388 results on '"Vezzoli, Giovanni"'
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52. From Patagonia to Río de la Plata: Multistep long‐distance littoral transport of Andean volcaniclastic sand along the Argentine passive margin
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Garzanti, Eduardo, primary, Limonta, Mara, additional, Vezzoli, Giovanni, additional, and Sosa, Numa, additional
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- 2021
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53. Petrology of Rifted‐Margin Sand (Red Sea and Gulf of Aden, Yemen)
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Garzanti, Eduardo, Vezzoli, Giovanni, Andò, Sergio, and Castiglioni, Giovanna
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- 2001
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54. Correction: Corrigendum: Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment
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Nie, Junsheng, Stevens, Thomas, Rittner, Martin, Stockli, Daniel, Garzanti, Eduardo, Limonta, Mara, Bird, Anna, Andò, Sergio, Vermeesch, Pieter, Saylor, Joel, Lu, Huayu, Breecker, Daniel, Hu, Xiaofei, Liu, Shanpin, Resentini, Alberto, Vezzoli, Giovanni, Peng, Wenbin, Carter, Andrew, Ji, Shunchuan, and Pan, Baotian
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- 2016
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55. Physical controls on sand composition and relative durability of detrital minerals during ultra-long distance littoral and aeolian transport (Namibia and southern Angola)
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GARZANTI, EDUARDO, RESENTINI, ALBERTO, ANDÒ, SERGIO, VEZZOLI, GIOVANNI, PEREIRA, ALCIDES, and VERMEESCH, PIETER
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- 2015
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56. Sand and mud generation from continental flood basalts in contrasting landscapes and climatic conditions (Paraná–Etendeka conjugate igneous provinces, Uruguay and Namibia)
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Garzanti, Eduardo, primary, Dinis, Pedro, additional, Vezzoli, Giovanni, additional, and Borromeo, Laura, additional
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- 2021
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57. The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals
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Garzanti, Eduardo, primary, Pastore, Guido, additional, Resentini, Alberto, additional, Vezzoli, Giovanni, additional, Vermeesch, Pieter, additional, Ncube, Lindani, additional, Niekerk, Helena Johanna Van, additional, Jouet, Gwenael, additional, and Dall’Asta, Massimo, additional
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- 2021
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58. The Congo deep-sea fan: Mineralogical, REE, and Nd-isotope variability in quartzose passive-margin sand
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Garzanti, Eduardo, primary, Bayon, Germain, additional, Dennielou, Bernard, additional, Barbarano, Marta, additional, Limonta, Mara, additional, and Vezzoli, Giovanni, additional
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- 2021
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59. Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina)
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Garzanti , Eduardo, Capaldi , Tomas, Vezzoli , Giovanni, Limonta , Mara, and Sosa , Numa
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Central Argentina from the Pampean flat-slab segment to northern Patagonia (27-41°S) represents a classic example of a broken retroarc basin with strong tectonic and climatic control on fluvial sediment transport. In this provenance study, we combine framework petrography and heavy-mineral data to trace multistep dispersal of volcaniclastic detritus first eastwards across central Argentina for up to ~1500 km and next northwards for nearly another 1000 km along the Atlantic coast. Compositional signatures reflect different tectono-stratigraphic levels of the orogen uplifted along strike in response to varying subduction geometry as well as a different character and crystallization condition of arc magmas through time and space. In the presently dry climate, fluvial discharge is drastically reduced to the point that even the Desaguadero trunk river has become endorheic and orogenic detritus is dumped in the retroarc basin, reworked by winds, and temporarily accumulated in dune fields. At Pleistocene to early Holocene times, instead, much larger amounts of water were released by melting of the Cordilleran ice sheet or during pluvial events. The sediment-laden waters of the Desaguadero and Colorado rivers then rushed from the tract of the Andes with greatest topographic and structural elevation, fostering alluvial fans inland and flowing in much larger valleys than today toward the Atlantic Ocean. Sand and gravel supply to the coast was high enough not only to promote rapid progradation of large deltaic lobes but also to feed a cell of littoral sediment transport extending as far north as the Río de la Plata estuary.
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- 2021
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60. The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals
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Garzanti, Eduardo, Pastore, Guido, Resentini, Alberto, Vezzoli, Giovanni, Vermeesch, Pieter, Ncube, Lindani, Niekerk, Helena Johanna Van, Jouet, Gwenael, Dall’asta, Massimo, Garzanti, Eduardo, Pastore, Guido, Resentini, Alberto, Vezzoli, Giovanni, Vermeesch, Pieter, Ncube, Lindani, Niekerk, Helena Johanna Van, Jouet, Gwenael, and Dall’asta, Massimo
- Abstract
The Zambezi River rises at the center of southern Africa, flows across the low-relief Kalahari Plateau, meets Karoo basalt, plunges into Victoria Falls, follows along Karoo rifts, and pierces through Precambrian basement to eventually deliver its load onto the Mozambican passive margin. Reflecting its polyphase evolution, the river is subdivided into segments with different geological and geomorphological character, a subdivision finally fixed by man’s construction of large reservoirs and faithfully testified by sharp changes in sediment composition. Pure quartzose sand recycled from Kalahari desert dunes in the uppermost tract is next progressively enriched in basaltic rock fragments and clinopyroxene. Sediment load is renewed first downstream of Lake Kariba and next downstream of Lake Cahora Bassa, documenting a stepwise decrease in quartz and durable heavy minerals. Composition becomes quartzo-feldspathic in the lower tract, where most sediment is supplied by high-grade basements rejuvenated by the southward propagation of the East African rift. Feldspar abundance in Lower Zambezi sand has no equivalent among big rivers on Earth and far exceeds that in sediments of the northern delta, shelf, and slope, revealing that provenance signals from the upper reaches have ceased to be transmitted across the routing system after closure of the big dams. This high-resolution petrologic study of Zambezi sand allows us to critically reconsider several dogmas, such as the supposed increase of mineralogical “maturity” during long-distance fluvial transport, and forges a key to unlock the rich information stored in sedimentary archives, with the ultimate goal to accurately reconstruct the evolution of this mighty river flowing across changing African landscapes since the late Mesozoic.
