Sedimentary Features Research Articles

Late Pleistocene Climatic Changes in Central Brazil Indicated by Freshwater Sponges

The Cemiterio Palaeolake deposit in Catalao, Goias State, Brazil, comprises a single, complete lacustrine sequence, dated from less than 27,500 ± 4000 yr B.P. to more than 51,780 ± 400 14C yr B.P. The unprecedented presence of spongillite and diatomite layers in this deposit was investigated using spicules of continental sponges as proxy data for environmental and climate reconstruction, which was relatively extensive for the ages examined. From the analysis of the sedimentary features and the associations of spicules preserved in the deposit, it was possible to reconstruct the evolution of the limnic system. Five developmental stages were thus identified, corresponding to the installation (lotic and erosion phase), establishment and development of the lake and its colmatation, the latter correlating to the Last Glacial Maximum (LGM). Moreover, based on the ecological requirements of the sponge species identified in the deposit, it was possible to infer the likely weather patterns related to respective phases of the lake. The presence of the sponge species Corvoheteromeyenia australis, presently recorded only from southern South America, indicated that polar incursions originating from the Antarctic were frequent during the last glacial period and might have played a notable role in what is now central Brazil. However, for a short time, drier and hotter weather conditions might have predominated, as suggested by the presence of the species Corvomeyenia thumi.

云南昭通中新世晚期生物地层化学元素的组合特征及古埋藏环境分析

文中对云南昭通市昭阳区水塘坝中新世晚期湖沼相沉积地层昭通组剖面11层含化石层逐层共采集16件分析样品，并采用电感耦合等离子体原子发射光谱法对样品中与生物体生存关系密切的19种元素进行了测试。根据分析数据同时结合生物地球化学理论推断得出：昭通地区中新世晚期沉积盆地大量不同种类动物化石丰富埋藏极有可能是因这些动物长期通过食物、饮水等途径，将铬、锶元素摄入动物体内并不断累积，从而造成生物体内铬、锶元素的高异常含量，长期作用导致动物正常的生理机能发生紊乱，故而在此大规模的埋藏保存。此外，依据元素的化学组成特征和化石层沉积环境的分析，认为该地区中新世晚期应该属于流水较弱的湖泊沼泽地带，以及滨湖相环境，气候条件曾经历了由较温暖潮湿向逐渐干燥转变的过程。We collected 16 samples from the 11 fossiliferous layers respectively within Zhaotong Formation in Shuitangba, representing the late Miocene lacustrine deposits of Shaoyang District, Zhaotong Yunnan. 19 biogenic elements were analyzed from these samples using ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry). Based on the biogeochemical theory, the results indicate the potential reason of the abundant vertebrate fossil assemblages preserved in the basin during latest Miocene. Chromium and strontium were ingested through food and water by the animals inhabited around; the two elements reached in a high abnormal level in organism by long term accumulation, caused the physiological function disorder of these animals and finally led to the regional faunal extinction. In addition, according to the characteristics of the chemical compo- sition and the sedimentary features of the fossiliferous beds, the paleoenvironment of the region was considered as lakes, swamps or off-shore lake with low hydrodynamic condition; climate also experienced the gradual shift from humid and warm to dry condition during latest Miocene.

Río de la Plata inner estuary (Argentina): main forms, sedimentary infill and Holocene evolution

Abstract The emerged part of the Río de la Plata estuary is characterized by striking coastal geomorphic features. Aerial and satellite images, field observations of the outcrops, shallow boreholes, radiometric dating of sand and shells and Ground Penetrating Radar surveys were analysed. The main sedimentary features are: a large coastal barrier (up of 220 km long), old coastal lagoons, attached beach ridge (about 210) sets distributed along 170 km, the Ibicuy sand body variously interpreted as a reworked shoal/island or delta, and cheniers. The tidal flats and the modern Paraná Delta are located in the centre and on the right side of the inner estuary. The height of the estuarine coastal barrier represents the maximum flooding surface (MFS) of the last transgression at about 6000 aBP. Other main sedimentary forms developed as a falling stage systems tract (FSST) during the sea-level drop between the aforementioned date and the present. The sea surface was about 5 m above sea-level in the inner part of the estuary during the middle-Holocene. This MFS was subsequently followed by a continuous and slow sea-level fall that controlled the generation of the large sedimentary forms developed in the innermost part of the Río de la Plata Estuary.

