Strandplain Research Articles

Simulated CO2 storage efficiency factors for saline formations of various lithologies and depositional environments using new experimental relative permeability data

Saline formations are attractive geologic reservoirs for permanent carbon dioxide (CO2) storage. The U.S. Department of Energy's National Energy Technology Laboratory (DOE-NETL) has worked to develop and refine methods and tools for the calculation of CO2 storage potential in subsurface reservoirs. DOE-NETL's CO2-SCREEN provides an online tool for executing these storage methods. CO2 storage efficiency terms are input parameters in DOE-NETL's methods and equations embedded in the CO2-SCREEN, which assesses pore space available for CO2 storage. In this work, a modeling workflow was initiated to refine two CO2 storage efficiency terms - volumetric displacement (EV) and microscopic displacement (Ed). The models are based on new experimental relative permeability data that are specific to homogenous lithology and depositional environments of key subsurface saline formations targeted for CO2 storage. In future work, heterogenous features will be added to this initial modeling effort to update efficiency factors as described in DOE-NETL's methods and CO2-SCREEN tool. EVaccounts for the volume utilized in the reservoir under the areal plume, while Ed accounts for saturation values in the plume to assess efficiency of CO2 storage at the pore scale. The results of this work are significant in that prior values were based on a limited geologically non-specific relative permeability data set that were collected prior to 2009. Specifically, we applied numerical simulations using TOUGH3 models to update CO2 storage efficiency values for supercritical CO2 injection into brine-saturated reservoirs for three lithologies (clastics, limestone, dolomite) and six depositional environments (Marginal Marine, Strand Plain, Deltaic Complex Fluvial, Aeolian, Shallow Marine, and Reef) that have a high potential for geologic CO2 storage. Experimental relative permeability data in cores from these environments were utilized in the models with corresponding rock type/sedimentary environment. Results of this study showed that dolomite followed by limestone generated higher ranges of storage efficiency compared to clastics. The updated values provided a tighter efficiency range for clastics, lower P10 but higher P90 range for limestone, and higher P10 and P90 for dolomite. In general, tighter reservoirs with relatively low permeability and porosity were associated with higher EV and Ed, showing efficient reservoir and pore utilization in these scenarios. High reservoir pressure and temperature associated with increasing depth increased the EV, and high CO2 injection rates resulted in increases in EV and Ed, while the impact of permeability anisotropy was minimal after the 30-year injection period.

Ichnology and Sedimentology of the Lower Cretaceous Wabiskaw Member (Clearwater Formation) Alberta, Canada

Identifying facies and paleoenvironmental interpretation of the rock record is complicated due to the interplay of independent variables (i.e. wave-, river- and tidal-input) in marginal- and shallow-marine environments. This study integrates sedimentology and ichnology to characterize the depositional environments of the Lower Cretaceous Wabiskaw Member. The deltaic and strand plain shoreface-offshore deposits of Wabiskaw Member of Clearwater Formation of northeast Alberta provide an excellent case study to evaluate the ichnological and sedimentological characteristics associated with laterally and vertically variable stresses in wave-influenced nearshore settings. The Wabiskaw Member is studied using four sedimentary facies associations (Ten sedimentary facies). Facies association 1(FA-1) consists of massive, sharp-based mudstones and lenticular sandstone with small-scale soft-sediment deformation features, syneresis cracks and small-scale oscillation ripples. The ichnological suite mainly includes small grazing and deposit-feeding traces, representing the Phycosiphon Ichnofacies. Facies association 1(FA-1) is interpreted to record deposition in a prodeltaic setting. Facies association 2 (FA-2) is fine-to-medium-grained sandstone and thin mudstone with current, oscillation and combined flow ripples. The low angle and trough cross-beds, soft-sediment deformation structure, mud chips and coal debris are common. The trace fossil suite includes sporadically distributed deposit-feeding traces belonging to the Rosselia Ichnofacies. This facies association is interpreted to be deposited in the delta front to a mouth bar setting. Facies association 3 (FA-3) is gray to bluish-gray mudstone with minor sandstone interbeds (massive, planar parallel to hummocky cross-stratified). FA-3 is moderate to highly bioturbated. The ichnodiversity and abundance is high with dominant horizontal and subordinate vertical traces, including the dominance of deposit and detritus feeding traces representing the archetypal Cruziana Ichnofacies ichnological suite. Facies association 3 (FA-3) is interpreted as being deposited in a storm-influenced offshore environment. Facies association 4 (FA-4) is upper fine to fine-grained glauconitic sandstone with minor mudstone interbeds at the base. Physical sedimentary structures including massive and planar (horizontal and low angle), hummocky, and swaley crossing-stratification. FA-4 is heavily burrowed with a diverse suite of horizontal and vertical traces of deposit and detritus-feeding structures, representing a proximal expression of Cruziana Ichnofacies. Facies association 4 (FA-4) represents distal lower to middle shoreface deposition. The Wabiskaw Member deltaic (prodelta-delta front) deposits, producing characteristic sedimentological-ichnological signatures, distinguishing these deposits from related strand plains. In addition to characteristic deltaic traits (e.g. soft-sediment deformation structures, fluid mud and syneresis cracks), these deposits commonly contain comparably stressed low-diversity and diminutive trace-fossil suites. On the other hand, fully marine strand plain shoreface-offshore complexes are characterized by comparably robust trace fossils with high ichno-diversity and bioturbation intensities.