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- 2021
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61. Skeletal assemblages and terrigenous input in the Eocene carbonate systems of the Nummulitic Limestone (NW Europe)
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Coletti, G, Mariani, L, Garzanti, E, Consani, S, Bosio, G, Vezzoli, G, Hu, X, Basso, D, Coletti, Giovanni, Mariani, Luca, Garzanti, Eduardo, Consani, Sirio, Bosio, Giulia, Vezzoli, Giovanni, Hu, Xiumian, Basso, Daniela, Coletti, G, Mariani, L, Garzanti, E, Consani, S, Bosio, G, Vezzoli, G, Hu, X, Basso, D, Coletti, Giovanni, Mariani, Luca, Garzanti, Eduardo, Consani, Sirio, Bosio, Giulia, Vezzoli, Giovanni, Hu, Xiumian, and Basso, Daniela
- Abstract
Terrigenous input is often considered detrimental for carbonate producing organisms, however, the common occurrence of mixed siliciclastic–bioclastic deposits indicates that the relationship between carbonate factories and terrigenous fluxes is a complex issue. To investigate this subject, we analyzed the skeletal assemblages of the Paleogene Alpine foreland basin in a wide area encompassing NW Italy and SE France. Four different sections, Mortola, Loreto, Braux and Lauzanier, deposited between the Bartonian and the Priabonian, were studied in detail and, based on microfacies analysis, six main biofacies were recognized: i) nummulitid biofacies and ii) acervulinid and coralline algal biofacies related to shallow water; iii) nummulitid and orthophragminid biofacies and iv) coralline-algal branches and large benthic foraminifera biofacies related to intermediate depth; v) orthophragminid biofacies and vi) orthophragminid and coralline algal biofacies related to deeper settings. Thin sections and X-ray diffraction analyses show that these biofacies can be related to two major carbonate factories. The former was dominated by free-living benthic foraminifera and was characterized by a relevant terrigenous fraction, indicating free-living benthic foraminifera as the most terrigenous-tolerant group of carbonate producers of the Nummulitic Limestone system. The latter was dominated by encrusting acervulinids and coralline algae and thrived far-off major terrigenous sources. Conversely, recent and Neogene coralline algae are known to be able to tolerate high sedimentation rates. The distribution of coralline-algal-rich skeletal assemblages in the Nummulitic Limestone thus hints that Eocene coralline algae might have been fundamentally different (probably less adaptable) than their more modern counterparts.
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- 2021
62. Tracking sediment provenance and erosional evolution of the western Greater Caucasus
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Vezzoli, Giovanni, Garzanti, Eduardo, Vincent, Stephen J., Andò, Sergio, Carter, Andrew, and Resentini, Alberto
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- 2014
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63. Interplay of Holocene surface faulting and climate in the Central Po Plain, Italy.
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Zanchi, Andrea, Ravazzi, Cesare, Cavallin, Angelo, Deaddis, Massimiliano, De Amicis, Mattia, Arosio, Tito, Marchetti, Mauro, and Vezzoli, Giovanni
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HOLOCENE Epoch ,EARTHQUAKE hazard analysis ,PLAINS ,RADIOCARBON dating ,PALEOSEISMOLOGY - Abstract
Understanding the recent events marking the late Quaternary history of the Po Plain (N-Italy) is of overriding importance to decipher the record of depositional versus erosional phases, and their interplay with climatic, tectonic, and human forcing. We reconstructed the structural setting and chronostratigraphy of a Holocene succession crosscut by a thrust fault located south of Montodine (Cremona, Italy) within the Po Plain. The fault shows a maximum displacement up to one meter. Radiocarbon dating fixes a minimum age of 11.9 cal ka BP for the postglacial river entrenchment and constrains the fault movement age between 5.9 and 3.4 cal ka BP. Undeformed Late Medieval coarse gravels cover the faulted succession. Due to the outcrop position, lying above the buried frontal thrusts of the Southern Alps and North Apennines, we propose that faulting results from secondary surface effects induced by seismic shaking. We discuss two main mechanisms, both related to lateral spreading, that can result in the formation of reverse faults close to the surface. The Soncino area, recording one of the strongest historical earthquakes of the central Po Plain (1802), is considered as a possible source for seismic shaking. The results of this study are a contribution for the assessment of the potential seismic hazard in one of the most populated regions of Europe. [ABSTRACT FROM AUTHOR]
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- 2022
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64. The exhumation of the Indo-Burman Ranges, Myanmar
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Najman, Yani, Sobel, Ed, Millar, Ian, Stockli, Dan, Govin, Gwladys, Lisker, Frank, Garzanti, Eduardo, Limonta, Mara, Vezzoli, Giovanni, Copley, Alex, Szymanski, Eugene, Kahn, Alicia, Zhang, Peng, Najman, Yani, Sobel, Ed, Millar, Ian, Stockli, Dan, Govin, Gwladys, Lisker, Frank, Garzanti, Eduardo, Limonta, Mara, Vezzoli, Giovanni, Copley, Alex, Szymanski, Eugene, Kahn, Alicia, and Zhang, Peng
- Abstract
