Glaciations

This article argues that far from being a marginal Black Metal subgenre, Industrial Black Metal is central in bringing out Black Metal’s often disavowed appropriation of machinic noise and its critique of machine society. Through its engagement with “becoming machine” logic and robot apocalypse, cybernetic, and cosmic science fictions, Industrial Black Metal reconfigures Black Metal’s drive toward the inorganic inhuman as vehement critique of capitalist modernity and the industrial death state.

The Bastar Craton of India is composed of Archaean nuclei of tonalite–trondhjemite–granodiorite gneisses, enveloped by an older granite–greenstone belt (~3000 Ma) with banded iron formation (BIF), and an auriferous younger granite–greenstone belt with BIF. Available geological, geochemical and geochronological data indicate multiple episodes of orogeny with high-grade metamorphism at 3200–3300, 2600–2700, 2100–2200, 1900–2000, 1800–1850, 1500–1600 and 1400–1450 Ma, and continental rifting and basin development marked by emplacement of mafic dyke swarms at c. 2900 (subalkaline mafic dykes; BD-1A), 2480 (high-Mg mafic dykes; BD-1B), 2100 (Fe–tholeiite dykes; BD-2A), 1880 (Fe–tholeiites dykes; BD-2B), 1776 and 1422 Ma. Associations of extensive bimodal volcanics and riftogenic sediments are found in the Neoarchaean and Palaeoproterozoic basins of the craton. Evidence of Palaeoproterozoic (Huronian) glaciation and associated ‘cap carbonate’ followed by deposition of fine clastics with manganese ore is found in the Palaeoproterozoic Sausar Group. The lithological association of the Sausar Group is comparable to the carbonate–tillite association of the Huronian Supergroup, Snowy Pass Supergroup, Transvaal Supergroup and Turee Creek Group. The geological evolution of the Bastar Craton matches that of Western Australia and South Africa. Such similarities can be analysed to develop a unified Palaeoproterozoic assembly for these provinces.

The current theory of axial precession of the earth relative to the distant stars resulting in continuous precession of the equinoxes and the corresponding pole shift in a circle around the zodiac in a cycle of approximately 26000 years is not recognized by the Indic Thought that proposes a short cycle of 7200 years consisting of forward and backward motion of the equinoxes and a corresponding limited number of pole stars spread across the span of the constellation of Ursa Minor, known as Shishumara in Puranas and Vedic texts. The decipherment of the 'difficult passage' of Siddhanta Shiromani reveals the cycle of eccentricity of the earth's orbit that differs from that of Milankovitch which suffers from '100 000 year problem'. The precession cycle of Milankovitch stands disputed by the Surya Siddhantic cycle and the 'Yuga of Ayana' of Munjāla and Vishnuchandra that consists of three cycles of equinoxes. The concept of obliquity of Milankovitch absent in Indic Thought is also non-existent in the emerging scientific revelation from lunar data and solar path-based movement that is mistaken as precession of the axial tilt. The three Indic cycles enumerated from Siddhantas and checked against the Milankovitch cycles are verified with paleocliamtic data. It is found that the sequence of glacial events since Last Glacial Maximum match with the mid-point of the Ayana cycle of equinoxes. The incidence of Dansgaard-Oeschger events that remain unexplained by any current theory are found to match with Ayana cycles, besides giving credence to the sinusoidal path of the sun that is observed as to and fro motion from the earth.

El cambio climático, profundizado por el hombre está haciendo de nuestro planeta un lugar complejo e inestable para vivir, tanto para el hombre como para el resto de las especies que están sufriendo las alteraciones climáticas como de la alteración o desaparición de los biomas. Este articulo trata las causas del cambio climático, sus consecuencias, la problemática del cambio climático para la agricultura, algunos conceptos
relacionados.

RESUMEN
Se presentan los resultados de un análisis detallado de facies de la sucesión de diamictitas de la Formación Cancañiri en el área de Sella – Negro Muerto al norte de Tarija. La sección estudiada cubre sedimentos del Ordovícico inferior al Silúrico inferior. La Formación Cancañiri yace discordantemente sobre los sedimentos marinos de poca profundidad del Arenigiano medio y está sobrepuesta por areniscas ferruginosas del Llandoveriano basal. La edad de las diamictitas está considerada como ashgilliana superior. La formación está compuesta por tres miembros de diamictitas macizas, poco variables y con abundantes intercalaciones de cuerpos lenticulares de pelitas, areniscas, cuarcitas y conglomerados. Las diamictitas (tilitas) se depositaron en un ambiente glacioterrestre con las tres unidades representando tres avances de un escudo glacial a la región. Los clastos abundantes de rocas cristalinas indican una procedencia del basamento del Masivo Pampeano al sudeste.

ABSTRACT
The results of a detailed facies analysis of the succession of diamictites of the Cancañiri Formation in the region of Sella – Negro Muerto, north of Tarija are presented herein. The studied section is covering sediments of lower Ordovician to lower Silurian age. The Cancañiri Formation rests disconformably upon shallow marine sediments of middle Arenigian age and is overlain by ferriferous sandstones of the basal Llandoverian. The age of the diamictites is considered as upper Ashgillian. The formation is composed of three units of massive diamictites with little variability but with abundant lenticular intercalations of mudstones, sandstones, quartzites and conglomerates. The diamictites (tillites) have been deposited in a glacioterrestrial environment with the three units representing three advances of an ice shield into this region. The abundant crystalline basement clasts indicate a provenance from the basement of the Pampean Massif to the southeast.

