ALBERT

Description: Igneous sheet-complexes transport magma through the crust, but most studies have focused on single segments of the magma-transport-system or have low resolution. In the Jameson Land Basin in East Greenland, reflection-seismic data and extensive outcrops give unparalleled constraints on mafic intrusions down to 15 km. This dataset shows how sill-complexes develop and how magma is transported from the mantle through sedimentary basins. The feeder zone of the sill-complex is a narrow zone below basin, where a magmatic underplate body impinges on thinned crust. Magma was transported through the crystalline crust through dykes. Seismic data and published geochemistry indicate magma was supplied from a magmatic underplate, without perceptible storage in crustal magma-chambers and crustal assimilation. As magma entered the sedimentary basin, it formed distributed, bowl-shaped sill-complexes throughout the basin. Large magma volumes in sills (4-20 times larger than the Skaergaard Intrusion), and few dykes highlight the importance of sills in crustal magma-transport. On scales smaller than 0.2 km, host-rock lithology, and particularly mudstone tensile strength-anisotropy, controls sill-architecture in the upper 10km of the basin, whereas sills are bowl-shaped below the brittle-ductile transition zone. On scales of kilometres and towards basin margins, tectonic stresses and lateral lithological changes dominate architecture of sills.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5670470

Description: The Gepatsch Glacier in Tirol (Austria) is a rapidly retreating valley glacier whose host valley and forefield reveal subglacial, proglacial, and reworked sediment-landform assemblages. Structures include roches moutonées develop on gneiss, compound bedrock-sediment bedforms (crag and tail structures), flutes, and small diamicton ridges. The glacial sediments and landforms are undergoing incision and terrace development by meltwater streams. Glacial geomorphological and surface geological maps maps, in concert with elevation models of difference between July 2019 and July 2020 highlight considerable changes to the forefield over a 12-month time period. Till exposed within the last 20 years has undergone substantial mass wasting and re-deposition as subaerial mass flows, or reworked into stream deposits. The lee sides of many roches moutonées completely lack subglacial sediment, and instead contain a sand and gravel deposit interpreted to result from glaciofluvial deposition. Thus, insights into the rates of erosion and deposition in a complex, proglacial setting, allow some of these processes to be quantified for the first time. Repeated monitoring of glacier forefields is expected to yield a better understanding of the preservation potential of proglacial sedimentary facies, and hence their preservation potential in Earth's sedimentary record.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5664299

Description: This chapter considers advances in geomorphological modelling from 1965 to 2000, a period that coincides with enormous progress resulting from the digital revolution. The status of computer technology and the discipline of geomorphology leading up to the period covered in this chapter is outlined. The emergence of electronic, digital computers was a significant development in computing history. The invention of the microchip resulted in a generation of mainframe computers that were increasingly efficient and powerful. Throughout the 1960s, universities and research organizations acquired mainframe computers, with time-sharing replacing batch processing. Until the mid-20th century, geomorphological research focused on qualitative studies of landscape history. Thereafter, geomorphological research focused on process-based studies over smaller scales. At the time that mainframe computers allowed for complexity in mathematical modelling, geomorphologists began to concentrate on an agenda that did not necessitate their use. Some mathematical models in geomorphology were introduced between 1965 and 1980, although equations were often solved analytically. Despite accessibility to powerful computers in the 1980s, mathematical modelling in geomorphology was not widespread. Mathematical models in geomorphology appeared with increasing frequency in the 1990s. Disciplinary engagement with computationally-intensive approaches was strong during this decade, and continued into the 21st century.

