Ancient Coastline Research Articles

Mesophotic benthic communities associated with a submerged palaeoshoreline in Western Australia.

Key ecological features (KEFs) are elements of Australia's Commonwealth marine environment considered to be important for biodiversity or ecosystem function, yet many KEFs are poorly researched, which can impede effective decision-making about future development and conservation. This study investigates a KEF positioned over the Last Glacial Maximum (LGM) shoreline on the northwest shelf of Australia (known as the 'Ancient Coastline at ~125m depth contour'; AC125). Seafloor bathymetry, sedimentology and benthic habitats were characterised within five study areas using multibeam sonar, sediment samples and towed video imagery. Direct evidence for the existence of a palaeoshoreline formed during the LGM was not found, however candidate areas to find palaeoshoreline material at or just below the modern seabed were discovered. Approximately 98% of the seabed surveyed was comprised of unconsolidated soft sediment habitat (mud/sand/silt) supporting negligible epibenthic biota. The prevalence of soft sediment suggests that post-glacial sediments have infilled parts of the palaeoshoreline, with cross-shelf, probably tidal currents in the northern section of the study area responsible for some of the sediment mobilisation and southern study areas more influenced by oceanic conditions. Within study areas, total biotic cover ranged from 0.02% to 1.07%. Of the biota encountered, most comprised filter feeder organisms (including gorgonians, sponges, and whip corals) whose distribution was associated with pockets of consolidated hard substrate. Benthic community composition varied with both study area and position in relation to the predicted AC125. In general, consolidated substrate was proportionally higher in water shallower than the AC125 compared to on the AC125 or deeper than the AC125. Spatially continuous maps of predicted benthic habitat classes (pre-determined benthic communities) in each study area were developed to characterise biodiversity. Spatial modelling corroborated depth and large-scale structural complexity of the seafloor as surrogates for predicting likely habitat class. This study provides an important assessment of the AC125 and shows that if a distinct coastline exists in the areas we surveyed, it is now largely buried and as such does not provide a unique hard substrate habitat. However, much work remains to fully locate and map the ancient coastline within the vast region of the AC125 and additional surveys in shallow waters adjacent to the AC125 may identify whether some sections lie outside the currently defined KEF.

Palaeoenvironmental Framing of the O Areal Roman Saltworks and Related Anthropogenic Activities in North-western Iberia

ABSTRACT The NW Iberian city of Vigo contains buried structures of a Roman salinae that follow the ancient coastline. To investigate its environmental legacy, we studied two pedo-sedimentary profiles at the O Areal saltworks to reconstruct human activities during and after the salinae use, as well as framing them within the last two millennia of climate variability. The bottom layer consists of organic-rich sands, with marine palynomorphs, confined within the saltworks’ structures that operated during the Early Roman Empire, when the demand in fish-salted products increased and the salting industry fluorished on the Atlantic coast of Iberia. During the Late Roman Empire, salt production at the O Areal may have ended, coeval with the development of a marsh with hydro-hygrophyte vegetation and the salting industry demise. The Roman environment also experienced intense agropastoralism that triggered water eutrophication. After Roman times, a dune phase sealed the archaeologicl structures. The overall trend points to a shift from a marine to a terrestrial setting coeval to known periods of climate variability. Therefore, humans and climate impacted the coast during the last two millennia, including the very intense Roman-period saltworks, agriculture and livestock. Roman times climate would have also influenced the saltworks’ establishment and abandonment.