The uppermost portion of the Taciba Formation, Itararé Group, Paraná Basin, Brazil, records a succession of depositional environments tied to the demise of late Paleozoic glaciation. In the study area, Teixeira Soares county, state of Paraná, the unit is dominated by massive to laminated diamictites with inclusions of sandstones and other coarse-grained lithotypes, representing re-sedimented material in proximal areas. These are succeeded by fine to medium-grained sandstones with tabular cross-stratification and pectinid-rich shell pavements, interpreted as nearshore deposits. Above this, laminated and intensely bioturbated siltstones with closed articulated bivalve shells are recorded, probably deposited in inner shelf settings. Fine to very fine sandstones/siltstones with hummocky cross-stratification and intercalated mudstones, including infaunal in situ shells, are interpreted as stacked storm deposits, generated in distal shoreface environments. These are succeeded by fossil-poor, massive to laminated siltstones/mudstones or gray shales (=Passinho shale) that are inferred to be outer shelf deposits, generated in organic-rich, oxygen-deficient muddy bottoms. In this sedimentary succession dropstones or ice-rafted debris are missing and locally the Passinho shale marks the maximum flooding surface of the Itararé succession. These are capped by the fluvio-deltaic deposits of the Rio Bonito Formation (Sakmarian–Artinskian). Six facies-controlled, bivalve-dominated assemblages are recognized, representing faunal associations that thrived in aerobic to extreme dysaerobic bottoms along a nearshore–offshore trend. Within these assemblages, nineteen bivalve species (three of them new) were recorded and described in detail. The presence of Myonia argentinensis (Harrington), Atomodesma (Aphanaia) orbirugata (Harrington) and Heteropecten paranaensis Neves et al. suggests correlation with bivalve assemblages of the Eurydesma-bearing Bonete Formation, Pillahuincó Group, Sauce Grande-Colorado Basin (Buenos Aires Province), Argentina, indicating a possible Asselian age for this diverse post-glacial bivalve fauna. Despite that, typical members of the icehouse-style Eurydesma–Trigonotreta biota (stricto sensu) have not yet been found in the studied bivalve assemblages.

Türkiye’nin güneybatısında bulunan Batı Toroslar dağ kuşağında Kuvaterner buzullaşmalarının izlerini taşıyan dağlar vardır. Bu kuşakta yer alan dağlardan biri olan Dedegöl Dağı’nda (2992 m), Kuvaterner’in soğuk dönemlerinde buzullaşmalar meydana gelmiştir. Bu çalışmayla buzullaşmalara bağlı olarak oluşan buzul jeomorfolojisine ait şekiller, buzullaşmada etkili olan faktörler, buzullaşmanın yayılış alanları, kalıcı kar sınırının tespit edilmesi, buzullaşmanın meydana geldiği tarihler ve paleoiklim özelliklerinin belirlenmesi amaçlanmıştır. Bu amaçlara ulaşmak için arazi çalışmaları, coğrafi bilgi sistemleri, morfometrik analizler, fiziksel temelli modellemeler, OSL tarihlendirme yöntemi ve paleoiklim modellemeleri gerçekleştirilmiştir. Dedegöl Dağı’nda, topografyanın sınırladığı dağ buzullaşmaları meydana gelmiş olup, buzullaşmalara ait morfolojik deliller; buzul vadileri, sirkler, aretler, piramidal zirveler, törpülenmiş yüzeyler, hörgüç kayalar, buzul çizikleri ve cilaları, değişik türde moren depoları ve sandur oluşumu olarak günümüze ulaşmışlardır. Buzullaşmalar ve bunlara bağlı olarak oluşan şekiller, sahadaki tektonik, karstik ve periglasiyal etken ve süreçlerden etkilenmiş, bazı alanlarda topografya kompleks bir özellik kazanmıştır. Çalışma alanında, buzul rekonstrüksiyonundan elde edilen veriler çerçevesinde, daimi kar sınırının 2230 m olduğu, buzulların 21,2 km² alan kapladıkları, buzul dillerinin 1500 m yükseltisine kadar indikleri ve 7 km’yi geçen uzunluğa ulaştıkları belirlenmiştir. Moren depolarının OSL yöntemiyle yapılan tarihlendirilmesinde birden fazla buzullaşmanın kanıtlarına ulaşılmıştır. Dedegöl Dağı’nda, buzullaşmanın gerçekleştiği dönemde daha soğuk ve daha nemli iklim koşulları hakim olmuş, bu dönemde sıcaklıklar günümüz sıcaklık değerlerinden yaklaşık olarak 10-11ºC azalmıştır.

There are mountains that have traces of Quaternary glaciations in western Taurus mountain range, southwestern Turkey. As one of the glaciated mountains in this range, multiple glaciations occurred on Mount Dedegöl (2992 m) during cold periods of Quaternary. In this study, it has been aimed to specify glacial geomorphology of Mount Dedegöl, determine factors having affected glaciations, define extent of former glaciers, elevation line altitude of former glaciers, glaciation periods and paleoclimate features of Mount Dedegöl. To achieve this aims, we used geographic information systems and carried out field work, morphometric analysis, physically-based glacier modeling, OSL dating methods and paleoclimate modellings. Topographically controlled mountain glaciations occurred on Mount Dedegöl. Those glaciations left behind glacial landforms such as glacial valleys, cirques, arêtes, horns, roches moutonnees, scoured and polished surfaces, glacial striea, different kind of moraine deposits and an outwash plain. Glaciations and their relevant landforms have been affected by karst, tectonic and periglacial processes and the landscape transformed to create complex and intricate landforms. Within the framework of the data collected from glacial reconstruction have revealed that the ELA was 2230 m, the glaciers covered an area of 21 km², glacier lobs descended down around the altitude of 1500 m and their lengths exceeded 7 km. Moraine deposits were processed with OSL dating method to obtain timing of glaciation and the results indicated evidence of multiple glacier advances. In the cold periods of Quaternary, colder and wetter climate conditions prevailed on Mount Dedegöl, and temperatures in these periods were approximately 10-11ºC lower than those of today.
Keywords: Glacial geomorphology, Quaternary glaciations, Mount Dedegöl, glacial reconstruction.