Литолого - геофизические свойства сланцевых пород с повышенным содержание керогена

The key features of unconventional shale hydrocarbon accumulations include the following: a) all source rocks act as low permeability oil and gas res-ervoir rocks requiring no cover rock; b) effective pore space is distributed within the bulk of mature kerogen resulting from katagenetic transformations in organic material. Evaluating the properties of reservoir rocks with a high content of kerogen attracts a lot of interest due to new approaches to unconven-tional hydrocarbon exploration and the challenge of applying the technology of hydraulic fracturing in low-permeability formations. This research into the lithological and physical properties of facies with a high kerogen content was prompted by a correlation between the sedimentary features of the proven productive shale formations and similar formations of different ages in the Dnieper-Donets basin. The sedimen-tary conditions of shale formation in DDb being similar to those of forming oil and gas producing shales with a high content of kerogen in Utica/Point Pleasant paleobasins, the highest kerogen content was assumed to be associated with certain lithotypes holding interest for further study. Mathematical equations were derived to describe the correlation between radioactivity, uranium content, bulk density, electrical resistivity and organic carbon content for shales from the Utica formation and the DDb shales. There were clarified mathematical dependences of bulk density on organic carbon content for a number of Lower Carboniferous formations in DDb. As using separate mathematical expressions is likely to pro-duce results of doubtful validity, preference should be given to a system of equations to describe the nature of changes in different physical prop-erties of shales depending on the organic component content. That will provide accurate data on the share of kerogen in the studied reservoir rocks. Values of hydrogen and oxygen indices only predict low molecular weight products and their subsequent extraction. The findings on the lithological properties and mathematical relationships have been reported and discussed at international conferences.

Sand Transport and Sedimentary Features Based on Feldspar Thermoluminescence: A Synthesis of the Tenryu–Enshunada Fluvial System, Japan

Liu, H.; Takagawa, T., and Sato, S., 2014. Sand transport and sedimentary features based on feldspar thermoluminescence: a synthesis of the Tenryu–Enshunada fluvial system, Japan. On the basis of the feldspar thermoluminescence (TL) measurement, sediment transport features were investigated in the entire Tenryu River watershed and the corresponding littoral sediment zone of the Enshunada coast. Subsequently, the sedimentary configuration and sand provenance in the river mouth area were studied using subsurface samples. In the Tenryu River watershed, TL intensities of the riverine samples fluctuated with respect to the local geological characteristics. Comparing with samples collected from the main river route, branch samples generally present larger TL intensities. Nevertheless, sediment supply from branches is considered to be rather limited in terms of their small discharges. Increase in the riverine TL property can be detected in the immediate dam downstream area, as well as the region with mass sand movements. Taking into account the Enshunada coastal samples, measured sediment TL intensities present a local peak value around the river mouth and a decreasing trend with the increasing distance away from the river mouth. This is attributed to the river sand supply and the gradual sunlight exposure during the longshore sediment transport. In general, riverine samples present much larger TL intensities than coastal samples, and a criterion on the basis of a TL intensity value of 5 was recognized to distinguish these two types of sands in the study area. Applying this criterion to the subsurface samples collected in the river mouth sand spit, a sedimentary interface at Tokyo Peil −1 m was confirmed with coastal sands (small TL intensity with wave experience) located on the top and riverine sands (large TL intensity without wave experience) deposited at the bottom, which is in agreement with estimations from other physical and geomorphological approaches.

