A number of papers since Rampino and Stothers published in Science 1984 have reported common periodicities in a wide range of climate, geomagnetic, tectonic and biological proxies, including marine extinctions. Single taper and multitaper spectral analysis of marine fluctuations between the Late Cretaceous and the Miocene replicates a number of the published harmonics. Whereas these common periodicities have been argued to have a galactic origin, this paper presents an alternative fractal model based on large scale fluctuations of the magnetic field of the Sun. The fluctuations follow a self-similar matrix of periodicities and the solutions of the differential equation allow for models to be constructed predicting extreme events for solar emissions. A comparison to major Phanerozoic extinction, climate and geomagnetic events, captured in the geological record, show a striking loop symmetry summarised in major 66 Ma irradiance and electromagnetic pulses from the Sun.

Gas content and gas composition trends with depth have been investigated for the Sydney Basin. Four distinct zones have been identified, which can be classified according to depth below ground surface. An upper low gas zone (Zone 1, 0-100 m), dominated by CO2 and with very low gas contents (<0.7 m(3)/t), is underlain by a biogenic methane-rich zone (Zone 2, 100 to similar to 250 m), with a rapid rate of increase in gas content with depth, followed by a mixed gas zone (Zone 3, similar to 250 to similar to 600 m), comprising biogenic and thermogenic methane and magmatic CO2, and having a lower rate of gas content increase with depth relative to Zone 2, and Zone 4 (similar to 600 m+), which contains thermogenic methane and other 'wet gases.' A model is proposed that provides a rationale for the origin and timing of emplacement of the various coal seam gases in the Sydney Basin.

Beach ridges at Keppel Bay, central Queensland, Australia, preserve a record of sediment accumulation from the historical period back to middle Holocene times. The ridges comprise fine, well-sorted, feldspar-rich quartz sand that was eroded from the Fitzroy River catchment, deposited in Keppel Bay during floods of the Fitzroy River, and reworked onshore into beach and foredune deposits by the prevailing currents, waves and wind. These floods have an average recurrence interval of at least 7 yr and are induced by the passage of cyclones onshore into the large Fitzroy catchment. The youngest series of beach ridges sit sub-parallel to the modern beach and comprise six accretional units, each unit formed by a set of ridges and delineated by prominent swales. Optically stimulated luminescence (OSL) ages of beach ridges in these units indicate they were deposited in periods of rapid progradation approximately 1500,1000,450 and 230 yr BP, when there was an enhanced supply of sediment to the beach from the Fitzroy River via Keppel Bay. Estimates of the mass of sediment stored in the beach-ridge strandplain show that it represents a significant sediment store, potentially trapping the equivalent of 79% of the estimated long-term (100 yr) average annual bedload of the Fitzroy River that is deposited in Keppel Bay. There has been a reduction in the rate of sediment accumulation in the strandplain since around 1000 yr BP, which is consistent with other coastal records in eastern Australia of a relatively wetter phase of climate in the late Holocene compared to the present. The youngest beach ridges (OSL ages < 100 yr BP) are tall relict foredunes that reflect a low rate of sediment accumulation. These ridges have a distinctive trace-element composition produced by a greater contribution from catchment areas with basaltic soils. The change in catchment provenance has likely been a consequence of erosion that followed clearing of native vegetation in these areas. Our findings demonstrate the important insights that beach-ridge deposits proximal to a river sediment source can provide into processes of sediment accumulation and the response to variations in climate in tropical coastal sedimentary systems. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