During the Quaternary, there were a series of environmental changes linked to cycles of glaciations on a global scale that profoundly affected and shaped the landscapes and life forms of our planet Earth. The major glaciation occurred 110 thousand years ago during the Last Glacial Period, which had its apogee in the Last Glacial Maximum (LGM) about 18,000 years ago; At this time the mountain glaciers of the Sierra de Santo Domingo, belonging to the Venezuelan Andes, had their maximum extension and volume, the temperature was about 7ºC lower and the precipitation ranges were about 400 mm lesser than nowadays. With the arrival of the Holocene (about 10,000 years ago), the environmental conditions became more humid and warm, which caused the melting of large masses of ice and the increase of plant colonization to higher altitudes. However, during this period there were some cold periods of which the Little Ice Age (LIA) stands out, which corresponds to the last  holocene glacial advances, particularly after the Last Glacial Maximum (LGM). During the LIA the temperature decreased between 3 to 1.4 ºC and precipitation values ​​were about 20% higher than the current ones. The Holdridge Bioclimatic Life Zones Model (1971) is used for the paleobiogeographic reconstruction of the aforementioned mountain range in order to determine its climate characteristics and their incidence in the distribution of life zones during the LGM and the LIA, testing the results obtained with current glacial morphological and paleo-palynological  evidence. Through the model, the successive transformations in the zones of life of the mountain range are determined under certain climatic conditions through the time.The reconstruction of paleo-glaciers allows an approximation that shows the role of tropical paleo-glaciares evidences as indicators of the global climatic variability. It is expected that if the current climate change (global warming) is keeping to continue in the mountain range, there will be a shift of life zones to higher altitudes, and we will witness the future disappearance of some of them such as. the Nival and Alpine rain tundra life zone, triggering profound ecological changes

Recently NATURE published a discussion on construction of sills in attempt to prevent or slow melting glaciers that are discharging ice into the ice fjords. Several further papers promptly followed publication of this essentially erroneous article in a respected NATURE magazine. Here it is pointed out that there is a discrepancy of several magnitudes thus excluding a long-term viability to manage the edges of ice fjords or continental ice shelves/sheets due to a phenomenon known as the mega-erratics. These are blocks of hard rocks that are several kilometres in size that have been dislocated by a warmed and wet edges of glacier/ice sheet/ice shelf. This Parliament evidence points out the error that was not apparent to the peer-reviewers at the time and in subsequent papers that followed. The Parliament was shown evidence that large enough obstacles cannot be possibly made to prevent ice discharges due to a progression of melting, that softens and lubricates glaciers, ice caps and ice sheets. The forces unleashed by the ice front exceeds several magnitudes from the conceived objects that sills were proposed. The only, and very only effect is temporary and limited to prevention of warm water incursion where these methods will work for a while in a cold, dry, and relatively stable ice formations. A long-term projections suggested to prevent warmed and water-infested glaciers from discharging ice into the ocean cannot be made as the forces of ice exceed many magnitudes of the sills and levies that can be made of concrete blocks, aggregates or other materials. Thus the prevention of sea level rise by this method for centuries or millennia is not functional one and thus the mitigation and prevention of rubbish gyros in ocean, the supply of housing, nuclear and food production security must be looked at as solution by the ocean littoral states. Several examples of various types of risk to the sustainability of oceans have been presented in addition to the above exposed misconception. This comes with much regret as it appears that one 'hoped-for-solution' to manage the future climate change impacts has largely foundered on the issue that the sills cannot be made strong enough to contain most important, warmed glaciers or edges of unstable ice shelves. However, for a short-term this may offer small-scale solutions provided that costs remain sufficiently small. Aggressively melting ice formations with darkened surfaces, wide spread melt water ponds, or water filled crevasses it does not offer much, if any, prolonged ice stability. (The document is best viewed as a .pdf file due to the lay-out of graph and legends.)

Climate changes have occurred several times throughout the Earth's history; however, current global warming episode may be occurring at a faster rate. Species may respond to this changes by adapting to the new conditions or by shifting their distributions tracking their niches spatially. Recent studies projected climate change effects in Mexico concluded that one major spatial foci of serious effects of global warming on biodiversity would be the Chihuahuan Desert. We analyzed if two desert species have tracked their niches in drastic climate change events: 1) in the past (across the Pleistocene–Recent transition), 2) present and 3) future (2020, 2050 years). We used ecological niche modeling to project geographical distributions across these periods, and fieldwork to support our findings. Results show that during the last glaciation the two species were restricted to few sites where environmental conditions were suitable. In the present, we detected evidence of species’ responses at the population level, as we found low abundances and recruitment rates in sites where models predicted unsuitable environmental conditions, and recent colonization in new suitable areas for a species with high dispersal rate and successful establishment, but no range expansion for a species with low dispersal capacity. Finally, future projections suggest high risk for the species with current restricted distribution.

