Quarterly G eological Notes Issued By ISSN 0584-3219 THE GEOLOGICAL SURVEY OF SOUTH

( ^ e n t e n t e

• FLINT R.B., RANKIN L.R. and FANNING C.M. - Definition - the Palaeoproterozoic St Peter Suite of the western Gawler Craton.

• KEELING J.L.- The provenance and accumulation of coarse-grained sand on Silica Beach, Baird Bay, Eyre Peninsula.

• SHEARD M.J.— Glendonites from the southern Eromanga Basin in : palaeoclimatic indicators for Cretaceous ice.

APRIL 1990 NUMBER 114 KEYWORDS: INDUSTRIAL MINERALSISEDIMENTARY GEOLOGYfMINERAL RESOURCES[ Construction materials/Beach sands/Provenance/Sedimentation/GraveliSize classification/Petrology/Pantoulbie Formation/Bridgewater Formation/Hiltaba Suite!Silica Beach sand deposit/Baird Bay sand depositlBaird BaylTyringa BeachlPoint LabattfSI 5306, 57311

REFERENCES

Barnett, S J., 1978. Late Tertiary sediments on Eyre Peninsula. South Australia. Quarterly Geological Notes. Geological Survey, 67:1-4. Flint, R E., 1989. ELLISTON map sheet. South Australia. Geologcal Survey. Geological Atlas 1:250 000 Series, sheet SI 53-6. Johnson, P.D., 1978. Baird Bay beach sand, Eyre Peninsula, South Australia. Mineral Resources Review, South Australia, 149:54-56. Radke, F., 1989. Petrological report, Eyre Peninsula samples. Amdel report G7940/89 (unpublished). Segnit, R.W. and Dridan, J.R., 1938. Geology and development of groundwater in the Robinson fresh water basin, Eyre’s Peninsula. South Australia. Geologcal Survey. Bulletin, 17:13.

palaeodimatic indicators

OCCURRENCE AND DESCRIPTION Regional geological mapping of CALLABONNA sheet area (Fig, 1) included, examina­ tion of large areas of at the margins of the northeastern Flinders Ranges. Several northerly flowing creeks debouch onto the plains north of the Flinders Ranges and these have incised the Bulldog Shale exposed on these plains, revealing its internal features.

Bulldog Shale was deposited in the intra- cratonic basin known as the Eromanga Basin during the Early Cretaceous (Valanginian to Albian in age) as a marine mudstone (Fig 1,2), The shale consists of dark grey, bioturbated, shaly mudstone with silty to very fine sandy layers. It also contains large, exotic multi- lithic clasts mainly of quartzite (Precambrian and Devonian) and volcanic rocks up to 3 m diameter (Krieg eta l, 1990; Frakes and Francis, 1988; Alley, 1987; Flint eta l, 1980). These clasts occur as lone-stones or clasts scattered along bedding planes, or as occasional lag deposits at the basin/basement margin. They are well rounded and often polished, probably deriving from riverine and coastal environments.

17 A site on Petermorra Creek, 4 km north west of Prospect Hill (Fig. 3) was examined for specimens of molluscan fauna, calcified wood and limestone nodules containing microflOra for dating purposes. Here Bulldog Shale is exposed in vertical cliffs three to four metres high (Plate 1). Within a 50 m length of cliff were found numerous, randomly scattered, spheroidal calcite crystal rosettes or crystal clusters (Plates 2, 4). Clusters are spaced from 0.15 to 0.4 m apart and range in size from 20 to 150 mm (diam) with individual crystals from 2 x 2 x 15 mm to 20 x 30 x 65 mm in dimension. One specimen measured 30 x 190 mm and was partially enclosed within a calcified shale (Plate 3). The smaller crystals are triangular to trapezoidal in cross-section and acutely wedge shaped in longitudinal section. Large crystals have more bladed forms with curved faces and edges, these large forms are not as common as the small (pineapple-like) clusters. Secondary overgrowth (1 mm thick) of white calcite occur on some clusters or crystals and also form fracture fillings within clusters. The crystals are dark to medium grey-brown in colour AGE STRATIGRAPHY (Munsell: 10 YR 2/2,10 YR 4/1, 10 YR 5/3, wet) and are com­ to z posed of calcite with a rhombohedral cleavage. Colouration is D < O produced by the inclusion of fine dark brown silt ( 2 to 5%) < WINT0N S FORMATION and pale yellow angular quartz sand ( 0.5 mm, ~ 2%). The

