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    Rocky reefs form an important habitat on the continental shelf and one subject to disproportionate fishing pressure given the high productivity of this habitat relative to adjacent sandy seabed. Despite this, little is known of the extent and nature of these systems beyond their value to the fishing industry. This project collated all known mapping data from government and industry (including data acquired during CERF and NERP Hubs) to provide an updated map of this key habitat around Australia. A geomorphological classification system is also being developed for these reefs, and associated cross-shelf habitats with the aim of it being accepted and adopted nationally, and it is being tested and refined for biological applicability. This record describes the national habitat map data product generated from multiple datasets collated as part of NESP MBH Project D3. The individual habitat mapping datasets collected as part of the data collation process have also been published and are linked to this record.

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    A comprehensive and detailed multibeam sonar-based map of the shelf-break region of the Central Flinders Commonwealth Marine Reserve (CMR). It illustrates the extent that several canyon-head incisions are present in this region, and that inset from the shelf-break is a relatively extensive area of cross-shelf reef. Some of the canyon-head incisions are characterised by exposed reef areas, and these are indicated by localised regions of rapid change in depth. The cross-shelf reef is generally very low profile, but characterised by distinct reef ledges where bedding planes in the sedimentary rock types have eroded. These ledges, often between 1-2 m in height, can run for several kilometres as distinct features. The method of data extraction is based on Lucieer (2013). Three are three classes of seafloor map- one from GEOBIA, one from digitisation and one from Probability of Hardness based on Angular Profile Correction. Lucieer, V (2013) NERP broad-scale analysis of multibeam acoustic data from the Flinders Commonwealth Marine Reserve, Prepared for the National Environmental Research Program. Internal report. IMAS, Hobart, TAS [Contract Report]

  • Marine sediments often represent an important reservoir of carbonate minerals that will react rapidly to changing seawater chemistry as a result of ocean acidification. Ocean acidification (the reaction of CO2 with seawater) lowers the saturation state with respect to carbonate minerals and may lead to dissolution of these minerals if undersaturation occurs. There are three main carbonate minerals found in marine sediments: 1. aragonite 2. calcite (also referred to as low-magnesium calcite, containing less than 4mol% MgCO3) 3. high-magnesium calcite (greater than 4 mol% MgCO3) Due to the different structure of these minerals, they have different solubilities with high-Mg calcite the most soluble, followed by aragonite and then calcite. As seawater CO2 increases and the saturation state with respect to carbonate minerals decreases, high-Mg calcite will be the first mineral subject to undersaturation and dissolution. By measuring the carbonate mineral composition of sediments, we can determine which areas are most at risk from dissolution. This information forms an important baseline with which we can assess future climate change. The effect of ocean acidification on carbonates in marine sediments will occur around the world, but due to the lower seawater temperatures in Antarctica, solubility is much lower so the impacts will occur here first. This dataset is a compilation of carbonate mineralogy data from surface sediments collected from the East Antarctic margin. The dataset includes sample metadata, bulk carbonate content, %calcite, % aragonite and mol% MgCO3 (i.e. the magnesium content of high-Mg calcite). This dataset was compiled from new (up to 2020) and archived sediment samples that contacted sufficient carbonates (typically greater than 3% CaCO3)/

