Elsevier

Quaternary International

Volume 584, 20 May 2021, Pages 152-170
Quaternary International

A multi-scalar approach to marine survey and underwater archaeological site prospection in Murujuga, Western Australia

https://doi.org/10.1016/j.quaint.2020.09.005Get rights and content

Abstract

During the past 20,000 years approximately one-quarter of the continental landmass of Australia was inundated by postglacial sea-level rise, submerging archaeological evidence for use of these landscapes. Underwater archaeological sites can offer substantial insights into past lifeways and adaptations to rapidly changing environments, however the vast scale of inundation presents a range of challenges in discovering such sites. Here we present a suite of methods as a model methodology for locating sites in submerged landscapes. Priority areas for survey were based on palaeoenvironmental contexts determined from the onshore archaeological record. Remote sensing was used to identify seabed composition and indicators of palaeolandscapes where high potential for human occupation and site preservation could be identified in Murujuga (or the Dampier Archipelago), northwestern Australia. Target locations were surveyed by scientific divers to test for the presence of archaeological material. Application of this methodology resulted in the discovery of the first two confirmed sub-tidal ancient Aboriginal archaeological sites on Australia's continental shelf. Survey methods are discussed for their combined value to identify different classes of landscapes and archaeological features to support future underwater site prospection.

Introduction

For most of human history, global sea level was substantially lower than present. In the deglaciation following the Last Glacial Maximum (LGM) c. 24–18 ka, sea level rose from −130 m to reach its present position at 6–7 ka (Fig. 1). Approximately 2.12 million square kilometres (km2) of Australia's continental land mass, which was occupied by humans since at least 65 ka, was drowned (Barrows et al., 2002; Clark et al., 2009; Ishiwa et al., 2016; Clarkson et al., 2017; Williams et al., 2018). These drowned coastal landscapes would have presented numerous attractive locations for human occupation and resource exploitation, and were able to support high population densities, facilitating pathways for movement around and into the continent (Bird et al., 2016). The investigation of submerged landscapes surrounding Australia is essential to several broad themes in archaeological research, including the first peopling of Australia, the pattern of settlement of the continent, the use of coastal resources and ancient maritime economies, and adaptation to rapid climate change. Since there has been little focus on the ancient, now submerged landscapes, traditional archaeological narratives have relied on data from terrestrial, inland and upland assemblages (Bailey and Flemming, 2008).

Prospection for archaeological sites on the continental shelf is logistically challenging. It requires an understanding of palaeoenvironments that are likely to have attracted past settlement and activity, knowledge of the potential for site preservation and suitable taphonomic conditions (Benjamin, 2010; Ward et al., 2013). While chance finds by recreational divers and fishers have contributed extensively to the development of submerged landscape archaeology internationally (Werz and Flemming, 2001; Stanford et al., 2014; Peeters et al., 2020), this has occurred alongside the archaeological community's development of systematic survey methodologies (Fischer, 1995; Westley et al., 2011; Tizzard et al., 2014; Missiaen et al., 2017). Despite the difficulty of locating archaeological material, the preservation of Pleistocene to early Holocene sites has been demonstrated in several parts of the world (Masters and Flemming, 1983; Benjamin et al., 2011; Evans et al., 2014; Harff et al., 2016; Bailey et al. 2017, 2020; Flemming et al., 2017bib_Bailey_et_al_2020). Within the Australian continent, numerous attempts were made to locate underwater Indigenous cultural heritage on the continental shelf (Flemming, 1982; Dortch, 2002; Nutley, 2014; Nutley et al., 2016) but to date no direct archaeological evidence had been found until recently (Benjamin et al., 2020). This is despite the discovery of Indigenous artefacts in the intertidal zone (McNiven, 2004; Ulm, 2006; Lewczak and Wilby, 2010; Rowland and Ulm, 2011; Kreij et al., 2018; Dortch et al., 2019) and freshwater environments (Dortch, 1996; Hudson and Bowler, 1997). This prior lack of positive identification of in situ submerged sites has undoubtedly reduced the research interest in this area within the Australian archaeological community, which has focused mainly on the underwater archaeology of recent historic periods (Green, 1995; McCarthy, 1998; Staniforth and Nash, 2006). Aside from the issue of positive identification of sites and results, there remains a matter of research bias in Australian archaeology, which has largely seen Australian maritime archaeology and Australian Indigenous archaeology segregated into mutually exclusive entities related to research, management and funding. Maritime archaeology in Australia, as a discipline, is focused primarily on historic periods, which has created a research bias in the underwater archaeological record toward shipwrecks, sunken aircraft and maritime infrastructure by the primary community that studies underwater archaeology. Similarly, Australian Indigenous archaeology is often focused on the present-day landscape to the neglect of the marine environment (with some notable exceptions cited above). This situation of sub-field silos has created a gap in archaeological research and heritage management. It is therefore timely that archaeologists integrate these distinct sub-disciplines of Australian archaeology, to reduce the barriers that have contributed to an under-representation of Australia's ancient past that is now under water.

