Using an OPEN UMS format for document flow formalization in medicine

The question about construction of medical documents by means of AURRORA MIS with the use of the Open UMS format is considered in the work. The approach suggested allows data storage in the electronic form suitable for generation of required statistical reports and different researches and preserves a possibility of correct data interpretation

Tectonic structure of the convergent Pacific margin offshore Costa Rica from multichannel seismic reflection data

The Middle America Trench between the Cocos Ridge and a well-studied corridor off the Nicoya Peninsula has a more varied morphology and structure than previously reported. The morphological positive features on the lower plate significantly affect the upper plate structure. The Cocos Ridge has uplifted the margin opposite the Osa Peninsula. Northwest of Cocos Ridge, numerous seamounts on the oceanic crust sculptured the margin as they subducted. A seamount and a huge slump in the trench axis that currently block lateral sediment transport affect the sediment currently accreted and subducted. The greater portion of the trench sediment is subducted beneath a lower slope accretionary mass. Beneath the middle and upper slope is a margin wedge consisting of a high-velocity rock with few internal reflections. Its upper surface has a nondirectional random relief commonly 500 m high in the middle slope area. Overlying this surface is a low-velocity cover of slope sediment which shows little transgressive stratigraphy and can be traced landward into an inferred Eocene section beneath the shelf. The shelf basement is composed of Nicoya complex (ophiolite) with the same acoustic velocity, similar structure, and no apparent dividing geologic boundary with the margin wedge. We favor a seaward continuation of the Nicoya complex to the middle slope and emphasize the evidence for a non-steady state Tertiary tectonic history

Grain-size distribution dataset of supercritical flow sediments from a Gilbert-type delta that are associated with disaggregation bands

This is a dataset of grain-size distribution in sub- and supercritical flow sediments of a Gilbert-type delta from an outcrop in North Germany. Thirteen samples of ca 2.5 kg were dried (at 105°C), and homogenised twice with a sample divider. A representative sample of 1-2 g was then analysed using laser diffraction. The grain-size distribution of the sand has a maximum between fine to medium sand, with a long fine fraction tail down to 0.06 µm and occasional coarse fractions (up to 1.5 mm) in some samples. Specific grain-size distributions correlate with the different sedimentary bedforms from which the samples were taken. This data is important for two reasons: Firstly, sedimentary structures formed by Froude supercritical flows are controlled by grain-size. However, few studies have provided grain-size datasets from the natural record, which often have a much wider grain-size distribution than experimentally-produced supercritical flow deposits. Secondly, the sands were deformed subsequently by disaggregation bands, a type of geological fault that only develops in porous granular materials, i.e. well-sorted, medium sand. The disaggregation bands are indicative of seismic or even aseismic, creeping movement of basement faults

Impact of Middle Pleistocene (Saalian) glacial lake-outburst floods on the meltwater-drainage pathways in northern central Europe: Insights from 2D numerical flood simulation

The terrestrial margins of the Middle Pleistocene ice sheets in northern central Europe were characterised by the formation of extensive ice-dammed lakes, which were controlled by the blockage of spillways by the ice margin. The largest ice-dammed lake had a volume of ∼224 km³ and formed in a late stage of the first Saalian ice advance (MIS 6) in central Germany. The failure of the ice dam in the bedrock-outlet channel triggered a major glacial lake-outburst flood. Flood-related erosional and depositional features include large-scale scours, trench-like channels, streamlined hills, giant bars and run-up deposits, indicating a wide spreading of the outburst flood in an early stage and the incision of trench-like valleys in a later stage. The incision of large valleys in the proximal flood pathway strongly impacted the regional drainage system by providing an efficient drainage network. The trench-like channels initiated by the lake-outburst flood became a crucial part of the ice-marginal drainage and subsequent fluvial system. The reconstructed outlet hydrographs imply peak discharges of 465,000–673,000 m³s −1 . The numerical simulation indicates flow depths of up to 87 m, flow velocities of up to 7 ms −1 , peaks of the bed-shear stress of 2500 Nm −2 and the inundation of large parts of northwestern Germany and the northern Netherlands. The numerical simulation of the outburst flood was conducted on both the modern digital elevation model and on palaeotopographic models, representing the palaeotopography prior to the outburst flood and during maximum flood-related incision, respectively. Distally, the outburst flood probably followed an east-west trending route through northwestern Germany and the central Netherlands into the ice-dammed lake in the southern North Sea Basin. The added water volume might have led to the overspill and drainage of the proglacial lakes in the central Netherlands and the North Sea Lake in a chain reaction, eventually opening an east-west trending meltwater-drainage pathway along the southwestern margin of the decaying ice sheet. © 2019 The Author