  • These dataset files (2 tables) are supplementary material to: Halpin, J.A., Daczko, N.R., Direen, N.G., Mulder, J.A., Murphy, R.C., Ishihara, T., 2020. Provenance of rifted continental crust at the nexus of East Gondwana breakup. Lithos 354-355. https://www.sciencedirect.com/science/article/pii/S0024493719305237?via%3Dihub https://doi.org/10.1016/j.lithos.2019.105363 They include: Supplementary Table 1. Zircon U-Pb datasets Supplementary Table 2. Zircon Lu-Hf datasets Sample details from Halpin et al. (2020): Ishihara et al. (1996) made initial reports of the dredge sites from which our analyses have been made. Dredging at four sites on the eastern margin of the Bruce Rise was undertaken during cruise TH-94 of the R/V Hakurei-Maru during the austral summer of 1994/5, along with other geophysical data acquisition reported in Ishihara et al. (1996). Of the four sites dredged, sites D1502, D1503 and D1504 all recorded hauls of basement rocks, including crystalline basement fragments. These dredge sites and hauls are summarised in Table 1. The recovered dredge samples have variable shapes, but the samples analysed here (two granites from D1502; Fig. 3) contain sharp and unweathered faces consistent with dredging from in situ basement. The interpretation of composite seismic profiles TH94/21 and GA-229/19 from the eastern flank of the Bruce Rise (Fig. 1b) shows a folded and faulted syn-rift sequence that thickens towards the south and is separated from flat-lying post-rift sediments by a prominent erosional unconformity (Stagg et al., 2006). The outermost ridge, flanked by the Vincennes Fracture Zone, is interpreted to comprise exposed crystalline basement, and we interpret the granitic samples studied here to represent parts of this basement complex. Sample D1502-A is a medium to coarse-grained (~2–4 mm) red granite, whereas sample D1502-B is a fine to medium-grained (~1–1.5 mm) cream-grey granite (Fig. 3a). Both samples comprise quartz, plagioclase, alkali feldspars (including microcline), biotite and accessory magnetite and zircon. Sample D1502-B additionally contains minor biotite-amphibole-rich schlieren. Biotite is variably orientated suggesting weak magmatic foliation. The low-strain character of the samples is supported by very limited undulose extinction of some grains, minor development of sub grains in quartz, and preserved igneous microstructures that include subhedral feldspar grains presenting some crystal faces (red lines, Fig. 3b), quartz-feldspar interstitial textures (blue ‘i’, Fig. 3b), low dihedral angles (double blue arrow heads, Fig. 3b), elongate mineral films along grain boundaries that are inferred to have pseudomorphed former melt, and growth twinning in plagioclase. Minor low-temperature alteration of feldspar and biotite to sericite ± chlorite is observed in sample D1502-A. High resolution whole thin section photomicrographs are available at https:// imagematrix.science.mq.edu.au/. Details of analytical methods from Halpin et al. (2020): Initial sample preparation including zircon separation and mounting was performed at Curtin University. Zircon grains were imaged via cathodoluminescence (CL) on a FEI Quanta 600 SEM at the Central Science Laboratory, University of Tasmania, to reveal internal structure in order to optimise and contextualise U-Pb analyses. U-Pb zircon analyses were performed on an Agilent 7500cs quadrupole ICPMS with a 193nm Coherent Ar-F gas laser and the Resonetics S155 ablation cell at the Discipline of Earth Sciences, University of Tasmania. Each analysis was pre-ablated with 5 laser pulses to remove the surface contamination then the blank gas was analysed for 30 s followed by 30 s of zircon ablation at 5 Hz and ~2 J/cm2 using a spot size of 29 μm. Isotopes measured include 49Ti, 56Fe, 91Zr, 178Hf, 202Hg, 204Pb, 206Pb, 207Pb, 208Pb, 232Th and 238U. The down hole fractionation, instrument drift and mass bias correction factors for Pb/U and Pb/Th ratios on zircons were calculated using the primary standard (91500, Wiedenbeck et al., 1995) and secondary standards (TEMORA 1, Black et al., 2003; Plešovice, Sláma et al., 2008) analysed at the beginning of the session and every 15–20 unknowns using the same spot size and conditions as used on the samples to provide an independent