Natural and Cultural Lost Landscape during the Holocene along the Central Tyrrhenian Coast (Italy)

Landscape evolution over the last 8000 years in three areas located along Tuscany, Latium, and Campania coasts (central Tyrrhenian) has been deduced through a morphological, stratigraphical, and historical approach considering the physical evolution and human activity. Between 8000 and 6000 yr BP, the Sea Level Rise (SLR) dominated and, near the river mouths, inlets occurred. In the Tuscany area, Mt. Argentario was an island and to SE of the Ansedonia promontory a lagoon occurred. The areas were covered by a dense forest and the human influence was negligible. Between 6000 and 4000 yr BP, humans organized settlements and activities, and a general coastline progradation occurred. A tombolo linked Mt. Argentario to the mainland. In the Tiber and Campania areas, coastal lakes and a strand plain developed. Between 4000 and 3000 yr BP, near Mt. Argentario, two tombolos enclosed a wide lagoon. At the SE of the Ansedonia promontory, the lagoon split into smaller water bodies. In the Tiber and Campania areas, delta cusps developed. The anthropogenic presence was widespread and forests decreased. During the last 3000 years, anthropic forcing increased when the Etruscans and Romans changed the territory through towns, salt pans, and ports. After the Roman period, natural forcing returned to dominate until the birth of the Italian State and technological evolution.

First report of the Southern Gulf Coast Toad (Incilius valliceps Wiegmann), Common House Gecko (Hemidactylus frenatus Duméril and Bibron), Schmidt’s Black-Striped Snake (Coniophanes schmidti Bailey), and Cozumel Whiptail (Aspidoscelis cozumela Gadow), on Turneffe Atoll, Belize

Each year from 2012 to 2019, during a 12-day period in November or December, we photographed common herpetofauna on Calabash Caye, a small mangrove-dominated island on the eastern edge of Turneffe Atoll, Belize. Turneffe Atoll is home to the newest, largest, and most biodiverse marine protected area in Belize. Calabash Caye exemplifies the islands on Turneffe’s eastern edge whose elevated beach ridges enable the development of coastal strand plain and littoral forest habitats, which are among the most threatened habitats in the world. As no herpetofaunal survey has been published for Turneffe in over twenty years, and as the herpetofauna is a conspicuous indicator of the health of terrestrial ecological communities on islands, we leveraged our annual field excursions to Calabash Caye to compile a photographic record of the island’s reptiles and amphibians. In multiple years, we documented the presence of five lizards (Anolis sagrei mayensis, Aspidoscelis cozumela, Ctenosaura similis, Phyllodactylus tuberculosus, and the invasive species Hemidactylus frenatus), three snakes (Boa imperator, Leptophis mexicanus hoeversi, and Coniophanes schmidti), and one amphibian (Incilius valliceps). This represents the first report of A. cozumela, H. frenatus, C. schmidti, and I. valliceps on Calabash Caye or on any island in Turneffe Atoll; H. frenatus, C. schmidti, and I. valliceps have never been reported on any of the Belizean cayes. We did not observe four species that have previously been reported on Calabash Caye: Brown Basilisk (Basiliscus vittatus), Mesoamerican Cane Toad (Rhinella horribilis), Mayan Skink (Marisora lineola; formerly Mabuya unimarginata), or a blindsnake, provisionally identified as Indotyphlops braminus. We also include photos of Anolis allisoni, Ctenosaura similis, and Anolis sagrei mayensis obtained during four single-day excursions to Half Moon Caye on Lighthouse Atoll; this represents three of four species reported from that location during the 1990s.