LATE 0

ETACE z rosettes occur within a 2 m thick section of Bulldog Shale that c c LU 0 O has a 6-8° east dip and is grey to dark yellow-grey, and laminated. Ellipsoidal limestone concretions ranging up to 0.5 m across 00DNA0ATTA are also present in the Bulldog Shale. Some of these within the FORMATION 2 m thick section enclose or partially enclose the calcite roset­ tes and large individual crystals. Many of these concretions contain well preserved Aptian molluscs such as Euspira reflecta, Fissilunula clarkei, Maccoyella sp. and Cyrenopsis sp. (Ludbrook, 1966; pers. comm. 1990), some of which are shallow-water, near-shore species. A stratigraphic position within the Bulldog Shale has yet to be established for the zone of clusters, but they lie ~ 10 to 20 m below the main zone of dark grey limestone to concretions which is located within the middle portion of the D O shale. LU U< 1— LU MINERALOGY, FORMATION AND ORIGIN OF THE occ CLUSTERS cc < The crystal clusters found at Petermorra Creek resemble LU others found at Coober Pedy, South Australia (replaced by gypsum; Francis and Alley, pers comm., 1990) and also at CADNA-0WIE White Cliffs, N.S.W. (replaced by opaline silica; Anderson and : o FORMATION Jevons, 1905; England, 1976). Both of these occurrences are ■8 LU also in Bulldog Shale. The large crystals (Plate 3) resemble z those found in Permian glacial sequences of the Hunter Valley region, N.S.W. (England, 1976) and similarly those from the < ~ZL w — Permian glacial sediments of Tasmania (Banks etal.. ,1955; -* il tr o Jago, 1972). They were named glendonites by David et al LU O LU (1905) because they were found at Glendonbrook, N.S.W. ALGEBUCKINA SANDSTONE Glendonites are pseudomorphs, usually of calcite or gypsum, o after a range of minerals that include: glauberite Na2S0 4 *CaSC>4, LLJ ¥ 2 lT CO gaylussite Na2Ca (CO32.5 H2O), mirabillite Na2SCL*10H2O, nee<< D England (1976); and after ikaite CaC0 3 *6H 2 0 , (Kemper, 1987;

Drn J R 91-173 SADME Jansen eta l, 1987). Figure 2. Stratigraphy.

18 It is the smaller crystals ( < 15 mm, in small cross-section) that closely resemble ikaite morphology, while the larger forms (bladed, curved faces and edges) resemble the glauberite/mirabillite morphology. England (1976) demonstrated that, although many glendonites are associated with glacial erratics, indicating low temperature conditions, phase studies of glauberite show an inability to crystallise below 25°C. However, mirabillite does crystallise in large quantities as seawater freezes. Ikalte was discovered in icy coastal springs in Ika Fjord, Greenland (Pauly, 1963) and has been described in greater detail by Kemper (1987). It has also been described from cold deep-water sediments by Suess et al. (1982) and Jansen et al. (1987). This hexahydrate of calcite occurs as translucent brown crystals which are unstable above 5°C, inverting to white microcrystalline calcite and water within an hour or so at room temperature, (Pauly, 1963; Jensen etal, 1987). All ikaite specimens sampled for min era logical work have been collected and stored using dry ice to prevent inversion to calcite. Stearman and Smith (1985) argue that most of the occurrences of glendonites/ jarrowites/gerstemkorner from around the world are pseudomorphs of ikaite. Suess et al (1982) and Jensen eta l (1987) argue that the carbonate in ikaite from marine sediments is mostly of organic origin.