The Kola Peninsula and Russian Lapland (Murmansk Oblast, northwest Arctic Russia) represents a major sector of the Fennoscandian Ice Sheet (FIS) where empirical geomorphological, sedimentological, and chronological data are lacking and thus, where the pattern, style, and timing of glaciation is not well established. In this study, we present a critical review of published empirical data and interpretations of Late Weichselian (c. 40e10 ka) glaciation for the region. The review includes, for the first time, information published in Russian-language journal articles (n ¼ 37), and is accompanied by a new Geographic Information System (GIS) numerical age database (spanning 472.3e6.2 ka) that collates known published numerical dates associated with the advance and retreat of the FIS in the study area. Our review suggests that an ice mass existed over the Kola Peninsula and Russian Lapland during the Early-Middle Weichselian (c. 115e40 ka), and likely retreated during the Ålesund interstadial (c. 38e34 ka). During the Late Weichselian, it is likely that the FIS advanced eastwards across Russian Lapland and the Kola Peninsula, establishing the White Sea Ice Stream before the local-Last Glacial Maximum (c. 19 e15 ka). Through an evaluation of the existing Last Glacial-Interglacial Transition (c. 20e10 ka) glaciation models for the region, we propose that the Kola Peninsula and Russian Lapland was deglaciated by the FIS, rather than the Ponoy Ice Cap or the Kara Sea Ice Sheet. In collating, discussing, and critically evaluating empirical data and interpretations, this paper provides a valuable resource to inform FIS dynamics at both a regional-and ice sheet-scale, and offers a framework through which numerical ice sheet models can be constrained. Precise FIS dynamics on the Kola Peninsula and Russian Lapland, including the position of the Younger Dryas ice marginal zone, remain unclear due to low-resolution geomorphological data. In concluding, we recommend that further work is needed in the form of a revised glacial reconstruction using high-resolution, peninsula-wide geomorphological data.

Atmospheric CO 2 and global climate are closely coupled. Since 800 ka CO 2 concentrations have been up to 50% higher during interglacial compared to glacial periods. Because of its dependence on temperature, humidity, and erosion rates, chemical weathering of exposed silicate minerals was suggested to have dampened these cyclic variations of atmospheric composition. Cooler and drier conditions and lower non-glacial erosion rates suppressed in situ chemical weathering rates during glacial periods. However, using systematic variations in major element geochemistry, Sr–Nd isotopes and clay mineral records from Ocean Drilling Program Sites 1143 and 1144 in the South China Sea spanning the last 1.1 Ma, we show that sediment deposited during glacial periods was more weathered than sediment delivered during interglacials. We attribute this to sub-aerial exposure and weathering of unconsolidated shelf sediments during glacial sealevel lowstands. Our estimates suggest that enhanced silicate weathering of tropical shelf sediments exposed during glacial lowstands can account for $9% of the carbon dioxide removed from the atmosphere during the glacial and thus represent a significant part of the observed glacial–inter-glacial variation of $80 ppmv. As a result, if similar magnitudes can be identified in other tropical shelf-slope systems, the effects of increased sediment exposure and subsequent silicate weathering during lowstands could have potentially enhanced

The quaternary period is the source of numerous studies for the diversity of scenarios that caused its climatic changes marked by glacial and interglacial cycles. Knowing the size of these changes and their forcing is essential to enable the projection of models that can estimate the future climate. It will also provide reliable and safe data for society that is still subject to incorrect and unsupported information regarding climate change. Source of certain controversy and argument repeated by skeptics of climate change it is a possible entry of the planet into a new glaciation, having these events been present in the geological past of the earth. The present study aims to offer a brief review of the characteristic oscillations of the quaternary period followed by a brief discussion of studies that infer about future climate changes seeking to answer the following question: "Are we heading for a glaciation?"

Jörg Lang (1), Muayyad Al Hseinat (2), Christian Brandes (1), Andrea Hampel (1), Christian Hübscher (2), and Jutta Winsemann (1)

(1) Leibniz Universität Hannover, Institut für Geologie, Hannover, Germany (lang@geowi.uni-hannover.de), (2) Universität Hamburg, Institut für Geophysik, Hamburg, Germany

A correlation between salt structures, glacigenic features and faulting of Pleistocene deposits above salt structures has been recognized in many places of the formerly glaciated areas in northern central Europe and attributed to ice-sheet loading. Conceptual models predict that the load applied by an ice sheet will favour ice-marginal salt rise and obstruct salt rise beneath the ice sheet (e.g., Liszkowski, 1993). To test these models, we simulated the response of salt structures to ice-sheet loading using a 2D finite-element model (ABAQUS). The subsurface geometries used in our models are based on regional geological cross-sections and 2D seismic profiles of salt structures in the Central European Basin System. The model layers represent (i) sedimentary rocks of elastoplastic rheology, (ii) a viscoelastic salt structure and (iii) elastoplastic basement rocks. At the model surface a temporarily and spatially variable pressure simulates ice-sheet loading. All our simulations show a response of salt structures to ice-sheet loading, which strongly depends on the location of the ice margin relative to the salt structure. Salt structures rise in front of the ice margin (up to 4 m), if load is applied to the salt source layer. Beneath an ice sheet salt structures are pushed down (up to 36 m). Much of the subglacial downwards displacement is compensated by a reversal of the movement during ice retreat. The resulting surface displacements are therefore rather low and depend on the spatial and temporal configuration of the ice load (Lang et al., 2014). Permanent deformation is restricted to the model layers above the salt structure, which either have a low yield stress to represent the unconsolidated infill of secondary rim-synclines or are dissected by steeply dipping crestal graben faults. Ice-induced salt movements will reactivate faults above the crests of salt structures, although the resulting displacements will be low due to the repeated reversals of the sense of movement. The surface displacement due to ice-load induced salt movement will impact the pattern of glacigenic deformation, erosion and deposition. Ice-marginal uplift will provide favourable conditions for push-moraine formation, while subglacial subsidence of salt structures will enhance erosion and contribute to tunnel-valley incision.


