OFR 151.pdf - CRC LEME

More documents

Recommendations

Info

3.2.2 North-East Australia 1. Carpentaria Basin Microfloras recovered from the Late Albian possibly to Cenomanian marine Allaru Mudstone (BMR Dobbyn-1) in northwestern Queensland (Playford et al. 1975) are dominated by gymnosperms, in particular araucarians (including Araucaria), brachyphyll araucarians (Hoegisporis) and podocarps (Microcachrys, Podocarpus-Prumnopitys), and ferns (chiefly Gleicheniaceae). Angiosperms are relatively rare but include Chloranthaceae (Clavatipollenites), Liliaceae (Liliacidites) and a diverse group of small tricolpate and tricolporate types. Inferred climate The source vegetation appears to have been araucarian-podocarp Austral Conifer Forest growing on uplands on the western margin of the basin. Climates were humid and probably warm (mesotherm range) but neither the palynofloras nor the associated foraminifera include taxa whose NLRs imply subtropical-tropical environments. 3.2.3 Central Australia 1. Eromanga Basin Dettmann et al. (1992) note that the conifer/cycad woodlands and fern/angiosperm heath surrounding freshwater lakes and swamps in the Eromanga Basin during the Albian survived into Cenomanian time. Data from the Winton Formation (Martin 1998b) provide evidence that some ferns (Blechnaceae, Cyatheaceae, Gleicheniaceae) remained abundant, but indicate that araucarians may have been locally extinct whilst Anemia (Plicatella, Ruffordiaspora) pteridosperms, podocarps (Microcachrys) and angiospermids had become uncommon to rare. Inferred climate The continuing high relative abundance of ferns such as Gleicheniaceae is likely to reflect an expansion of fern heath into the depression formerly occupied by the Eromanga-Surat Seaway. Other taxa imply that climates remained locally, or seasonally, humid. Nonetheless, effectively drier climates and/or a rise in mean minimum temperatures (possibly to an upper microtherm) best explain the contraction in range and/or relative abundance of both canopy trees and ground ferns. The latter inference is supported by the absence of dropstones and other evidence for ice (Frakes 1999). 3.2.4 South-West Australia 1. Carnarvon Basin Ingram and Morgan (1988) note that spores and pollen becomes slightly more common in marine sediments (5-10%) during the Late Cenomanian but the only named taxa are dinoflagellates. Little can be interpreted from these data. 2. Perth and Eucla Basins Balme (1964) lists brachyphyll araucarians (Balmeiopsis, Hoegisporis) and Gleicheniaceae as one of the more commonly occurring types in Cenomanian microfloras from the Perth and Eucla Basins (palaeolatitude ~60-65 0 S). 183
Inferred climate Dettmann et al. (1992) propose these microfloras are evidence for seasonal but relatively warm (possibly lower mesotherm) and dry climates. This reconstruction, which is based on the prominence of Gleicheniaceae along modern subtropical and tropical rivers (M.E. Dettmann pers. comm.), is consistent with global warming at high latitudes. Dry conditions however are difficult to reconcile with microfossil data from the Duntroon Basin located further to the east within the same narrow seaway (see below). 3.2.5 Central southern Australia 1. Duntroon Basin Limited pollen evidence (Morgan and Hooker 1993a, 1993d) indicate that ferns (Cyathidites, Cicatricosisporites, Ruffordiaspora) dominated the coastal, riparian vegetation at about palaeolatitude 70 0 S whilst pteridosperms (Alisporites) and podocarps (Microcachrys) may have formed forests and woodlands in adjacent uplands. Araucariaceae (Agathis/Wollemia) appears to become common to abundant in Austral Conifer Forest close to the top of the A. distocarinatus Zone in some offshore wells (possibly due to the Neves Effect). Cheirolepidacean conifers are uncommon relative to north-west Western Australia. A contributing factor may be low light levels during winter months. Inferred climate The data strongly imply climates were humid and seasonally cool (upper microtherm-lower mesotherm) rather than cold. The expansion of araucarians towards the end of the Cenomanian is not inconsistent with more temperate conditions (higher mean minimum temperatures) in marine flooded regions in the rift valley between Australia and Antarctica (Australo-Antarctic Seaway). 