Response of deep-water fore-arc systems to sea-level changes, tectonic activity and volcaniclastic input in Central America

The incipient island-arc system of southern Central America (Cretaceous - early Oligocene) is characterized by thick turbidite systems, which mainly filled inner fore-arc troughs. Outcrop data show four second-order depositional sequences in the deep-water sediments. The formation of these depositional sequences is strongly related to the morphotectonic evolution of the island-arc system. Each depositional sequence reflects the complex interaction between global sea-level fluctuations, sediment supply and tectonic activity. Strong marginal uplift and high volcaniclastic sediment supply during early to late Paleocene and late Eocene times caused the formation of coarse-grained channel-lobe systems. During late Paleocene and mid-Eocene times, fine-grained, thin-bedded turbidite systems were deposited, owing to regional subsidence and a decrease in volcanic supply. Uplift and subsidence of sediment-source areas acted as major controls on deposition of basinal cycles

3D architecture of cyclic-step and antidune deposits in glacigenic subaqueous fan and delta settings: Integrating outcrop and ground-penetrating radar data

Bedforms related to supercritical flows are increasingly recognised as important constituents of many depositional environments, but outcrop studies are commonly hampered by long bedform wavelengths and complex three-dimensional geometries. We combined outcrop-based facies analysis with ground-penetrating radar (GPR) surveys to analyse the 3D facies architecture of subaqueous ice-contact fan and glacifluvial delta deposits. The studied sedimentary systems were deposited at the margins of the Middle Pleistocene Scandinavian ice sheets in Northern Germany. Glacifluvial Gilbert-type deltas are characterised by steeply dipping foreset beds, comprising cyclic-step deposits, which alternate with antidune deposits. Deposits of cyclic steps consist of lenticular scours infilled by backset cross-stratified pebbly sand and gravel. The GPR sections show that the scour fills form trains along the delta foresets, which can locally be traced for up to 15 m. Perpendicular and oblique to palaeoflow direction, these deposits appear as troughs with concentric or low-angle cross-stratified infills. Downflow transitions from scour fills into sheet-like low-angle cross-stratified or sinusoidally stratified pebbly sand, deposited by antidunes, are common. Cyclic steps and antidunes were deposited by sustained and surge-type supercritical density flows, which were related to hyperpycnal flows, triggered by major meltwater discharge or slope-failure events. Subaqueous ice-contact fan deposits include deposits of progradational scour fills, isolated hydraulic jumps, antidunes and (humpback) dunes. The gravel-rich fan succession consists of vertical stacks of laterally amalgamated pseudo-sheets, indicating deposition by pulses of waning supercritical flows under high aggradation rates. The GPR sections reveal the large-scale architecture of the sand-rich fan succession, which is characterised by lobe elements with basal erosional surfaces associated with scours filled with backsets related to hydraulic jumps, passing upwards and downflow into deposits of antidunes and (humpback) dunes. The recurrent facies architecture of the lobe elements and their prograding and retrograding stacking pattern are interpreted as related to autogenic flow morphodynamics

Re-examining models of shallow-water deltas: Insights from tank experiments and field examples