control to assess accuracy and precision. The correction factor for the 207Pb/206Pb ratio was calculated using 17 analyses of the international glass standard NIST610 analysed throughout the analytical session and corrected using the recommended values (Baker et al., 2004). All data reduction calculations and error propagations were done within Microsoft Excel® via macros designed at the University of Tasmania (see Halpin et al., 2014; Sack et al., 2011). No common Pb corrections were applied. However, time-resolved isotopic ratios for each analysis were scrutinised on concordia diagrams to investigate the presence of common Pb and/or ancient Pb-loss and/or mixing of age zones, and analyses (or parts of analyses) were excluded from the dataset where a combination of these trends was detected. Uncertainties quoted in Supplementary Tables and in figures are the internal measured uncertainty only (i.e., those from random based sources of error, e.g., counting statistics). External sources of uncertainty (i.e., from systematic sources of uncertainty, e.g., decay constant uncertainty, uncertainty in the age of the primary zircon standard) calculated after Horstwood et al. (2016) and Thompson et al. (2018) are quoted in parentheses for the standard data below (see also Supplementary Table 1). 206Pb/238U ages for the secondary zircon standards Plešovice and TEMORA 1 over the course of this study (at 95% confidence) are 333.6 ± 2.7 (4.3) Ma (n = 7, MSWD = 1.3) and 415.1 ± 3.2 (5.3) Ma (n = 6, MSWD = 0.4), compared to the published TIMS zircon ages of 337.13 ± 0.37 Ma (Sláma et al., 2008) and 416.8 ± 1.1 Ma (Black et al., 2003), respectively. Although Plešovice is slightly outside 2σ of the internal uncertainties, it is well within the published values when considering the external uncertainties. The primary zircon standard 91500 yields a 207Pb/206Pb weighted mean age of 1065.3 ± 8.8 (10.5) Ma (n = 27, MSWD = 0.71) within error of the recommended value of 1065.4 ± 0.3 Ma (Wiedenbeck et al., 1995). Tera-Wasserburg diagrams and age calculations were made using Isoplot v4.11 (Ludwig, 2003). Uncertainties for individual analyses as quoted in text and as error bars on U\\Pb plots have been calculated to the two-sigma level. Weighted mean and intercept ages are reported at 95% confidence limits. Hf isotope analyses were performed in situ on a subset of the same grains analysed for U-Pb using a Photon Machines Excimer 193 nm Ar-F laser ablation micro-probe attached to a Nu Plasma multi- collector (MC)-ICPMS system at Macquarie University GeoAnalytical (MQGA)(see Griffin et al., 2004 for a detailed methodology). A gas blank was analysed for 30 s followed by up to 120 s of ablation at a beam diameter of 40–50 μm, 5 Hz and ~7.5 J/cm2. Zircon CL images were used to ensure that Hf isotope analyses overlapped the same do- main analysed for U-Pb. The Mud Tank and Temora-2 zircon standards were used as a reference standard for Hf analysis; our weighted average 176Hf/177Hf values for these standards are 0.282526 ± 41 (n = 17, MSWD = 1.6) and 0.282678 ± 10 (n = 7, MSWD = 2.1), respectively, within error of the published values of 0.282523 ± 43 (Mud Tank; Griffin et al., 2006) and 0.282680 ± 24 (Temora-2; Woodhead et al., 2004). Uncertainties quoted are the internal measured uncertainty and do not include any propagation of error from the reference standard. The initial 176Hf/177Hf value (Hfi) in zircon is calculated using the measured 176Lu/177Hf, 176Hf/177Hf and apparent 207Pb/206Pb age and the 176Lu decay constant of Scherer et al. (2001) of 1.865 x 10-11. Model age calculations (TDM) are based on a depleted-mantle source with Hfi = 0.279718 and 176Lu/177Hf = 0.0384. This provides a value of 176Hf/177Hf (0.28325) similar to that of average mid-ocean ridge basalt over 4.56 Ga. The calculated TDM ages use the measured 176Lu/177Hf of the zircon and give a minimum age for the source material of the magma from which the zircon crystallised. Two-stage model ages (TDM2) are calculated assuming that the parental magma was derived from the average continental crust (176Lu/177Hf = 0.015), which in turn was originally derived from the depleted mantle.