PALAEOCLIMATIC IMPLICATIONS The origin of the Bulldog Shale glendonites as pseudomorphs after ikaite, and their association with Aptian sediments in the Eromanga Basin, are indications for very cold basinal waters during part of the Creta­ ceous. Size ranges exhibited by glendonites and their occurrence over a 2 m zone at this locality imply that cold conditions (possibly periglacial) lasted long enough for repeated crystal growth to take place without inver­ sion. A periglacial palaeoclimate is consis­ tent with interpretation based on other evidence, such as the existence of lone-stones within the mudstone (Frakes and Francis, 1988) and palaeolatitude modelling (Barron etal., 1981; Barron, 1983; Barron and Washington, 1982).

The presence of smoothed, rounded, lone- stones, of many lithotypes and provenances within the Bulldog Shale and underlying Cadna-Owie Formation sandstone, is probl­ ematic. Glacial activity, or at least seasonal Figure 3. Location of glendonite occurrences ice-rafting of lone-stones during the Cretaceous north west Prospect Hill in the southwestern Eromanga Basin, has

19 Creek bed alluvium and vegetation

u,njh ______9T-193 SAOMs Plate 1. (Top) Southern creek bank exposure, Petermorra Creek, where glendonite zone dips east and is truncated by an erosional unconformity. Photo, no. 39340 been proposed (Brown, 1905; Jack, 1915; Wooolnough and David, 1926; David, 1950; Frakes and Francis, 1988), although this argument has been refuted by Parkin (1956) who suggests the clasts are reworked Permian glacials. Flint et al (1980) argued that, as some of the quartzite clasts contain Devonian fossils related to rocks near Cobar (N.S.W.) and similar clasts are not known from the Permian in South Australia, ice transport (possibly Cretaceous) was likely. Palaeotemperatures for the central Australian region during the Cretaceous have been modelled by Barron and Washington (1982) and yielded the range -18° to + 27° C using a palaeolatitude range of 65° to 70° south. The discovery of glendonites within Bulldog Shale of the southern Eromanga Basin, as calcite pseudomorphs after ikaite, lends weight to the argument for times when very cold to frigid conditions applied during the Cretaceous.

20 Plate 2. Glendonites, one broken (above scale), one complete and protruding from shale (below scale). Photo, no. 39341

Plate 3. Large star-shaped cluster ofcalcite after ikaite crystals enclosed within calcified Bulldog Shale. Crystals facing viewer are broken off, leaving only stubs. Photo, no. 39342

21 Plate 4. Glendonites displaying various forms, secondary white calcite veining (c), and a split glendonite (g), displaying stellate radiating crystal growth pattern. Photo, no’s 39343 - 39349

Acknowledgements Thanks go to my field assistant Lyn Broadbridge (SADME) who independently found the smaller clusters; Dr N.F. Alley (SADME) for initial identification using a comparison sample from Coober Pedy; Dr J.E. Francis (Adelaide University) for identification, a com­ parison sample from Coober Pedy and the loan of several articles oh glendonites; and C.G. Gatehouse (SADME) for providing a comparison sample of Permian age from Tasmania.

KEYWORDS: SEDIMENTARY GEOLOGY/Mineralogy/Glendonitellkaite/Pseudomorphismf Palaeoclimatology/Glacial erraticflce rafting/Eromanga Basin/Bulldog Shale/Petermorra CreekiProspect Hill/Moolawatana/SH5406, 6838.