Geomorphological sedimentary characteristics in the coastal area of Ma river delta, Thanh Hoa province

The coastal area of the Ma river delta is formed by the interaction of continental and marine processes, between neo-tectonic activities and exogenous processes, between natural factors and human activities during the Late Holocene. Using remote sensing and geoscience research methods (granulometry, paleontology, geochemistry, clay mineralogy) and geomorphological studies (geneses, morphology, dynamics) combined with field survey, this coastal area, except the denuded mountainous remnants, could be distinguished into 12 morpho-sedimentary units formed and developed by the dynamic interactions of the river, waves and tides. The units formed by fluvial dynamics include: 1) Point bar is composed of clayey silt and sandy silt, 2) Channel bar composed of silty sand, 3) Levee with the composition of silty sand and 4) The flood plain of silty clay. The Late Holocene evolution of the Ma river delta was dominated by wave dynamics, reflected by a wave-formed association of dunes, interdune swamps and current sand beaches. The wave-formed units include 5) Dune’s sand and silty sand, 6) Back-dune depressions composed of sand silt clay, 7) Beach composed of sand, 8) Lagoon plain of silty clay and 9) Strand plain composed of silty sand. The tide-influenced units include 10) Supratidal flat with the composition of silty clay, 11) Intertidal flat characterized by clay or silty clay interbedded with thin fine sand or silty sand layers, 12) Subtidal flat of sand and silty sand.

Verification of the 1703 CE Genroku Kanto earthquake tsunami at Katakai Village, Kujukurihama Strand Plain, using the historical and geological records

Verification of the 1703 CE Genroku Kanto earthquake tsunami at Katakai Village, Kujukurihama Strand Plain, using the historical and geological records

Signatures of late Quaternary land-sea interactions and landform dynamics along southern Kerala coast, SW India

The Kerala coast displays a spectrum of varied geomorphic features that are evolved as a function of Late Quaternary land-sea interaction. The southern Kerala coast, south of Achankovil Shear Zone (ASZ) has been characterised by cliffed coast with entrenched estuarine basins, pocket beaches, promontories, older and younger strand plains, etc., that are evolved as a result of the transgressive-regressive phases to which the coast has been subjected during the late Quaternary Period. In spite of having varied geomorphic features, lacuna in comprehending the evolutionary phases of the coastal landform features is the primary impediment that bolstered us to unravel the Late Quaternary land-sea interactions and landform changes of the coast between Thottapally and Vizhinjam. Moreover, the last two centuries are known to have been witnessing many natural as well as human induced environmental perturbations in the area.The present study attempts to reconstruct the late Quaternary landform dynamics based on the satellite data while the last century changes were extracted from the Digital Shoreline Analysis System (DSAS). The evidences based on geomorphic variations suggest that the present study area hosts two distinct paleo-coastlines – 1) coincides with the eastern boundary of the older strand plains (accreted during Late Pleistocene) and, 2) marks the boundary between older and younger strand plains (accreted during Early–Middle Holocene). A sector-wise analysis reveals that the northern half of the study area is characterised by many coast perpendicular estuarine basins with well-developed Bay Head Deltas in its fluvial end, and Flood Tide Islands near the estuarine mouth. On the contrary, the southern half is characterised by pocket beaches and coast parallel backwater bodies developed during the regressive phases of the sea. A high-resolution study of the shoreline changes during the period, 1920–2018 reveals that the younger strandlines are vulnerable to severe coastal erosion and shoreline retreat at many places compared to coastal accretion. The study stresses the imminent need for continuous monitoring and implementation of site-specific mitigation measures for the conservation and management of this coast known for its outstanding natural beauty and strategic beach placer deposits.