  • Sediment cores were collected from the East Antarctic margin, aboard the Australian Marine National Facility R/V Investigator from January 14th to March 5th 2017 (IN2017_V01; Armand et al., 2018). This marine geoscience expedition, named the “Sabrina Sea Floor Survey”, focused notably on studying the interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles. The cores were collected using a multi-corer, allowing to sample the surface of the sediment (top ~ 30cm). The cores were then sliced every centimetre, wrapped up in plastic bags, and stored in the fridge. The sediment samples were dated using 210-Pb analysis for future paleo-reconstructions. 210-Pb is a radioisotope which allows to date sediment back to 150 years, which is ideal for surface (i.e. recent) sediment samples. Sediment samples were dried, ground and sent to Edith Cowan University (Joondalup, Western Australia) for sample preparation and analysis. Total 210Pb was determined through the analysis of its granddaughter 210Po by alpha spectrometry after complete sample digestion using an analytical microwave in the presence of a known amount of 209Po added as a tracer (Sanchez-Cabeza et al., 1998). The concentrations of excess 210Pb were determined as the difference between total 210Pb and 226Ra (supported 210Pb), the later determined by gamma spectrometry through the measurement of its decay products 214Pb and 214Bi using a HPGe detector (CANBERRA, Mod. SAGe Well). References L.K. Armand, P.E. O’Brien and On-board Scientific Party. 2018. Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report, Research School of Earth Sciences, Australian National University: Canberra. Sanchez-Cabeza J. A., Masqué P. and Ani-Ragolta I. (1998) 210Pb and 210Po analysis in sediments and soils by microwave acid digestion. J. Radioanal. Nucl. Chem. 227, 19–22.

  • Samples were collected from the East Antarctic margin, aboard the Australian Marine National Facility R/V Investigator from January 14th to March 5th 2017 (IN2017_V01; Armand et al., 2018). This marine geoscience expedition, named the “Sabrina Sea Floor Survey”, focused notably on studying the interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles. Ten litres seawater samples were collected using a CTD rosette equipped with Niskin® bottle and filtered through a 0.45µm Acropak® capsule filter directly into acid-cleaned 10 L polyethylene jerrycans. Samples were then acidified to pH 2 with 2 mL/L of distilled 6M HCl in a laminar flow hood. These samples were analysed for neodymium (Nd) isotopes, a tracer of ocean circulation. In the home laboratory (IMAS Trace-Metal Lab, UTAS, Hobart, Australia), seawater samples were pre-concentrated using pre-packed Nobias® PA1L (Hitachi Technologies, Japan) chelating resin cartridges following the method of Pérez-Tribouillier et al., (2019). Rare Earth Elements were separated using anion-exchange chromatography (Anderson et al., 2012) and cation-exchange chromatography (Struve et al., 2016). Finally, Nd isotopes were isolated using LN-Spec column chemistry (Pin and Zalduegui, 1997). Purified seawater sample Nd concentrations were checked prior to isotopic analysis using Sector Field Inductively Coupled Mass Spectrometry (ICP-MS) at the Central Science Laboratory (UTAS, Hobart, Australia). Nd isotope ratio measurements were then carried out at the Geochemistry Laboratory of the School of Geography, Environment and Earth Sciences of Victoria University of Wellington, New Zealand, using a Thermo Finnigan Triton thermal ionization mass spectrometer (TIMS). Data were reduced offline for outlier rejection and corrected using 146Nd/144Nd = 0.7219 for mass fractionation using the exponential law, and 144Sm/147Sm = 0.20667 for the Sm interference correction on mass 144. JNdi standard data produced for two load sizes using two amplifier configurations were identical: 143Nd/144Nd = 0.512110 ± 24 2sd (46 ppm 2rsd, n = 16) for 1 ng loads using 1013Ω