References
Lang, J., Hampel, A., Brandes, C., Winsemann, J. (2014) Response of salt structures to ice-sheet loading: implications for ice-marginal and subglacial processes. Quaternary Science Reviews 101, 217-233.
Liszkowski, J. (1993) The effects of Pleistocene ice-sheet loading-deloading cycles on the bedrock structure of Poland. Folia Quaternaria 64, 7-23.

Understanding the relationship between geological processes and landscape evolution is important in promoting and popularizing geology as a discipline, and in linking together
the combined needs of geological and landscape
conservation and resource management. However, the relationship between processes of landscape change and resultant landscape morphology is generally poorly defined and qualitative, especially where the 'character' of different
landscapes results from a number of geological
processes and environments over long time periods.

Las glaciaciones cuaternarias han dejado registro en diversos espacios geográficos de la corteza terrestre. Esto no ha sido una excepción en los Andes Centrales de Argentina y Chile, donde enormes valles labrados por la erosión glacial y depósitos morrénicos evidencian el fenómeno. Sin embargo, aún no se ha logrado establecer a nivel regional el alcance geográfico de éstas glaciaciones, ni los volúmenes de agua que fueron descargados durante el retroceso de los glaciares. En éste trabajo se presenta un mapa geomorfológico de temática glacial de una región de los Andes Centrales y además se realiza por primera vez una reconstrucción geomorfológica de la zona en el momento del máximo avance glacial. Este trabajo ha sido realizado mediante el reconocimiento de las áreas ocupadas por valles en forma de U, valles asimétricos y depósitos morrénicos a partir de imágenes satelitales, fotografías aéreas y registro de geoformas en el campo. Los resultados obtenidos indican que en el área de estudio los glaciares pleistocenos llegaron a cubrir una superficie total de 582,3 km2, es decir, un 25,5% del total del área analizada (2.085 km2). Actualmente, en dicha zona los glaciares y heleros ocupan el 3,94 % de la superficie total.

Here we present initial 187Os/188Os (Osi) values integrated with δ13Corg for the first Paleozoic section — the Ordovician/Silurian boundary GSSP at Dob's Linn, Scotland. Our 187Os/188Os data tracks major changes in climate that occurred during the Late Ordovician (Hirnantian glaciation), which coincides with the second largest known mass extinction. During the complanatus and early anceps Biozones Osi values increase from 0.28–1.08. This provides evidence for a period of increased silicate weathering of radiogenic continental crust, likely from the Caledonian Orogen. This increase in weathering was likely the driving mechanism for the drawdown in atmospheric CO2 and global cooling that resulted in the onset of the Hirnantian Glaciation. A decrease to less radiogenic Osi occurs at the base Hirnantian extraordinarius Biozone and coincides with the trend to more positive δ13Corg values that mark the onset of the Hirnantian Glaciation. The trend in Osi during this interval is ascribed to Hirnantian ice cover and reduced chemical weathering rates cutting the supply of radiogenic material to the Iapetus Ocean. The reduction in silicate weathering enabled atmospheric CO2 to return back to greenhouse levels, causing rapid deglaciation during the mid persculptus Biozone. This period is marked by an abrupt increase in Osi values from 0.6 to 1.08 over 19 cm of stratigraphy and coincides with the deglacial limb of the δ13Corg profile. We interpret the Osi data to reflect the leaching of exposed radiogenic 187Os/188Os bearing glacial deposits and increased weathering of radiogenic 187Os/188Os silicate terrane during the deglaciation. Previous workers have identified the Hirnantian glaciation primarily through δ13C stratigraphy. However, our Os isotope data indicate that an initial mechanism (i.e. increased silicate weathering) was the driving mechanism behind the Hirnantian Glaciation and subsequent mass extinction. Thus, by coupling Osi and δ13Corg proxies we provide the most direct evidence for the initiation and cessation of the Hirnantian glaciation. Furthermore, this study demonstrates the first use of 187Os/188Os chemostratigraphy for the Paleozoic as a proxy for reconstructing the Earth's climate system, particularly palaeoceanography.

Erosional surfaces within the late Ediacaran upper Kuibis and lower Schwarzrand Subgroups of the Nama Group, that extend from the Klein Karas Mountains in Namibia eastward to the Namibian-South African border and from southern Namibia to Nigramoep (near Springbok) in South Africa, are interpreted to form one discontinuous regional
unconformity termed the Vingerbreek Unconformity (VGU). This unconformity formed by glacial, proglacial and fluvial erosion. The palaeochannels (palaeovalleys) associated with this unconformity in southern Namibia and northwestern South Africa are interpreted to have formed distant from major glaciers as a result of predominantly
glacio-eustatic sea level fall. Our findings are consistent with a late Ediacaran (ca 547 Ma) glaciation, that is also recorded in South America and Eurasia. The evolutionary implications of a glacial event just before the Ediacaran/Cambrian are considerable, because climate deterioration could have acted as an evolutionary bottleneck and thus promoted the Cambrian explosion in its aftermath.