Evidence of Repeated Wildfires Prior to Human Occupation on San Nicolas Island, California

Understanding how early humans on the California Channel Islands might have changed local regimes requires a baseline knowledge of the frequency of natural wildfires on the islands prior to human occupation. A sedimentary sequence that was recently discovered in a small canyon on San Nicolas Island contains evidence of at least 24 burn events that date to between ~37 and 25 ka (thousands of calibrated 14C years before present), well before humans entered North America. The evidence includes abundant macroscopic charcoal, blackened sediments, and dis- crete packages of oxidized, reddish-brown sediments that are similar in appearance to sedimentary features called fire areas on Santa Rosa Island and elsewhere. Massive fine-grained sediments that contain the burn evidence are inter- preted as sheetwash deposits and are interbedded with coarse-grained, clast-supported alluvial sediments and matrix- supported sands, pebbles, and cobbles that represent localized debris flows. These sedimentary sequences suggest that the catchment area above our study site underwent multiple cycles of relative quiescence that were interrupted by and followed by slope instability and mass wasting events. Our 14C-based chronology dates these cycles to well before the arrival of humans on the Channel Islands and shows that natural wildfires occurred here, at a minimum, every 300-500 years prior to human occupation.

High-resolution morpho-bathymetric imaging of the Messina Strait (Southern Italy). New insights on the 1908 earthquake and tsunami

The 28 December, 1908 Reggio Calabria and Messina earthquake (named after the two most damaged cities on the coasts of Messina Strait) was one of the strongest (MW 7.1) ever to occur in Italy, and was also followed by a tsunami that severely impacted the coasts of the Strait. Although there is general agreement that its epicentre is located offshore in the Messina Strait, the source fault has never been detected; a century-long question is therefore pending on the source of both the 1908 earthquake and tsunami. Within the ongoing debate on this subject, little attention has been given, so far, to morphological insights from high resolution bathymetric (multibeam) data, particularly as regarding the evidence of faults affecting the seafloor and the question of whether a submarine landslide may had been the cause of the tsunami. We aim to address this issue by presenting the results of a morpho-bathymetric study in the Messina Strait and surroundings, investigated by means of high-resolution swath bathymetry. The primary morpho-structural feature in this area is the axial channel of the Messina Canyon, towards which flow several tributary canyons that incise the steep continental slope on the Calabrian and Sicilian margins. These canyons carve deeply into a very narrow (almost lacking) continental shelf and merge laterally forming a continuous erosional margin rimming the Messina Strait. This giant, composite canyon environment is the locus of intense erosional and depositional processes that superimpose on active tectonic deformation, resulting in a complex geomorphology that hinders the distinction between tectonic and sedimentary features. Seafloor ruptures that may be linked to fault systems compatible with the source of the 1908 earthquake and tsunami could not be identified based from our morpho-bathymetric analysis; however, we provide evidence of several geomorphic features indicative of tectonic deformation in the Messina Strait, define the presence and distribution of submarine landslides, and evaluate their possible role as tsunami sources.

Sedimentary features, occurrence, and cyclicity of microbialite facies in the Roubidoux and Jefferson City Formations of Missouri and Kansas

Outcrop studies of sedimentary and stratigraphic features of microbial buildups are important in developing conceptual models for exploration of potential microbialite reservoirs. This study examines the occurrence and distribution of Lower Ordovician microbial fabrics in central Missouri and Kansas. The units studied include the Roubidoux, Jefferson City, and Cotter Formations of the Arbuckle Group. To determine the depositional environments suitable for microbialite development, micro-, meso-, and macroscale features were examined, and their stratigraphic relationships were established to the surrounding lithofacies. Microscopic-scale analysis reveals heavy dolomitization of strata; however, remnant depositional features provide vital clues about the microbialite development. The occurrence of microbial structures is placed within a cycle stratigraphic framework. The microbialites occurred within cyclical shallow-marine deposits and are grouped into three cycle types. Type 1 deposits include subtidal mudstones to packstones that grade into intertidal stromatolites. Type 2 deposits are composed of subtidal mudstones and packstones with thrombolite fabrics that grade into supratidal facies. Type 3 deposits include intertidal or supratidal facies that grade into supratidal facies.