Description: This paper presents a summary of palynologic data for Pennsylvanian age coal beds in the Appalachian Basin, discussed primarily from a biostratigraphic perspective. Coal bed palynofloras of Lower Pennsylvanian through Early Permian age are compared and correlated with miospore assemblage zones established for western Europe, and the Eastern Interior (Illinois) and Western Interior Basins of the mid-continent USA.Lower Pennsylvanian palynofloras, which are dominated by lycopsid spores, are correlative with the Langsettian of western Europe and the Morrowan of the Eastern and Western Interior mid-continent USA Basins. Stratigraphically useful palynotaxa include Dictyotriletes bireticulatus, Radiizonates striatus, Schulzospora rara, Granasporites medius, Laevigatosporites minor and Endosporites globiformis.Middle Pennsylvanian palynofloras change through time, being lycopsid dominant in the lower part and more heterogeneous in the middle and upper parts with increased contributions from other Pennsylvanian plant groups. They are correlative with the Duckmantian, Bolsovian and Asturian of western Europe and the Atokan and Desmoinesian of the Eastern and Western Interior mid-continent USA Basins. Stratigraphically useful palynotaxa include Secarisporites remotus, Microreticulatisporites sulcatus, Vestispora fenestrata, Triquitrites sculptilis, Laevigatosporites globosus, Radiizonates difformis, Torispora securis, Triquitrites minutus, Mooreisporites inusitatus, Murospora kosankei, Thymospora pseudothiessenii and Schopfites dimorphus.Upper Pennsylvanian and Lower Permian coal beds in the Appalachian Basin, in contrast to their Lower and Middle Pennsylvanian counterparts, are strongly dominated by tree fern spore palynotaxa. Palynofloras correlate with the Stephanian and Autunian of western Europe and the Missourian, Virgilian and Wolcampian of the Eastern and Western Interior mid-continent USA Basins.

Description: The chalk porosity plays a decisive role in the transport of solutes and heat in saturated chalk. From a geological point of view, there are at least two types of porosities: the porosity of pores corresponding to the micro-spaces between the fossil coccoliths that form the chalk matrix, and the porosity due to the micro- and macro-fractures (i.e., secondary porosity). For groundwater flow, the fracture porosity is a determining factor at the macroscopic scale. The multi-scale heterogeneity of the porous/fractured chalk is inducing different effects on solute and heat transport. For solute transport considered at the macroscopic scale, tracer tests have shown that the ‘effective transport porosity’ is substantially lower than the ‘effective drainable porosity’. Moreover, breakthrough curves of tracer tests are showing an important influence of diffusion in a large portion of ‘immobile water’ (‘matrix diffusion’) together with quick preferential advection through the fractures. For heat transport, the matrix diffusion in the ‘immobile water’ of the chalk is hard to distinguish from conduction within the saturated chalk.

Description: Swelling soils cause serious damage to engineering structures, and they pose a problem worldwide. The fluctuation of water content is known as one of the most important factors that cause the swelling pressure of soils, especially for soils found in arid and semi-arid regions. The swelling soils found in these regions are exposed to cycles of volume increase and decrease in the rainy and dry periods. Thus, low-rise buildings and infrastructure constructed on/in these soils are exposed to potential damage. Although the relationship between swelling parameters and the physical-index properties of soils have been investigated in detail in previous research, the effect of variations in the initial water content on the swelling pressure of soils has not yet been sufficiently studied. For this reason, samples were prepared at the same dry unit weight and with different initial water contents to examine the effect of water content on the swelling behaviour of soils. According to swelling test results reported here, there is a statistically significant linear relationship between initial water content and swelling pressure. Some predictive empirical models with high correlation coefficients are obtained. In addition, a new approach called “Swelling Pressure Designation (SPD)” is recommended to be used for predicting the swelling pressure of soils of any water content.

Description: We greatly appreciate Dr Morton's interest in our paper and his appreciative comments. The features at Beinn na Leac are, in our opinion, of particular interest to geologists interested in the pattern of deglaciation and neotectonics in this part of western Scotland. The location is unique in Scotland in the magnitude of Younger Dryas/Holocene fault dislocation. We respond to Dr Morton's comments as follows:

Description: From 1965-2000 glacial geomorphology became increasingly specialised and developed significantly due to technological improvements, particularly in remote sensing, surveying and field-based glaciological process studies. The better understanding of basal thermal regimes in ice sheets and glaciers led to the development of concepts such as spatial and temporal migration of ice divides in dynamic ice sheets that could overprint subglacial landform assemblages, debris entrainment processes related to polythermal glacier systems, and glacier and ice sheet beds composed of cold and warm based mosaics. Process observations at the ice-bed interface led to the discovery of the third glacier flow mechanism, substrate deformation, which provided the impetus to reconstruct the genesis of subglacial bedforms such as drumlins and to evaluate the origins and potential flow law for till. Numerical evaluations of glacial erosion led to a better understanding of abrasion and quarrying as well as the erection of genetic models and erosion rates for larger scale features such as U-shaped valleys and cirques. Linkages were made between debris transport pathways and moraine construction in supraglacial environments, with the role of glacier structure being linked to specific landforms, such as medial, lateral, hummocky and ice-cored moraines as well as rock glaciers. Our appreciation of the erosional and depositional impacts of glacifluvial systems was enhanced significantly with the advent of process observations on the hydrology of modern glaciers as well as the final vindication of J.H. Bretz and his proposed jökulhlaup origins of the Channelled Scablands and the Missoula Floods. In addition to the increasing numbers of studies at modern glacier snouts, the embracing of sedimentology by glacial geomorphologists was to result in significant developments in understanding the process-form regimes of subglacial, marginal and proglacial landforms, particularly the recognition of landform continua and hybrids. Advances resulting from this included the recognition of different modes of moraine and glacitectonic thrust mass development, lithofacies models of the varied glacifluvial depositional environments, and the initial expansion of the sediments and depo-centres of glacimarine settings, the latter being the result of glacial research taking to submersibles and ice-strengthened ships for the first time. A similarly new frontier was the expansion of research on the increasingly higher resolution images returning from Mars, where extraterrestrial glaciations were recognised based on comparisons with Earth analogues. Holistic appreciations of glaciation signatures using landform assemblages were developed, initially as process-form models and later as glacial landsystems, providing an ever expanding set of templates for reconstructing palaeoglaciology in the wide variety of topographic and environmental settings, which also acknowledge spatial and temporal change in glacier and ice sheet systems.

Description: The vast majority of extrusive carbonatites are calcitic rocks which may be confused with sedimentary limestones, thus requiring a disambiguation criterion. Extrusive carbonatites are classified based on quantitative criteria that tend to avoid genetic mechanisms. Carbonatite nomenclature is in progress but regulated by the IUGS norm for igneous rocks. Carbonate sedimentary rock nomenclature is mainly regulated by the Dunham (1962), Embry & Klovan (1971) and Sibley and Gregg (1987) classification systems. These limit the description of rock types from various depositional mechanisms and makes comparison with sedimentary rocks difficult. Igneous and sedimentary carbonate rocks display no apparent differences in the field and at meso-micro-scale. They may be layered, massive crystalline or show discrete clasts in a matrix which make both rock-types resemble each other. The study analyses situations in which classification inconsistencies are most common. Adopting these guidelines may increase confidence, reliability, and value in the petrographic classification of igneous and sedimentary lithologies. This study poses a challenging target. Can igneous carbonate rocks be classified using the same approach used for sedimentary carbonate rocks and vice versa? So far, the scheme chosen was arbitrary or limited to the aim of the study being undertaken. The authors start an unexperienced dialogue for the first time between volcanologists and sedimentologists by examining a range of sedimentary and volcaniclastic rock textures which may resemble each other.

Description: Coastal ecosystems consist of diverse habitats, such as reed beds, salt marshes, mangrove swamps, tidal flats, river deltas, seagrass fields, coral reefs, sandy/rocky-shore beaches and other habitats that harbour biodiversity. The Great East Japan Earthquake of March 2011 caused severe damage to one-third of the fishing communities along the Pacific Ocean of northeastern Japan. Coastal species, such as seagrasses, function as nursery areas for commercially important species. Coastal ecosystems provide natural infrastructure for the prevention and reduction of hazardous events, a process known as ecosystem-based disaster risk reduction (Eco-DRR). The preparation of topographic and thematic maps of coastal marine environments is essential to establish and visualise the concept of Eco-DRR. Experience gained following the Japanese earthquake, as well as examples from Indonesia and Thailand in the wake of 2004 Indian Ocean tsunami showed that Eco-DRR is an affordable and sustainable approach. Dissemination of habitat maps should be further promoted as a means to ‘Build Back Better’. To scale up and promote Eco-DRR, scientists must work in a transdisciplinary manner and engage with society through understanding the roles of ecosystems by monitoring and analysing, providing solutions and raising the awareness of community and policy makers, enabling them to better implement Eco-DRR.