Alice M. Doughty, Joerg M. Schaefer, Aaron E. Putnam, George H. Denton, Michael R. Kaplan, David J.A.
Barrell, Bjørn G. Andersen, Samuel E. Kelley, Robert C. Finkel, and Roseanne Schwartz

Here we address a long-standing puzzle of ice-age climate called
the “fly in the ointment of the Milankovitch theory.” Using geomorphic mapping and 10Be surface-exposure dating, we show that five moraine belts were formed during maxima of the last ice age by the Pukaki glacier in New Zealand’s Southern Alps. They afford ages of 41.76 ± 1.09 ka, 35.50 ± 1.26 ka, 27.17 ± 0.68 ka, 20.27 ± 0.60 ka, and 18.29 ± 0.49 ka. These five maxima spanned an entire precessional cycle in summer insolation intensity at the latitude of the Southern Alps. A similar mismatch between summer insolation and glacier extent also characterized the Chilean Lake District in the mid-latitudes of South America. Thus, in apparent contrast to northern ice sheets linked by Milankovitch to summer insolation at 65°N latitude, the behavior of southern mid-latitude glaciers was not tied to local summer insolation intensity. Instead, glacier extent between 41.76 ka and 18.29 ka, as well as during the last termination, was aligned with Southern Ocean surface temperature and with atmospheric carbon dioxide.

This study characterizes precipitation and temperature variability for the whole region of Gilgit-Baltistan (GB), covering winter dominated high mountain region. Trend analyses of the historical data for the period 1955-2010 show that winter season temperatures have increased in this region during the past 55 years. Relatively higher increase in maximum winter temperatures was observed, whereas minimum temperatures during winter showed a slight decline which is negligible. These results suggest that days have become warmer whereas nights have become cooler during the winter season in the high mountain areas. Monsoon temperatures have also decreased in this region. More interestingly, average temperatures in the transitional periods " October-November " and " April-May " are at a rising trend. The results indicate that the maximum temperatures have increased all around the year last 55 years. Precipitation has also increased in GB. The paper included an annual and...

Two cap carbonates overlying glaciogenic diamictites crop out extensively in the eastern Vaza Barris Domain of the Sergipano Belt, northeastern Brazil. They are represented by carbonates of the Jacoca Formation, resting on top of diamictite of the Ribeiropolis Formation, and by the Olhos D'Agua Formation (carbonates, organic-rich towards the top), which overlies diamictite of the Palestina Formation. These two sequences were deformed and metamorphosed at sub-greenschist facies-conditions during the Brasiliano cycle (650-600 Ma). In the western Vaza Barris Domain, dolostone of the Acauã Formation rest, in sharp contact, on diamic-tites of the Juetê Formation and are much less deformed than the Olhos D'Agua Formation. Values of (13 C for the Jacoca and Acauã Formations cluster around −4 to −5‰. In the Olhos D'Agua Formation, however, negative values (around −5‰) in the shallow-marine base of the sequence are replaced up section by values close to zero and, abruptly, by positive values between +8 and +10‰ at the top. Strontium-isotope ratios for carbonates of these three formations are within the range of late Neoproterozoic seawater (0.7060-0.7090). The Acauã Formation displays 87 Sr/ 86 Sr ratios from 0.7072 to 0.7073, while the Jacoca and Olhos D'Agua formations display values within the range from 0.7077 to 0.7081. Strontium-isotopes coupled with available C-isotopes, detrital zircon U-Pb ages and structural data suggest that the Jacoca Formation and Acauã are probably correlative and mid Cryogenian in age, and that the Olhos D'Agua Formation is lowermost Ediacaran (Marinoan) in age. Mercury concentrations in carbonates of the Jacoca, Olhos D'Agua and Acauã formations are usually much higher than those observed in carbonates deposited not concomitantly with volcanic activities (<3 ng g −1). They are, in fact, similar to those in carbonates deposited during volcanic activity (e.g. Tertiary Punta Rocallosa carbonates in Chile), with concentration values between 20 and 80 ng g −1 , suggesting that CO 2 in the basal portion of these carbonate formations is mostly mantle-derived, accumulated in the atmosphere during Cryogenian-Ediacaran glacial events. Published by Elsevier B.V.

The Lipalian or Vendian Period (600-541 million years ago) begins and ends with global environmental perturbations. It begins as the worst glaciation on record draws to a close. It ends with a sudden appearance of abundant skeletonized animals that mark the beginning of Cambrian ecology. Several key events in Earth history occur during the Lipalian, bracked between severe glaciation (white or snowball Earth) and the initiation of modern marine ecosystems. The most notable of these events is the appearance of an unusual and conspicuous marine biota ("Garden of Ediacara"). This biota appears to have characteristics inherited from its sojourn beneath the ice. This chapter examines the role the cryophilic biota, consisting largely of cyanobacteria and chryosphyte and chlorophyte algae, may have played in ending the great ice age. It is hypothesized here that these microbes induced albedo reductions and other changes that rapidly improved global climate.

