *

3

Z

1

Fig. 2: Multi-stage evolution of shore platforms.Pecked line shows initial coastal slope, solid lines theshore profile at Pleistocene stages of higher sea level,and dotted line the profile prior to the Recent marine

transgression.

also difficult to find evidence of formerplanation on foreshores dominated by struc-tural benches, but on the Central SouthCoast, where steeply-dipping Lower Palaeo-zoic formations of varied resistance outcropat the shoreline, the serrated profile oftenshows a broad accordance in the ridge crestsof harder material, suggesting an earlierplanation 5-10 feet above present mean mid-tide level.

Shore platforms thus raise difficulties ingeomorphological interpretation. The mostuseful approach is factorial, taking accountof lithology, structure, hinterland and off-shore conditions, weathering processes,wave climate, tide range, the availability ofabrasive material, particularly shingle, inthe sphere of wave activity, and the signi-ficance of local aspect within the generalconfiguration of the coastline. As these fac-tors vary intricately along many coasts, it isunwise to propound 'normal' modes ofshore zone evolution from local investiga-tions. Relict features are likely to persist,and any scheme of shore zone evolutionshould take account of past as well as pre-sent sea levels and climatic environments.On the South Coast of New South Wales,where many of these factors are relativelyuniform, there are marked contrasts in thedevelopment of shore platforms which canbe related to geological structure and out-crop lithology.

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80 THi: AUSTRALIAN GEOGRAPHER

REFERENCES

1. C. A. Cotton (1963), 'Levels of planation of marinebenches,' Zeitschrift fiir Geomorph., 7, pp. 97-111(includes bibliography).

2. A. B. Edwards (1941), 'Storm wave platforms,' J.Geomorph., 4, pp. 223-36.

3. R. W. Fairbridge (1952), 'Marine erosion,' Proc.7th Pacific Science Congr., 3, pp. 347-59.

4. E. S. Hills (1949), 'Shore platforms,' Geol. Mag.,86, pp. 137-52.

5. J. Tricart (1959), 'Problèmes géomorphologiques dulittoral oriental du Brésil,' Cahiers Ocćanogr., 11,pp. 276-308.

6. A. B. Edwards (1958), 'Wave-cut platforms atYampi Sound in the Buccaneer Archipelago,' J.Roy. Soc. W. Australia, 41, pp. 17-21.

7. C. K. Wentworth (1938), 'Marine bench-formingprocesses; water-level weathering.' J. Geormorph., 1,pp. 6-32. E. S. Hills (op. cit., 1949) suggestedwater-layer weathering as a more accurate term.

8. W. J. Dakin (1952), Australian Seashores, Chapter9.

9. O. F. Dent (1965), Shore zone morphology on theSouth Coast of N.S.W., Hons. thesis, AustralianNational University.

10. I. A. Brown (1933), 'The geology of the SouthCoast of N.S.W., Proc. Linn. Soc. N.S.W., 58,pp. 334-62.

11. f. T. Jutson (1939), 'Shore platforms near SydneyN.S.W.' J. Geomorph., 2, pp. 237-50.

12. D. W. Johnson (1931), 'Supposed two-metre eus-tatic bench of the Pacific Shores,' C.R. Int. Geogr.Congr., 2, pp. 158-63.

13. C. T. McElroy and G. Rose (1962), ReconnaissanceGeological Survey: Ulladulla 1-mile Military Sheet.Geol. Surv. N.S.W., Bull. 17.

14. I. A. Brown (1925), 'Geology of the Milton district.N.S.W.,' Proc. Linn. Soc. N.S.W., 50, pp. 448-65(detailed map of Warden Head).

15. T. W. E. David (ed. W. R. Browne) (1950), 'TheGeology of the Commonwealth of Australia, Vol. 1.p. 124.

16. I. A. Brown (1930), 'The geology of the SouthCoast of N.S.W., Devonian and older Palaeozoicrocks,' Proc. Linn. Soc. N.S.W., 55, pp. 145-58.

17. R. S. Boesen (1964), The monzonitic complex atMount Dromedary N.S.W.—a re-examination, Thesis.Australian National University.

18. I. A. Brown (1930), 'The monzonitic complex of theMount Dromedary district,' Proc. Linn. Soc. N.S.W.,55, pp. 637-98.

19. E. C. F. Bird (1966), 'Sand deposition on the SouthCoast of New South Wales.' Aust. Geogr. Studies,(in press).

20. J. R. Hails (1965), 'A critical review of sea-levelchanges in Eastern Australia since the Last Glacial,'Aust. Geogr. Studies, 3, pp. 63-78.

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