How Australia’s Pama–Nyungan Language Family Conquered the Continent

A family of languages spoken by ancient and modern hunter-gatherers rapidly replaced other tongues as it swept the Australian continent more than four millennia ago, modelling work suggests.

Australia’s Pama–Nyungan language family includes more than 300 languages, which are spoken across 90% of the continent. Twenty-seven other language families are restricted to the far north. Previous genetic and linguistic studies have led to competing theories about how Pama–Nyungan rose to dominance.

To help resolve this mystery, Quentin Atkinson at the University of Auckland in New Zealand and his colleagues used a statistical method to analyse the shared roots of 200 words across 306 Pama–Nyungan languages. Their findings suggest that Pama–Nyungan spread quickly from north-central Australia to the rest of the continent about 4,500–7,000 years ago.

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Coprolites Give Evidence of Early Triassic Polar Predators

An Early Triassic polar predator ecosystem revealed by vertebrate coprolites from the Bulgo Sandstone (Sydney Basin) of southeastern Australia

Authors:

Niedźwiedzki et al

Abstract:

Vertebrate trace fossils often provide a measure of cryptic biodiversity, and are especially pertinent when skeletal remnants are exceptionally rare. The Lower Triassic (lower Olenekian) Bulgo Sandstone at Long Reef in the Sydney Basin of southeastern Australia constitutes just such a deposit, having yielded isolated bones of giant capitosaurian temnospondyls and proterosuchid archosauriforms, together with abundant coprolites that are geochemically rich in elemental phosphate and carbon denoting vertebrate predators. Microstructural analysis of these preserved droppings reveals occasional bone fragments, fish scales, insect cuticles, plant material and bacterial traces (pseudomorph voids), as well as silicate mineral particles. REE concentrations indicate that burial and early diagenesis occurred explicitly within fluvial sediments. Furthermore, external morphological characterization permits attribution of spiral coprolites to chondrichthyan or osteichthyan fishes, polygonal, ovoid–spherical and typically flattened feces to temnospondyls, and conspicuously large cylindrical droppings to archosauriforms or other amniote apex predators. Collectively, the Bulgo Sandstone coprolite assemblage thus offers new insights into ecosystem structure and palaeoenvironment in what was an earliest Triassic near polar setting. Such data compliments the documented skeletal record, but indicates a greater range of aquatic and possibly terrestrial carnivores — the latter being enigmatically sparse in the Australian Triassic and yet detected here via the hitherto underexplored trace fossil evidence of their ecological presence.

Scuffle in the South China Sea #70

China carried out military exercises in the South China Sea with a focus on search and rescue.

China is enjoying Duterte's twist to them, but will it last?

The Chinese have allowed Filipino fishermen back to the disputed shoal after Duterte's last visit.  Originally Manila claimed the Chinese had left and the US & Philippines were looking to confirm.

The future of American-Philippines military exercises is to be determined in the next month (Duterte stating they are over).

The US chastised Duterte again.

Some are saying the US-Philippines alliance is stronger than most realize.

Philippines is attempting to get Japan to invest in Filippino defense industries.  

Duterte lashed out at the US again and wants to have joint military exercises with the Japanese.

The US COngress blocked the sale of guns to the Philippines over the rights abuses for Duterte's drug war.  Duterte referred to the congress as monkeys but stated he'd consider sticking with American weapons all the same.

Philippines' new frigates will primarily be used to hunt subs.

The Philippines special envoy to China has quit.

Australia and Indonesia are considering joint patrols of the South China Sea.

Indonesia is considering placing passive radar stations on the Natuna Islands.

Here are some general updates to the South China Sea dispute.

Microleo attenboroughi: a Fossil Marsupial Carnivore From Miocene Neogene Australia

It weighed a little more than that 20-ounce bottle of Mountain Dew on your desk and is named after one of the giants in nature broadcasting: Meet the pocket-sized marsupial lion that you wish you could have met for real 19 million years ago.