A preliminary study on the mechanism of the Liangzhu culture’s migration across the Yangtze river

The Liangzhu culture (5300–4200 cal BP) was the most famous Neolithic culture of who settled near the lower reaches of the Yangtze River in China. The core and initial distribution area of Liangzhu originated around Taihu Lake, located on the south bank of the Yangtze River delta. Recently, archaeological studies believe that the Jianghuai area and Huanghuai area north of the Yangtze River are also important distribution areas of Liangzhu culture. The route for Liangzhu culture migrating across the Yangtze River is inferred as follows: One would have crossed the Yangtze River from Nanjing-Zhenjiang belt and continued to migrate northward; while the other would have crossed the River near the estuary before moving north along the ancient coastline to the Jianghuai during the late period of Liangzhu, or crossed the Yangtze River from the east of the present Beijing-Hangzhou Grand Canal to Jianghuai and Huanghuai. According to the formation of the Yangtze River delta during the Holocene and the evolution of the estuarine sand bar, it is believed that there were large shoals in the Yangtze River channel in the middle-Holocene. The Liangzhu ancestors around 5000 cal BP had the ability of making canoes over 8 m. Based on the archaeological research of the Neolithic period, the evolution of the Yangtze River channel in the Holocene, the history of ancient Chinese shipbuilding, and the modern examples of crossing the Yangtze River with boat, it can be concluded that the present Changzhou–Jiangyin–Zhangjiagang line should be the main and reasonable route for the Liangzhu culture migrating across the Yangtze River.

Літогенез верхньоюрських відкладів Зовнішньої зони Передкарпатського прогину

Geological- and biological-paleogeographical conditions of sedimentogenesis within the Carpathian segment of Tethys ocean during Tithonian were considered. The rock-forming organisms with calcic function (flora and fauna), which compose main lithological types of carbonate rocks were identified. On the base of biological-paleoceanographical and lithological investigation of different genetic types of Upper Jurassic carbonate rocks of the Outer zone of the Carpathian Foredeep and analysis of literature data on modern carbonate sediments, the structural classification of Late Jurassis epipelagic sediments of the Carpathian segment of the Meso-Tethys was made. In that classification pelitic, aleuritic, psammitic and ruditic fractions of sediments were distingnished. Geological-paleogeographical model of occurrence of the Tithonian sediments within the Carpathian segment of the Meso-Tethys (the Outer zone of the Carpathian Foredeep) was built by the author. That model presents areals of biogenic and abiogenic epipelagic sediments and depicts their facial variations. Geological-paleogeographical study of Upper Jurassic sediment complexes of epipelagic part of the Meso-Tethys has shown that they were formed within widespread interior shelf, probably, with small inclination of the sea bottom. In Upper Jurassic there was abundant growth of the benthos with calcic function and avalanchecal sedimentation of their skeletal remains took place with forming of biogenic carbonate sediments. The coral-algae biocoenosis there were biological indicators of considered parts of Tethys region. In modern basins of the World ocean analogous processes take place at the depths of about 50 m, in temperature conditions about 23–25 °C and the salinity of the sea waters about 2.7–3.8 ‰. The manifestations of diagenetic and katagenetic processes in the Upper Jurassic carbonate rocks of Outer zone of the Carpathian Foredeep have been investigated and their influence of the formation of the reservoir properties of rocks has been found out. During the diagenesis, the rocks were recrystallized, micritizated and cemented. From the mineralogical point of view, the changes consisted in the transformation of primary aragonite and magnesium-calcite skeletal remains of organisms into calcite, as well as processes of dolomitization, ferruginization and silicification. At the stage of diagenesis, Fe-containing minerals ̶ glauconite and pyrite ̶ has been formed. The dolomitization of Jurassic organogenic limestones of Outer zone of the Carpathian Foredeep has been caused by the mixing of the fresh meteoric waters with buried marine pore waters in the underground phreatic zone adjacent to the ancient coastline. Silicification is a consequence of the metasomatic substitution of the carbonate substance by silicate, which has been caused by decrease of the pH occurred after dolomitization. Katagenetic transformation of the rocks are manifested in the dissolution of the remains of organisms, grains of carbonate cement and the late cementation of pores and microfractures. Changes of carbonate rocks are associated with the bringing of certain substances in the sediment (sulphatization, celestinization) or their removal (dedolomitization, decementation). Neoplasm minerals of the katagenesis stages are represented by anhydrite and celestine. The proceses of recrystallization of carbonate rocks at different stages of katagenesis contributed to the selective leaching of limestones and dolomites and led to formation of secondary cavities and caverns, different in shape and size. The predominance of cavities of certain types determines the type of reservoir, among which are distinguished pores, pore-caverns and joint caverns. The processes of diagenesis and katagenesis are associated with the dissolution of carbonate material, which differently affects the reservoir properties of sediments. Authigenous mineral formation, with the exception of dolomitization, impairs the reservoir properties of the Upper Jurassic carbonate rocks, and recrystallization improves. Burial of carbonate rocks at depth contributes to the preservation and even improvement of their reservoir properties both due to dissolution and textural heterogeneity (jointing develops at the boundary of the elements of textural heterogeneity). Observations show that the most favourable in this respect are organogenic and detrital varieties of carbonate rocks. The presence of clay minerals in the composition of their cement increases the textural heterogeneity and, as a consequence, the ability to formation of joints.