Coseismic coastal subsidence associated with unusually wide rupture of prehistoric earthquakes on the Kamchatka subduction zone: A record in buried erosional scarps and tsunami deposits

The prograding strand plain of Avachinsky Bay, Kamchatka, Russia, along the highly active Kamchatka subduction zone, exhibits geological evidence--buried erosional scarps--for coseismic subsidence only three times in the last four millennia, the last event about 1200 years ago. This same coast has a historical record (since A.D. 1737) of five subduction-zone earthquakes with large tsunami runup (>5 m), the last of which was the 1952 Mw 9 Kamchatka earthquake, and a geological record of more than 30 large tsunamis in the last 4000 years. This rarity of buried scarps relative to large earthquakes contrasts with the Cascadia strand plain in SW Washington State, where most or all large events are represented by buried scarps. A strong factor in the amplitude and sign of coseismic deformation is distance from the seaward edge of a subduction zone (the trench); the Avachinsky Bay coastline is 180–200 km from the trench, with ∼25° slab dip, requiring unusually wide ruptures to generate significant coseismic subsidence. This coastal zone is undergoing net subsidence approximately equivalent to the total of the three coseismic subsidence events, generating a sequence of beach ridges that increase in elevation seaward.Each of the three unusual (coseismic subsidence) events comprises a) an earthquake whose deformation field caused b) onshore coseismic subsidence, thus local sea-level rise and c) sufficient deformation offshore to produce a large tsunami; a,b,c followed by d) a period of coastal erosion and shoreline retreat, leaving e) an erosional beach scarp that was f) subsequently buried once progradation resumed. We identified, dated and correlated the scarps and tsunami deposits from these events with several field methods, including trenching, tephrostratigraphy and ground penetrating radar. The scarps were correlated over an alongshore distance of 50–70 km. The most recent event (event 1) occurred ∼800 cal AD (1100–1250 14С years BP), event 2–600 cal BC (2400–2450 14С years BP), and event 3–1700 cal BC (3300–3500 14С years BP). We developed methods for quantifying subsidence, coastal erosion and tsunami size for each of these events. All three retain evidence of ∼0.4–1.2 m of coseismic subsidence; coastal erosion in the case of event 1 averaged more than 100 m; all three “event” tsunamis were amongst the largest in the last 4000 years.

Tsunami deposits refine great earthquake rupture extent and recurrence over the past 1300 years along the Nankai and Tokai fault segments of the Nankai Trough, Japan

Study of prehistoric to medieval-age tsunami deposits along a riverbank site near the eastern Nankai Trough, central Japan, show that, not only did Tokai earthquakes occur with a higher frequency than previously thought, but that contemporaneous ruptures of the Tokai and Nankai fault segments were also more common. The site revealed a ∼1-km long coast-normal cross section of the strand plain and exposed four sandy tsunami deposits, each of which indicates inundation over 2 km inland of the coast. Radiocarbon dating of previously studied and newly discovered deposits in the region indicates a shorter recurrence time for Tokai earthquakes and clarifies their linkage with Nankai earthquakes. We attribute the younger two tsunami deposits to the 1498 and 1096 CE Tokai earthquakes. The older two deposits confirm the occurrence of the Tokai earthquakes in 887 CE and in the latest 7th century. These events are not reliably recorded in historical documents in the Tokai region but were noted in the Nankai area. The 887 CE earthquake likely represents a full-length rupture of the Tokai and Nankai segments, as was the case for the 1707 CE earthquake. Integrated with the previous studies, these new results show that nine Tokai earthquakes occurred over the last 1300 years, the oldest in the latest 7th century, and in 887, 1096, 1361, 1498, 1614, 1707, 1854 and 1944 CE. Recalculated recurrence intervals range from 90 to 265 years. Except for the 1498 Meio Tokai earthquake, the Tokai earthquakes occurred simultaneously with Nankai earthquakes.

From the strand plain to the reef: A sedimentological–geomorphological study of a Holocene coast affected by mud diapirism (Archipélago Rosario- Barú, Colombia)

The Archipélago Rosario-Barú evolved off-shore of the Caribbean Coast in N Colombia during the Holocene. From the geodynamic point of view its host rocks belong to the rather stable foreland of the modern Andean fold belt, from the sedimentological point of view the environment has, however, to be ranked among the highly mobile zones. The swiftly rising orogen in the hinderland triggered a huge amount of sediment load that is very rapidly dumped at the end of the river run in wave-induced deltas which subsequently were reworked into large barrier sands along the Caribbean Coast. The modern terrigenous sedimentation in context with a pervasive neotectonic faulting along deep-seated lineaments contributed to the instability of the clastic substrate and sparked mud diapirism which is accountable for the built-up and destruction of the cays and reefs of the Archipélago Rosario-Barú. Mineralogical, chemical, paleontological, and sedimentological studies were combined with radio‑carbon dating to decipher the stepwise evolution of the archipelago and applied in a catena-like approach covering the entire sequence from the onshore strand plain to the offshore reef. The impact of the mud diapirism is indicated by marker minerals such as smectite and chlorite, and displays a set of typical chemical features in the base metal contents and the stable carbon and oxygen isotopes straddling around zero. All of these characteristics point to a deep-seated basic source of the fluids vented as a slurry along lineamentary zones. The actuogeological study of these sites rife with mud volcanoes can be taken on one hand as a modern equivalent to ancient limestone-hosted Cu deposits and on the other hand use as a replica of ancient salt deposit undergoing halokinetic processes as far as the petrophysical processes are concerned.