Depositional environments and hydrocarbon potential of the Miocene deposits of Zakynthos Island

Structure, sedimentary features, and biostratigraphy were taken into account to provide additional knowledge into the depositional conditions that influenced the sedimentary sequence along the southern coast of Zakynthos. This succession is exposed from Keri village to Ag. Sostis peninsula and appears to have been influenced by intense tectonic activity. The active tectonics resulted in the formation of at least four coarsening upward cycles. The co-occurrence of Bouma sequence subdivisions and slump horizons within the studied sediments suggest a deep-sea depositional environment. Grain size analysis indicates a regional swallowing upward trend. TOC and CaCΟ3 contents are presented with both positive and negative correlations while the TOC values indicate that the study area contain samples with source rock potential.

Seismic‐stratigraphic record of a deglaciation sequence: from the marine Laflamme Gulf to Lake Saint‐Jean (late Quaternary, Québec, Canada)

The stratigraphy of the last deglaciation sequence is investigated in Lake Saint‐Jean (Québec Province, Canada) based on 300 km of echo‐sounder two dimensional seismic profiles. The sedimentary archive of this basin is documented from the Late Pleistocene Laurentidian ice‐front recession to the present‐day situation. Ten seismic units have been identified that reflect spatio‐temporal variations in depositional processes characterizing different periods of the Saint‐Jean basin evolution. During the postglacial marine flooding, a high deposition rate of mud settling, from proglacial glacimarine and then prodeltaic plumes in the Laflamme Gulf, produced an extensive, up to 50 m thick mud sheet draping the isostatically depressed marine basin floor. Subsequently, a closing of the water body due to glacio‐isostatic rebound occurred at 8.5 cal. ka BP, drastically modifying the hydrodynamics. Hyperpycnal flows appeared because fresh lake water replaced dense marine water. River sediments were transferred towards the deeper part of the lake into river‐related sediment drifts and confined lobes. The closing of the water body is also marked by the onset of a wind‐driven internal circulation associating coastal hydrodynamics and bottom currents with sedimentary features including shoreface deposits, sediment drifts and a prograding shelf‐type body. The fingerprints of a forced regression are well expressed by mouth‐bar systems and by the shoreface–shelf system, the latter unexpected in such a lacustrine setting. In both cases, a regressive surface of lacustrine erosion (RSLE) has been identified, separating sandy mouth‐bar from glaciomarine to prodeltaic muds, and sandy shoreface wedges from the heterolithic shelf‐type body, respectively. The Lake Saint‐Jean record is an example of a regressive succession driven by a glacio‐isostatic rebound and showing the transition from late‐glacial to post‐glacial depositional systems.

Middle Eocene Nummulites and their offshore re-deposition: A case study from the Middle Eocene of the Venetian area, northeastern Italy

The Middle Eocene Calcari nummulitici formation from northeastern Italy, Venetian area, represents a shallow-marine carbonate ramp developed on the northern Tethyan margin. In the Monti Berici area, its main components are larger foraminifera and coralline red algal communities that constitute thick carbonate sedimentary successions. Middle ramp and proximal outer ramp environments are recognized using component relationships, biofacies and sedimentary features. The middle-ramp is characterized by larger flattened-lenticular Nummulites on palaeohighs between which rhodoliths formed. Larger Nummulites palaeohighs containing Nummulites millecaput, Nummulites crassus, Nummulites discorbinus and Nummulites cf. gizehensis developed more basin-wards. The following relatively quiet environments of basin-wards of the palaeohighs represent areas of maximum carbonate production. The transition between the distal middle- and the proximal outer-ramp settings is marked in the study area by a large erosional surface which is interpreted to have been formed as a result of an erosive channel body filled in by deposits re-sedimented from shallower depths. These off-shore re-sedimented channelized deposits, ascribed to the Shallow Benthic Zone SBZ 15, lying on hemipelagic marls (planktonic foraminiferal zone E9 (P11)) allow for a biostratigraphic correlation to the Late Lutetian.The studied deposits, represented by packstone to rudstones, were displaced whilst still unlithified. The Lutetian–Bartonian regression along with the local tectonic activity promoted the production of a high amount of biogenic shallow-water carbonates mainly produced in the Mossano middle-ramp settings. These prograded towards the basinal areas with high-sedimentation rate of carbonate deposits characterized by the larger Nummulites rudstones. Such high amounts of sediment led to sediment instability which potentially could be mobilized either by return currents due to occasional major storms or by earthquakes induced by tectonic activity. These will have led to the offshore re-deposition of the Nummulites sediments into deeper water setting via the observed channels. Since potential migration pathways are short, such distal re-sedimented channel-filled material surrounded by hemipelagic marls is optimally placed for the formation of potential subsurface oil reservoirs.