The internal sedimentology of the Armoy moraine, which marks a late Devensian (Weichselian) incursion of Scottish ice into the north of Ireland, is described from a temporary exposure near Armoy village. The exposure (up to 30 m long, 10 m high) comprises folded gravel beds, massive clay grading up to pebbly diamicton, massive gravel, overfolded and deformed sand, and a gravel and massive diamicton cover. These sediments overlie glacially smoothed basalt bedrock. The sediment succession records the interaction of near-touching Scottish and Irish ice margins, and the formation, infilling and drainage of an ice-supported proglacial lake. Scottish ice likely advanced into the north of Ireland by a short-lived glacier surge during the Killard Point Stadial (coeval with Heinrich Event 1 at 14.5 14C ka BP), forming the Armoy moraine at its maximum extent. The presence of rafted sediment blocks within the moraine suggests ice-marginal thrusting and deformation of proglacial sands, and syntectonic resedimentation into low points on the sediment surface. Asynchroneity between Scottish and Irish ice-marginal fluctuations may reflect differing responses to climate forcing during the Killard Point Stadial, or the effects of local factors such as substrate type and basal ice thermal regime.

Although global warming is not overlooked as an anthropogenic climate change, this book is focused on natural climate changes and their environmental and societal implications in the last ten thousand years.
The motivation for this collective work originated in the impressive scientific progress in climate sciences, in the evaluation techniques of archaeological material, and in genetics and modelling in the last decade. It is astonishing that detailed past environmental information is recorded in natural archives, which can now be retrieved and analyzed and this necessitates the closer synergy, the consilience, of natural sciences and humanities.
The book, a collective work, is practically an application of the Unity of Knowledge, as highlighted by Wilson (Edward O. Wilson, 1998. Consilience: The Unity of Knowledge. New York: Vintage Books), and the current transition of the focus of the natural sciences from the search for new fundamental laws toward new kinds of synthesis in order to understand complex systems based on coherent cause-and-effect explanations. The system of our interest is the climate, in the frame of the Earth system, over the short— but critical for our civilization— period of the current interglacial.
CO-AUTHORS: Marie-Michele Ouellet-Bernier and Anne de Vernal, Michel Crucifix, Natalie Krivova, Sebastian Wagner and Eduardo Zorita, P. Nick Kardulias, Konstantinos Voskarides, Lisa J. Lucero and Jean T. Larmon, Savino di Lernia, Barbara E. Barich, Julien Charbonnier, Hans Georg K. Gebel and Kai Wellbrock, Guy D. Middleton, Cameron A. Petrie and Lloyd Weeks, Renato Sala, Mika G. Tosca, Nikolaos Koukouzas, Vasiliki Gemeni, and Nikolaos Tsoukalas, Timothy Karpouzoglou and Feng Mao.

The glacial morphology of southern South American presents invaluable evidence to reconstruct former glacier behaviour and its relation to climate and environmental changes. However, there are still spatial and temporal gaps in the reconstruction of the Holocene Patagonian glacial landscape. Here we present the first geomorphological record for the Sierra Baguales Mountain Range (SBMR), forming the eastern foothills of the Southern Patagonian Andes 200 km from the Pacific coast. This area is topographically isolated from the Southern Patagonian Ice Field (SPIF), and is affected by the Westerly Winds. The study area shows evidence of ice sheet and alpine glaciations related to Andean uplift, which caused a marked climatic contrast between its western and eastern flanks since the Last Glacial Maximum (LGM). The regional rock mass strength and precipitation gradient acted as a controlling factor in the glacial cirque distribution and sizes, as well as in the development of glaciation types. We report new radiocarbon dates associated with warm/dry to cold/wet climatic changes during the middle Holocene, when former small alpine glaciers were located in the uppermost section of the SBMR basins, and eventually converged to form a small ice field or a composite valley glacier at lower elevations. This can be explained by an estimated regional temperature drop of 3.8°C±0.8°C, based on a 585±26 m Equilibrium Line Altitude (ELA) descent, inferred by geomorphological evidence and the Accumulation Area Ratio (AAR), in addition to a free-air adiabatic lapse rate. Subsequently, the glaciers receded due to climatic factors including a rise in temperature, as well as non-climatic factors, mainly the glacier bedrock topography.

Antarctic climate changes have been reconstructed from ice and sediment cores and numerical models (which also predict future changes). Major ice sheets first appeared 34 million years ago (Ma) and fluctuated throughout the Oligocene, with an overall cooling trend. Ice volume more than doubled at the Oligocene-Miocene boundary. Fluctuating Miocene temperatures peaked at 17–14 Ma, followed by dramatic cooling. Cooling continued through the Pliocene and Pleistocene, with another major glacial expansion at 3–2 Ma. Several interacting drivers control Antarctic climate. On timescales of 10,000–100,000 years, insolation varies with orbital cycles, causing periodic climate variations. Opening of Southern Ocean gateways produced a circumpolar current that thermally isolated Antarctica. Declining atmospheric CO 2 triggered Cenozoic glaciation. Antarctic glaciations affect global climate by lowering sea level, intensifying atmospheric circulation, and increasing planetary albedo. Ice sheets interact with ocean water, forming water masses that play a key role in global ocean circulation.