Microleo attenboroughi is the latest fascinating fossil to emerge from northern Australia, which earlier this year gave us the hypercarnivore Whollydooleya tomnpatrichorum (go on, just say that name aloud. You know you want to). Researchers unearthed M. attenboroughi at the fossiliferous Riversleigh UNESCO World Heritage Site and dated the animal to about 19 million years ago, when the area was a lush rainforest.

Named in honor of beloved broadcaster Sir David Attenborough (also arguably the world’s most famous naturalist and, come on, the guy everyone wishes would turn up at a dinner party), this mini-marsupial got his academic debut this week in the online, open-access Palaeontologia Electronica.

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Kollikodon ritchiei: a Second Specimen of the Rare Australosphenidan Mammal Found, Sister Group to Monotremes

The upper dentition and relationships of the enigmatic Australian Cretaceous mammal Kollikodon ritchiei

Authors:

Pian et al

Abstract:

Mesozoic mammals from Australia are rare, so far only known from the Early Cretaceous, and most are poorly represented in terms of dentitions much less cranial material. No upper molars of any have been described. Kollikodon ritchiei is perhaps the most bizarre of these, originally described on the basis of a dentary fragment with three molars. Here we describe a second specimen of this extremely rare taxon, one that retains extraordinarily specialised upper cheekteeth (last premolar and all four molars). Each molar supports rows of bladeless, rounded cuspules many of which exhibit apical pits that may be the result of masticating hard items such as shells or chitin. Reanalysis of the phylogenetic position of this taxon suggests, based on a limited number of apparent synapomorphies, that it is an australosphenidan mammal and probably the sister group to Monotremata. This reanalysis also supports the view that within Monotremata, tachyglossids and ornithorhynchids diverged in the early to middle Cenozoic.

Evidence of a Supervolcano Eruption From Albian Cretaceous Australia

The answers are blowin' in the wind: Ultra-distal ashfall zircons, indicators of Cretaceous super-eruptions in eastern Gondwana

Authors:

Barham et al

Abstract:

An Early Cretaceous siliceous large igneous province (SLIP) that developed on the eastern margin of Gondwana produced some of the most voluminous siliceous volcaniclastic deposits known globally. We report U-Pb ages and trace-element and Hf-isotopic signatures of detrital zircons from the Madura Shelf (onshore Bight Basin), Western Australia. These zircons include a geochemically distinct 106 Ma component with age and Hf characteristics that match SLIP volcanics some 2300 km distant in eastern Australia. This young subpopulation shows limited grain abrasion, which contrasts with older detrital components that are stratigraphically persistent. Regional detrital zircon provenance demonstrates that sediment routing systems were disconnected in the eastern and western Bight Basin, negating terrestrial transport mechanisms as a possible vector of the zircons from the SLIP to their recovered position. Palynology indicates that the 106 Ma zircons are syn-depositional, and we interpret them as being significantly transported in an eruption plume. Given the grain size and distance from source, such distal zircon emplacement suggests previously undocumented 106 Ma super-eruptions. The 106 Ma zircons likely reflect Southern Hemisphere winter eruptions when tropospheric polar easterly winds would have been favored across southeastern Australia.

Sexual Dimorphism in Miocene Neogene Mihirung Dromornis stirtoni

Sexual dimorphism in the late Miocene mihirung Dromornis stirtoni (Aves: Dromornithidae) from the Alcoota Local Fauna of central Australia

Authors:

Handley et al

Abstract:

The dromornithids were giant flightless birds endemic to Australia from the late Paleogene to the late Pleistocene. Dromornithids are generally considered to be divergent members of the Anseriformes, but they display many convergent features with extant ratites. In this study, we investigate Dromornis stirtoni from the Alcoota Local Fauna, a species for which little is known of its biology. We used traditional methods of comparative morphology, mass estimation, landmark-based morphometrics, and histological investigations to determine the presence of medullary bone, to assess the possible presence, form, and extent of sexual dimorphism in D. stirtoni. Two morphological groups were identified for each main leg element, differing primarily in relative robustness. Core samples from femora and tibiotarsi shafts revealed medullary bone in the less robust morph, indicating that these were females. Mass, as estimated by algorithms applied to our preferred measurement of least-shaft circumference of tibiotarsi, was significantly different between males (mean = 528 kg) and females (mean = 451 kg). Therefore, male D. stirtoni were more robust but not much taller than the females and challenge the elephant bird, Aepyornis maximus, for the title of the most massive bird to have existed. Sexual dimorphism in this largest of all dromornithids, therefore, was like that of extant Anseriformes. We infer long-term monogamy, mutual display, shared parental care, female incubation, and aggressive defense of nests in these birds. The techniques of geometric morphometrics applied in this study maximize the use of fragmentary material, helping to overcome the common paleontological challenge of limited sample sizes.

Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars

Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars

Authors:

Schröder et al

Abstract:

Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1 3.8="" 4.8="" 5.4="" 6.3="" a="" analogue="" and="" another="" area="" as="" at="" be="" between="" blackish="" brownish="" by="" could="" desiccation="" differ="" differences="" dominated="" evaporation="" events="" explain="" extent="" fe="" flooding="" for="" from="" furthermore="" goethite="" has="" hematite="" high="" identification="" identified.="" identified="" implications="" in="" influenced="" interpretation="" iron="" is="" jarosite="" lake="" lakes="" least="" likely="" main="" make="" mars="" meridiani="" mineralogy="" minerals="" not="" observed="" of="" on="" orange="" orr="" p="" paramagnetic="" particular="" ph="" phase="" planum="" processes="" pyrite.="" pyrite="" range="" red="" salinity="" salt="" sampling="" secondary="" sediment="" sediments.="" sediments="" some="" strongly="" such="" suitable="" tentative="" tentatively="" that="" the="" these="" this="" to="" two="" values="" was="" were="" where="" which="" whurr.="" whurr="" zones="">

More Delightful Extinct Marsupial Mammals From Riversleigh World Heritage site in Australia

Riversleigh World Heritage site in Australia is a who's who of weird extinct animals. It is a limestone cave packed with huge number of skeletons, leftovers of poor creatures that have got accumulated over the course of millions of years.

Scientists have found fossils of the Thingodonta from its depths. Thingodonta is a woodpecker-like marsupial that gnawed bugs out of tree bark using its teeth. They have discovered proof of an extinct tusked kangaroo relative, with the scientific name Balbaroo fangaroo.

They've dug out the leftovers of drop crocs, ancient crocodiles that killed their prey by making them fall out of trees. And they came across the gigantic Dromornis, also called ‘Demon Duck of Doom’, which is 10 feet tall and is one of the world’s biggest birds.

Scientists now said that they have a tiny, but quite strange new creature to include in the collection. The latest creature is malleodectes mirabilis, or ‘wondrous hammer biter’, which is a ferret-sized cousin of present day Tasmanian devils that survived on escargot diet.

In a statement, University of New South Wales paleontologist Mike Archer, the main author of a study on the fossil appeared in Scientific Reports, said that Malleodectes mirabilis was an extremely weird mammal, odd in its own way just like a koala or kangaroo.

The creatures had massive, hammer-like premolars that let them eat entire snails, including shell and all. The researchers haven’t seen such characteristics in a mammal before.

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Evidence of an Impact During the PaleoArchean Found in Australia

Scientists have found evidence of a huge asteroid that struck the Earth early in its life with an impact larger than anything humans have experienced.

Tiny glass beads called spherules, found in north-western Australia were formed from vaporised material from the asteroid impact, said Dr Andrew Glikson from The Australian National University (ANU).

"The impact would have triggered earthquakes orders of magnitude greater than terrestrial earthquakes, it would have caused huge tsunamis and would have made cliffs crumble," said Dr Glikson, from the ANU Planetary Institute.