Carbon fluxes and stocks in a carbonate-rich chenier plain

Coastal wetlands play an important role in the global carbon cycle because they have high ecosystem productivity and carbon sequestration capability. Previous research focused on the carbon dynamics of organic-rich ecosystems (e.g., salt marshes, mangroves), while little attention has paid to the carbon cycling of carbonate-rich ecosystems such as chenier plains, sandy or shelly beach ridges that are parts of strand plains. Here we examined the carbon stocks and fluxes of the poorly studied chenier plain in the Yellow River Delta, China. The inorganic and organic carbon pools in the top 1 m sediment were 444 ± 92 Mg C ha−1 and 89 ± 7 Mg C ha−1, respectively. The average CO2 net sequestration was −177 ± 51 Mg C ha−1, indicating that the chenier plain had a net CO2 evasion during the entire soil formation process. With plant growth, however, the chenier plain provided a significant carbon sink (395 g C m−2 a−1) on a per-unit area basis. The annual gross ecosystem productivity (GEP) and ecosystem respiration (Re) were 1067 and 672 g C m−2 a−1, respectively. The carbon sink strength of the chenier plain was comparable to that of organic-rich salt marshes on a per-unit area basis. The biomass carbon pool was 5.0 ± 1.4 Mg C ha−1 in the chenier plain. Moreover, the sediment inorganic carbon content in mudflats was significantly lower than that of vegetated habitats. Our results showed that plant grown in a chenier plain could significantly enhance carbon sequestration by increasing organic carbon storage. Inorganic carbon storage should be considered in blue carbon inventories because inorganic carbon dominates the carbon pool and is important in the carbon cycling in a chenier plain. Our findings can help us better understand the carbon cycling of carbonate-rich coastal ecosystems and can inform chenier plain conservation and restoration efforts.

Coastal barriers, northern Gulf - Last Eustatic Cycle; genetic categories and development contrasts. A review

A large body of chronologically well-constrained and detailed Quaternary data accumulated in the last decades from the coastal-shelf region of the northern Gulf of Mexico. Consequently, a preliminary synthesis of major aspects of the late Quaternary barrier and mainland coastal development on the northern Gulf of Mexico is timely. Several major factors account for the striking differences between barrier size and development styles in the three northern Gulf coast regions. Barriers are nearly continuous in the NW where they dominate by the greatest dimensions and continuity. Sand supply from shelf and mainland sources, continued at variable rates throughout six stages of the Last Eustatic Cycle (LEC). Differences in antecedent topography, in fluvial runoff volumes and relative sea level rise, including rapid overstepping-flooding events were critical in the regional distinctions. Leaving fewer and smaller relict fluvial delta behind, drowned shore and nearshore landforms on the shelf, only two large fluvial systems impacted the NE. The NW shelf and nearshore received abundant sediment supply from the Mississippi and lesser streams; indirectly by ravinement erosion of relict landforms and landward-directed cross-shelf sediment transfer. Sands originated mainly in relict deltas, fluvial, tidal channel, and inlet fill, as well as from submerged shore ridge remnants on the continental shelf. Shelf-margin deltas represented major secondary sources. Barrier formation categories and their respective importance in specific areas represent critical aspects of coastal development. The authorship of various formation concepts (e.g., Penck, Gilbert, McGee, Haage, Ganong, and Keilhack) often is still miscredited or remains unrecognized in the literature. Recognition of the stratigraphic and sedimentological diagnostic characteristics of the basic genetic barrier categories plays a key role in testing the validity of barrier evolution models.Closely-knit process-form relationships prevail between hydrodynamic (sea level change, storm, tidal current, overwash), sedimentary (shoal and island aggradation, rollover, and eolian accumulation) processes, and the resulting landform morphology. The most detailed accounts that deal with the development of the Alabama-Louisiana and Apalachicola barrier chains are particularly instructive. Almost all modern Gulf barriers with identifiable genetic background formed by shoal aggradation between 5.5 and 2.0 ka, during a marked deceleration in sea level rise. Concurrently, a sizable mainland strand plain complex extended the NE coastal plain. Tide- and storm-driven sediment transport to the large Mobile Bay ebb-delta, the focal role of composite east Dauphin Island in establishing the MS-LA island chain and the island-blocking role of Mississippi Delta advance were prime factors in a complex barrier history. Migration, paradoxically, may also occur by transgressive rollover concurrently with regressive landward progradation of island strand plains. Stream discharge and sand reworked from relict lithosomes on the shelf were insufficient in compensating for wave- and tide-related sediment loss. Gulf levels stayed below the present throughout the mid- and late Holocene.