Shallow-water deltas remain enigmatic in terms of placing the observed facies within a coherent process-based depositional model. Here we report tank experiments on mouth-bar formation from shallow water pure and stratified jets that, combined with recent flume experiments on bedforms, suggest new interpretations of field observations from shallow-water delta outcrops. Our experiments imply that the height, geometry and bedforms of the mouth bars depend on the jet properties and grain size of the supplied sediment. Pure jets with very coarse-grained sediment formed a high and steep mouth bar that is characterised by steep angle-of-repose cross bedding with related avalanche processes (grain flows) on the lee side. The experiments with stratified jets imply that mouth-bar deposition and growth are dominated by supercritical density flows that evolve from the initial jets on the lee side of the growing mouth bar. In stratified jets with very coarse-grained sediment, deposition on the mouth-bar lee side was both from grain-flow avalanches and density flows. While deposition on the upper lee slope was dominated by grain flows, a concentric field of low relief, asymmetric, downflow-migrating bedforms evolved on the lower slope and beyond the mouth bar. In the stratified jet with medium-grained sediment a very low relief mouth bar formed within a concentric field of low, asymmetric, downflow-migrating bedforms covering the entire lee slope and the area beyond. Many previous field studies show that mouth bars deposited from dense stratified jets (hyperpycnal flows) are characterised by a distinct facies assemblage of coarse-grained cross-stratified or low-angle cross-stratified sandstone passing downslope into finer-grained plane-parallel, or “quasi-parallel” laminated sand and into climbing-ripple cross-laminated sandstone. Comparison to flume and tank experiments suggests that the proximal coarse-grained planar and trough cross-stratified sandstones could represent deposition by supercritical dunes that pass downslope into antidunes, characterised by sinusoidal stratification and/or low-angle cross stratification. The repeated vertical transition between antidune deposits and climbing-ripple cross-laminated sandstone may indicate the superposition of ripples onto antidunes in finer-grained sediments, indicating ripple formation under supercritical flow conditions. Similar bedforms/sedimentary structures have previously been interpreted as hummocky cross-stratification or swaley cross-stratification and attributed to combined flows in storm-dominated settings, which probably in some cases must be revised

Upper-flow regime bedforms in a subglacial triangular-shaped landform (murtoo), Late Pleistocene, SW Finland: Implications for flow dynamics and sediment transport in (semi-)distributed subglacial meltwater drainage systems

We know less about subglacial meltwater flow properties in distributed inefficient and semi-efficient systems in comparison to those of ice marginal eskers and proglacial environments. While previous studies have indicated the overall common presence of upper-flow-regime (UFR) bedforms in glacigenic settings, facies expressions of subglacial meltwater flows remain poorly documented. Three ca. 3 m deep and up to 70 m long trenches excavated across a triangle-shaped subglacial landform called a murtoo in a Lateglacial to Holocene meltwater route in SW Finland provide a detailed window into sedimentary structures presumably formed ca. 40–50 km away from the coeval subaqueous margin of the Fennoscandian Ice Sheet (FIS). The aim of this paper is to document small-scale bedforms, which formed subglacially by meltwater flow and to characterize the proximal and central parts of the studied murtoo during its early evolutionary phase. We defined seven main facies types that characterize the depositional processes of the unit. Overall, the studied deposits reflect increasing meltwater delivery through time and are characterized by abrupt lateral changes in sedimentary structures and grain size. While the initial deposits are dominated by massive and horizontally laminated silt with sand lenses interpreted as lower-flow-regime deposits, the latter sediments are characterized by sinusoidal stratification, sigmoidal cross-stratification and scours with backsets or chaotic fill interpreted as deposits of antidunes, humpback dunes, chutes-and-pools and cyclic steps of the upper-flow regime. The upper-flow-regime bedforms developed on a 1 m high and 15 m long bed slope and are associated with the formation of a short-lived enlarged water-filled cavity or pond, where supercritical density flows allowed for the deposition of upper-flow regime bedforms. The final coarse-grained murtoo head-bar development, characterized by planar-cross stratified gravel and pebbly sand, indicates avalanche processes that were controlled by grain size. Our results confirm that the core of the murtoo is depositional and meltwater processes played a key role in its deposition. Despite the subglacial setting with a subaqueous ice-sheet margin, the meltwater flow was not permanently characterized by pipe-flow conditions. Overall, the findings contribute to the understanding of semi-distributed subglacial meltwater systems during the retreat of a continental ice sheet (FIS) in a rapidly warming climate