"Material from the impact would have spread worldwide. These spherules were found in sea floor sediments that date from 3.46 billion years ago."

The asteroid is the second oldest known to have hit the Earth and one of the largest.

Dr Glikson said the asteroid would have been 20 to 30 kilometres across and would have created a crater hundreds of kilometres wide.

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How Japan Biffed Selling its Soryu Submarine to Australia

As the dust settles on Japan’s unsuccessful bid to sell its Soryu-class submarines to Australia, Tokyo has a lot to think about. The failure in Canberra was Japan’s second strike in its politically-led push to export its homegrown weaponry.

The joint bid by the Japanese government on behalf of two defense heavyweights — Mitsubishi Heavy Industries and Kawasaki Heavy Industries — lost out to a conventionally-powered variant of France’s Barracuda-class nuclear submarine. Germany was also in the running with its Type 214.

Australia wants 12 new long-range, non-nuclear submarines to replace its current six Collins-class boats starting around 2030. The program could cost more than $15 billion.

While Tokyo’s hopes of selling Soryus to Australia and P-1 maritime patrol aircraft to the United Kingdom have been dashed, Prime Minister Shinzo Abe’s dream of a healthy defense export market survives—but only if Japan can learn from its failure down under.

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"Australian" Marsupials in Paleogene South America?

On The existence of non-microbiotherian Australidelphian marsupials (Diprotodontia) in the Eocene of Patagonia

Authors:

Lorente et al

Abstract:

A diverse assemblage of extinct mammals of early–middle Eocene age (Ypresian–Lutetian boundary) come from the Patagonian localities of La Barda and Laguna Fría around Paso del Sapo in northwestern Chubut Province (Argentina). Metatherians are well represented, mostly by dental remains of ‘Didelphimorphia’, Paucituberculata, Sparassodonta, Microbiotheria, and Polydolopimorphia. Here we analyse three calcanea and one astragalus referable to the same, indeterminate taxon, from La Barda, showing the fusion of their ectal and sustentacular facets. This facet arrangement characterizes the Australidelphia, a marsupial clade represented by Microbiotheria from South America and Antarctica, plus all Australasian lineages. Other australidelphian features shown by these tarsals include: in the calcanea, a reduced peroneal process and a tripartite cuboid facet; in the astragalus, a round, very small astragalar head in relation to the body; a convex trochlea with a half for the tibia and half, in slightly lower position, for the fibula. Their size and other anatomical features suggest that the new tarsals cannot be referred to the Microbiotheria. Phylogenetic analysis suggests that the La Barda taxon lies within the Australidelphia, and that it is either closely related or belongs to, the Diprotodontia. The existence of advanced australidelphians in Patagonia adds further evidence of the close relationship between Patagonia, Antarctica, and Australia during the Late Cretaceous – early Palaeogene.

Excitement and Concern Over France's Win of the Australian Submarine Contract

Australia’s choice of French shipbuilding giant DCNS to lead the country’s ambitious 12-ship submarine construction program caught most observers by surprise. The quasi-government-owned DCNS — which often competes in international naval programs but rarely scores a major win — had been seen as an also-ran in competition with Germany’s ThyssenKrupp Marine Systems (TKMS) and the Japanese government for the lucrative, Australian $50 billion (US $38 billion, €33.2 billion) Future Submarine contract.

But Prime Minister Malcolm Turnbull’s April 26 announcement that the decision was “unequivocally” in favor of the French design set champagne corks popping in Paris even as Australian politicians and commentators debated the choice.

“This was the absolutely unambiguous recommendation from the Department of Defence that came through the competitive evaluation process,” Turnbull said, adding that all three bids were of a “very high quality.”

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France to Build Australian Submarines, but With American Components

Australia may have awarded France a bumper contract to build its next generation of submarines, but its highly secretive combat system will come from close ally the United States.