The absence of positive identification of material culture in the marine environment in Australia, stands in contrast to the relative abundance of such finds in the Northern Hemisphere. The lack of positive results to date is partly a result of the scale and duration of previous investigations and the limited range of techniques applied, particularly at a landscape scale, and partly due to the issue of research bias in Australian Archaeology, creating a feedback loop of lack of research interest, and a subsequent lack of results.

Previous attempts to locate submerged Indigenous archaeology in Australia have targeted areas based on assessments of palaeolandscapes and terrestrial archaeological records. Flemming (1982) explored the Cootamundra Shoals, located 240 km northwest of Darwin, which would have been topographic highs during the earliest known occupation of Australia (evaluated as c. 30 ka at the time of the original survey led by Flemming). Diver survey was undertaken over the course of one month, but no archaeological material was recovered. More recently a survey by Dortch (2002) targeted submerged rhyodacite outcrops in the Dampier Peninsula, based on the extensive rock art assemblages found on similar outcrops on land. Prior to the fieldwork, Dortch (2002) undertook a review of onshore sites to establish the types of material that would survive inundation, including rock engravings, quarry sites, and stone artefacts and material embedded in indurated carbonate sediments. Seven dive stations between −10 m and −20 m were selected across the archipelago. While no engravings were identified, some volcanic outcrops without marine growth were located, supporting the premise that prospective locations for rock art may preserve under water. Both Flemming (1982) and Dortch (2002) demonstrated the potential value of diver survey, however, both projects were undoubtedly limited by the small area that targeted diver survey could cover within the time that was available.

Flemming (1982) suggested that increasingly advanced remote sensing technology would contribute greatly to future investigations, while Dortch (2002) concluded that prospecting for rock art in the marine environment did not warrant the expenditure of a large sea-going expedition and recommended a shore-based approach for future work as the much lower costs would allow more time for prospection. Nutley examined environmental factors influencing preservation (Nutley, 2005) and reviewed the state of inundated Indigenous site research in Australia (Nutley, 2014), including the Cootamundra Shoals survey and the earlier Dampier Archipelago surveys, and outlined potential preservation scenarios for various types of material culture. The proposed features include shell middens, carved trees, earthen circles, fish traps, stone artefacts, quarries, rock shelters, and rock art. Fish traps, quarries, and rock shelters are relatively durable features, and Nutley suggested that these should be prioritised in future survey, emphasising the need for the Australian archaeological community to progress submerged landscape research by demonstrating submerged landforms associated with human occupation. These predictions are similar to those put forth in the regionally specific example by Dortch (2002), as rock outcrops are both durable and also features where evidence of quarrying would preserve. A further diver survey, including participation of avocational divers, was undertaken in New South Wales (Nutley et al., 2016) covering 1800 m and identifying several submerged rock overhangs, which could potentially have served as rock shelters, although no archaeological evidence was found. While coastal areas and riverine corridors in Australia support high population densities, the material remains of hunter-gatherer societies are nonetheless relatively ephemeral. In the analysis of underwater palaeolandscapes and environments, it is vital to assess how these now submerged features, situated in a dynamic marine context, have been modified (i.e., through erosion or sediment deposition) from their primary sedimentary and geomorphic form in response to hydrodynamic processes.