The Dangeard and Explorer canyons, South Western Approaches UK: Geology, sedimentology and newly discovered cold-water coral mini-mounds

The Celtic Margin is a complex area in terms of sedimentary dynamics and evolution, with a number of submarine canyons dissecting the continental slope and outer continental shelf. The complex terrain and diverse range of sea-bed sediments play a part in submarine canyons being described as areas of high habitat heterogeneity. This study has concentrated on the heads of two canyons: Dangeard (also known as Dangaard) and Explorer (first named here) located in UK territorial waters, in water depths between 138 and 1165m. Multibeam echosounder, 2D reflection seismic and photographic ground-truthing data have been combined to map the sea-bed geomorphology, sedimentary features and canyon megafauna of these canyons. In addition, two previously unknown provinces of cold-water coral (CWC) mini-mounds were discovered on the interfluves of the Dangeard and Explorer canyons.The study area comprises a dendritic network of gullies feeding into the canyon thalwegs. Amphitheatre rims, where slope angles are commonly in excess of 20°, occur along the margins and heads of both canyons and are interpreted as drainage basins indicative of retrogressive mass-wasting in a shelfward direction.The CWC mini-mounds occur in water depths between 250m and 410m, with more than 400 mounds identified. They are up to 3m in height and 50–150m in diameter with no sub-surface expression, suggesting these mounds are, in geological terms, relatively young and possibly Holocene in age. Biological analyses revealed that the mounds form a habitat for ophiuroids and Munida associated with Lophelia pertusa coral rubble, suggesting these mini-mounds are not present-day living features.

Sedimentology and palaeontology of the Upper Jurassic Puesto Almada Member (Cañadón Asfalto Formation, Fossati sub-basin), Patagonia Argentina: Palaeoenvironmental and climatic significance

Six facies associations are described for the Puesto Almada Member at the Cerro Bandera locality (Fossati sub-basin). They correspond to lacustrine, palustrine, and pedogenic deposits (limestones); and subordinated alluvial fan, fluvial, aeolian, and pyroclastic deposits. The lacustrine–palustrine depositional setting consisted of carbonate alkaline shallow lakes surrounded by flooded areas in a low-lying topography. The facies associations constitute four shallowing upward successions defined by local exposure surfaces: 1) a Lacustrine–Palustrine-pedogenic facies association with a ‘conchostracan’–ostracod association; 2) a Palustrine facies association representing a wetland subenvironment, and yielding ‘conchostracans’, body remains of insects, fish scales, ichnofossils, and palynomorphs (cheirolepidiacean species and ferns growing around water bodies, and other gymnosperms in more elevated areas); 3) an Alluvial fan facies association indicating the source of sediment supply; and 4) a Lacustrine facies association representing a second wetland episode, and yielding ‘conchostracans’, insect ichnofossils, and a palynoflora mainly consisting of planktonic green algae associated with hygrophile elements. The invertebrate fossil assemblage found contains the first record of fossil insect bodies (Insecta-Hemiptera and Coleoptera) for the Cañadón Asfalto Formation. The succession reflects a mainly climatic control over sedimentation. The sedimentary features of the Puesto Almada Member are in accordance with an arid climatic scenario across the Upper Jurassic, and they reflect a strong seasonality with periods of higher humidity represented by wetlands and lacustrine sediments.