French shipbuilder DCNS last week beat off Germany and Japan to secure the Aus$50 billion (US$39 billion) deal to design and build the 12 subs, a scaled down conventionally-powered version of its 4,700-tonne Barracuda, to be named Shortfin Barracuda.

But it will have little to do with armaments and the complex combat system, which American defence giant Lockheed Martin — which is in the running to be involved — said was “essentially the eyes, ears and sword of the boat”.

Australia has made clear it prefers the American AN/BYG-1 system, along with the joint Australian-US heavyweight Mark-48 torpedoes as its main weapon.

A decision has yet to be made on which company will be responsible for integrating the system — essentially to detect, acquire and track targets — with US defence contractor Raytheon also said to be a contender.

Given the close relationship and the fact that its technology will be used, Washington was always going to take a keen interest in Canberra’s choice to build the boats.

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France to Build Australia's new Attack Submarine (ssk)

France has beaten Japan and Germany to win an Australian mega-deal to build a fleet of 12 new submarines in Australia, for the Australian Navy SEA 1000 program. The decision was formally announced by Australian Defense Minister Malcolm Turnbull today. The SEA 1000 program is the largest acquisition program in the history of Australian defense, representing an investment of around $50 billion. The submarines will replace the six Collins class submarines (Kockums’ Type 471 submarine) commissioned between 1996 and 2003. The lead ship of the Collins class is expected to retire by the early 2030s.

The Australian Government’s requirements addressed by the new design are superior sensor performance, stealth characteristics and range and endurance similar to the current Collins Class submarine.

Industry watchers had anticipated a decision to come later in the year, but Turnbull’s gamble on a July 2 general election sped up the process. The submarines selected for the Australian Navy are based on a diesel-electric version of the 4,200-tonne Barracuda nuclear-powered submarine designed by DCNS. The first Barracuda submarine is expected to be commissioned with the French Navy next year. Subject to discussions on commercial matters, the design of the Future Submarine with DCNS will begin this year.

The variant offered by DCNS is a conventionally powered diesel-electric design of the submarine – named ‘Shortfin Barracuda Block 1A’, a version of the Barracuda specially designed for the Australian Navy. The boat has a length of 94 meters, and displacement of 4,000 tons (when submerged), 200 tons lighter than the French Barracuda. It is designed as a sea-going submarine for long range and long endurance.

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Evidence of the Separation of Laurentia From Australia During the Rifting of the Coulmbia Sueprcontinent found?

Rifting of Columbia to form a deep-water siliciclastic to carbonate succession: The Mesoproterozoic Pinguicula Group of northern Yukon, Canada

Authors:

Medig et al

Abstract:

The Mesoproterozoic Pinguicula Group (less than 1.38 Ga) is exposed in the Wernecke and Hart River inliers in northern Yukon, Canada. The Pinguicula Group records deposition of non-cyclic siliciclastic and carbonate strata on low-energy slopes affected by rare high-energy deposits in a tectonically active epicratonic setting. The succession is ∼1.4 km thick at its measured type sections and comprises three newly formalised formations: the Mount Landreville, Pass Mountain, and Rubble Creek formations (formerly units A, B, and C, respectively). The Mount Landreville Formation is a predominantly siltstone succession with minor conglomerate and sandstone deposited below storm wave-base on a relatively gentle slope. The Pass Mountain Formation is a wispy- to planar-laminated carbonate succession deposited on a low-energy slope mostly below storm wave-base and is punctuated by rare high-energy gravity-flow deposits including debrites, grain-flows, turbidites, and micro-turbidites. The Rubble Creek Formation is dominated by repetitive centimetre- to decimetre-scale lime mudstone beds; it is distinguished from the Pass Mountain Formation by abundant zebra texture (an alternating dark grey and white banding caused by late diagenetic or hydrothermal fluid influx) and a lack of sediment gravity-flow deposits.

The Pinguicula Group is the middle of five, unconformity-bounded, Proterozoic stratigraphic successions deposited on the northwestern margin of Laurentia (ancestral North America). The Pinguicula basin was epicratonic and deepened to the south (present coordinates). The basin formed during an amagmatic extensional event that contributed to the break-up of Columbia and the separation of Laurentia from Australia.

