Basin‐scale fluvial correlation and response to the Tethyan marine transgression: An example from the Triassic of central Spain     

Maximilian Franzel  Stuart J. Jones  Neil Meadows  Mark B. Allen  Ken McCaffrey  Tim Morgan 《Basin Research》2021,33(1):1-25

The relationships between large‐scale depositional processes and the stratigraphic record of alluvial systems, e.g. the origin and distribution of channel stacking patterns, changing architecture and correlation of strata, are still relatively poorly understood, in contrast to marine systems. We present a study of the Castillian Branch of the Permo‐Triassic Central Iberian Basin, north‐eastern Spain, using chemostratigraphy and a detailed sedimentological analysis to correlate the synrift Triassic fluvial sandstones for ~80 km along the south‐eastern basin margin. This study investigates the effects of Middle Triassic (Ladinian) Tethyan marine transgression on fluvial facies and architecture. Chemostratigraphy identifies a major, single axially flowing fluvial system lasting from the Early to Middle Triassic (~10 Ma). The fluvial architecture comprises basal conglomerates, followed by amalgamated sandstones and topped by floodplain‐isolated single‐ or multi‐storey amalgamated sandstone complexes with a total thickness up to ~1 km. The Tethyan marine transgression advanced into the basin with a rate of 0.04–0.02 m/year, and is recorded by a transition from the fluvial succession to a series of maximum flooding surfaces characterised by marginal marine clastic sediments and sabkha evaporites. The continued, transgression led to widespread thick carbonate deposition infilling the basin and recording the final stage of synrift to early‐post‐rift deposition. We identify the nonmarine to marine transition characterised by significant changes in the Buntsandstein succession with a transition from a predominantly tectonic‐ to a climatically driven fluvial system. The results have important implications for the temporal and spatial prediction of fluvial architecture and their transition during a marine transgression.  相似文献   

Lateral terrestrial water flow contribution to summer precipitation at continental scale – A comparison between Europe and West Africa with WRF-Hydro-tag ensembles     

Joël Arnault  Benjamin Fersch  Thomas Rummler  Zhenyu Zhang  Gandome Mayeul Quenum  Jianhui Wei  Maximilian Graf  Patrick Laux  Harald Kunstmann 《水文研究》2021,35(5):e14183

It is well accepted that summer precipitation can be altered by soil moisture condition. Coupled land surface – atmospheric models have been routinely used to quantify soil moisture – precipitation feedback processes. However, most of the land surface models (LSMs) assume a vertical soil water transport and neglect lateral terrestrial water flow at the surface and in the subsurface, which potentially reduces the realism of the simulated soil moisture – precipitation feedback. In this study, the contribution of lateral terrestrial water flow to summer precipitation is assessed in two different climatic regions, Europe and West Africa, for the period June–September 2008. A version of the coupled atmospheric-hydrological model WRF-Hydro with an option to tag and trace land surface evaporation in the modelled atmosphere, named WRF-Hydro-tag, is employed. An ensemble of 30 simulations with terrestrial routing and 30 simulations without terrestrial routing is generated with random realizations of turbulent energy with the stochastic kinetic energy backscatter scheme, for both Europe and West Africa. The ensemble size allows to extract random noise from continental-scale averaged modelled precipitation. It is found that lateral terrestrial water flow increases the relative contribution of land surface evaporation to precipitation by 3.6% in Europe and 5.6% in West Africa, which enhances a positive soil moisture – precipitation feedback and generates more uncertainty in modelled precipitation, as diagnosed by a slight increase in normalized ensemble spread. This study demonstrates the small but non-negligible contribution of lateral terrestrial water flow to precipitation at continental scale.  相似文献   

Quartz zoning and the pre-eruptive evolution of the ~340-ka Whakamaru magma systems,New Zealand   总被引：1，自引：1，他引：0  

N.?E.?MatthewsEmail author  D.?M.?Pyle  V.?C.?Smith  C.?J.?N.?Wilson  C.?Huber  V.?van?Hinsberg 《Contributions to Mineralogy and Petrology》2012,163(1):87-107