Beach ridge sets reflect the late Holocene evolution of the St Lucia estuarine lake system, South Africa

Sets of sandy beach ridges and intervening swales define shoreline sections of the shallow St Lucia wetland system within the iSimangaliso Wetland Park, World Heritage Site in northern KwaZulu-Natal province, South Africa. The sets comprise 3–10 beach ridges, the most prominent being 80–150 m wide and rising 0.5–2 m above the adjacent swales. The highest beach ridge crests elevated 3.2–4.6 m above mean sea level are furthest from the present shoreline and the lowest ridges, rising about 0.5 m above the swales, occur closest to the present mean lake level shoreline. This investigation assesses the genesis of the sandy beach ridges on five strand plain remnants within the estuarine lake. The ridges were topographically surveyed and their ages estimated using optically stimulated luminescence (OSL) dating. OSL dating reveals that the oldest beach ridge formed around 6240 years ago, with a sequence of beach ridges having accumulated during the period ~4000 to 1500 years ago reflecting coeval accretion around the lake. The present mean lake level shoreline was only reached within the past ~600 years. Sedimentation changed from marine-dominated to lacustrine deposition in the estuary during the period of beach ridge accretion. The dated beach ridges, supported by new radiocarbon dates of fixed biological indicators from Holocene intertidal zone settings on the coast, are used with published sea-level curves to set the context of periodic beach ridge accretion in the marine-linked estuarine lake. The dated ridges suggest that episodic regression of the estuarine lake shoreline occurred after a mid-Holocene sea-level highstand. The record of sea-level change is also reflected by the long-term natural shrinking and shallowing of the proto-St Lucia lagoon/estuarine lake in the context of reduced marine influences due to closure of former marine channels by progressive barrier dune accretion. The sequence of coeval beach ridges reflects a pulsed lowering of relative sea-level in the shallowing estuarine lake. Height differences between the coeval ridges at sites around the lake reflect local environmental controls including the range of wind fetch distances across shallow lake compartments, wave height and wind-induced seiche effects.

Late Quaternary depositional sequences and landforms in relation to sea-level changes in the Osaka intra-arc basin, Japan: A borehole database analysis

Development of Late Quaternary depositional sequences in the Osaka intra-arc basin was reconstructed, based on the analysis of sequence stratigraphy and new “Shazam stratigraphy”, using numerous and high-density borehole data. The latest Pleistocene to Holocene sequence (I) and the lower late Pleistocene sequence (II) underwent several significant phases: 1) formation of alluvial fans and terraces during regression from marine isotope stage (MIS) 5 to MIS 2; 2) formation of a boundary between the two sequences during rapid sea-level fall of ca. 30–20 ka; 3) development of ravinement surfaces by wave and tidal erosion during the transgression from MIS 2 to MIS 1; 4) development of barrier systems and coastal cliffs during the transgression to the maximum high-stand of 6–5 ka; and 5) progradation of alluvial fans, deltas and strand plains during the high-stand since 5 ka. Depositional facies and systems of the two sequences are different among the western study area around Kobe, the central area with the Nishinomiya-Amagasaki lowland, and the eastern area with the Osaka plain, due to differences in sediment flux, wave, tide, shore current, basement and landforms distribution such as plateau and hills. Development of the sequence II could be also affected by tectonic differences, which fault, fold structure, and flexure. Three regions with different landforms and depositional systems were identified within the Osaka basin. The systems of the three regions correspond to the three major types of the latest Pleistocene to Holocene transgressive/regressive depositional sequences and alluvial plains recognized in Japan.

Middle-to late-Holocene environmental changes in the Garigliano delta plain (Central Italy): which landscape witnessed the development of the Minturnae Roman colony?