The Indo-Burman Ranges (IBR) are a mountain range comprised of Mesozoic-Cenozoic rocks which run the length of Western Myanmar, extending into India and Bangladesh; to the west lies the Indian Ocean, and to the east lies the Central Myanmar Basin (CMB) along which the Irrawaddy River flows. The IBR are considered to be an accretionary prism, developed at the juncture of the Indian and Sunda plates, and a number of hypotheses have been proposed for their evolution. However, in order for these hypotheses to be evaluated, the timing of IBR evolution needs to be determined. We undertook a two-pronged approach to determining the timing of uplift of the IBR. (1) We present the first low-temperature thermochronological age elevation profiles of the IBR using ZFT, AFT and ZHe techniques. Our data show: a major period of exhumation occurred around the time of the Oligo-Miocene boundary; we tentatively suggest, subject to further verification, an additional period of exhumation at or before the late Eocene. (2) We carried out a detailed multi-technique provenance study of the sedimentary rocks of the IBR and Arakan Coastal region to their west, and compared data to coeval rocks of the CMB. We determined that during Eocene times, rocks of the CMB and IBR were derived from similar local provenance, that of the Myanmar arc to the east. Therefore at this time there was an open connection from arc to ocean. By contrast, by Miocene times, provenance diverged. Rocks of the CMB were deposited by a through-flowing Irrawaddy River, with detritus derived from its upland source region of the Mogok Metamorphic Belt and Cretaceous-Paleogene granites to the north. Such a provenance is not recorded in coeval rocks of the IBR, indicating that the IBR had uplifted by this time, providing a barrier to transport of material to the west. To the previously published list of viable proposals to explain the exhumation of the range, we add a new suggestion: the period of exhumation around the time of
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- 2020
65. Provenance of Cenozoic Indus Fan Sediments (IODP Sites U1456 and U1457)
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Garzanti, E, Andò, S, Vezzoli, G, Garzanti, Eduardo, Andò, Sergio, Vezzoli, Giovanni, Garzanti, E, Andò, S, Vezzoli, G, Garzanti, Eduardo, Andò, Sergio, and Vezzoli, Giovanni
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Provenance analysis of IODP Expedition 355 cores in the Laxmi Basin sheds new light on the erosional evolution of the Himalayan belt and its western syntaxis during the Neogene and on large-scale mass-wasting and magmatic events that affected the western continental margin of India in the mid-Miocene and early Paleocene. In the cored Laxmi Basin succession, heavy minerals are far less affected by selective diagenetic dissolution than in forelandbasin sandstones exposed along the Himalayan front. Occurrence of euhedral aegirine and apatite in lower Paleocene mudrocks can be tied to alkaline volcanism affecting the adjacent western Indian margin during the late stage of Deccan activity. In the mid-Miocene Nataraja Slide (the second-largest mass-transport deposit reported from passive margins worldwide), dominant carbonate detritus and depleted heavy-mineral suites (including apatite, garnet, and locally augite or rare aegirine) reveal gravitational failure and sliding of the entire succession of carbonate and siliciclastic Paleogene to lower Neogene strata originally accumulated offshore of the Saurashtra margin of western India. Contrary to previous inferences, reworking of Indus-derived detritus by the slide was negligible. The overlying upper Miocene to lower Pleistocene turbidite package has the same feldspatho-litho-quartzose to litho-feldspathoquartzose signature of modern Indus fluvio-deltaic sand, indicating that amphibolite-facies metamorphic rocks have been widely exposed in the Himalaya–Karakorum orogen since at least the mid-Miocene. Pleistocene nannofossil oozes with planktonic foraminifera at the top of the fan contain a very subordinate litho-feldspatho-quartzose terrigenous fraction including augitic clinopyroxene, suggesting mixing of dominant biogenic debris with minor detritus contributed both by the Indus River and by a river draining western peninsular India, possibly the paleo-Narmada or the paleo-Tapti.
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- 2020
66. Testing Models of Cenozoic Exhumation in the Western Greater Caucasus
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Vincent, S, Somin, M, Carter, A, Vezzoli, G, Fox, M, Vautravers, B, Vincent, Stephen J., Somin, Mark L., Carter, Andrew, Vezzoli, Giovanni, Fox, Matthew, Vautravers, Benoit, Vincent, S, Somin, M, Carter, A, Vezzoli, G, Fox, M, Vautravers, B, Vincent, Stephen J., Somin, Mark L., Carter, Andrew, Vezzoli, Giovanni, Fox, Matthew, and Vautravers, Benoit
- Abstract
The Greater Caucasus form the northernmost deformation front of the Arabia-Eurasia collision zone. Earlier thermochronometric studies on the crystalline core of the western Greater Caucasus highlighted an abrupt along-strike increase in cooling ages to the west of Mt. Elbrus. Twenty-eight thermochronometric analyses conducted as part of this study confirm this pattern. Overall Cenozoic exhumation was restricted to less than 5–7 km, with slow to moderate punctuated Oligo-Miocene cooling. Cooling rates increased during the Late Miocene to Pliocene. These are most rapid east of Mt. Elbrus, where they probably increased later than farther west (at c. 5 Ma rather than 10–8 Ma). Differential cooling rates do not appear to be driven by lateral variations in tectonic shortening. The region undergoing rapid young cooling does coincide, however, with an area of mantle-sourced Late Miocene and younger magmatism. Thermal relaxation or overprinting is ruled out because geomorphic and modern sediment flux data mirror the thermochronometric trends. The buoyancy effects of demonstrable mantle upwelling are capable of causing the magnitude of exhumation-related cooling recorded in this study, but typically act over wavelengths of several 100 km. We suggest that lithospheric heterogeneities are responsible for modulating the shorter wavelength differences in exhumation rate documented here. These heterogeneities may include the continuation of the same structures responsible for the eastern margin of the Stavropol High to the north of the Caucasus, although further work is required. Similar abrupt variations in mantle-supported uplift and exhumation modulated by crustal structure may occur in other mountain belts worldwide.