3.2.6 South-East Australia 1. Otway Basin Pollen evidence from marine sediments in the western Otway Basin (palaeolatitude ~75 0 S), indicate that Austral Conifer Forest communities were more diverse than those found in the Duntroon Basin (Macphail and Hos 1990). For example, the podocarp component included frequent to common Podocarpidites and Podosporites as well as Microcachrys although araucarians never become frequent. Conversely, fern spores (Anemia, Cyatheaceae, Gleicheniaceae) are only sporadically frequent, although this may reflect limited opportunities for the development of fern-heath along the coast rather than climate per se. Spores of the important fern genus Lophosoria (Cyatheacidites tectifera) first appear in low numbers towards the top of the A. distocarinatus Zone. Inferred climate Climates were as humid, but probably seasonally cooler, (upper microtherm-possible lower mesotherm) than regions further to the west along the Australo-Antarctic Seaway. 184
Page 1 and 2:
CRCLEME Cooperative Research Centre
Page 3 and 4:
Electronic copies of the publicatio
Page 5 and 6:
and, for Tertiary continental seque
Page 7 and 8:
2. Analysis of a Plio-Pleistocene l
Page 9 and 10:
Table A (cont.) Basin and related s
Page 11 and 12:
Figure A: Generalised climatic curv
Page 13 and 14:
Carpenter, R.J., Hill, R.S., Greenw
Page 15 and 16:
Hill, S.M., Eggleton, R.A. and Tayl
Page 17 and 18:
Macphail, M.K. and Stone, M.S., 200
Page 19 and 20:
Swenson, U., Backlund, McLoughlin,
Page 22 and 23:
EXECUTIVE SUMMARY This review prese
Page 24 and 25:
Temperature Climates in palaeo-sout
Page 26 and 27:
SUMMARY OF INFERRED CRETACEOUS PALA
Page 28 and 29:
INTRODUCTION Mineral resources, whe
Page 30 and 31:
Professor B. Balme (Geology Departm
Page 32:
Section 7 (Tertiary climates) This
Page 35 and 36:
vegetation. Moreover, individual ta
Page 37 and 38:
1.3 Flora, vegetation and climate 1
Page 39 and 40:
TABLE 2: Classification of vegetati
Page 41 and 42:
Figure 2: Relationship of different
Page 43 and 44:
Accordingly, only at sites with exc
Page 45 and 46:
2.1.3 Palaeoecology Palaeoecology i
Page 47 and 48:
wind-pollinated trees and shrubs bu
Page 49 and 50:
1. The usual practice of equating t
Page 51 and 52:
1. Palaeontological evidence Like p
Page 53 and 54:
5. Facies architecture and lithostr
Page 55 and 56:
Subsequent developments include mel
Page 58 and 59:
SECTION 4 (GEOGRAPHIC BOUNDARIES AN
Page 60 and 61:
SECTION 5 (EARLY CRETACEOUS CLIMATE
Page 62 and 63:
events on other continents and sugg
Page 64 and 65:
If these considerations apply to th
Page 66 and 67:
surrounding basins. Thick sands ero
Page 68 and 69:
Haig and Lynch 1993, Erbacher et al
Page 70 and 71:
SECTION 6 (LATE CRETACEOUS CLIMATES
Page 72 and 73:
has highlighted the roles played by
Page 74 and 75:
6.4.2 Palaeobotany Cenomanian flora
Page 76 and 77:
Palaeo-southern Australia Dryland c
Page 78 and 79:
6.7 Time Slice K-6. Late Campanian-
Page 80 and 81:
7.1. Global backdrop SECTION 7 (TER
Page 82 and 83:
Explanations for the PETM are centr
Page 84 and 85:
East Antarctica and strengthening o
Page 86 and 87:
amplifying, pacing and potentially
Page 88 and 89:
southeastern Australia than elsewhe
Page 90 and 91:
7.4 Time Slice T-1. Paleocene [65-5
Page 92 and 93:
Palaeo-southern Australia Unlike no
Page 94 and 95:
Palaeo-central Australia As for the
Page 96 and 97:
7.6.2 Palaeobotany The palaeobotani
Page 98 and 99:
Zone microfloras imply temporary wa
Page 100 and 101:
in the Bass Basin, the basal Seaspr
Page 102 and 103:
Similarly it is difficult to summar
Page 104 and 105:
However, the data are emphatic that
Page 106 and 107:
margin of plateau were cooler (~7 0
Page 108 and 109:
fossil taxa that are morphologicall
Page 110 and 111:
during Late Pleistocene glacial max
Page 112 and 113:
SECTION 8 (CONCLUSIONS) Climatic in
Page 114 and 115:
• On present indications, Early C
Page 116 and 117:
TABLE 8a: INFERRED CRETACEOUS PALAE
Page 118 and 119:
8.2 Results in prospect (recommenda
Page 120 and 121:
The 10 μm sieved, oxidised extract
Page 122 and 123:
phenology. The method also provides
Page 124 and 125:
SECTION 9 (REFERENCES) Acton, G.D.