References

Alley, N.F., 1987. Palynological dating and correlation of Late Jurassic and Early Cretaceous sediments around part of the southeastern margin of the Eromanga Basin South Australia. Department of Mines and Energy. Report Book, 87/59. Anderson, C. and Stanley Jevons, H,, 1905. Opal pseudomorphs from White Cliffs, . Australian Museum. Record, 6:31-41. Banks, M.R., Hale, G.E. and Yaxley, M.L., 1955. The Permian rocks of Woody Island, Tasmania. Royal Society of Tasmania. Papers and Proceedings, 89:219-229. Barron, E J., 1983. A warm, equable Cretaceous: the nature of the problem. Earth Science Review, 19:305-338. 22 Barron, E J., Thompson, S.L. and Schneider, S.H., 1981. An ice-free Cretaceous? Results from climate model simulations. Science, 212:501-508. Barron, E J. and Washington, W.M., 1982. Cretaceous climate: a comparison of atmospheric simulations with the geologic record. Palaeogeogaphy, Palaeoclimatology, Palaeoecology, 40:103-133. Brown, H.Y.L., 1905. Report on geological explorations in the west and northwest of South Australia. South- Australia. Parliamentary Papers, 71. David, T.W.E., 1950. The geology of the Commonwealth of Australia. Vol. 1, E. Arnold, London. David, T.W.E., Woolnough, W.G., Taylor, T.G. and Foxall, H.G., 1905. Occurrence of the pseudomorph Glendonite in New South Wales. New South Wales. Geological Survey. Records, 8:161-179. England, B.M., 1976. Glendonites, their origins and description. MineratogicalRecord, 7:60-68. Flint, R.B., Ambrose, G J. and Campbell, K.S.W., 1980. Fossiliferous Lower Devonian Boulders in Cretaceous sediments of the Great Australian Basin. Royal Society o f South Australia, Transactions, 104:57-65. Frakes, L A . and Francis, J.E., 1988. A guide to Phanerozoic cold polar climates from high-latitude ice-rafting in the Cretaceous. Nature, 333:547-549. Jack, RX., 1915. The geology and prospects of the region to the south of the Musgrave Ranges, and the geology of the western portion of the . South Australia, Geological Survey, Bulletin, 5. Jago, JJ3., 1972. Geology of the Maydena Range. Royal Society of Tasmania Papers and Proceeding?, 106:45-57. Jansen, J.H.F., Woensdregt, C.F., Kooistra, M J. and van der Gaast, S J., 1987. Ikaite pseudomorphs in the Zaire deep-sea fan: an intermediate between calcite and porous calcite. Geology, 15:245-248. Kemper, E., 1987. Das klima der Kreide-Zeit (The climate of the Cretaceous Period). Geologisches Jahrbuch, 96:5-185. Krieg, G.W., Rogers, PA ., Callen, R.A., Freeman, PJ., Alley, N.F. and Forbes, B.G., 1990. Explanatory Notes Phanerozoic) for the CURDIMURKA 1:250 000 Geological Map, South Australia. Department o f Mines and Energy. Report Book, 90/55. Ludbrook, N.H., 1966. Cretaceous biostratigraphy of the Great Artesian Basin in South Australia. South Australia. Geological Survey. Bulletin, 40. Munsell Color, 1975. Munsell Soil Color Charts. Munsell Color, Baltimore, Maryland, United States of America. Parkin, L.W., 1956. Notes on the younger glacial remnants of northern South Australia. Royal Society of South Australia, Transactions, 79:148-151. Pauly, H., 1963. “Ikaite”, a new mineral from Greenland. Arctic, 16:263-264. Shearman, D J. and Smith, A.J., 1985. Ikaite, the parent mineral of jarrowite-type pseudomorphs. Geologists Association of London. Proceedings, 96:305-314. Suess, E., Balzer, W., Hesse, K.-F., Muller, P J., Ungerer, C A . and Sefer, G., 1982. Calcium carbonate hexahydrate from organic-rich sediments of the Antarctic Shelf: precursors of Glendonites. Science, 216:1128-1130. Woolnough, W.G. and David, T.W.E., 1926. Cretaceous glaciation in South Australia. Geological Society of London. Quarterly Journal, 82:332-351.

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