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- 2020
67. Tracing erosion patterns in South Tibet: Balancing sediment supply to the Yarlung Tsangpo from the Himalaya versus Lhasa Block.
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Liang, Wendong, Garzanti, Eduardo, Hu, Xiumian, Resentini, Alberto, Vezzoli, Giovanni, and Yao, Wensheng
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RARE earth metals ,EROSION ,HEAVY minerals ,SUTURE zones (Structural geology) ,SEDIMENTS ,SEDIMENT control - Abstract
The Yarlung Tsangpo, draining the Himalayan‐Tibetan orogen along the Indus‐Yarlung suture zone, receives detritus from the deformed remnants of both Indian margin to the south and Asian margin to the north. High resolution petrographic, heavy‐mineral and geochemical datasets, combined with published geochronological data, allow us to monitor compositional changes, estimate erosion rates and investigate lithologic, climatic and anthropic controls on sediment fluxes along this large sediment‐routing system entirely developed within high mountain areas. Sediment generated from the Lhasa Block along the southern margin of Asia is characterized by abundant feldspar and volcanic rock fragments, amphibole‐dominated transparent heavy mineral suite and high concentrations of K, Rb, Be, Th and Pb. Himalayan‐derived sand, instead, is characterized by sedimentary to low‐rank metasedimentary rock fragments, poor transparent heavy mineral suite dominated by durable recycled (zircon, tourmaline) or metamorphic minerals (chloritoid, garnet) and high Ca concentration. Sand from the ophiolitic suture is distinguished by serpentinite grains and mafic volcanic or metavolcanic detritus, transparent heavy mineral suite including olivine, Cr‐spinel, enstatite and clinopyroxene, and high Mg, Cr, Ni and low rare earth elements. Himalayan detritus is prominent in Yarlung Tsangpo upper reaches, whereas detritus from the Lhasa Block becomes progressively predominant in the middle and lower reaches. Provenance budgets based on integrated petrographic, heavy‐mineral and geochemical datasets indicate that ca. 83% of the detritus is supplied by the Lhasa Block and the rest mostly from the Himalaya (ca. 12%) and subordinately from the ophiolitic suture (5%). A low average erosion rate of ca. 0.06 mm/a was estimated for the Yarlung Tsangpo catchment upstream of the Namche Barwa syntaxis, which resulted from dry climate, relatively mild average relief and sediment storage in wide valley tracts of the middle and lower reaches. The decrease in sediment flux recorded in recent decades is mainly ascribed to growing human activities, which are becoming a prominent control on sediment generation and transportation even in the high‐mountain area of South Tibet. [ABSTRACT FROM AUTHOR]
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- 2022
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68. Provenance of Cenozoic Indus Fan Sediments (IODP Sites U1456 and U1457)
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Garzanti, Eduardo, primary, Andò, Sergio, additional, and Vezzoli, Giovanni, additional
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- 2020
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69. Deciphering relationships between the Nicobar and Bengal submarine fans, Indian Ocean
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Pickering, Kevin T., primary, Carter, Andrew, additional, Andò, Sergio, additional, Garzanti, Eduardo, additional, Limonta, Mara, additional, Vezzoli, Giovanni, additional, and Milliken, Kitty L., additional
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- 2020
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70. Tectono-stratigraphic evolution of the intermontane Tarom Basin (NW sectors of the Arabia-Eurasia collision zone): insights into the vertical growth of the Iranian Plateau margin
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Paknia, Mohammad, primary, Ballato, Paolo, additional, Mattei, Massimo, additional, Heidarzadeh, Ghassem, additional, Cifelli, Francesca, additional, Hassanzadeh, Jamshid, additional, Vezzoli, Giovanni, additional, Mirzaie Ataabadi, Majid, additional, and Ghassemi, Mohammad R., additional
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- 2020
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71. Testing Models of Cenozoic Exhumation in the Western Greater Caucasus
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Vincent, Stephen J., primary, Somin, Mark L., additional, Carter, Andrew, additional, Vezzoli, Giovanni, additional, Fox, Matthew, additional, and Vautravers, Benoit, additional
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- 2020
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72. The exhumation of the Indo-Burman Ranges, Myanmar
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Najman, Yani, primary, Sobel, Edward R., additional, Millar, Ian, additional, Stockli, Daniel F., additional, Govin, Gwladys, additional, Lisker, Frank, additional, Garzanti, Eduardo, additional, Limonta, Mara, additional, Vezzoli, Giovanni, additional, Copley, Alex, additional, Zhang, Peng, additional, Szymanski, Eugene, additional, and Kahn, Alicia, additional
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- 2020
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73. Pyroxene-rich Orange sand highway from basaltic highlands to the ocean: Modern sediment-routing system of an Early Jurassic river
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Garzanti, Eduardo, Pastore, Guido, Andò, Sergio, Barbarano, Marta, Resentini, Alberto, Vezzoli, Giovanni, Vermeesch, Pieter, Dinis, Pedro, Hahn, Annette, Wiles, Errol, Ncube, Lindani, and Van Niekerk, Helena-Johanna
- Abstract
·Orange River formed as dome-flank drainage after Jurassic Karoo magmatic upwelling.·Zircon is mostly recycled: prominent Pan-African ages without Pan-African basement.·> 4000 km of high-energy fluvial and coastal transport traced by pyroxene-rich sand.
