Mountain Peaks of Nepal Himalaya

Nepal is a mountainous country with numerous peaks and pinnacles. It is shaped by tectonic movement, the action of gravity, and erosion. It is a gradual transition process from plain to mountain terrain. The present study explores the peaks of the Nepal Himalaya and visualizes the peaks as open sources for mountaineering. The height of Nepal Himalaya is derived from 'Nepal Himalaya Inventory' Gurung (1994), 'Inventory of Nepal Himalaya' (CDG, 2002), and 'Spot Height Shapefile' (DOS, 1998). The total number of peaks opened and mountaineering royalty are derived from the Department of Tourism. The spot height and administrative boundary are derived from the Department of Survey (DOS, 1998 & 2020). Shapefiles and Google Earth are used to map the distribution of the Himalayan peaks of Nepal, and the height categories are based on mountaineering royalty reports. This study also discusses some essential aspects of royalty generation and seeks a better understanding in exploring and identifying peaks for further mountaineering activities.

Tracing the Provenance of the Devonian Limestone of Telen River, East Kalimantan

H. Witkamp found an outcrop with Devonian Limestone in East Kalimantan in 1925. In 1989, an expedition run by Institute of Technology Bandung (ITB) reinvestigated the outcrop and concluded that the Devonian Limestones in Telen River were boulders within a Permian formation. This paper gives a wider overview on the distribution of Devonian rocks in Asia Pacific region and discusses their possible origin.Based on the distribution map of Devonian rocks in the region, the Devonian limestone in Borneo is very isolated. The closest Devonian limestones are about more than 2000 km away. Probably the Devonian limestone in Telen River has been separated away from its origin by significant tectonic movement. There are several theories and models related to the formation history of this area, which makes it very complex. To understand the origin of these limestones, the geology needs to be restored to their time and place of deposition of the Devonian limestone.

Morphological classification and origin of lake depressions in Mongolia

An improved classification of the origin of lake depressions due to geological, geomorphological factors and climate change is a requirement of the day in Mongolia. We present a new holistic classification using comparative analysis method. This study suggests a two-tier classification in terms of origin and morphological feature of the lakes, which replaces the previous one-tier classification. Mongolia has identified 11 main and 26 subtypes of origin, and 8 main types of morphology, based on the features of 32 lake depressions. The result of the study shows that the lakes of Mongolia developed in 3 stages, first, affected by tectonic movement, followed by glacial and finally, owing to other exogenic factors. This morphological classification study will create the basic conditions for preserving and using these lakes more efficiently and ecologically in the future by making the classification of the origin of lake depression.

Analysis of the Coal and Gas Outburst Mechanism from the Perspective of Tectonic Movement

Coal and gas outburst is the extreme instability caused by stress, gas, and coal. In this review article, dominant factors and inducing factors of outburst were summarized; geologic features of typical outburst cases and the effects of tectonic movement on outbursts were analyzed; the outburst stages with considerations to geologic factors were divided. It was found that inducing factors, including buried depth, tectonic movement, gas composition, coal seam conditions, overlying/underlying rock conditions, and mining mode, control the outburst by influencing the dominant factors (stress, gas, and coal). Among them, tectonic movement is the key of outburst. Influenced by tectonic movement, the primary structure of coals is damaged/pulverized due to the tectonic stress and unique tectonic mode, resulting in the formation of tectonic coals. When external dynamic factors are changed, tectonic coals are crucial to outburst control for its evolution of porous structure as well as the unique mechanical behaviors and gas flowing responses. Besides, the preparation stage of outburst includes the tectonic process and mining process. The former one refers to the restructuring process of the original coal-bearing strata by tectonic movement, while the mining process is the prerequisite of outburst and it refers to the disturbance of human mining activities to the initial coal seams. It is suggested that more work is required on geological factors of outburst, and a few research areas are proposed for future research.

How does increased palaeosurface reconstruction contribute to understanding of the Arctic? - Developing a deep time palaeoclimate field laboratory in Svalbard.