Whereas most preserved Mesoproterozoic basins are dominated by shallow-water lithofacies deposited in rift and epicratonic settings, with few deep-water lithofacies preserved, the carbonate strata of the Pinguicula Group provide a rare insight into deeper-water carbonate environments.

Could Robo Subs Replace the Australian Collins Class Submarines?

The decision to replace Australia's submarines has been stalled for too long by politicians afraid of the bad media about "dud subs" the Collins class got last century.

Collins class subs deserved criticism in the 1990s. They did not meet Royal Australian Navy (RAN) specifications. But in this century, after much effort, they came good. Though they are expensive, Collins class boats have "sunk" US Navy attack submarines, destroyers and aircraft carriers in exercises.

Now that the Collins class is up for replacement, we have an opportunity to reevaluate our requirements and see what technology might meet them. And just as drones are replacing crewed aircraft in many roles, some military thinkers assume the future of naval war will be increasingly autonomous.

The advantages of autonomy in submarines are similar to those of autonomy in aircraft. Taking the pilot out of the plane means you don't have to provide oxygen, worry about g-forces or provide bathrooms and meals for long trips.

Taking 40 sailors and 20 torpedoes out of a submarine will do wonders for its range and stealth. Autonomous submarines could be a far cheaper option to meet the RAN's intelligence, surveillance and reconnaissance (ISR) requirements than crewed submarines.

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Evidence of Microbial Activity From PaleoArchean Australia

Carbonaceous microstructures from sedimentary laminated chert within the 3.46 Ga Apex Basalt, Chinaman Creek locality, Pilbara, Western Australia

Authors:

Hickman-Lewis et al

Abstract:

Hydrothermal black chert veins intruding the 3.46 Ga Apex Basalt contain some of Earth’s oldest microfossil-like objects, whose biogenicity has been questioned. Whilst these black chert veins have been studied in great detail, relatively little is known about the stratiform, seafloor, sedimentary cherts that are conformably interbedded with volcanic rocks of the Apex Basalt.

Herein, we document and assess the biogenicity of carbonaceous microstructures present in the lowermost of the stratiform chert units (informally known as the ‘Apex chert’), at the Chinaman Creek locality in the Marble Bar greenstone belt, Pilbara Craton, Western Australia. Carbonaceous material mostly occurs within clotted grey-black cherts and microgranular ‘grainstone-like’ cherts within the stratiform unit, the latter being the major focus of this study. In the clotted cherts, carbon occurs as lobate, fluffy grains, rare compressed flakes, and as a grain boundary phase around spherulitic silica. There is no morphological evidence to support the biogenicity of these microstructures. In contrast, the microgranular chert contains fluffy and flaky carbonaceous grains, plus laminated grains comprising multiple non-isopachous wrinkled carbonaceous laminae, with noted thickening towards some ridge crests, as determined by confocal laser scanning microscopy. Roll-up structures provide evidence of an initial plasticity, interpreted to have formed via the tearing-up and current-induced plastic deformation of microbial mat fragments. Geochemical mapping, using laser Raman micro-spectroscopy and NanoSIMS, respectively demonstrates the antiquity of the carbon, and reveals a close correlation between carbon, nitrogen and sometimes sulphur, concentrated within dark brown to black laminae. Adjacent to microgranular zones are zones of more persistent carbonaceous, undulose, filament-like laminae that entrain relict sediment grains. These microstructures are directly comparable to a sub-type of microbially induced sedimentary structure (MISS), widely reported from younger siliciclastic sediments colonised by microbial biofilms.