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- 2024
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74. Sand petrology and focused erosion in collision orogens: the Brahmaputra case
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Garzanti, Eduardo, Vezzoli, Giovanni, Andò, Sergio, France-Lanord, Christian, Singh, Sunil K., and Foster, Gavin
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- 2004
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75. Erosion in the Western Alps (Dora Baltea basin): 1. Quantifying sediment provenance
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Vezzoli, Giovanni, Garzanti, Eduardo, and Monguzzi, Stefano
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- 2004
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76. Erosion in the Western Alps (Dora Baltea Basin): 2. Quantifying sediment yield
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Vezzoli, Giovanni
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- 2004
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77. The initiation and evolution of the River Nile
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Fielding, Laura, Najman, Yani, Millar, Ian, Butterworth, Peter, Garzanti, Eduardo, Vezzoli, Giovanni, Barfod, Dan, and Kneller, Ben
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The Nile is generally regarded as the longest river in the world. Knowledge of the timing of the Nile's initiation as a major river is important to a number of research questions. For example, the timing of the river's establishment as a catchment of continental proportions can be used to document surface uplift of its Ethiopian upland drainage, with implications for constraining rift tectonics. Furthermore, the time of major freshwater input to the Mediterranean is considered to be an important factor in the development of sapropels. Yet the river's initiation as a major drainage is currently constrained no more precisely than Eocene to Pleistocene.\ud \ud Within the modern Nile catchment, voluminous Cenozoic Continental Flood Basalts (CFBs) are unique to the Ethiopian Highlands; thus first detection of their presence in the Nile delta record indicates establishment of the river's drainage at continental proportions at that time. We present the first detailed multiproxy provenance study of Oligocene–Recent Nile delta cone sediments. We demonstrate the presence of Ethiopian CFB detritus in the Nile delta from the start of our studied record (c. 31 Ma) by (1) documenting the presence of zircons with U–Pb ages unique, within the Nile catchment, to the Ethiopian CFBs and (2) using Sr–Nd data to construct a mixing model which indicates a contribution from the CFBs. We thereby show that the Nile river was established as a river of continental proportions by Oligocene times. We use petrography and heavy mineral data to show that previous petrographic provenance studies which proposed a Pleistocene age for first arrival of Ethiopian CFBs in the Nile delta did not take into account the strong diagenetic influence on the samples.\ud \ud We use a range of techniques to show that sediments were derived from Phanerozoic sedimentary rocks that blanket North Africa, Arabian–Nubian Shield basement terranes, and Ethiopian CFB's. We see no significant input from Archaean cratons supplied directly via the White Nile in any of our samples. Whilst there are subtle differences between our Nile delta samples from the Oligocene and Pliocene compared to those from the Miocene and Pleistocene, the overall stability of our signal throughout the delta record, and its similarity to the modern Nile signature, indicates no major change in the Nile's drainage from Oligocene to present day.
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- 2018
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78. Provenance of Bengal Shelf Sediments: 2. Petrology and Geochemistry of Sand
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Garzanti, Eduardo, primary, Vezzoli, Giovanni, additional, Andò, Sergio, additional, Limonta, Mara, additional, Borromeo, Laura, additional, and France-Lanord, Christian, additional
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- 2019
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79. The provenance of Taklamakan desert sand
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Rittner, Martin, Vermeesch, Pieter, Carter, Andrew, Bird, Anna, Stevens, Thomas, Garzanti, Eduardo, Andò, Sergio, Vezzoli, Giovanni, Dutt, Ripul, Xu, Zhiwei, and Lu, Huayu
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- 2016
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80. Tracing Transcontinental Sand Transport: from Anatolia–zagros To the Rub' Al Khali Sand Sea
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Garzanti, Eduardo, primary, Vermeesch, Pieter, additional, Al-Ramadan, Khalid Abdulsamad, additional, AndÒ, Sergio, additional, Limonta, Mara, additional, Rittner, Martin, additional, and Vezzoli, Giovanni, additional
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- 2017
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81. The upper Palaeozoic Godar-e-Siah Complex of Jandaq: Evidence and significance of a North Palaeotethyan succession in Central Iran
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Berra, F, Zanchi, A, Angiolini, L, Vachard, D, Vezzoli, G, Zanchetta, S, Bergomi, M, Javadi, H, Kouhpeyma, M, ZANCHI, ANDREA MARCO, VEZZOLI, GIOVANNI, ZANCHETTA, STEFANO, BERGOMI, MARIA ALDINA, Kouhpeyma, M., Berra, F, Zanchi, A, Angiolini, L, Vachard, D, Vezzoli, G, Zanchetta, S, Bergomi, M, Javadi, H, Kouhpeyma, M, ZANCHI, ANDREA MARCO, VEZZOLI, GIOVANNI, ZANCHETTA, STEFANO, BERGOMI, MARIA ALDINA, and Kouhpeyma, M.