amplifiers, vs. 143Nd/144Nd = 0.512112 ± 3 2sd (6 ppm 2rsd, n = 6) for 100 ng loads using 1011Ω amplifiers. The corrected 143Nd/144Nd were normalised to the JNdi standard with the published value of 0.512115 (Tanaka et al., 2000). Nd isotopic compositions are reported as eNd = [(143Nd/144Nd)sample / (143Nd/144Nd)CHUR - 1]x10,000 , where CHUR is the Chondritic Uniform Reservoir with 143Nd/144Nd)CHUR = 0.512638 (Jacobsen and Wasserburg, 1980). References - Anderson R. F., Fleisher M. Q., Robinson L. F., Edwards R. L., Hoff J. A., Moran S. B., van der Loeff M. R., Thomas A. L., Roy-Barman M. and Francois R. (2012) GEOTRACES intercalibration of 230Th, 232Th, 231Pa, and prospects for 10Be. Limnol. Oceanogr. Methods 10, 179–213. A - Armand L. K., O’Brien P. E., Armbrecht L., Baker H., Caburlotto A., Connell T., Cotterle D., Duffy M., Edwards S., Evangelinos D., Fazey J., Flint A., Forcardi A., Gifford S., Holder L., Hughes P., Lawler K.-A., Lieser J., Leventer A., Lewis M., Martin T., Morgan N., López-Quirós A., Malakoff K., Noble T., Opdyke B., Palmer R., Perera R., Pirotta V., Post A., Romeo R., Simmons J., Thost D., Tynan S. and Young A. (2018) Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report. ANU Res. Publ. - Jacobsen S. B. and Wasserburg G. J. (1980) Sm-Nd isotopic evolution of chondrites. Earth Planet. Sci. Lett. 50, 139–155. - Pérez-Tribouillier H., Noble T. L., Townsend A. T., Bowie A. R. and Chase Z. (2019) Pre-concentration of thorium and neodymium isotopes using Nobias chelating resin: Method development and application to chromatographic separation. Talanta, 1–10. - Pin C. and Zalduegui J. F. S. (1997) Sequential separation of light rare-earth elements , thorium and uranium by miniaturized extraction chromatography: Application to isotopic analyses of silicate rocks. Anal. Chim. Acta 339, 79–89. - Struve T., Van De Flierdt T., Robinson L. F., Bradtmiller L. I., Hines S. K., Adkins J. F., Lambelet M., Crocket K. C., Kreissig K., Coles B. and Auro M. E. (2016) Neodymium isotope analyses after combined extraction of actinide and lanthanide elements from seawater and deep-sea coral aragonite. Geochemistry, Geophys. Geosystems 17, 232–240. - Tanaka T., Togashi S., Kamioka H., Amakawa H., Kagami H., Hamamoto T., Yuhara M., Orihashi Y., Yoneda S., Shimizu H., Kunimaru T., Takahashi K., Yanagi T., Nakano T., Fujimaki H., Shinjo R., Asahara Y., Tanimizu M. and Dragusanu C. (2000) JNdi-1: A neodymium isotopic reference in consistency with LaJolla neodymium. Chem. Geol. 168, 279–281.

  • Ice-rafted debris is characterised by coarse material with typically angular grains, transported within icebergs and deposted in the ocean as the icebergs melt. This iceberg rafted debris (IBRD) flux data submitted here, was calculated by quantifying the coarse sand fraction (CSF) as a percentage of the bulk sample (weight of grains in the 250 micron to 2 mm size fraction), the dry bulk density (DBD) and the linear sedimentation rate (LSR) (following Krissek et al., 1995, Patterson et al., 2014). A method for quantifying the IBRD flux uses the coarse sand fraction (CSF) as a percentage of the bulk sample, dry bulk density (DBD) and the linear sedimentation rate (LSR) (Krissek et al., 1995, Patterson et al., 2014): The CSF (250μm-2mm) was acquired from samples at 10cm intervals along KC14 by wet-sieving approximately 20g of sediment per sample. Authigenic grains and microfossils were removed from the samples under a microscope. The remaining material was weighed on a microbalance and calculated as a percentage of the bulk sample. The DBD was calculated by subsampling approximately 8cm3 of sediment from the same depth intervals and dividing the dry weight of the sediment by the volume of the subsampler. The LSR was approximated by dividing the distance (cm) between the calibrated bulk carbon ages by the difference in time (kyr). The IBRD flux was then quantified using the above equation for each depth interval.

