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Full-Text Articles in Medicine and Health Sciences
Recent Sedimentation And Geomorphological Changes, Lake Illawarra, Nsw, Australia, Craig R. Sloss, Brian G. Jones, Colin V. Murray-Wallace, Bryan E. Chenhall
Recent Sedimentation And Geomorphological Changes, Lake Illawarra, Nsw, Australia, Craig R. Sloss, Brian G. Jones, Colin V. Murray-Wallace, Bryan E. Chenhall
B. G. Jones
Assessing recent changes in landforms associated with Lake Illawarra was achieved by identifying changes in geomorphological features observed in early mapping of the region, aerial photographs and satellite imagery. Quantifying rates of sedimentation associated with prograding fluvial bay-head deltas and within the central basin of Lake Illawarra was established within the framework of amino acid racemisation, radiocarbon, and cesium 137 dating. Results indicate that sedimentation rates associated with fluvial bay-head deltas range from 31 mm/yr proximal to the delta front and fall to between 3 and 7 mm/yr in the pro-delta region. This is a significant increase in sedimentation rate …
Litho- And Chronostratigraphy Of Holocene Sedimentary Successions Preserved In Lake Illawarra, Nsw, Australia, Craig R. Sloss, Brian G. Jones, Colin V. Murray-Wallace
Litho- And Chronostratigraphy Of Holocene Sedimentary Successions Preserved In Lake Illawarra, Nsw, Australia, Craig R. Sloss, Brian G. Jones, Colin V. Murray-Wallace
B. G. Jones
Using a Holocene barrier estuary, Lake Illawarra, New South Wales, Australia, as an example, a detailed litho- and chrono-stratigraphy of the Holocene estuarine deposits has been investigated. Forty kilometres of seismic surveys, 61 vibracores, supplemented by auger drill holes and trenches, and faunal analysis were used in this study. A detailed chronology of the infilling of the barrier estuary has been established using 121 aspartic acid derived ages and 14 radiocarbon ages. The results provide a detailed chronology for the deposition of marine transgressive deposits between ca. 8 and 5 ka years ago. Barrier growth, initiated with rising sea levels …
Geochemical Consequences Of The Permian-Triassic Mass Extinction In A Non-Marine Succession, Sydney Basin, Australia, M Williams, B Jones, P Carr
Geochemical Consequences Of The Permian-Triassic Mass Extinction In A Non-Marine Succession, Sydney Basin, Australia, M Williams, B Jones, P Carr
B. G. Jones
The identification of the Permian–Triassic boundary (PTB) and Permian–Triassic mass extinction event (PTME) in eastern Australia is based primarily on palynological and plant fossil evidence with limited δ13Corg data from the northern part of the Sydney Basin. Consequently, the PTB in the Sydney Basin has been placed at the top of the last Permian coal measures. Here we report carbon and nitrogen isotopic data, together with major element, trace element and mineralogical data, for a continuous non‐marine Permian–Triassic (P–Tr) section from the southern Sydney Basin. The PTME is identified by a negative shift in δ13Corg of ~ 3.8‰ occurring approximately …
Heavy Minerals In Modern Sediments Of The Minnamurra Estuary And Shelf Environment, Nsw, Australia, Rabea Haredy, Brian Jones, Adrian Hutton
Heavy Minerals In Modern Sediments Of The Minnamurra Estuary And Shelf Environment, Nsw, Australia, Rabea Haredy, Brian Jones, Adrian Hutton
B. G. Jones
Provenance and sediment distribution have been investigated in the Minnamurra estuary and the adjacent shelf in NSW, Australia. Heavy mineral assemblages in the sand fractions (63-250 f.lm) of 110 surficial sediment samples were assessed using microscopic and microprobe analyses. In addition to the dominant opaque minerals, twelve translucent heavy mineral species were identified. The translucent assemblage is dominated by pyroxene, zircon, tourmaline and hornblende. Statistical cluster analysis of heavy mineral percentages in the surficial sediments revealed the existence of five mineralogical facies: the upper fluvial part of the estuary, the Minnamurra spit and elevated inner sand terrace, the estuary inlet …
The Influence Of Palaeoenvironment And Lava Flux On The Emplacement Of Submarine, Near-Shore Late Permian Basalt Lavas, Sydney Basin (Australia), Paul Carr, Brian Jones
The Influence Of Palaeoenvironment And Lava Flux On The Emplacement Of Submarine, Near-Shore Late Permian Basalt Lavas, Sydney Basin (Australia), Paul Carr, Brian Jones
B. G. Jones