New age constraints for the Saalian glaciation in northern central Europe: Implications for the extent of ice sheets and related proglacial lake systems

A comprehensive palaeogeographic reconstruction of ice sheets and related proglacial lake systems for the older Saalian glaciation in northern central Europe is presented, which is based on the integration of palaeo-ice flow data, till provenance, facies analysis, geomorphology and new luminescence ages of ice-marginal deposits. Three major ice advances with different ice-advance directions and source areas are indicated by palaeo-ice flow directions and till provenance. The first ice advance was characterised by a southwards directed ice flow and a dominance of clasts derived from southern Sweden. The second ice advance was initially characterised by an ice flow towards the southwest. Clasts are mainly derived from southern and central Sweden. The latest stage in the study area (third ice advance) was characterised by ice streaming (Hondsrug ice stream) in the west and a re-advance in the east. Clasts of this stage are mainly derived from eastern Fennoscandia. Numerical ages for the first ice advance are sparse, but may indicate a correlation with MIS 8 or early MIS 6. New pIRIR290 luminescence ages of ice-marginal deposits attributed to the second ice advance range from 175 ± 10 to 156 ± 24 ka and correlate with MIS 6. The ice sheets repeatedly blocked the main river-drainage pathways and led to the formation of extensive ice-dammed lakes. The formation of proglacial lakes was mainly controlled by ice-damming of river valleys and major bedrock spillways; therefore the lake levels and extends were very similar throughout the repeated ice advances. During deglaciation the lakes commonly increased in size and eventually drained successively towards the west and northwest into the Lower Rhine Embayment and the North Sea. Catastrophic lake-drainage events occurred when large overspill channels were suddenly opened. Ice-streaming at the end of the older Saalian glaciation was probably triggered by major lake-drainage events

Ice-marginal forced regressive deltas in glacial lake basins: geomorphology, facies variability and large-scale depositional architecture

This study presents a synthesis of the geomorphology, facies variability and depositional architecture of ice-marginal deltas affected by rapid lake-level change. The integration of digital elevation models, outcrop, borehole, ground-penetrating radar and high-resolution shear-wave seismic data allows for a comprehensive analysis of these delta systems and provides information about the distinct types of deltaic facies and geometries generated under different lake-level trends. The exposed delta sediments record mainly the phase of maximum lake level and subsequent lake drainage. The stair-stepped profiles of the delta systems reflect the progressive basinward lobe deposition during forced regression when the lakes successively drained. Depending on the rate and magnitude of lake-level fall, fan-shaped, lobate or more digitate tongue-like delta morphologies developed. Deposits of the stair-stepped transgressive delta bodies are buried, downlapped and onlapped by the younger forced regressive deposits. The delta styles comprise both Gilbert-type deltas and shoal-water deltas. The sedimentary facies of the steep Gilbert-type delta foresets include a wide range of gravity-flow deposits. Delta deposits of the forced-regressive phase are commonly dominated by coarse-grained debrisflow deposits, indicating strong upslope erosion and cannibalization of older delta deposits. Deposits of supercritical turbidity currents are particularly common in sand-rich Gilbert-type deltas that formed during slow rises in lake level and during highstands. Foreset beds consist typically of laterally and vertically stacked deposits of antidunes and cyclic steps. The trigger mechanisms for these supercritical turbidity currents were both hyperpycnal meltwater flows and slope-failure events. Shoal-water deltas formed at low water depths during both low rates of lake-level rise and forced regression. Deposition occurred from tractional flows. Transgressive mouthbars form laterally extensive sand-rich delta bodies with a digitate, multi-tongue morphology. In contrast, forced regressive gravelly shoal-water deltas show a high dispersion of flow directions and form laterally overlapping delta lobes. Deformation structures in the forced-regressive ice-marginal deltas are mainly extensional features, including normal faults, small graben or half-graben structures and shear-deformation bands, which are related to gravitational delta tectonics, postglacial faulting during glacial-isostatic adjustment, and crestal collapse above salt domes. A neotectonic component cannot be ruled out in some cases. © 2018 The Authors. Boreas published by John Wiley & Sons Ltd on behalf of The Boreas Collegiu