We report the presence of Late Pleistocene piedmont glaciers represented by the largest hummocky
moraine field observed in the Eastern Mediterranean. The piedmont glaciers originated from the
Geyikdag ice cap (~40 km2), situated between 2350 and 2650 m above sea level (a.s.l.) (Central Tauride
Mountains of Turkey), and deeply carved the north-facing hillslopes before reaching the Namaras Valley
(2000e2050 m a.s.l). The hummocky moraines resulted from in-situ deposition of stagnant glacier ice
where debris cover was heterogeneously distributed on the glacier surface. Thirty-four boulders from
hummocky, disintegration, lateral and terminal moraines from the Namaras Valley and the tributary
Susam Valley (2100e2200 m a.s.l.) were dated by cosmogenic 36Cl surface exposure dating. The moraine
ages indicate three phases of deglaciation during the Late Pleistocene. The oldest deglaciation occurred in
the Namaras Valley at 18.0 ± 1.1 ka (ka: thousand years ago) towards the end of the Last Glacial
Maximum (LGM) and is recorded entirely by hummocky moraines. We speculate that hummocky
moraine forming processes with cycles of relief inversion gave rise to boulder apparent ages up to a few
thousand years younger in our study area. Therefore, 18.0 ± 1.1 ka should be regarded as a minimum age
with a probable true age much closer to the local-LGM values (~20 ka) as observed in the surrounding
mountains. Paleo-piedmont glaciers also deposited several lateral moraines that are ~50 m higher than
the hummocky moraines. Although the lateral moraines probably represent the build-up and the
hummocky moraines the final phase of the same local-LGM-pulse, both lateral moraines started to
retreat from the Late-glacial (14.0 ± 2.7 ka) and gradually disappeared by mid-Holocene (5.2 ± 1.0 ka),
encompassing the Younger Dryas (YD) stadial. In the Susam Valley, the Late-glacial is represented by a
terminal moraine (13.4 ± 1.5 ka). The glacier retreat was very fast as indicated by an almost instantaneous
disappearance of 5 km long Susam Valley glacier, represented by disintegration and hummocky
moraines (14.0 ± 1.3 ka). Alternatively, in case the oldest boulder age is taken into account, the Susam
Valley glacier can be also attributed to the late LGM (~17 ka) to Late-glacial (~14 ka) transition. Near the
exit of the Susam Valley a right lateral moraine was deposited 11.6 ± 1.3 ka ago, confirming the presence
of the YD in Geyikdag. Comparable glacial chronologies were obtained from other Turkish and Mediterranean
mountains.

"A recent paper by Hall (2010) argues that Quaternary ice masses in the Lesotho–Drakensberg region produced no subglacial erosional imprints and were therefore cold based. This argument is based upon (1) the comparison with cold-based glaciers in Tibet and Antarctica which occupy V-shaped fluvial valleys, and (2) an absence of reported evidence
for subglacial erosional forms, including striated clasts, in the Lesotho–Drakensberg region. Here, I suggest that Hall’s arguments are based on an incorrect understanding of glaciers and mountain systems, unsound inferences based thereon and failure to consider other explanations that are glaciologically and geomorphologically more likely. I first describe the glaciological and geomorphological factors that require further consideration,
and then identify the more likely processes and controls that could account for the landforms described by Hall."

Foreword: This paper was shortlisted in 2012 by the Royal Society of Chemistry as a contending hypothesis to explain the phenomenon known as the Mpemba Effect: whereby warm samples of water are sometimes observed to freeze more rapidly than colder samples of water under the same conditions. The presented hypothesis was ultimately deemed too radical an idea by the committee, because it contravenes received scientific wisdom on the thermodynamics of water. However, the theory obeys fundamental laws of physics and logic, and therefore offers an empirically tenable new paradigm about the behaviour of water that has potential significance for our understanding of the science of water and associated phenomena, including global warming. It is named Density Interface Energy Acquisition (DIEA). When water freezes it expands in volume, which is a rare characteristic shared with only few other substances, such as bismuth and antimony. Scientific law demands that for a substance to expand against atmospheric pressure it requires energy. Therefore, water requires energy from the environment in order to freeze, which appears to contradict the very concept of freezing, which is generally taken to mean the result of a linear loss of energy. This is why warm water can freeze more rapidly than colder water under controlled conditions, as it uses the additional energy to undergo the expansion process, thereby explaining the Mpemba Effect. This paradigm shows that ice is an energy store, which opposes received wisdom. It means that melting ice relinquishes that energy, thereby accelerating the melting process exponentially by providing the environment with more energy to warm the air. Clearly this has profound implications, as it means that a global thaw would be self-amplifying and result in a switching effect rather than a gradual process. The energy storage capacity of ice can be precisely calculated by the effort required to displace the atmosphere, so we know how much energy it surrenders when it melts. The amount of energy stored by ice is quite low per unit volume, but ice exists in vast quantities, so the accumulative effect of a thaw is to release enough energy to raise atmospheric temperature significantly. Warmer air means more ice melts, which means more energy is released to the atmosphere than the amount of energy used for the melting itself. In reverse, water relinquishes energy as it cools to zero degrees centigrade, but it then uses energy to become ice. Thus, if water is cooled very slowly to zero but has no access to expansive energy it will remain as a liquid and become supercooled. This can be achieved under carefully controlled conditions, as even vibrations can provide kinetic energy for the supercooled water to harvest for the purpose of forming ice. The kinetic energy doesn't raise the water temperature because it is solely used for expansion. The new paradigm counters common intuition, yet it conforms with fundamental physical principles and logic. The crucial detail is that it takes energy to push against atmospheric pressure. It is Newton's third law that states, whenever two objects interact they exert equal and opposite forces on one another. Ice would be unable to expand against the atmosphere without exerting force and the required energy has to come from somewhere. Furthermore, the energy cannot be stolen from the water itself, unless it has surplus, as that would require it to fall further in temperature within an environment that does not. Thus, the Mpemba Effect has revealed an unexpected behaviour in water that has been hiding in plain sight.