Комплексные археологические и геофизические исследования в портовой части Херсонеса Таврического

The best results of researching archaeological sites in the coastal zone come from integrated interdisciplinary approach involving modern geophysical methods. The analysis of the archaeological material obtained during excavations of the “diamond-shaped tower” in the water area near the port quarters of Chersonese suggests that the structure was constructed in the ninth and tenth centuries AD. The results of research on this site show that from the ninth and tenth to the period from the late eleventh to the first half of the thirteenth centuries the sea level in Karantinnaia Bay rose by ca 1 meter. The data obtained by continuous seismoacoustic profiling were used to identify continuous changes of the coastline in result of transgression and accumulation of the bottom sediments in the section of the water area near the port district of Chersonese. The analysis of the built-up seismogeological sections and isobath map enabled the research group to identify 3 terraces and associated morphological elements indicating the location of ancient coastlines in different historical periods. A spatial relationship has been established between the archaeological objects found at the sea bottom and the position of the underwater terraces. A reconstruction of the ninth- and tenth-century coastline has been suggested according to the archaeological data. The location of the “diamond-shaped tower” and the construction remains discovered in 2019 on the same terrace suggests that the structures existed approximately at the same time. Electrical prospecting research using bottom electrotomography explored the sediment structure of marine terraces to a depth of 10 m. The research results have determined bottom anomalies corresponding to various stages of development of the coast of Karantinnaia Bay. An extended linear anomaly, located 40–50 m from the modern coast and hidden by a layer of bottom soil up to 3 m thick, most likely corresponds to the early period of the ancient city. The sea in this area is ca 2–3 m deep.

New chronological evidence reveals a continuously inhabited Neolithic–historical settlement in south China

The Xindian Ancient City (XAC) site is the most complete and frequently excavated urban site in the lower reaches of the Minjiang River. Archaeological and chronological research of this area helps clarify the history of human activity at the site and restore the geographical background of the ethnic minority regimes who lived in the coastal areas of south China during the Eastern Zhou dynasty and the related influence on regional civilisation. Dating results suggest that the site was built during the Spring and Autumn and Warring States periods (3.2–2.4 thousand years ago), which can reasonably explain the presence of relics from the Warring States period on and within the wall. Our dating results are also consistent with the late Neolithic stone tools and pottery fragments found in the area, suggesting that the site was an ideal settlement before castles were constructed. Based on the spatial distribution of the Neolithic sites and Holocene transgression records in the Fuzhou Basin, it was found that coastline advance and retreat were the main factors affecting the paleo-human activity in the Fuzhou Basin during the late Neolithic period. Previous studies showed that the seawater gradually withdrew from the basin around 2 ka BP. Before this, humans mainly lived in the crescent-shaped area on the west side of the Fuzhou Basin, close to the ancient coastline. Based on existing archaeological results and chronological data, it can be shown that the lower reaches of the Minjiang River, where Fujian Province's capital is located, has long been the centre of ancient human activity in the coastal areas of south China, with a civilisation history of 6–4 ka and a city construction history of at least 2.9 ka.