There is a similarity in the pattern of Holocene sea-level change at Rottnest Island and a number of other locations in southern Western Australia. Rottnest Island was one of the field study areas that Fairbridge (1961) used to develop his fluctuating Holocene sea-level curve. Eight 14 C ages obtained from fixed shell material of Serpulid tubeworms from tightly constrained inter-tidal zones are presented from Rottnest Island, and thirteen more from a transect extending 1000 km along the coast of southwest Australia. The age-elevation profiles show a consistent mid- to late-Holocene sea-level fluctuation over the entire southwest Australian region, which argues against a strong local tectonic or a broader hydro-isostatic influence. A comparison of the southwest and southeast coasts of Australia, based on fixed inter-tidal biological indicators obtained by similar methods, indicates a broadly similar mid- to late-Holocene oscillating sea-level curve up to two metres higher-than-present. Peak levels are preceded and followed by sharp similar to 1 metre falls, which appear to be associated with cooling sea temperatures at similar to 5200 and similar to 3800 cal years BP. Both rising sea levels and warmer-than-present sea surface temperatures occur at all locations at similar to 4200 and similar to 6500 cal years BP, with a net sea-level fall to the present, but a slight warming beginning at similar to 1400 cal yr BP. There also appears to be a common pattern of species change suggestive of synchronous climatic variations. These mid-latitude fluctuations and environmental changes on the Australian coastline are similar to some events over the same period in the equivalent far-field locations of southern Brazil and southeast Asia. The synchronicity of these oscillations and their climatic underpinnings, in mid-latitude sites far from the complications of glacial isostasy, is not inconsistent with Fairbridge's (1961) basic thesis of world-wide eustatic Holocene sea-level change.

The interpretation by Yim and Huang (2002) of our discovery of a relic encrustation of the oyster (Saccostrea cucullata) 1.9 m above the comparative present intertidal zone at Big Wave Bay on Hong Kong Island needs clarification. It is unlikely that a 4–5-m-higher mid-Holocene sea level is a corollary to this discovery. Their comments related to tidal variance and the incidence of storm surges do not explain the formation. Further, the discovery of the same formations in similar contexts for matching time periods in Malaysia, Indonesia, New Caledonia and Australia and the robust nature of data fits for the time elevation distributions support a global forcing effect, not local circumstances.

A meteorite crashed through the roof and ceiling of a house at Dunbogan on the north coast of New South Wales, Australia, on 14 December 1999, and 30 g of fragments were recovered. The fall was observed by a girl at Tinonee, 50 km to the SSW. The meteor was observed in the mid northern sky at about 22h00 East Australian DST (GMT + 11 hrs), moving in a SSE direction. In mid-flight the meteor broke into at least 3 fragments. Detailed mineralogical and petrological examination of the meteorite have revealed that it is comparable to an L6 ordinary chondrite with mean olivine composition Fa25 and pyroxene Fs21

Data relating to Holocene sea‐level elevations and ages, obtained by radiocarbon dating of relict calcareous skeletons of intertidal organisms from widely spaced parts of the Australian coast, a far‐field region of comparative tectonic stability, are divisible into two sets, namely: pre‐ and post‐ ca. 3600 yr BP. The older ages are from material consistently between 1.5 m and 2.2 m higher than present sea‐level, whereas the younger ages (ca. 3600–1500 yr BP) generally cluster around 1 m above present sea‐level. The elevations do not display any decline in amplitude from north to south over an extensive transect, contrary to predictions by hydro‐isostatic models. Also, there appears to be little difference between time–elevation results for the coasts of North Queensland, New South Wales and the Bass Strait region adjacent to Tasmania, despite differences in the width of the continental shelf in these three locations, and the expectation of some hydro‐isostatic warping of the continental shelf subsequent to the onset of the Holocene transgression. Results from the south and southwest coasts of Western Australia also display similar elevations to the east coast for the same time periods. There is sufficient evidence extending over 20° of latitude to suggest that north–south differences related to hydro‐isostatic influence is limited or non‐existent. There is insufficient data to test hydro‐isostatic models across continental shelves. Hydro‐isostasy, and the lithological elasticity it reflects, may not be as pronounced in far‐field sites with narrow continental shelves as models predict. Stable far‐field passive continental margins may be the best place to measure the ratio of inputs of eustatic and hydro‐isostatic influences on Holocene relative sea‐levels. Copyright © 2002 John Wiley & Sons, Ltd.