Direct sediment transfer from land to deep-sea: Insights into shallow multibeam bathymetry at La Réunion Island

Abstract Submarine canyon heads are key areas for understanding the triggering factors of gravity currents responsible for the transfer of detrital sediment to the deep basins. This contribution offers a detailed picture of canyon heads off La Reunion Island, with high-resolution multibeam bathymetry in the water depth range of 4–220 m. The present feeding of the Cilaos turbidite system, one of the largest modern volcaniclastic systems in the world, is deduced from morphological and sedimentological interpretations of newly acquired data. The study highlights small-scale sedimentary features indicating hydrodynamic and sedimentary processes. A direct connexion between the Saint-Etienne river mouth and submarine canyons is evidenced by the complete incision of the shelf and the presence of canyon heads connected to the modern deltaic bar. This direct connection, supplied by river torrential floods (cyclonic floods every two or three years), suggests the continuity of high-density fluvial flows to submarine gravity flows, forming hyperpycnal flows in the canyon. The initiation of secondary submarine gravity flows by storm waves (large austral waves and cyclonic waves) is also proposed for submarine canyons with large canyon heads developed in the surf zone from a sandy coastal bar. Bedforms in active canyon axis are considered as an indicator of the frequent activity of high-density turbidity currents. Moreover, a morphological record of last glacial and deglacial sea level variations is preserved, and particularly the Last Glacial Maximum sea level with the presence of small vertical cliffs, observed in this bathymetric data, which likely corresponds to a paleo-shoreline or paleo-reefs.

Research on Residual Oil Distribution Regular of Steam Flooding after Polymer Flooding

The study on distribution laws of remaining oil in high water cut stage is the difficulty of oil field development in the mid-to late period. Aiming at the long development time of Western Bei 2 area of Saertu oilfield in Daqing Oilfield and its complicated well history conditions undergone water flooding, polymer flooding and steam flooding, the 3D geological static model has been established in this test area based on the study on its structure characteristics and sedimentary features. By applying the method of fine reservoir numerical simulation, the paper completes the numerical simulation of remaining oil in the test area and summarizes types of remaining oil as well as their distribution laws in the test area, which provides a reliable basis for the further deployment and adjustment measures in the oilfield.

Geochemical Characteristics and Tectonic Implications of the early Permian Volcanic Rocks from Ongniud Banner, Inner Mongolia

The Early Permian volcanic-sedimentary sequences of Ongniud Banner consist mainly of andesite, rhyolite, perlite, volcanic breccia, tuff, tuffaceous sandstone, siliceous rock. Rock assemblage and sedimentary formations indicate that are of fore-arc basin sedimentary feature between subduction zone and island arc in Early Permian. The volcanic rocks from Elitu Formation have SiO2=50.23%~74.83%, Mg#=6.21~49.54, Na2O+K2O=5.27%~10.73%, Na2O/K2O=0.36~4.17, belonging to high-K cal-alkaline (HKCA)~shoshonite (SHO) series. The volcanic rocks are characterized with (La/Yb)N=5.52~9.89, moderate - intense negative Eu anomalies, LILE enrichment such as Ba, Ra, K, Th and HFSE depletion such as Ta, Nb, P, Ti, and indicating that magma could be formed in the tectonic setting of the island arc and active continental margin related to the plate subduction. R1-R2 diagram also indicates that volcanic rocks were generated at syn-collision or post-orogenic period, perhaps representing the mid-later subduction stage of the Palaeo-Asian Ocean Plate and North China Plate. Taken together, the authors suggest that the region was located still in the Palaeo-Asian Ocean, rather than the intracontinental taphrogenic trough in Early Permian.