- Abstract
The Upper Palaeozoic Godar-e-Siah Complex of Jandaq, Central Iran, comprises three isolated, fault-bounded outcrops exposing Palaeozoic fossiliferous carbonates, volcanics and siliciclastics, which are markedly distinct from the surrounding sedimentary successions. The three outcrops, that emerge below Cretaceous and younger sediments, are the Chah Rizab outcrop, the Godar-e-Siah northern outcrop, and the Godar-e-Siah central outcrop. Their sedimentary successions strongly differ from the typical passive margin successions of Gondwanan affinity that characterize the Yazd, Lut and Tabas blocks of Central Iran and the Alborz in North Iran. To understand the origin of these profound differences, we first calibrated the age of the Jandaq successions: U-Pb radiometric zircons ages, obtained from granitoid boulders in the conglomerates at Chah Rizab and in the Godar-e-Siah northern outcrop, gave a Late Devonian to Mississippian age. Biostratigraphic data from brachiopods and fusulinids from the Godar-e-Siah northern and central outcrops indicate a Pennsylvanian age. The age of the successions is thus post-Visean to Pennsylvanian. The petrographic composition of the siliciclastic deposits indicates the erosion of a magmatic arc. To understand where the Jandaq complex could have been located at that time, we have assessed the palaeobiogeographic affinity of the faunas. The collected brachiopods and fusulinids assemblages are mostly similar to coeval faunas from Spain, Donbass, Urals, and Yukon Territory (Canada) and have a North-Palaeotethyan affinity. The Godar-e-Siah Complex of Jandaq likely represents part of the southern active margin of Eurasia (northern margin of the Palaeotethys), in contrast to the surrounding Central and North Iran blocks, which were at that time located along the southern margin of the Neotethys. Our investigations confirm a complex palaeogeographic evolution for the studied outcrops, suggesting that they represent fragments of the southern Eurasi
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- 2017
82. Sedimentary processes controlling ultralong cells of littoral transport: Placer formation and termination of the Orange sand highway in southern Angola
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Garzanti, Eduardo, primary, Dinis, Pedro, additional, Vermeesch, Pieter, additional, Andò, Sergio, additional, Hahn, Annette, additional, Huvi, João, additional, Limonta, Mara, additional, Padoan, Marta, additional, Resentini, Alberto, additional, Rittner, Martin, additional, and Vezzoli, Giovanni, additional
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- 2017
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83. The upper Palaeozoic Godar-e-Siah Complex of Jandaq: Evidence and significance of a North Palaeotethyan succession in Central Iran
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Berra, Fabrizio, primary, Zanchi, Andrea, additional, Angiolini, Lucia, additional, Vachard, Daniel, additional, Vezzoli, Giovanni, additional, Zanchetta, Stefano, additional, Bergomi, Maria, additional, Javadi, Hamid Reza, additional, and Kouhpeyma, Meyssam, additional
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- 2017
- Full Text
- View/download PDF
84. Petrology of the Tista and Rangit river sands (Sikkim, India)
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Vezzoli, Giovanni, primary, Lombardo, Bruno, primary, and Rolfo, Franco, primary
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- 2017
- Full Text
- View/download PDF
85. From build-up to pebbles: brief history of a crustose coralline build-up of the Upper Eocene of Northwestern Italy
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COLETTI, GIOVANNI, BASSO, DANIELA MARIA, DI CAPUA, ANDREA, VEZZOLI, GIOVANNI, Coletti, G, Basso, D, DI CAPUA, A, and Vezzoli, G
- Subjects
Gonfolite Group ,Ternate Formation ,GEO/02 - GEOLOGIA STRATIGRAFICA E SEDIMENTOLOGICA ,Eocene ,Coralline algae - Abstract
Fossil crustose coralline framework are known from the Eocene onward, with occurrences in middle Eocene of Spain, the Upper Eocene of Northern Italy, the Miocene of Malta and Poland and the Plio-Pleistocene of the Mediterranean. The studied example presents a coralline algae framework from the Upper Eocene of Northwestern Italy. Although the carbonate platform where the build-up developed is lost, its remains are preserved. Reworked skeletal grains, transported off shore by debris-flow, are preserved in the Ternate Formation, a deep-water sub-marine fan. In the Upper Oligocene conglomerates of the Gonfolite Lombarda Group, biogenic carbonate pebbles of Upper Eocene age are preserved. Textural characteristics, skeletal assemblages, coralline-algae flora and benthic foraminifers composing the pebbles were studied and compared to those of Ternate Fm. The same rhodalgal skeletal-assemblage, the same species of coralline algae and the same association of benthic foraminifers were found in both set of samples, suggesting their common origin. While Ternate Fm. materials were undoubtedly reworked during transport, the limestone pebbles are pristine fragments of the original carbonate platform which was uplifted and eroded between Upper Eocene and Upper Oligocene. They actually have no internal textural features suggesting reworking (common orientation of the grains, high degree of sorting, presence of rip-up clasts, fragmentation of delicate skeletal elements). The remnant of the crustose coralline framework was preserved in these pebbles. Neogoniolithon sp. is the most common crust-forming species, this alga has the ability to grow directly over fine grained mobile substrate and thus has a pivotal role in framework formation. Although the preserved framework was only observed in limestone pebbles, fragments of Neogoniolithon sp. crusts were commonly observed in all the samples of Ternate Fm., testifying the importance of this framework builder in the carbonate factory. Sporolithon aschersonii and the encrusting foraminifer Acervulina linearis, together with encrusting bryozoans also contributed to the building of the framework. Compared to other European examples of the same age the studied skeletal association lacks fragments of hermatypic corals. The exclusion of corals may have been caused by the general instability of the environment. Ternate Fm. sub-marine fan was supplied by periodic debris flow, probably started by river floods. These events were able to sweep away the platform with enough energy to carry large boulders and to rip away fragments of the substrate several meters in length. Lumps of sediment, rich in hydrocarbons and pyrite, have been observed in the Ternate Fm., suggesting that bottom waters were occasionally and locally depleted in oxygen. The lack of oxygen was probably caused by recurrent high riverine discharge of organic matter and nutrients. The combined stressful effects of bottom instability and riverine discharge probably excluded corals from the association. The integrated study of the abundant but reworked materials of the Ternate Fm. and of the pristine, but rare, limestone pebbles of the Gonfolite Group allowed the reconstruction of a otherwise lost Eocene carbonate factory.