Here we discuss the successful application of an iterative multi-scalar approach that led to the discovery of Australia's first underwater Aboriginal archaeological sites on the continental shelf, located in the Dampier Archipelago (Fig. 2). The ‘Deep History of Sea Country’ project (DHSC) developed an approach to the underwater prospection of cultural heritage in Murujuga, Western Australia, based on predictive criteria for site preservation in Murujuga (Benjamin et al., 2018; Veth et al., 2019), and application of airborne LiDAR and marine geophysics to enable the team to then focus on discrete targets, enhanced significantly through community engagement and finally confirmed by diver survey. This iterative approach led to the identification of two submerged archaeological sites (Benjamin et al., 2020). We evaluate the success of this methodology's application in Murujuga, and indicate areas requiring refinement to allow for implementation elsewhere in Australia. We discuss this approach in terms of a ‘model methodology’ based on international standards, but with specific adaptation to the study area in question (cf. Benjamin, 2010; Veth et al., 2019). We present the survey and seabed mapping methods employed, and describe how the visualisation of submerged features and their interpretation can be influenced by the particular geophysical survey technique used. The lithic artefacts found underwater at Murujuga are discussed in greater detail by Benjamin et al. (2020), while here we focus on the combination of methods used to identify the material. The approach outlined here provides a model for future underwater cultural heritage surveys in the Asia-Pacific region.

Section snippets

Rationale for study area

Murujuga comprises a series of 42 islands off the arid Pilbara coast of Western Australia. Throughout the archipelago, landforms predominantly consist of Archaean granites and volcanics, and more recent Quaternary and Holocene coastal sedimentary deposits (Kojan 1994; Jones, 2004). The submerged geology is similarly composed of igneous rocks overlaid by Pleistocene coastal sedimentary sequences (including beach ridges and estuarine channels) and mid-to-late Holocene marine sediments. There is

Methodological approach

Predictive modelling gauges potential, or ranks the probability, of archaeological site location, and forms a significant aspect of this submerged landscape study, variations of which have been applied in North America, Europe, and the Middle East (Fischer, 1993, 1995; Faught, 2004; Gaffney et al., 2007, 2009; Galili et al., 2019). When combined with large-scale survey operations, predictive models are particularly important to determine survey priorities. Understanding the types, distribution

Reviewing available data: satellite imagery and nautical charts

The European Space Agency launched two Earth Observation Satellites, Sentinel-2a and -2b, in 2015 and 2017 respectively. The two satellites are placed in the same sun-synchronous polar orbit, phased at 180° to each other. These platforms provide open access satellite imagery at 10 m resolution in the blue, green, and red NIR spectral bands. This represents a significant improvement on the previous open source imagery (i.e., Landsat 8), thus providing a more effective way to assess large

Results

The protected waters and islands of Murujuga cover an area of approximately 1200 km2, making a detailed seabed survey of the entire region cost-prohibitive and impractical. Our approach used satellite imagery and nautical charts to build a regional picture of the Archipelago's submerged landscapes and preserved palaeoenvironments. With this landscape reconstruction and in consideration of site selection and preservation characteristics, we targeted specific regions and features of interest with

Evaluation of survey methodology and data integration

Through a combination of predictive modelling, remote sensing, and diver/snorkel survey to test the predictions of Veth et al. (2019), we built on similar models for the prospection of submerged landscapes elsewhere. Benjamin (2010) considered the ‘Danish Model’ as a means for expanding international submerged landscape research that built upon a simple set of guidelines set out by Fischer's (1993) fishing site location model. The model proposed by Benjamin (2010) describes 6 phases: 1)

Conclusion

The DHSC study has successfully developed and implemented a suite of methods for the analysis of submerged landscapes and the identification of high priority survey areas, resulting in the confirmation of two in situ sub-tidal Aboriginal archaeological sites, at Cape Bruguieres and Flying Foam Passage. This multi-scalar approach started at a large area scale using a varied suite of remote sensing data, gradually narrowing the focus through assessment of geomorphological and archaeological

Funding

This work was supported by the Australian Research Council’s Discovery Projects funding scheme (DP170100812), with additional support from the Murujuga: Dynamics of the Dreaming Project (LP140100393), Flinders University and the Hackett Foundation of Adelaide and ARC Centre of Excellence for Australian Biodiversity and Heritage (CE170100015).

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The authors wish to recognise the Murujuga Aboriginal Corporation Council of Elders and Land and Sea Rangers Unit as core collaborators on this project. Peter Veth, Geoff Bailey, Peter Jeffries, Ken Mulvaney, Shakti Chakravarty, Victoria Anderson, Hiro Yoshida, Tom Allardyce and Graham and Michelle Evans and the AustMarine staff are all thanked for their support.