  • 40Ar/39Ar geochronology data of basalt samples from the Kerguelen Plateau and Broken Ridge The samples include basalts from ODP drilling cores and dredge sites. The drilling core samples were stored in the Kochi Core Centre, Japan and the dredged samples were stored in the National Museum of Natural History, France. Analytical methods of the 40Ar/39Ar geochronology data: Samples were crushed and minerals/groundmass were separated using a Frantz magnetic separator. Plagioclase, pyroxene, amphibole, sericite, and basaltic glass crystals and groundmass were separated from either the 125–212 μm or the 212–355 μm size fractions using a Frantz isodynamic magnetic separator. Minerals and groundmass were subsequently hand-picked grain-by-grain under a binocular stereomicroscope. Plagioclase and groundmass were further leached using diluted HF (2N) for 5 minutes and thoroughly rinsed in distilled water. Samples were loaded into several large wells of 1.9cm diameter and 0.3 cm depth aluminium discs. The discs were Cd-shielded to minimise undesirable nuclear interference re-actions and irradiated for 40 hours in the Oregon State University nuclear reactor (USA) in the central position. The samples were irradiated alongside FCs and GA1550 standards, for which ages of 28.294 ± 0.037 Ma and 99.738 ± 0.100 Ma were used, respectively. The 40Ar/39Ar analyses were performed at the Western Australian Argon Isotope Facility at Curtin University. The samples were step-heated using a continuous 100 W PhotonMachine© CO2 (IR, 10.4 µm) laser fired on the crystals during 60 seconds. Each of the standard crystals was fused in a single step. The gas was purified in an extra low-volume stainless steel extraction line of 240cc and using one SAES AP10 and one GP50 getter. Ar isotopes were measured in static mode using a low volume (600 cc) ARGUS VI mass spectrometer from Thermofisher© set with a permanent resolution of ~200. Measurements were carried out in multi-collection mode using four faradays to measure mass 40 to 37 and a 0-background compact discrete dynode ion counter to measure mass 36. We measured the relative abundance of each mass simultaneously using 10 cycles of peak-hopping and 33 seconds of integration time for each mass. Detectors were calibrated to each other electronically and using air shot beam signals. The raw data were processed using the ArArCALC software. The criteria for the determination of plateau are as follows: plateaus must include at least 70% of 39Ar released. The plateau should be distributed over a minimum of 3 consecutive steps agreeing at 95% confidence level and satisfying a probability of fit (P) of at least 0.05. Plateau ages are given at the 2σ level and are calculated using the mean of all the plateau steps, each weighted by the inverse variance of their individual analytical error. Uncertainties include analytical and J-value errors.

  • Amery Ice Shelf AM03 borehole drilled mid-December 2005. Sub-shelf water profiling measurements conducted over a period of a few days. Partial video recording of borehole walls and sea floor benthos. Sediment sample collected from sea floor. Long term monitoring instruments installed (thermistors in ice, 3 x CTD in ocean cavity). This is a parent record - see the child records for further information.

  • Amery Ice Shelf AM04 borehole drilled mid-January 2006. Sub-shelf water profiling measurements conducted over a period of a few days. Partial video recording of borehole walls and sea floor benthos. Collection of targeted ice core samples. Sediment sample collected from sea floor. Long term monitoring instruments installed (thermistors in ice, 3 x CTD in ocean cavity). This is a parent record - see the child records for further information. This device stopped working by the 2011/2012 season, and all sensors were declared non-functional.