Mangrove vegetation changes on Holocene terraces of the Doce River, southeastern Brazil

High-resolution sedimentological, geochemical and pollen analysis on sediment core from the coastal plain of the Doce River, southeastern Brazil, revealed changes in the depositional system and vegetation caused by combined action of oscillations in relative sea-level (RSL) and sedimentary supply during the Holocene. Two main phases were discerned using sedimentary features, δ 13 C, δ 15 N, total organic carbon (TOC), total nitrogen (N), C/N and cluster analysis of pollen data, temporally synchronized with radiocarbon age dating. The data indicates the presence of a lagoon system surrounded by a tidal plain colonized by mangroves and its sedimentary organic matter sourced from C 4 plants between ~ 8050 and ~ 7115 cal yr BP. However, during the mid- and late-Holocene the mangroves shrank and freshwater vegetation expanded (C 3 plants), probably, due to a marine regression. During this phase, the development of a lacustrine environment was followed by the colonization of herbs, trees and shrubs. The continuous sediment infilling into the lake allowed the expansion of a herbaceous plain as seen today. This geomorphologic and vegetation evolution is in agreement with the mid-Holocene RSL maximum above present RSL and subsequent fall to the present time. • We analyze pollen, sediment and geochemical data of a core from a coastal plain in Brazil. • Changes in the depositional system and vegetation were caused by relative sea-level changes. • During the early Holocene occurred a lagoon system surrounded by mangroves. • In the middle and late Holocene the mangroves shrank and freshwater vegetation expanded.

Assessment and geological characterisation of the CO2CRC Otway Project CO2 storage demonstration site: From prefeasibility to injection

The CO2CRC Otway Project, located in south-eastern Australia, has demonstrated geological storage of CO2 in a depleted natural gas field. Prior to injection, a comprehensive site characterisation study established that the site should meet the requirements of safe and effective storage. In contrast to the conventional methods applied to characterising oil and gas reservoirs for production purposes, CO2 storage site assessments place greater emphasis on injectivity, capacity, and long-term containment. The site location was assessed in the context of accessibility for monitoring activities and impact on local communities and natural resources. Additional well-log data and cores were acquired from the gas field, in conjunction with the drilling of the CRC-1 injector well, in order to reduce the uncertainty surrounding the geological heterogeneity of the reservoir, capacity of the seal to retain CO2, fault seal geomechanics, and regional hydrodynamics. Specialised core analysis revealed that small scale sedimentary features, related to depositional environment impact reservoir quality, CO2 trapping and plume migration behaviour. Based on these effects, a depositional model was established to better understand storage potential away from well control. Finally, a nearby gas storage facility provided a valuable analogue for the project and added confidence that the CO2CRC Otway Project site would be suitable to inject, store and contain CO2 within the technological and economical limits of the project. Following the injection period, long term monitoring of the reservoir, as well as the overlying aquifers, soil, groundwater and the atmosphere above the site, have confirmed the storage concept is effective and that the CO2 is safely contained. As a result, the site characterisation methodology serves as an example for others contemplating CO2 storage into depleted gas fields.

Geological setting and age of the Middle Paleolithic site of Nahal Mahanayeem Outlet (Upper Jordan Valley, Israel)