A reassessment of the origin and distribution of the subterranean genus Pseudolimnocythere Klie, 1938 (Ostracoda, Loxoconchidae), with description of two new species from Italy

Groundwater ecosystems host a rich and unique, but still largely unexplored and undescribed, biodiversity. Several lineages of ostracod crustaceans have subterranean representatives or are exclusively living in groundwaters. The stygobitic genus Pseudolimnocythere Klie, 1938 has a West Palearctic distribution, and includes few living and fossil species of marine origin. Through a comprehensive literature review and the description of the two new living species, Pseudolimnocythere abditasp. nov. and Pseudolimnocythere sofiaesp. nov., from springs in the Northern Apennines, Italy, a morphological analysis was carried out with the aim of comparing the valve morphology of living and fossil species, and to discuss previous hypotheses about time and mode of colonization of inland waters. Pseudolimnocythere species show a low variability in valve morphology, with a remarkable stasis over geological times. The distribution of extant and fossil species is consistent with a scenario of multiple and independent events of colonization of continental habitats linked to sea level variations starting from Middle Miocene in the Paratethys and, later, in the Mediterranean. The most common colonization routes of inland waters have taken place through karst formations along ancient coastlines, although we cannot exclude some minor active migration through the hyporheic zone of streams. Available distribution data suggest a poor dispersal ability of Pseudolimnocythere species after they had colonized continental waters.

Postglacial Black Sea level rising, urban development and adaption of historic places. The case-study of the city-peninsula of Nesebar (Bulgaria)

The strengthening of a coastal zone considers a complex of hydrodynamic factors (waves, currents, wind and materials carried by them), climate, rock stability, sedimentation and eustatic fluctuations at sea level. The sea terrace on which the urban structures of Nessebar are located is formed on almost horizontal Miocene limestone sandstones, marl lime stones and clays. It is limited by the steeply abraded coast, subjected to the destructive energy of the sea surf until the end of the last century. The destruction of ancient and early Byzantine constructions can be identified along the slope of the sea-cliff between the 8th and 13th isohypses and the coastline and along the seabed to at least the 4th isobath. In the process of tracing the fortifications, the ancient coastline is not followed, but rather the proximity to the base of the peninsular slope.

Transient motion of the largest landslide on earth, modulated by hydrological forces

Sea-level rise of the Caspian Sea (CS) during the early Khvalynian (approximately 40–25 ka BP) generated hundreds of giant landslides along the sea’s ancient coastlines in western Kazakhstan, which extended hundreds of kilometers. Although similar landslides have been observed along the present-day coastlines of the CS in the area of a prominent high escarpment, it remains unclear whether some of these ancient landslides are still active and whether the movement is slow or catastrophic, as previously suggested. The present study is the first to show evidence proving that the geomorphic responses to sea-level changes of the CS that were triggered in the Pleistocene are currently active. Using interferometric synthetic aperture radar (InSAR) data, we show that one of these giant landslides occurring along the western shore of the Kara-Bogaz-Gol (KBG) lagoon of the CS presents active transient motion, which makes it the world’s largest active landslide reported thus far. Extending more than 25 km along the eastern coast of the inundated KBG depression in a N–S direction with maximum landward expansion of 5 km from the shoreline to the flat Ustyurt Plateau, this landslide conveys ~ 10 × 109 m3 rocks toward the lagoon at a rate of ~ 2.5 cm/year. This event releases a nearly episodic aseismic moment of 6.0 × 1010 Nm annually, which is equivalent to the response of an Mw 5.1 earthquake. We analyze the present-day evolution of this giant coastal landslide at high temporal and spatial resolutions using Sentinel-1 radar images acquired on descending and ascending modes every 12 days between 2014 and 2020. Modelling with elastic dislocations suggests that the KBG landslide was accommodated mostly by a shallow basal décollement with a nearly horizontal listric slip plane. Moreover, our analysis reveals week-long accelerating slip events at changing amplitudes that occur seasonally with slow, lateral spreading rather than sudden catastrophic motion. A strong correlation between the episodic slip events and seasonal water-level changes in the KBG lagoon suggests a causative mechanism for the transient accelerating slip events. Although water-level changes are widely acknowledged to trigger transient motion on a land mass, such movement, which is similar to a silent earthquake, has not been observed thus far at this mega scale; on an extremely low-angle detachment planes at < 5° with modulation by sea-level changes. This study suggests that present-day sea-level changes can reactivate giant landslides that originated 40–25 ka.