Geomorphologic, stratigraphic, faunistic, palynological and 14C analyses were carried out in the area of the mouth of the Garigliano River characterized by two strand plains that are referred to the Eutyrrhenian and the Holocene, rimming two depressed zones separated by the Garigliano River channel. This study depicts the palaeoenvironmental evolution over the last 8200 years and the landscape context at the time of Minturnae Roman colony. Between 8200 and 7500 yr BP, a wet zone occurred in the northern zone, whereas in the southern part, a lagoon developed. During the final transgression stage and the beginning of the sea level still stand (7500–5500 yr BP), a freshwater marsh formed in the northern zone, and the width of the southern lagoon decreased. Between 5500 and 3000 yr BP, the coastal barrier changed into a delta cusp, a freshwater marsh also appeared in the southern part and the river wandered between the twin marshes. Because of local uplift, previously unknown in this area, part of the floor of the southern marsh emerged, and after 4000 yr BP, both marshes became coastal ponds with prevailing clastic sedimentation. A progressive increment in anthropic forcing on the land took place after 3000 yr BP. The Marica sanctuary was built (7th century BC), and the Roman colony of Minturnae was developed beginning the 3rd century BC. The shallow depth of the ponds prevented their use as harbours, and saltwork plants can be ruled out based on the faunal and palynological data. The ongoing infilling of both ponds was never completed, and their reclamation is still in progress.

Beach erosion under rising sea‐level modulated by coastal geomorphology and sediment availability on carbonate reef‐fringed island coasts

AbstractThis study addresses gaps in understanding the relative roles of sea‐level change, coastal geomorphology and sediment availability in driving beach erosion at the scale of individual beaches. Patterns of historical shoreline change are examined for spatial relationships to geomorphology and for temporal relationships to late‐Holocene and modern sea‐level change. The study area shoreline on the north‐east coast of Oahu, Hawaii, is characterized by a series of kilometre‐long beaches with repeated headland‐embayed morphology fronted by a carbonate fringing reef. The beaches are the seaward edge of a carbonate sand‐rich coastal strand plain, a common morphological setting in tectonically stable tropical island coasts. Multiple lines of geological evidence indicate that the strand plain prograded atop a fringing reef platform during a period of late‐Holocene sea‐level fall. Analysis of historical shoreline changes indicates an overall trend of erosion (shoreline recession) along headland sections of beach and an overall trend of stable to accreting beaches along adjoining embayed sections. Eighty‐eight per cent of headland beaches eroded over the past century at an average rate of −0·12 ± 0·03 m yr−1. In contrast, 56% of embayed beaches accreted at an average rate of 0·04 ± 0·03 m yr−1. Given over a century of global (and local) sea‐level rise, the data indicate that embayed beaches are showing remarkable resiliency. The pattern of headland beach erosion and stable to accreting embayments suggests a shift from accretion to erosion particular to the headland beaches with the initiation of modern sea‐level rise. These results emphasize the need to account for localized variations in beach erosion related to geomorphology and alongshore sediment transport in attempting to forecast future shoreline change under increasing sea‐level rise.

浜松平野西部における完新世後期の浜堤列の地形発達過程

浜松平野西部における完新世後期の浜堤列の地形発達過程

Elevation Trends in Wide Beach-Ridge Systems Retrieved from Landsat Images and the SRTM Digital Surface Model

ABSTRACT Sander, L.; Raniolo, L.A.; Alberdi, E., and Pejrup, M., 2015. Elevation trends in wide beach-ridge systems retrieved from Landsat images and the SRTM digital surface model. Beach-ridge systems are a common feature of prograding coastlines and they have been recognized as important archives of late Quaternary sea level. In this paper, the combination of Landsat images and shuttle radar topography mission (SRTM) surface model data is shown to provide a solid base to assess gross elevational trends in wide beach-ridge systems. The tilt of a strand plain is a useful first indication to assess possible scenarios of long-term relative sea-level development at new field sites. We identified morphological landscape units for a large and complex coastal lagoon system in NE Patagonia (Argentina) on the basis of a series of Landsat satellite images. A good correlation (R2 = 0.92) was found for the comparison of high-resolution GPS data with the extracted corresponding SRTM elevations of a 3.8-km-long transe...