<p>A complex tectonic history and global climate change has influenced the land masses bordering the Arctic ocean.  On land tectonic movement affects runoff patterns, local hydology such as increased precipitation and local surface elevation, which again affects landform development, coastline distribution, discharge routing and vegetation distribution. Land- atmosphere- biosphere links and feedback loop with the ocean are continuously refined for use in earth system models for the youngest part of geological history. With access to large data sets, improved technology and new knowledge and methodologies it is now increasingly possible to also reconstruct direct surface response to tectonic movement in deep time.</p><p>The Paleogene Central Tertiary Basin, Svalbard, Norway formed in response to the complex opening and collision at the entrance to the Arctic Ocean, causing uplift in the west and basin formation and fill in the Central Spitsbergen area. Well exposed outcrops and extensive work in the area for decades provides a framework of palaeogeographic change within the basin. The basin deposits range from continental to deep marine with changing coastline positions largely caused by tectonic activity. The timing of the basin development coincides with the time period immediately before and after the PETM and thus provides an example of a terrestrial system in a warm Arctic. Syndepositional volcanic eruptions in the Arctic area are reflected in tephra layers, which also provide opportunity for correlation and absolute time estimates (Jones et al. 2017).</p><p>We use data from two formations deposited within the basin as a field laboratory for surface response to tectonic and climate change in the Arctic. The Paleocene Firkanten Fm, is deposited during the early stages of basin formation and pre-PETM. The Eocene Aspelintoppen Formation, is deposited during late stages of basin filling and is post-PETM. Both formations are characterized by continental to paralic deposits and contain traces of palaeovegetation such as coal seams, palaeosols and fossil leaves. A large amount of exploration drill holes through the Firkanten Fm provide a unique insight into the palaeotopography and depositional trends relative to topography during deposition (Marshall et al., submitted). The presence of coal seams allows for direct reconstruction of vegetation (peat bogs) and interaction between hydrology and deposition. The Aspelintoppen Formation comprises a thick succession of channel and floodplain deposits and reflects a balance between sediment supply and accommodation. We use virtual outcrops to provide 3D architecture from inaccessible mountain sides to improve the possibilities for quantification of precipitation and discharge parameters from the basin.</p><p>References:</p><p>Jones, M.T., Augland, L.E.,, Shephard, G.E., Burgess, S.D., Eliassen, G.T., Jochmann, M.M., Friis, B., Jerram, D.A., Planke, S. & Svensen, H.H., 2017: Constraining shifts in North Atlantic plate motions during the Palaeocene by U-Pb dating of Svalbard tephra layers. Nature Scientific Reports 7: 6822 DOI:10.1038/s41598-017-06170-7</p><p>Marshall, C., Jochmann, M., Jensen, M., Spiro, B.F., Olaussen, S., Large, D.J.: Time, hydrologic landscape and the long-term storage of peatland carbon in sedimentary basins. Submitted to Journal of Geophysical Research - Earth Surface</p>

Chronology of Tectonic Movement of Cratonic Basin: Insight from New Evidences from Ordos Basin, North China

<p>Craton is the stable unit of the lithosphere. The cratonic basin is thus the sedimentary basin developed upon craton. It has long been recognized as a kind of basin characterized by minor tectonic deformation and stable architecture. With the increasing evidences in the recent years, it is noticed that it has much more mobility, and is controlled not only by the lithospheric plate movements but also by the deep mantle activation. To explore the mobile behaviour of cratonic basin is an important window to address the intra-continental deformation mechanism. Taking the Ordos basin as an example, based on the new deep boreholes, the high-resolution seismic reflection profiles, cores, and the outcrops around the basin, the paper establishes the chronology of tectonic movement around the Ordos basin utilizing the integrated method of the isotopic dating, the bio-stratigraphy, and the sequence stratigraphy. It shows that, the basin developed the ten regional unconformities, underwent multi-period volcanic activities during the Middle Proterozoic, the late Early Paleozoic, the Late Triassic, and the Early Cretaceous. It was subjected to multi-stage compression, such as the Late Ordovician to Devonian, the Late Triassic, the Late Jurassic to Early Cretaceous, and the Neogene to Quaternary. Upon the crystalline basement of the Archaean and the Lower Proterozoic, the basin underwent five distinct extension-compression cycles, such as the extension in middle Proterozoic and compression in late Proterozoic, the extension in Cambrian to early Ordovician and compression in late Ordovician to Devonian, the extension in Carboniferous to middle Triassic and compression in late Triassic, the extension in early to middle Triassic and compression in late Jurassic to Cretaceous, and the extension in Paleogene and compression in Neogene to Quaternary, with a charter of a much longer period of the earlier cycle and a shorter period of the later cycle, and a longer period of extension and a shorter period of contraction in each cycle. The extension-compression cycle controlled the formation and evolution of the Ordos oil and gas super basin.</p>