Mesophotic fish communities of the ancient coastline in Western Australia.

Marine diversity across the Australian continental shelf is shaped by characteristic benthic habitats which are determined by geomorphic features such as paleoshorelines. In north-western Australia there has been little attention on the fish communities that inhabit an ancient coastline at ~125 m depth (the designated AC125), which is specified as a key ecological feature (KEF) of the region and is thought to comprise hard substrate and support enhanced diversity. We investigated drivers of fish species richness and assemblage composition spanning six degrees of latitude along sections of the ancient coastline, categorised as ‘on’ and ‘off’ the AC125 based on depth, across a range of habitats and seafloor complexity (~60–180 m depth). While some surveyed sections of the AC125 had hard bottom substrate and supported enhanced fish diversity, including over half of the total species observed, species richness and abundance overall were not greater on the AC125 than immediately adjacent to the AC125. Instead, depth, seafloor complexity and habitat type explained patterns in richness and abundance, and structured fish assemblages at both local and broad spatial scales. Fewer fishes were associated with deep sites characterized by negligible complexity and soft-bottom habitats, in contrast to shallower depths that featured benthic biota and pockets of complex substrate. Drivers of abundance of common species were species-specific and primarily related to sampling Areas, depth and substrate. Fishes of the ancient coastline and adjacent habitats are representative of mesophotic fish communities of the region, included species important to fisheries and conservation, and several species were observed deeper than their currently known distribution. This study provides the first assessment of fish biodiversity associated with an ancient coastline feature, improving our understanding of the function it plays in regional spatial patterns in abundance of mesophotic fishes. Management decisions that incorporate the broader variety of depths and habitats surrounding the designated AC125 could enhance the ecological role of this KEF, contributing to effective conservation of fish biodiversity on Australia’s north west shelf.

Quality characteristics of Ilmenit minerals in the south central of Vietnam by SEM and QEMSCAN analysis

Placer deposit along the South Central Coast of Viet Nam is formed by the enrichment of heavy minerals through a combination of transportation, weathering, erosion and deposition processes. Ilmenite placer forms continuously along the South Central Coast from local origin when the shoreline is far from the modern shoreline formed during the marine transgression process from the late Plestocene to Holocene. The morphological and localization characteristics of Ilmenite have been clarified on the distribution trend with SEM method combined with QEMSCAN. Meticulous research on Ilmenite's grain structure and chemical composition in the study area has shown a tendency to significantly enrich the quality of Ti placer according to the upward trend in the north-south direction. In the south, the Ilmenite placer has smaller particle size but better selective roundness and better quality than in the northern part of the study area. The enrichment of TiO2 content with increasing trend from North to South was observed due to the strong weathering process associated with ancient coastline which is very far away from current shoreline so heavy minerals are accumulates locally and light minerals are carried away. The southern region of the South Central Coast region is home to the highest gap between the ancient shoreline and the current coastline. This study has shown the trend of the quality distribution of Ilmenite as well as of other heavy minerals as the basis for future mineral exploration planning.

