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with intruding rocky ridges into the
Hawkesbury Sandstone. The drainage activity is ascertained by the Hawkesbury Sandstone's impotence, which were employed by early watercourses. As the creeks carved deeper into the plateau, they began undercutting the sandstone walls of the valley, and as such,
156:. The plateau's elevation ranges between 200-220 metres, with gullies that fall 80-100 metres deep along drainage lines. Steep slopes with drastic ascension of over 100 metres are present. The soil type is generally
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clay. At the end of the
Tertiary period, or about 80 million years ago, earth movements created an upheaval of 600 metres in most of coastal eastern Australia, due to the rifting and opening of the
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207:. Thus, these movements created the Blue Mountains and Hornsby Plateaux, with the lagging behind of the peneplain becoming the Cumberland Plain.
67:
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39:
324:
Herbert, C. & Helby, R. (eds) 1980, A Guide to the Sydney Basin, Dept. of
Mineral Resources, Geological Survey of NSW, bulletin no. 26.
387:
137:
301:
Chapman, G.A. & Murphy, C. L. 1989, Soil
Landscapes of the Sydney 1:100 000 Sheet, Soil Conservation Service of NSW, Sydney.
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Due to its hilly topography, the plateau was slow to develop. It has two main sedimentary rock layers:
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in the south along a warp line increasing from the proximity of
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are located on the
Hornsby Plateau. It is separated from the
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that rises 200 metres. The plateau is a part of the larger
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blocks of sandstone fell down, thus creating cliff lines.
234:, which supports richer vegetation. There are also a few
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and sand at a mean depth of 6 metres. As time went by,
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214:streams, which perforated a labyrinth of V-shaped
226:, consisting mostly of sandstone, but with some
175:is situated on the plateau, hence the namesake.
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191:layer up to 8 metres thick located beneath
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187:freshwater sediments, which were a rough
199:transformed much of the sandy silt into
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16:Place in New South Wales, Australia
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292:Sydney Vignerons Association Inc.
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28:The river valleys of the plateau
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278:Geology, topography and soils
144:. The plateau rises from the
373:Landforms of New South Wales
134:Berowra Valley National Park
290:Geology of the Sydney Basin
210:The plateau was scoured by
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280:Friends of Berowra Valley
238:throughout the plateau.
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388:Hornsby, New South Wales
311:Sydney Basin - landform
267:Sydney Basin-Subregions
383:Geography of Australia
349:33.70490°S 151.09901°E
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140:by the passage of the
138:Blue Mountains Plateau
112:lying to the north of
83:33.77274°S 151.18726°E
378:Plateaus of Australia
179:Rock deposits in the
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354:-33.70490; 151.09901
230:, and the overlying
224:Hawkesbury sandstone
88:-33.77274; 151.18726
403:Landforms of Sydney
398:Geography of Sydney
345: /
236:volcanic intrusions
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408:Dissected plateaus
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248:Woronora Plateau
146:Cumberland Plain
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102:Hornsby Plateau
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120:structure.
118:Sydney Basin
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352: /
340:151°05′56″E
130:North Shore
86: /
74:151°11′14″E
61:Coordinates
367:Categories
337:33°42′18″S
254:References
212:freshwater
205:Tasman Sea
197:weathering
183:area were
154:Botany Bay
142:Colo River
108:sandstone
71:33°46′22″S
201:siliceous
158:lithosols
124:Geography
106:dissected
242:See also
189:gravelly
185:tertiary
132:and the
216:valleys
173:Hornsby
164:Geology
110:plateau
181:Sydney
150:Cattai
228:shale
104:is a
193:silt
128:The
100:The
152:to
369::
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