Cathodoluminescence (CL) zoning in quartz crystals from rhyolitic pumices in two ignimbrite members of the ~340-ka Whakamaru super-eruption deposits, Taupo Volcanic Zone, New Zealand, is investigated in conjunction with the analysis of Ti concentration in quartz to reconstruct the history of changing magma chamber conditions and to elucidate the eruption-triggering processes. CL intensity images are taken as a proxy for Ti concentration and thus temperature and/or pressure and/or compositional variations during crystal growth history. Estimates of the maximum temperature changes (i.e., assuming other factors influencing Ti uptake remain constant) are made using the TitaniQ geothermometer based on the Ti concentration in quartz. These results are reviewed in comparison with Fe–Ti oxide, feldspar-melt and amphibole geothermometry. Core-to-rim quartz Ti profiles record a marked change in conditions (temperature increase and/or pressure decrease and/or change in melt composition) causing and then following a significant resorption horizon in the outer parts of the crystals. Two alternative models that could explain the quartz Ti zonation invoke a temperature increase caused by mafic recharge and/or a pressure decrease due to magma ponding and re-equilibration at shallow crustal levels. Concomitant changes in melt composition and Ti activity may, however, also have strongly influenced Ti uptake into the quartz. Some crystals also show other marked increases in CL brightness internally, but any accompanying magmatic changes did not result in eruption. Diffusion modelling indicates that this significant change in conditions occurred over ~10–85 years prior to caldera-forming eruption. This rapid thermal pulse or pressure change is interpreted as evidence for open-system processes, and appears to record a magma chamber recharge event that rejuvenated the Whakamaru magma system (melt-dominant magma plus crystal mush), and potentially acted as a trigger for processes that led to eruption.  相似文献   

Nanoparticles and their influence on radionuclide mobility in deep geological formations     

Thorsten Schäfer  Florian Huber  Holger Seher  Tiziana Missana  Ursula Alonso  Michael Kumke  Sascha Eidner  Francis Claret  Frieder Enzmann 《Applied Geochemistry》2012

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Stratigraphy and sedimentology of the Upper Cretaceous to Paleogene Kilwa Group, southern coastal Tanzania   总被引：2，自引：0，他引：2  

Christopher J. Nicholas  Paul N. Pearson  Paul R. Bown  Tom Dunkley Jones  Brian T. Huber  Amina Karega  Jackie A. Lees  Ian K. McMillan  Aoife O&#x;Halloran  Joyce M. Singano  Bridget S. Wade 《Journal of African Earth Sciences》2006,45(4-5):431-466

The geology of southern coastal Tanzania has remained poorly understood since the first comments on its stratigraphy were made over 100 years ago. However, new field surveys combined with shallow drilling along the coast between Kilwa and Lindi are beginning to resolve the depositional history and structural evolution of this region over the past 85 Ma. Here we present the first attempt to synthesize the results of these studies to provide a coherent sedimentological, litho- and sequence stratigraphic framework, including new geological maps, for the Upper Cretaceous and Paleogene of the coastal zone.Santonian to Oligocene sediments crop out along a broad coastal belt south of the Rufiji River from the Kilwa peninsula to Lindi Creek in southern Tanzania. During 55 Ma, over 1 km of a broadly homogeneous, mid to outer shelf clay-dominated succession was deposited across the passive margin, which we define here as the Kilwa Group. This lies disconformably across the shelf on Albian marls and is itself unconformably overlain by shallow water Miocene clays and more recent limestones, sands and gravels. Four formations can be identified within the Kilwa Group on the basis of characteristic secondary lithologies and facies, described here for the first time; the Nangurukuru, Kivinje, Masoko and Pande Formations. These formations include conformable stratigraphic intervals through both the Paleocene–Eocene and Eocene–Oligocene boundaries. Within the Kilwa Group, 12 sequence stratigraphic cycles can be identified at present, demonstrating relatively uniform and continual subsidence across the margin from Santonian to Early Oligocene time. A further major bounding surface is present between the Upper Cretaceous and Paleogene, but this may become partly conformable in the Lindi area. Although the principal lithology in all formations is clay or claystone, there are more permeable intervals containing pervasive coarser siliciclastic sediments and these have yielded traces of crude oil which is likely to have migrated from lower in the succession. The Kilwa Group thus also provides important new evidence for petroleum play development in the southern coastal zone.  相似文献   

Model simulations of the transport of Odra flood water through the Szczecin Lagoon into the Pomeranian Bight in July/August 1997     

S. H. Müller-Navarra  K. Huber  H. Komo 《Ocean Dynamics》1998,50(2-3):273-274

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Great-power politics,order transition,and climate governance: insights from international relations theory     