A giant sandy sediment drift in early Silurian (Telychian) and its multiple sedimentological prosess

Abstract This study describes a regional-scale sedimentary feature in the Upper Yangtze region of China that is identified as a Telychian age (438 Ma) sediment sandy drift that is 500–800 km long, 100–150 km wide, and 10–20 m thick. Graptolite zones is applied to recognize Telychian sandstone beds and reconstruct an isochronal stratigraphic framework for the study area. It is possible to observe numerous traction structures in Telychian sandstone beds, including ripples, cross-bedding, cross-laminations, wavy-laminations and horizontal-laminations and Bouma sequence. The palaeocurrent direction is towards SSW (200°–240°), which is measured by sedimentary structures (cross-bedding, cross-laminations and ripples) in outcrops. Besides, the alignment of elongate particles in thin section, and the distribution characteristics of heavy minerals also indicate a SSW palaeocurrent direction. This direction is parallel to palaeo-coastline, which is a characteristic feature of bottom current. A multiple sedimentary processs is identified based on analysing facies of each sections. Contourite-dominated sequences are observed in channel-related seaway while turbidite sequences are observed in shelf near palaeo-coastline. Based on provenance analysis, the Telychian drift (channel reworked sandy drift) is the production of a mixed depositional system (first turbidite deposition and then bottom current deposition). The turbidite sand on the shelf provides material source for the sandy drift, and the deposit is transported from the shelf to the channel (parallel to ancient coastline). The provenance direction is identified by analyzing the distribution of heavy minerals. The unstable heavy minerals content is higher in the turbidites samples (near provenance region) than the channel reworked sandstone samples (far away from provenance region). This Telychian deposit is a rare example of an ancient channel reworked sandy drift.

INVESTIGATION OF GEOARCHAEOLOGICAL FORMATIONS OF ANCIENT PORT CITIES IN THE LYCIA REGION

The effects of geological events that occurred in ancient times, on ancient cities are undeniably great, so geoarchaeology has become an important mutidisciplinary science. Using geological methods in archaeological researchs offers a much more comprehensive understanding for history. Today, the methods of remote sensing and geographical information systems have facilitated archaeological researches to a greater extent than before. In this study, Phaselis, Andriake and Patara ancient cities were investigated. In the research, help was obtained from satellite images as a method. By comparing the ancient coast line and the modern coast line, it is tried to be understood to what extent the sea level change occurred.

Innovation and technology in marine science: AIMS' North West Shoals to Shore Research Program – an update

In 2017, the Australian Institute of Marine Science and its partners commenced the North West Shoals to Shore Research Program. The program is designed to address significant scientific and environmental knowledge gaps pertinent to the management of the offshore petroleum industry, a key stakeholder in this ecologically and commercially important region of Australia. The program comprises four themes. 1. Marine noise monitoring and impacts: includes two seismic source (2600 cubic inch air-gun array) exposure experiments have been conducted to investigate selected responses by demersal fishes and pearl oysters across different spatial and temporal scales. 2. Seabed habitats and demersal biodiversity: seeks to understand the physical and biological characteristics of the ancient coastline key ecological feature around the 125 m depth contour and pearl oyster habitats offshore from Eighty Mile Beach. The work examines the ecological processes that maintain benthic communities on both ancient and contemporary coastlines 3. Protected and iconic species movement, distribution and threats: uses innovative sampling techniques to confirm biologically important areas for pygmy blue whales, hawksbill and green turtles. This will assist the quantification and mitigation of the risks vessel movements, industrial infrastructure and activities pose to marine megafauna on the Northwest Shelf. 4. Spatial dynamics of isolated coral reef atolls: develops a habitat model and adaptive monitoring program that informs the future condition of these remote coral reef atolls. Significant progress has been made by the program in 2018, including the development of innovative and technical approaches to sampling.

Опыт палинологических исследований в нефтяной геологии

The authors present the directions for palynological research: detailed (zonal) palynostratigraphy for clarifying the age and correlation of reservoirs; palynological facial analysis for reconstruct the position of the ancient coastline; determination of the degree of catagenesis of organic matter using the palynomorphs color index for assessing the oil and gas generation potential of terrigenous sediments of the Perm region.