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- 2015
86. What killed the Tertiary Southalpine carbonate platform?
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DI CAPUA, ANDREA, COLETTI, GIOVANNI, VEZZOLI, GIOVANNI, DI CAPUA, A, Coletti, G, and Vezzoli, G
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Southalpine, Carbonate Platform, Ternate Formation, Gonfolite Group ,GEO/02 - GEOLOGIA STRATIGRAFICA E SEDIMENTOLOGICA ,Eocene - Abstract
The carbonate platforms of the Tertiary Alpine basins (Northalpine Molassa and Southalpine Foredeep basin) are shaped by the different geodynamic settings. According to the classification of Bosence (2005-Sed.Geo.), the Northalpine basin hosted a foreland margin platform (Nummulitic Limestones), whereas the Southalpine basin probably hosted a thurst-top platform that supplied the shallow-water carbonate turbidites of the Ternate Formation. Actually, this latter carbonate platform is no more present, rapidly eroded during the Oligo-Miocene evolution of the Southern Alps, but a paleoecological reconstruction have been provided by Coletti et al. (in prep.) through the analysis of pebbles encountered in the Oligo-Miocene siliciclastic turbidite fan of the Gonfolite Lombarda Group. Here, we first reconstructed the suitable conditions of rise and growth of this narrow platform on top of the active thrusts of the Southern Alps during the Eocene and Early Oligocene, and then investigated the geodynamic processes that have contributed to killing it in the Early Oligocene. We envisaged a top-thrust platform grown up in front of gentle relieves of Jurassic to Cretaceous sedimentary covers, as suggested by the abundant and angular Mesozoic pebbles encountered in the turbidite fan of the Ternate Formation. The large presence of mass flow deposits and marly, often plurimetric soft clasts also suggests that a small, instable delta was frequently discharging terrigenous detritus through flash flood events moving across the platform deep into the basin. The abrupt disappearance of re-sedimented shallow-water carbonates probably corresponded to the death of the platform soon after the Early Oligocene, but doubts are still present on the causes that triggered it. The temporal gap (at least 5 Ma) that divides the top of the Ternate Formation and the first clastic inputs of the Gonfolite Lombarda Group (~27 Ma) may indicate that the onset of the major phase of growth of the Alpine belt was not the primary cause of the disappearance of the narrow Tertiary Southalpine platform, but maybe the changed climate conditions exposed it to karsification processes and prevented its survival.
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- 2015
87. Reconstruction of a lost carbonate factory based on its biogenic detritus (Ternate-Travedona Formation and Gonfolite Lombarda Group - Northern Italy)
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Coletti, G, Vezzoli, G, DI CAPUA, A, Basso, D, COLETTI, GIOVANNI, VEZZOLI, GIOVANNI, DI CAPUA, ANDREA, BASSO, DANIELA MARIA, Coletti, G, Vezzoli, G, DI CAPUA, A, Basso, D, COLETTI, GIOVANNI, VEZZOLI, GIOVANNI, DI CAPUA, ANDREA, and BASSO, DANIELA MARIA
- Abstract
This work reconstructs a now completely eroded late Eocene to earliest Oligocene carbonate factory of Northern Italy, through the analysis of a carbonate deep-water-fan sequence (Ternate-Travedona Formation) and the limestone detritus dispersed into the late Oligocene clastic-wedge of the Gonfolite Lombarda Group. Textural characteristics and skeletal assemblages of the Gonfolite pebbles were studied and compared to those of the Ternate-Travedona Formation. The same skeletal assemblage and the same taxa were found in samples from both areas, suggesting their common origin. Whereas the Ternate-Travedona Formation skeletal grains were reworked during transport, the Gonfolite Lombarda Group pure-limestone pebbles are pristine fragments of the carbonate platform, that was uplifted and eroded from the late Eocene to the early Oligocene. Using both these sources of information it was possible to reconstruct the late Eocene environment and its facies distribution. The areas undergoing high hydrodynamic energy were dominated by free-living coralline-algal branches, rhodoliths and larger thick-tested benthic foraminifera. A coralline framework, associated with thin-tested benthic foraminifera and boxwork rhodoliths, was present in slightly deeper and sheltered environments. Episodic debris flows, mainly triggered by river floods, supplied the sub-marine fan of the Ternate-Travedona Formation. These events were able to down-cut through the narrow platform and rip off large fragments of the substrate. River runoff probably also supplied large quantities of organic matter, leading to local oxygen-depletion and preservation of organic matter. The combined stressful effects of bottom instability and riverine discharge probably excluded corals from the association. The integrated study of the Ternate-Travedona Formation, and of the limestone pebbles in the Gonfolite Group, have enabled the reconstruction of this otherwise lost Eocene carbonate factory.