Relic inter-tidal assemblages of sessile organisms, which are referred to as fixed biological indicators (FBIs), are shown to be useful proxies for late Holocene climatic and environmental changes as well as direct indicators of short term fluctuations in sea-level. A detailed comparison of change in the inter-tidal assemblages of two Southern Hemisphere sites at comparable latitudes (Port Hacking, New South Wales, south–east Australia and the Laguna-Imbituba region of southern Brazil) indicates periods of marked similarities in the timing and nature of changes at ∼5200, ∼3800 cal. years BP and differences after ∼2400 cal. years BP. There is sufficient concurrence of cooling phases and falling sea-levels to strongly suggest that in some cases global rather than regional forcing factors are at work. The value of inter-tidal organisms as indicators of changed environments is developed by identifying the past and present distributions of the common marker species: tubeworms, barnacles and mussels. The δ18O content of these extant specimens at Port Hacking confirmed changes in ocean water temperature and associated sea-level behaviour corresponding to invasion or extinction of temperature-sensitive species. A similar pattern is repeated, although in a less marked fashion, in the Laguna-Imbituba region of southern Brazil.

The ‘Darwin Point’, where atolls drown, has been redefined as a function of climate, sea-level history, paleolatitude, seawater temperature and light. During the last 34 Ma, in the Hawaiian-Emperor Chain, the Darwin Point has been shown to shift at least between 24 and 30°N latitude. Atoll drowning there is correlated with decreased seawater temperature and light and depends on sea-level history as well as the elevation of atoll summits at the time of sea-level transgressions. If the atoll top falls below 30 m with respect to sea level and the rate of sea-level rise is more than 15 mm/yr, the atoll will drown. Results of the Ocean Drilling Program legs 143 and 144, which investigated the histories of several NW Pacific guyots, indicate that the demise of the shallow-water carbonate platforms there was related to either a temporal (110–100 Ma) eustatic sea-level event, the paleolatitude location (0–10°S) of nutrient-rich water, and/or increased seawater temperature (greenhouse effect) unconducive to the production of calcium carbonate by shallow-water organisms. Hence, the Darwin Point phenomena of atolls and guyots cannot be viewed as a manifestation of any single factor, rather, it results from a combination of factors including: decreased water temperature and light related to higher latitude; the amplitude and rate of sea-level changes; presence of nutrient-rich waters; and/or elevated seawater temperatures. It is indeed dynamic, both in time, space, and cause.

The reconstruction of mid- to late Holocene marine environments using the calcareous remains of inter-tidal fixed biological indicators as sea level proxies is reviewed. Useful palaeo-environmental information can be obtained from the fossil evidence of successive invasions and disappearances of tropical and temperate species within the sub-fossil inter-tidal biological sequences. Examples illustrating spatially synchronous late Holocene sea-level fluctuations are described from 3000 km of north–south coastline along eastern Australia. The method uses tightly constrained species (such as the tubeworm Galeolaria caespitosa) which allows for the precise measurement of relative sea-level fluctuations by using the differential between emerged sub-fossil encrustations and current distributions of the same species. The error range can be defined according to the extent of preservation of the relic distributions, particularly the extent that diagnostic boundaries between species limited to different inter-tidal zones have been preserved. The rapidity of sea-level fluctuations is inferred by the preservation from erosion of emerged shell layers, as well as discontinuities in the relic biological sequences, and the relative preservation of fragile species. This apparent rapidity of sea-level fluctuations, as well as evidence of near-uniform synchronous sea-level heights along the north–south span of the entire Australian coast, and equally consistent variations Australia-wide in Spencer Gulf and Rottnest Island, raises questions about the predicted poleward decline of sea-level curves derived from hydro-isostatic rebound modelling.

Dating of a relict shell horizon (Saccostrea cucullata) on Hong Kong Island located approximately 1.7m above present day high tide level constrains the timing of a late Holocene higher sea-level. At 5140±50yr BP sea-level in the South China area was 4–5m higher with respect to the Principal Datum (2.7m below high tide mark) than at present.