Submarine Landslides and their Distribution in the Gas Hydrate Area on the North Slope of the South China Sea

Integrated investigations have revealed abundant resources of gas hydrates on the northern slope of the South China Sea (SCS). Regarding the gas hydrate research of northern SCS, the gas hydrate related environment problem such as seabed landslides were also concentrated on in those areas. Based on 2D seismic data and sub-bottom profiles of the gas hydrate areas, submarine landslides in the areas of Qiongdongnan, Xisha, Shenhu, and Dongsha have been identified, characterized, and interpreted, and the geophysical characteristics of the northern SCS region investigated comprehensively. The results show 6 major landslides in the gas hydrate zone of the northern SCS and 24 landslides in the Shenhu and Dongsha slope areas of the northern SCS. The landslide zones are located mainly at water depths of 200–3000 m, and they occur on the sides of valleys on the slope, on the flanks of volcanoes, and on the uplifted steep slopes above magmatic intrusions. All landslides extend laterally towards the NE or NEE and show a close relationship to the ancient coastline and the steep terrain of the seabed. We speculate that the distribution and development of submarine landslides in this area has a close relationship with the tectonic setting and sedimentary filling characteristics of the slopes where they are located. Seismic activity is the important factor controlling the submarine landslide in Dongsha area, but the important factor controlling the submarine landslides in Shenhu area is the decomposition of natural gas hydrates.

Sub-marine Continuation of Peat Deposits From a Coastal Peatland in the Southern Baltic Sea and its Holocene Development

Coastal low-lying areas along the southern Baltic Sea provide good conditions for coastal peatland formation. During the Holocene, the transgression of the Littorina Sea has caused coastal flooding, submergence and erosion of ancient coastlines and former terrestrial material. The present Heiligensee & Hutelmoor peatland (located near Rostock in Northern Germany) was found to continue more than 90 m in front of the coastline based on on- and offshore sediment cores and geo-acoustic surveys. The seaward areal extent of the peatland is estimated with 0.16-0.2km2. The offshore limit of the former peatland roughly coincides with the offshore limit of a dynamic coast-parallel longshore bar, with peat deposits eroded seawards. While additional organic-rich layers were found further offshore below a small sand ridge system, no connection to the former peatlands can be established based on 14C age and C/N ratios. The preserved submerged peat deposits with organic carbon contents of 37 % in front of the coastal peatland Heiligensee & Hutelmoor was radiocarbon-dated to 6725 +/- 87 and 7024 +/-73 cal yr BP, respectively, indicating an earlier onset of the peatland as presently published. The formation time of the peat layers gives information about the local sea level rise. The local sea level curve derived from our 14C-dated organic-rich layers is in general agreement to nearby sea level reconstructions (North Rugen and Fischland, Northern Germany), with differences explained by local isostatic movements.