Maximilian Terhalle  Joanna Depledge 《Climate Policy》2013,13(5):572-588

The complex politics of climate change cannot be properly understood without reference to deeper geopolitical trends in the wider international system. Chief among these is the growing resurgence of ‘great-power politics’ between China and the US, along with failures of socialization and enmeshment into global governance structures in relation to these two powers. Traditional theoretical frameworks have failed to adequately account for these developments. Nonetheless, this current great-power contestation is at the core of an order transition that has prevented the large-scale institutional redesign required to remove deadlocks in existing global governance structures, including climate governance. Examples from the 2009 Copenhagen Climate Change Conference provide ample evidence for these claims. The slow progress of the climate change negotiations are due not just to the politics of the issue itself, but to the absence of a new political bargain on material power structures, normative beliefs, and the management of the order amongst the great powers. Without such a grand political bargain, which could be promoted through a forum of major economies whose wide-ranging remit would go beyond single issues, the climate change regime is only ever likely to progress in a piecemeal fashion.

Policy relevance

Despite the achievements of the 2012 Doha Climate Change Conference, the climate negotiations are not on course to limit warming to 2 °C, and thereby avoid ‘dangerous’ climate change. Several factors have been invoked to account for such slow progress: notably, the nature of the climate change problem itself, the institutional structure of the climate regime, and lack of political will among key players. An alternative explanation is proposed such that the failure to seriously address climate change – as well as other global problems – reflects a resurgent meta-struggle between the ‘great powers’ of China and the US over the nature of the global order. Without such a broader understanding of the deeper dynamics underlying the stalemates of the climate change negotiations, there is little chance of turning those negotiations around.  相似文献   

Cosmic‐ray exposure ages of pallasites          下载免费PDF全文

G. F. Herzog  D. L. Cook  M. Cosarinsky  L. Huber  I. Leya  J. Park 《Meteoritics & planetary science》2015,50(1):86-111

We analyzed cosmogenic nuclides in metal and/or silicate (primarily olivine) separated from the main‐group pallasites Admire, Ahumada, Albin, Brahin, Brenham, Esquel, Finmarken, Glorieta Mountain, Huckitta, Imilac, Krasnojarsk, Marjalahti, Molong, Seymchan, South Bend, Springwater, and Thiel Mountains and from Eagle Station. The metal separates contained an olivine fraction which although small, <1 wt% in most cases, nonetheless contributes significantly to the budgets of some nuclides (e.g., up to 35% for ²¹Ne and ²⁶Al). A correction for olivine is therefore essential and was made using model calculations and/or empirical relations for the production rates of cosmogenic nuclides in iron meteoroids and/or measured elemental concentrations. Cosmic‐ray exposure (CRE) ages for the metal phases of the main‐group pallasites range from 7 to 180 Ma, but many of the ages cluster around a central peak near 100 Ma. These CRE ages suggest that the parent body of the main‐group pallasites underwent a major break‐up that produced most of the meteorites analyzed. The CRE age distribution for the pallasites overlaps only a small fraction of the distribution for the IIIAB iron meteorites. Most pallasites and IIIAB irons originated in different collisions, probably on different parent bodies; a few IIIABs and pallasites may have come out of the same collision but a firm conclusion requires further study. CRE ages calculated from noble gas and radionuclide data of the metal fraction are higher on average than the ²¹Ne exposure ages obtained for the olivine samples. As the metal and olivine fractions were taken in most cases from different specimens, the depth‐dependency of the production rate ratio ¹⁰Be/²¹Ne in metal, not accounted for in our calculations, may explain the difference.  相似文献   

HIGH-RESOLUTION OBSERVATIONS OF THE EXTREME ULTRAVIOLET SUN     

Harrison  R. A.  Fludra  A.  Pike  C. D.  Payne  J.  Thompson  W. T.  Poland  A. I.  Breeveld  E. R.  Breeveld  A. A.  Culhane  J. L.  Kjeldseth-Moe  O.  Huber  M. C. E.  Aschenbach  B. 《Solar physics》1997,170(1):123-141

This paper presents first results of the Coronal Diagnostic Spectrometer (CDS) recently launched aboard the Solar and Heliospheric Observatory (SOHO). CDS is a twin spectrometer, operating in the extreme ultraviolet range 151–785 Å. Thus, it can detect emission lines from trace elements in the corona and transition region which will be used to provide diagnostic information on the solar atmosphere. In this paper, we present early spectra and images, to illustrate the performance of the instrument and to pave the way for future studies.  相似文献   

Circumstellar matter 1994     

Martin C. E. Huber 《Astrophysics and Space Science》1995,231(1-2):xiii-xiv

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