Water level history for Lake Turkana, Kenya in the past 15,000 years and a variable transition from the African Humid Period to Holocene aridity

Relict beaches adjacent to Lake Turkana, Kenya provide a record of water level variability for the Late Quaternary. This study focused on deciphering the geomorphology, sedimentology, stratigraphy and 14C chronology of strand plain sequences in the Kalokol and Lothagam areas, at the western margin of the Lake. Nine >30m oscillations in water level were documented between ca. 15 and 4ka. The earliest lake level oscillation between ca. 14.5 and 13ka is not well constrained with water level to at least 70m above the present surface and subsequently fell to at least 50m. Lake level increased to at least 90m between ca. 11.2 and 10.4ka, post Younger Dryas cooling. Water level fell by >30m by 10.2ka, with another potential rise at ca. 8.5ka to >70m above current level. Lake level regressed by >40m at 8.2ka coincident with cooling in the equatorial eastern Atlantic Ocean. Two major >70m lake level oscillations centered at 6.6 and 5.2ka may reflect enhanced convection with warmer sea surface temperatures in the western Indian Ocean. The termination of the African Humid Period occurred from ca. 8.0 to 4.5ka and is characterized by highly variable lake level (±>40m), rather than one monotonic fall in water level. This lake level variability reflects a complex response to variations in the extent and intensity of the East and West African Monsoons near geographic and topographic limits within the catchment of Lake Turkana. Also, for this closed lake basin excesses and deficits in water input are amplified with a cascading lake effect in the East African Rift Valley and through the Chew Bahir Basin. The final regression from a high stand of >90m above the present lake began at 5.2ka and water level was below 20m by 4.5ka; and for the remainder of the Holocene. This sustained low stand is associated with weakening of the West African Monsoon, a shift of the mean position of Congo Air Boundary west of the Lake Turkana catchment and with meter-scale variability in lake level linked to Walker circulation across the Indian Ocean.

Control of Late Holocene Geo-processes on the sustainable development plans of the Tineh Plain, NW Sinai coast, Egypt

The Tineh Plain NW Sinai coast has been the subjected of several studies related to its stratigraphy, geoarchaeology, and sustainable development. Recently, the name of the Tineh Plain has emerged following the government of Egypt’s decision to establish a new economic project to develop the Suez Canal Sector (Suez Canal Corridor Mega Project). Landsat and SPOT satellite images acquired for years 1984, 2000, 2006, 2008 and 2010 to detect temporal changes coupled with field relations, verification, sampling, analyzing and photographing were conducted. Change detection of LU/LC show six classes; the beach, the wetland (El-Mallaha lagoon), Sabkhas or salt marshes, urban, agriculture, and fish breeding farms. In 1984, the beach (4.2 km2), El-Mallaha lagoon (26.4 km2), sabkhas or salt marches (236.7 km2) were reduced due to expansion of agriculture (120.3 km2), fish breeding farms (35.7 km2) and controlled by sediment characteristic (salinity and grain size). Accordingly, fish farms grow northward of the Tineh Plain while reclamation and cultivation extends southward. Such activities may threaten the archaeological sits at Tell El-Farama (The City of Pelusium). Three geomorphic units detected, these are the beach, the strand plain, and the deltaic plain. The beach is flat with concavo (accreted) - convex (eroded) shoreline. The strand plain made of accreted beach ridges of very low bundles, set at slight mutual angles, which sometimes truncate one another. The deltaic plain surface composed of intercalations of sand and mud of shoreface, mouth bar, and distributary channel fill. The accreted ridges representing four paleoshorelines related to Late Holocene and dated back to 400–500BP, 1100–1200BP, 1400–1500BP, and 1700–1900BP, those record the Late Holocene history (sea level, floods, and tectonics) of the Tineh Plain. The study area is waiting a plan of sustainable development, it represents phase “A” East Port Said of the Suez Canal Corridor Mega Project. This study raise the alarm of constructing heavy industries and other logistics related to shipping on the fragile environments of the Tineh Plain. This is in fact due to active tectonism, and sediment characteristics. The activities related to agriculture, fish breeding, and salts and food industries are recommended in the framework of sustainable development. It is important to include the Suez Canal Corridor Project a plan to save the ruins of fortifications of Tineh Plain. These are not only Egyptian heritage but also a world one record the history from the Persian invasions of Egypt about 6th or 7th Century B.C., through the Byzantines in 859–860, the Greeks in 954–955, the Arabic Conquest, and the Crusaders in the 12th Century. A cooperation and support from the international organization such as UNESCO should be conducted.