Study on the inversion structure of rift system in central and west Africa

<p>In the process of plate tectonic movement, extensional faults and conversion faults occur.In the process of studying the rift system of central and west Africa, by comparing the basin types and fault plane distribution characteristics of Africa and South America on both sides of the Atlantic ocean, it can be seen that the main continental fault on both sides of the Atlantic ocean and the fault developed at the mid-ocean ridge on the bottom of the Atlantic ocean belong to the conversion fault.The function of conversion faults is to regulate the difference in the moving speed between blocks in the contemporaneous structure. Therefore, the conversion faults developed in these three regions are similar and interrelated in terms of structure type, structure style, block movement mode and direction.The main transference faults in various regions play a role in regulating the differences of continental extension and inversion tectonic rates in the Atlantic ocean, Africa and South America.</p><p>There are two transition fault systems in the rift system of central Africa and west Africa. Under the joint action of these two transition fault systems, extensional basins and transition basins are mainly developed in the rift system of central and west Africa. Moreover, these two transition fault systems play different roles in different stages of the tectonic movement of the whole African plate.</p><p>After detailed interpretation of seismic data, it can be found that there are mainly fault-controlled inversion structures in Doseo basin and Doba basin.</p><p>As a representative of transition basins, fault-controlled inversion structures are widely developed in the Doseo basin, but they have different distribution characteristics.Among them, fault-controlled inversion structures with large inversion ranges are distributed near large faults in the basin, while fault-controlled inversion structures with small inversion ranges are far away from the structural units of the main controlled faults, the inversion structures have a small amplitude, and the stratigraphic reconstruction fragmentation degree is relatively weak. The inversion structures with weak inversion are mainly developed in the middle, western depression and southern uplift of Doseo basin.And as the representative of the extensional basin. In Doba basin, fault-controlled inversion structures are mainly developed, and the structures with high inversion rate are distributed in the central depression zone of the basin. The low inversion rate structures are distributed in the uplift and slope areas in the western part of the basin. By studying the development types and distribution locations of inversion structures in basins, it can be known that different types of basins have different transformation conditions during inversion.</p><p>Therefore, by comparing the differences in the plane and vertical characteristics of the inversion tectonic development of Doseo and Doba basins, as well as the studies on the eastern and western and non-other basins, it can be concluded that during the tectonic evolution of the rift system in central and west Africa, especially during the transition inversion stage, there were significant differences between the transition basin and the extensional basin.</p>

A Mineralisation Age for the Sediment-Hosted Blackbush Uranium Prospect, North-Eastern Eyre Peninsula, South Australia

The Blackbush uranium prospect (~12,580 tonnes U at 85 ppm cut-off) is located on the Eyre Peninsula of South Australia. Blackbush was discovered in 2007 and is currently the single example of sediment-hosted uranium mineralisation investigated in any detail in the Gawler Craton. Uranium is hosted within Eocene sandstones of the Kanaka Beds and, subordinately, within a massive saprolite derived from the subjacent Hiltaba-aged (~1585 Ma) granites, affiliated with the Samphire Pluton. Uranium is mainly present as coffinite in different lithologies, mineralisation styles and mineral associations. In the sandstone and saprolite, coffinite occurs intergrown with framboidal Fe-sulphides and lignite, as well as coatings around, and filling fractures within, grains of quartz. Microprobe U–Pb dating of coffinite hosted in sedimentary units yielded a narrow age range, with a weighted average of 16.98 ± 0.16 Ma (343 individual analyses), strongly indicating a single coffinite-forming event at that time. Coffinite in subjacent saprolite generated a broader age range from 28 Ma to 20 Ma. Vein-hosted coffinite yielded similar ages (from 12 to 25 Ma), albeit with a greater range. Uraninite in the vein is distinctly older (42 to 38 Ma). The 17 ± 0.16 Ma age for sandstone-hosted mineralisation roughly coincides with tectonic movement as indicated by the presence of horst and graben structures in the Eocene sedimentary rocks hosting uranium mineralisation but not in stratigraphically younger sedimentary rocks. The new ages for hydrothermal minerals support a conceptual genetic model in which uranium was initially sourced from granite bedrock, then pre-concentrated into veins within that granite, and is subsequently dissolved and reprecipitated as coffinite in younger sediments as a result of low-temperature hydrothermal activity associated with tectonic events during the Tertiary. The ages obtained here for uranium minerals within the different lithologies in the Blackbush prospect support a conceptual genetic model in which tectonic movement along the reactivated Roopena Fault, which triggered the flow of U-rich fluids into the cover sequence. The timing of mineralisation provides information that can help optimise exploration programs for analogous uranium resources within shallow buried sediments across the region. The model presented here can be predicted to apply to sediment-hosted U-mineralisation in cratons elsewhere.