The morphology and chemical composition of both the non-isopachous laminated grains and the filament-like laminae are consistent with a biological interpretation, suggesting microscopic MISS were present in the microgranular stratiform ‘Apex chert’. However, the fact that neither macroscopic MISS nor bona fide microfossils have yet been reported from this unit, coupled with the proximity of these structures to active hydrothermal vents, potentially discharging hot carbon-rich fluids, urges caution in such an interpretation. The Chinaman Creek ‘Apex chert’ investigated here is one of at least five sedimentary, laminated cherts within the Apex Basalt. These horizons are promising targets in the search for biological activity within a dominantly volcanic Archaean environment.

Evidence of an Impact From the PaleoArchean in Australia

A new ∼3.46 Ga asteroid impact ejecta unit at Marble Bar, Pilbara Craton, Western Australia: a petrological, microprobe and laser ablation ICPMS study

Authors:

Glikson et al

Abstract:

The Archean record contains seventeen asteroid impact ejecta units interpreted in terms of terrestrial vestiges of an extended late heavy bombardment (LHB) (, and ). Correlated impact ejecta units include the 3.47 Ga in the Barberton Greenstone Belt, Kaapvaal Craton, South Africa, and Pilbara region of Western Australia, with multiple ejecta units in the 3.25–3.22 Ga and 2.63–2.48 Ga intervals. This paper reports the discovery and investigation of a new impact ejecta unit within the Marble Bar Chert Member (MBCM) of the felsic volcanic Duffer Formation, east Pilbara Craton, Western Australia. The age of the MBCM is constrained by a 3459±2 Ma U-Pb zircon date from the uppermost volcanic unit of the Duffer Formation and by a 3449±3 Ma U-Pb zircon date from the overlying felsic volcanic Panorama Formation, stratigraphically above the intervening un-dated Apex Basalt. The ejecta unit, observed in a drill core (ABDP 1) ∼4 km south-southwest of Marble Bar, consists of multiple lenses and bands of almost totally silicified impact spherules 1–2 mm in diameter. All internal primary textures of the spherules have been destroyed. Nonetheless, Fe-rich spherule rims, largely composed of secondary siderite, are well preserved. Chemical analyses of the rims reveal iron-magnesium carbonate displaying high Fe, Mg, Ni, Co and Zn. Whole-rock and in-situ analyses (X-ray fluorescence, Inductively Coupled Plasma Mass Spectrometry (ICPMS), electron-microprobe (EMP) and EMP-calibrated laser ICPMS) reveal that the rims contain high Ni abundances and high Ni/Cr ratios (less than 50). The spherules are separated by an arenite matrix and spherule lenses also occur within bedded chert. The spherules are particularly visible over some ∼14 m of true stratigraphic thickness in which chert breccia is interpreted to represent a tsunami-generated diamictite affected by hydrothermal fragmentation and veining. Despite the almost total silicification of the MBCM whole-rock nickel sulphide (NIS) results indicate high Ir (2 ppb) and a low Pd/Ir ratio (2.0), consistent with geochemical features of impact ejecta units. Dense concentrations of spherules at the 57-58 m level and the 77 m level of the core, separated by banded chert, raise the possibility of two distinct impact events. Stratigraphic and isotopic age data distinguish between the 3459–3449 Ma age of the MBCM ejecta unit and ∼3470.1 ± 1.9 Ma impact ejecta units in the Antarctic Creek Member, Mount Ada Basalt, about 40 km to the west of Marble Bar. In combination with a 3472 ± 2.3 Ma impact unit in the Barberton greenstone belt, these impact ejecta units record large Paleoarchean asteroid impacts, significant for understanding early earth bombardment rates and early crustal evolution.

The Arms Race in Asia: Japan and Australia Beefing up Amphibious Forces to Counter China

America’s most powerful allies in the Pacific, Australia and Japan, are building up their amphibious forces, buying amphibious vehicles, V-22 aircraft and big new warships. While far smaller than the Marine Corps, the Australian and Japanese units could assist America in stabilizing the region and deterring China — if they can overcome their self-imposed limitations. Japan is preparing for high-end warfare against China, but only in its backyard; Australia is ready to operate more broadly, but not at the high end.

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