Lava flux and a low palaeoslope were the critical factors in determining the development of different facies in the Late Permian Blow Hole flow, which comprises a series of shoshonitic basalt lavas and associated volcaniclastic detritus in the southern Sydney Basin of eastern Australia. The unit consists of a lower lobe and sheet facies, a middle tube and breccia facies, and an upper columnar-jointed facies. Close similarities in petrography and geochemistry between the basalt lavas from the three facies suggest similar viscosities at similar temperatures. Sedimentological and palaeontological evidence from the sedimentary units immediately below the Blow Hole flow suggests …
Aspartic Acid Racemisation Dating Of Mid-Holocene To Recent Estuarine Sedimentation In New South Wales, Australia: A Pilot Study, C Sloss, C Murray-Wallace, B Jones, T Wallin
Aspartic Acid Racemisation Dating Of Mid-Holocene To Recent Estuarine Sedimentation In New South Wales, Australia: A Pilot Study, C Sloss, C Murray-Wallace, B Jones, T Wallin
B. G. Jones
The degree of aspartic acid racemisation measured in radiocarbon-dated specimens of fossil estuarine molluscs, collected from Lake Illawarra, a Holocene barrier estuary in New South Wales, Australia, is evaluated in the context of results of laboratory-induced racemisation established in heating (simulated ageing) experiments. The general kinetic trend of aspartic acid racemisation in both heating experiments and fossil molluscs Anadara trapezia and Notospisula trigonella conforms to a model of apparent parabolic kinetics. Using the apparent parabolic kinetic model, numeric ages based on the degree of aspartic acid racemisation in the fossil molluscs have been calculated. An aminostratigraphy of the Lake Illawarra …
The Charophyte Lamprothamnium Succinctum As An Environmental Indicator: A Holocene Example From Tom Thumbs Lagoon, Eastern Australia, Adriana Garcia, Brian Jones, Bryan Chenhall, Colin Murray-Wallace
The Charophyte Lamprothamnium Succinctum As An Environmental Indicator: A Holocene Example From Tom Thumbs Lagoon, Eastern Australia, Adriana Garcia, Brian Jones, Bryan Chenhall, Colin Murray-Wallace
B. G. Jones
The palaeobiota from a middle to late Holocene succession in Tom Thumbs Lagoon, N.S.W., Australia, reflects a range of environmental conditions caused by sea-level changes and active estuarine sedimentation. At the base of the succession (~ -0.4 m AHD) a thin bed, containing molluscs dated at 6.7 ka B.P. by radiocarbon and amino acid racemisation, and foraminifers is indicative of open estuarine conditions. From +0.35 m AHD towards the top of the sequence the charophyte Lamprotharanium succinctum occurs in subrecent deposits. This species is charactedsed here by statistical measurements, and new characters are described and illustrated. The charophytes record a …
Anthropogenic Effects In A Coastal Lagoon: Geochemical Characterization Of Burrill Lake, Nsw, Australia, Brian Jones, Hannah Killian, Bryan Chenhall, Craig Sloss
Anthropogenic Effects In A Coastal Lagoon: Geochemical Characterization Of Burrill Lake, Nsw, Australia, Brian Jones, Hannah Killian, Bryan Chenhall, Craig Sloss
B. G. Jones
Burrill Lake, a small coastal lagoon on the south coast of New South Wales, developed as an impounded drowned river valley following the post-glacial marine transgression. Marine sand fills the entrance to the lagoon whereas the back-barrier basin has accumulated organic-rich mud and sandy bayhead deltas. The bilobate form of the estuary coincides with two different catchment lithologies and land use patterns. The northern lobe drains an agricultural catchment and has a much larger bayhead delta than the southern lobs that drains natural and state forest. Sedimentation rates within the muddy lagoonal deposits are about 1.7 mm/yr. The distributions of …
Fluvial Architecture Of The Hawkesbury Sandstone (Triassic), Near Sydney, Australia, Andrew Miall, Brian Jones
Fluvial Architecture Of The Hawkesbury Sandstone (Triassic), Near Sydney, Australia, Andrew Miall, Brian Jones
B. G. Jones
The Hawkesbury Sandstone has long been assumed to represent the deposits of a large braided river system, comparable in style and magnitude with the modern Brahmaputra River of Bangladesh. Such an interpretation is based mainly on the common occurrence of very large-scale crossbedding, but no architectural studies of the unit have hitherto been carried out. This paper represents a first attempt to estimate the magnitude of Hawkesbury channels and bars on the basis of the preserved architectural evidence. Photomosaics were constructed of two cliff sections south of Sydney, one 5.6 km in length. On the basis of these profiles we …