Page 126 and 127:
Ashley, P.M., Duncan, R.A. and Feeb
Page 128 and 129:
Birks, H.J.B. and Gordon, A.D., 198
Page 130 and 131:
Burnham, R.J., 1989. Relationships
Page 132 and 133:
Clarke, J.D.A., 1994. Evolution of
Page 134 and 135: Dettmann, M.E. and Playford, G., 19
Page 136 and 137: Evans, P.R., 1970b. Palynology of H
Page 138 and 139: Godthelp, H., Archer, M., Cifelli,
Page 140 and 141: Harris, W.K., 1974. Biostratigraphy
Page 142 and 143: Hill, R.S., 1994b. Nothofagus smith
Page 144 and 145: Holland, S.M. and Patzkowsky, M.E.,
Page 146 and 147: Australia: paleoceanographic implic
Page 148 and 149: Lindsay, J.M. and Harris, W.K., 196
Page 150 and 151: Macphail, M.K., Colhoun, E.A. and F
Page 152 and 153: McGowran, B. and Beecroft, A., 1985
Page 154 and 155: Morgan, R., 1977. Palynology of Ter
Page 156 and 157: Abstracts of the Annual General Mee
Page 158 and 159: Raymo, M.E., Grant, B., Horowitz, M
Page 160 and 161: Sereno, P.C., 1999. The evolution o
Page 162 and 163: Taylor, G., 1998. Prediction of mod
Page 164 and 165: Webb, L.G., 1968. Environmental rel
Page 166 and 167: Zachos, J.C., Stott, L.D. and Lohma
Page 168 and 169: APPENDIX 1 CRETACEOUS DATA 167
Page 170 and 171: 1. TIME SLICE K-1 Age Range: Berria
Page 172 and 173: Australian assemblages, located on
Page 174 and 175: 2. Officer Basin Dinoflagellates in
Page 176 and 177: 2. TIME SLICE K-2 Age Range: Aptian
Page 178 and 179: Inferred climate The combined data
Page 180 and 181: Dettmann et al. (1992) have argued
Page 182 and 183: 3. TIME SLICE K-3 Age Range: Cenoma
Page 186 and 187: 4. TIME SLICE K-4 Age Range: Turoni
Page 188 and 189: 1. Otway Basin Limited data (Macpha
Page 190 and 191: 5. TIME SLICE K-5 Age Range: Early
Page 192 and 193: Inferred climate The data indicate
Page 194 and 195: 6. TIME SLICE K-6 Age Range: Late C
Page 196 and 197: Contrary to global cooling trends d
Page 198 and 199: Inferred climate The relatively goo
Page 200 and 201: Inferred climate As for regions to
Page 202 and 203: APPENDIX 2 TERTIARY DATA 201
Page 204 and 205: 1. TIME SLICE T-1 Age Range: Paleoc
Page 206 and 207: also include relatively frequent No
Page 208 and 209: Inferred climate Some differences b
Page 210 and 211: Microfloras preserved in the Lower
Page 212 and 213: subtropical affinities are rare, hi
Page 214 and 215: 2. TIME SLICE T-2 Age Range: Early
Page 216 and 217: Inferred climate Climates appear to
Page 218 and 219: northern New South Wales. The assem
Page 220 and 221: 2.2.5 Central southern Australia Ha
Page 222 and 223: a number of distinctive Proteaceae
Page 224 and 225: Inferred climate The Regatta Point
Page 226 and 227: 3. TIME SLICE T-3 Age Range: Middle
Page 228 and 229: 2. Lake Torrens Basin Abundant leaf
Page 230 and 231: Dominance is highly variable. For e
Page 232 and 233: types (M.K. Macphail unpubl. data).
Page 234 and 235:
Dacrycarpus), Euphorbiaceae (Austro
Page 236 and 237:
(possibly upper mesotherm) and drie
Page 238 and 239:
Basin) on the Eyre Peninsula (Alley
Page 240 and 241:
explanation is that a warm water gy
Page 242 and 243:
several taxa, which first appear in
Page 244 and 245:
4. TIME SLICE T-4 Age Range: Oligoc
Page 246 and 247:
Inferred climate The southern limit
Page 248 and 249:
The lowest and possibly the oldest
Page 250 and 251:
Dominants include fresh to brackish
Page 252 and 253:
Based on the relative abundance of
Page 254 and 255:
(Morgan 1977, McMinn 1981a, Martin
Page 256 and 257:
common (up to 5-6%) in the middle s
Page 258 and 259:
Polypodiaceae, Palmae (Dicolpopolli
Page 260 and 261:
Strasburgeriaceae. Proprietary info
Page 262 and 263:
Rare taxa which first appear in the
Page 264 and 265:
Correlative microfloras in the onsh
Page 266 and 267:
impression of floristic impoverishm
Page 268 and 269:
(Lophosoria) reached Tasmania befor
Page 270 and 271:
2. Otway Basin Oxygen isotope strat
Page 272 and 273:
5. TIME SLICE T-5 Age Range: Late M
Page 274 and 275:
Casuarinaceae, Cunoniaceae, Elaeoca
Page 276 and 277:
maximum temperature of the hottest
Page 278 and 279:
Nothofagus-gymnosperm temperate rai
Page 280:
5.2.7 Tasmania Late Neogene sedimen
show all

OFR 151.pdf - CRC LEME

Create successful ePaper yourself

Delete template?

Save as template?