In this paper we present the sedimentary features and the luminescence chronology for Nahal Mahanayeem Outlet (NMO), an archaeological open air site at the southern margin of the Hula Basin (Northern Jordan Rift Valley, Israel). The site is characterized by a lithic assemblage ascribed primarily to the Middle Paleolithic Mousterian tradition, and by an excellent preservation of floral and faunal remains.Six geological units forming the stratigraphic sequence of the site were distinguished: (Unit 6) archaeologically sterile, light-colored limnic carbonates; (Unit 5) conglomerates of rounded basalt boulders and cobbles forming a hill-like topography; (Unit 4 and Unit 3) a sequence of similar dark silty sediments, attached to and overlaying the conglomerates, containing the archaeological horizons of the site; (Unit 2) a number of channels cutting into the top of Unit 3, filled with coarse sand and rounded basalt and limestone gravels of fluvial origin; and (Unit 1) a thin sand layer laid down by the present-day Jordan River covering another unconformity as a result of heavy machinery drainage operations in 1999.The OSL age for Unit 6 yielded a minimum age older than 460 ka. Sedimentary features and the embedded fossils suggest that Unit 1 can be linked to the Early Pleistocene Gadot Chalk. Unit 5 represents a local geological feature and could be an indicator for a period of increased erosion with formation of coarse grained sediments. The archaeological horizons form the lower parts of Unit 4 and yielded OSL-ages between 55 and 65 ka, indicating an affiliation to the sediments called “Ashmura Formation” with an Upper Pleistocene age for the site. The channel fills of Unit 2 can be dated by the recovered artifacts. These range in age from the Upper Paleolithic (Aurignacian) to historic times. Unit 1 is recent.The study of the complex NMO stratigraphy, combined with coherent OSL chronology, has enabled us to reconstruct parts of the geological history of the Hula Basin during the Late Pleistocene. It is this history that forms the background for the human migration and utilization of natural resources in the Upper Jordan Rift Valley.

The significance of mudstone fabric combined with palaeoecological evidence in determining sedimentary processes – an example from the Middle Jurassic of southern Poland

Mudstones were deposited below the storm wave base in the shallow epicontinental sea, however, structures reflecting quiet settling from the suspension are not common. Most of recognized lamina types resulted from activity of bottom suspension currents generated by storms, suggesting that accumulation of mudstones proceeded under prevailing energetic conditions. Composition of benthic association indicates that bottom environment was depleted in oxygen but reoxygenetion events, linked with storms, were frequent. Short oxygenetion episodes resulted in development of microbioturbation, which was the most effective in destruction of subtle lamination. L onger lasting oxygenation led to development of more diversified association, consisting of ichnofossils Chondrites , Trichichnus , pyritized burrows, Palaeophycus and Protovirgularia and bivalves Bositra , nuculids and nuculanids. Analysis of fabric of laminated black mudstones of the Ore-Bearing Częstochowa Clay Formation (Bathonian, southern Poland) was used for reconstruction of sedimentary processes and environmental energy. Small-scale sedimentary features indicate that ore-bearing clays were deposited below the storm-wave base in the shallow epicontinental sea but structures reflecting quiet settling from the suspension are not common. Most of recognized lamina types record activity of bottom suspension currents generated by storms, suggesting that mudstones accumulated under prevailing energetic conditions. Composition of benthic faunal association indicates that on the seafloor suboxic conditions prevailed, restricting infaunal activity to cryptobioturbation. Recurrent short-lived reoxygenetion events, linked probably with storms, resulted in development of dysoxic conditions, recorded by more diversified trace fossil association (consisting of Chondrites , Trichichnus , pyritized burrows, Palaeophycus and Protovirgularia ) and colonization of the seafloor by epifaunal bivalves Bositra . Truly anoxic conditions might establish only for a short time, leading to mass mortality of Bositra . Analysis of the fabric of laminated black mudstones of the Ore-Bearing Częstochowa Clay Formation (Bathonian, southern Poland) is used for reconstruction of sedimentary processes and conditions. Small-scale sedimentary features indicate that ore-bearing clays were deposited below storm-wave base in a shallow epicontinental sea, but structures reflecting quiet settling from suspension are not common. Most of recognized lamina types record the activity of bottom currents generated by storms. The benthic faunal association indicates that suboxic conditions prevailed on the seafloor, restricting infaunal activity to cryptobioturbation. Recurrent short-lived reoxygenetion events, linked probably to storms, resulted in the development of dysoxic conditions, recorded by a more diverse trace fossil association (consisting of Chondrites , Trichichnus , pyritized burrows, Palaeophycus and Protovirgularia ) and colonization of the seafloor by epifaunal bivalves ( Bositra ). Truly anoxic conditions might have been briefly established, leading to mass mortality of Bositra .