References (83)

  • N. Shtober-Zisu et al.

    Inland notches: implications for subaerial formation of karstic landforms-An example from the carbonate slopes of Mt. Carmel

    Israel Geomorphology

    (2015)
  • T. Stieglitz

    Submarine groundwater discharge into the near-shore zone of the Great Barrier Reef, Australia

    Mar. Pollut. Bull.

    (2005)
  • P. Veth et al.

    Early human occupation of a maritime desert, Barrow Island, north-west Australia

    Quat. Sci. Rev.

    (2017)
  • I. Ward et al.

    The potential for discovery of new submerged archaeological sites near the Dampier Archipelago, Western Australia

    Quat. Int.

    (2013)
  • A.N. Williams et al.

    Sea-level change and demography during the last glacial termination and early Holocene across the Australian continent

    Quat. Sci. Rev.

    (2018)
  • P.M. Astrup et al.

    Underwater shell middens: excavation and remote sensing of a submerged mesolithic site at Hjarno, Denmark

    J. Isl. Coast. Archaeol.

    (2019)
  • AODN Portal

    (2020)
  • J. Benjamin

    Submerged prehistoric landscapes and underwater site discovery: reevaluating the ‘Danish model’ for international practice

    J. Isl. Coast. Archaeol.

    (2010)
  • J. Benjamin et al.

    Aboriginal artefacts on the continental shelf reveal ancient drowned cultural landscapes in northwest Australia

    PLoS One

    (2020)
  • J. Benjamin et al.

    Underwater archaeology and submerged landscapes in western Australia

    Antiquity

    (2018)
  • M.I. Bird et al.

    Humans, water, and the colonization of Australia

    Proc. Natl. Acad. Sci.

    (2016)
  • T.J. Braje et al.

    Working from the known to the unknown: linking the subaerial archaeology and the submerged landscapes of santarosae island, alta California, USA

    Open Quat.

    (2019)
  • P.U. Clark et al.

    The last glacial maximum

    Science

    (2009)
  • C. Clarkson et al.

    Human occupation of northern Australia by 65,000 years ago

    Nature

    (2017)
  • J.W. Cook Hale et al.

    Spatial statistical analysis of coastal plain paleoindian site distributions and paleoecology: implications for the search for offshore submerged sites in Georgia

    Early Georgia

    (2017)
  • B. David et al.

    Nawarla gabarnmang, a 45,180±910 cal BP site in Jawoyn country, southwest Arnhem Land plateau

    Aust. Archaeol.

    (2011)
  • C.E. Dortch

    Prehistory down under: archaeological investigations of submerged aboriginal sites at lake jasper, western Australia

    Antiquity

    (1996)
  • C.E. Dortch

    Preliminary underwater survey for rock engravings and other sea floor sites in the Dampier Archipelago, Pilbara region, Western Australia

    Aust. Archaeol.

    (2002)
  • J. Dortch et al.

    Stone artifacts in the intertidal zone, Dampier Archipelago: evidence for a submerged coastal site in Northwest Australia

    J. Isl. Coast. Archaeol.

    (2019)
  • K. Edwards et al.

    3DMAPPR: a community-based underwater archaeological photogrammetry program in Perth, Western Australia

    J. Australas. Inst. Marit. Archaeol.

    (2016)
  • M. Faught

    The underwater archaeology of paleolandscapes, Apalachee Bay, Florida

    Am. Antiq.

    (2004)
  • M.K. Faught et al.

    Marine inundated archaeological sites and paleofluvial systems: examples from a karst‐controlled continental shelf setting in Apalachee Bay, Northeastern Gulf of Mexico

    Geoarchaeology

    (1997)
  • A. Fischer

    Stenalderbopladser På Bunden Af Smålandsfarvandet. En Teori Afprøvet Ved dykkerbesigtigelse

    (1993)
  • A. Fischer

    An entrance to the Mesolithic world below the ocean. Status of ten years' work on the Danish sea floor

  • S. Fitch et al.

    West Coast Palaeolandscape Survey Pilot

    (2009)
  • N.C. Flemming

    Sirius Expedition, Cootamundra Shoals Survey 1982, Expedition Report

    (1982)
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