Implications for measuring seasonality in the marine bivalve, Saxidomus gigantea

Sclerochronological and sclerochemical analysis of shellfish remains from archaeological sites afford the opportunity to understand environmental change and its impacts on human populations through time. During the Late Holocene in the Gulf of Alaska (GOA), the paleoenvironmental record reflects fluctuating marine conditions throughout the region. In the Kodiak archipelago in the Gulf of Alaska, changing environmental conditions, population growth, technological transitions, and contact with other communities likely promoted the transition from needs-based maritime hunting and gathering to surplus-based, semi-permanent villages. The precise role of climate in this transition is understudied. Few paleoclimate reconstructions are available for the Kodiak archipelago and climate reconstructions for the GOA are often insufficient for archaeological research because they lack sub-annual resolution and cannot produce a detailed understanding of seasonal behaviors in human populations.Analysis of shellfish remains from archaeological sites in the archipelago may provide additional paleoenvironmental information for the Gulf of Alaska. Measuring and comparing the length of seasonal shell growth in select species of bivalves may complement stable oxygen isotope analysis, together providing a more precise paleoclimate reconstruction. This research utilizes the growth of Saxidomus gigantea (also known as S. giganteus), abundant both on modern and ancient coastlines to provide information about the length of its growing seasons. To measure seasonality, a total of 25 modern samples were collected from Alaska and British Columbia and the number of lunar-daily growth increments (LDGI) was counted between annual winter growth bands confirmed by δ18O maxima measured in sinusoidal time series. Clams collected from Alaska grew a total of 143 ± 34 days while British Columbian clams grew 273 ± 14 days. δ18O values and the number of LDGI per year were then compared to previous studies along the Pacific Northwest coast. δ18O values were more positive from annual winter growth bands from Alaskan samples (average value of 1.0‰) than British Columbian samples (average value of −0.2‰). Maximum δ18O values from winter growth generally increased with latitude (R2 = 0.67), as did the number of LDGI per year (R2 = 0.74). Minimum δ18O values did not appear to be significantly related to latitude (R2 = 0.42).This method was then applied to three archaeological samples collected from the Rice Ridge site (KOD-363), the Uyak site (KOD-145), and the Settlement Point site (AFG-105) from the Kodiak archipelago, Alaska, which grew an average of 166 ± 22 days, to confirm that these methods can be applied to archaeological samples through time to detect spatial and temporal changes in seasonality. These results suggest that changes in sea surface conditions and seasonality are detectable both spatially and temporally through detailed sclerochronological and sclerochemical analysis of shellfish remains from archaeological sites and offer the potential to reconstruct marine environmental conditions throughout the Holocene.

New world paleoenvironments during the Last Glacial Maximum: Implications for habitable land area and human dispersal

The movement and dispersal of human populations during the Pleistocene is a complex question, and one that has been addressed extensively in the literature. During Pleistocene glacial periods, landscapes and coastlines altered dramatically, with old routes closing and new routes opening. One of the best understood of these glacial periods, the Last Glacial Maximum (between 22 and 18 ka), is of particular interest with regards to the colonization of the New World. Despite decades of study, archaeologists still do not fully understand the timing and tempo of that process. This study contributes to this discussion by presenting an estimation of habitable land area in the New World at the LGM when sea level was 120 m lower than present day using a previously published method for mapping ancient coastlines and calculating land areas in Google Earth. Areas defined as uninhabitable include those areas covered by ice sheets, glaciers, and ice fields, and areas of extreme aridity. Combined habitable land areas of North and South America are estimated as 34,149,094.81 km2. Added to data from the previous study, a new estimate of global habitable land area at the LGM is calculated to be 111,108,807.21 km2. Data on paleocoastlines are then used to predict locations where archaeological traces of early human dispersals may potentially be found.

Innovation and technology in marine science: AIMS' North West Shoals to Shore Research Program

The North West Shoals to Shore Research Program began in July 2017 and encompasses four themes, each of which addresses major gaps in scientific knowledge relevant to the environmental management of the offshore petroleum industry in north-west Australia. The themes are: 1. Marine Noise Monitoring and Impacts: investigate selected potential impacts of exposure to a seismic survey on demersal fishes and infauna across different spatial and temporal scales. 2. Benthic Habitats and Demersal Biodiversity: understand physical and biological characteristics of the Ancient Coastline Key Ecological Feature (125 m) and the ecological processes that maintain benthic communities from the ancient to contemporary coastlines, focusing on the distribution and genetic connectivity of pearl oysters. 3. Protected and Iconic Species Movement, Distribution and Threats: determine biologically important areas for pygmy blue whales and hawksbill and green turtles. This will lead to better quantification and mitigation of the risks to megafauna posed by vessel movements, industrial infrastructure and activities. 4. Spatial Dynamics of Isolated Coral Reef Atolls: developing a bio-physical model for benthic and fish communities at the Rowley Shoals and an adaptive monitoring program that quantifies and predicts their spatial dynamics. In this talk, we will discuss planning and progress of the program achieved to date, including innovative and technological approaches used to address scientific uncertainty currently faced by industry.