Facies and sequence stratigraphy of Eocene palaeovalley fills in the eastern Eucla Basin, South Australia

Eocene stratigraphic succession in the Eucla Basin of South Australia and correlation to major regional sea-level events

“…1 and 3), where it is unconformable on pre-Tertiary bedrocks. The unconformity is here interpreted as a basal sequence boundary between the bedrock and marginal marine-fluvial sediments (Hou et al, 2003c). The lithology of the Maralinga Member is typical of the Middle Eocene terrigenous sediments in the eastern margin of the basin, with upward fining cycles commonly capped by carbonaceous mud with a palynoflora of the lower N. asperus Zone (Alley and Beecroft, 1993;Alley and Lindsay, 1995;Hou et al, 2001).…”

“…The Eocene stratigraphy of the eastern Eucla Basin margin has recently been revised (Clarke et al, 2003;Hou et al, 2003c). The only significant difference between these two schemes is in the naming of the basal unit of the margin; the revised succession as shown in Fig.…”

“…Planktonic foraminiferal zones, Taylor (1983Taylor ( , 1986; pollen zones, Stover and Partridge (1973), Chaproniere et al (1996) and McGowran et al (1997); third-order sequences and dates, Hardenbol et al (1998);regional transgressions, McGowran et al (1997regional transgressions, McGowran et al ( , 2004; Great Australian Bight (GAB) slope-continental hiatuses, Li et al (2003). Correlations of stratigraphic boundaries of the GAB carbonates and Eucla Basin carbonates (Li et al, 2003) and fluvio-estuarine-marginal marine siliciclastics (Hou et al, 2003c) are chronologically questionable because of lack of dating information from Eucla Basin carbonates. P. adenanthoides, P. crassus, P. pachypolus, Reevesiapollis reticulatus, S. cainozoicus and Triporopollenites ambiguus.…”

“…3 and 6). The upper surface of the Maralinga Member is gradational into the calcareous Paling Limestone (see below), where present, or into the Anthony Member (new name, formerly upper Pidinga Formation) in the palaeovalleys; or it is truncated by an unconformity attributed to a sequence boundary at 37 Ma (Li et al, 2003;Hou et al, 2003c). Thus, the Maralinga Member includes the late Middle Eocene carbonaceous sediments that are widespread around the basin margin and adjacent palaeovalleys.…”

“…These activities require a tested lithostratigraphic scheme as an aid in mineral exploration of the prospective Eocene rocks. Due to the extent, isolation and poorly exposed nature of the basin, the complex and confused stratigraphic situation of these prospective sediments have resulted in a need for the stratigraphic nomenclature to evolve (Clarke et al, 2003;Hou et al, 2003c). The objectives of this paper are to rationalise the Eocene stratigraphic succession of the eastern Eucla Basin and its evolution by correlating to the major sea-level events, based on the understanding of selected drillholes and discontinuous outcrops and previous works (eg., Benbow, 1990Benbow, , 1993Benbow et al, 1995a;Clarke et al, 2003;Hou et al, 2003a,b,c).…”