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- 2016
88. Tracing provenance and sediment fluxes in the Irrawaddy River basin (Myanmar)
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Garzanti, E, Wang, J, Vezzoli, G, Limonta, M, GARZANTI, EDUARDO, VEZZOLI, GIOVANNI, LIMONTA, MARA, Garzanti, E, Wang, J, Vezzoli, G, Limonta, M, GARZANTI, EDUARDO, VEZZOLI, GIOVANNI, and LIMONTA, MARA
- Abstract
This study illustrates the petrographic, heavy-mineral, geochemical and geochronological signatures of sand transported by various branches of the Irrawaddy (Ayeyarwadi) River, one of the first in the world for sediment flux. Intrasample and intersample compositional variability, weathering and hydraulic-sorting controls are also discussed. Feldspatho-quartzose sand in Irrawaddy headwaters is largely derived first-cycle from mid-crustal metamorphic and plutonic rocks of the Mogok Belt and Lohit complex, whereas feldspatho-litho-quartzose Chindwin sand is largely recycled from supracrustal, sedimentary and very low-grade metasedimentary units. Additional mafic to ultramafic detritus is derived from ophiolites and blueschists exposed from the Indo-Burman Ranges to the Jade Mines and Myitkyina belts, linked northward to the Yarlung-Tsangpo suture of the Himalaya. Volcanic detritus derived from the Popa-Wuntho arc or recycled from forearc-basin strata also occurs. Decreasing concentration of most chemical elements along the Irrawaddy reflects progressive addition of detritus recycled from sedimentary rocks, most evident downstream of the Chindwin confluence. REE patterns with LREE enrichment and negative Eu anomaly reflect the occurrence of allanite, largely derived from granitoid rocks in the Mali catchment. Chemical indices indicate moderate weathering in the monsoon-dominated climate of Myanmar. Young U-Pb ages (15–170 Ma) represent 85% of detrital zircons in Irrawaddy headwater branches, reflecting long-lasting subduction-related magmatism along a ring of fire connecting with the southern and central Lhasa batholiths in Tibet and polyphase metamorphism in the Mogok belt. Chindwin sand contains larger amounts of finer-grained, recycled pre-Mesozoic zircons, also yielding early Mesoproterozoic to Archean ages. Such different petrographic, heavy-mineral, geochemical and geochronological fingerprints characterizing sand in different river branches allowed us to calculat
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- 2016
89. Quantitative Provenance Analysis of Sediments in the Changjiang (Yangtze) River (China)
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Janardhana Raju, N, Vezzoli, G, Limonta, M, Garzanti, E, Yang, S, VEZZOLI, GIOVANNI, LIMONTA, MARA, GARZANTI, EDUARDO, Yang, S., Janardhana Raju, N, Vezzoli, G, Limonta, M, Garzanti, E, Yang, S, VEZZOLI, GIOVANNI, LIMONTA, MARA, GARZANTI, EDUARDO, and Yang, S.
- Abstract
We use quantitative provenance analysis (geochemical analysis; high- resolution bulk-petrography and heavy-mineral analysis, exploratory compositional data analysis and Aitchison distance) on present-day river sediments of the Changjiang (Yangtze) River to quantify the contributions of each tributary to the Changjiang River Delta, and thus to evaluate sediment provenance in the distinct p arts of the drainage basin.
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- 2016
90. Erosion patterns in the Changjiang (Yangtze River) catchment revealed by bulk-sample versus single-mineral provenance budgets
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Vezzoli, G, Garzanti, E, Limonta, M, Ando', S, Yang, S, VEZZOLI, GIOVANNI, GARZANTI, EDUARDO, LIMONTA, MARA, ANDO', SERGIO, Yang, S., Vezzoli, G, Garzanti, E, Limonta, M, Ando', S, Yang, S, VEZZOLI, GIOVANNI, GARZANTI, EDUARDO, LIMONTA, MARA, ANDO', SERGIO, and Yang, S.
- Abstract
The Changjiang, the fourth longest river on Earth and the largest in Eurasia, has a complex sediment-routing system presently interrupted by the Three Gorges Dam, the world's largest hydroelectric engineering project. To study sediment-generation processes in the huge catchment and compare the different erosion patterns obtained by different methodological approaches, high-resolution petrographic and heavy-mineral analyses were performed on sands from the trunk river and its major tributaries. The frequency distributions of diverse groups of detrital amphiboles were also investigated. Rigorous statistical methods were used to define end-members, evaluate mineralogical variability, assess similarities among samples, and eventually calculate the relative contributions from each major tributary to the trunk river by forward end-member modelling of integrated compositional data. The litho-quartzose sand with few heavy minerals generated in Tibetan headwaters evolves downstream to feldspatho-litho-quartzose with medium-rank metamorphic rock fragments and moderately rich amphibole-epidote suites. Sand across the Sichuan basin and as far as the Three Gorges Dam is enriched in mafic volcanic, clinopyroxene, and carbonate grains eroded from Permian basalts and Paleozoic strata of the South China Block. The final (Yangtze) tract is characterized by litho-feldspatho-quartzose sand with moderately poor, amphibole-dominated suites with epidote, clinopyroxene, and garnet. The orogenic compositional signature acquired in the upper part of the basin is thus carried all the way to the Chinese passive margin, as observed also for the Yellow River in the north. Even after long-distance transport across wide continental areas, detrital modes thus reveal the tectonic character of the source rather than the geodynamic environment of the sink.Quantitative provenance analysis indicates that left-bank tributaries draining the Longmen and Qinlin mountains supply most of the sand reaching the
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- 2016
91. Indentation of the Pamirs with respect to the northern margin of Tibet: Constraints from the Tarim basin sedimentary record
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Blayney, T, Najman, Y, Dupont Nivet, G, Carter, A, Miller, I, Garzanti, E, Sobel, E, Rittner, M, Ando', S, Guo, Z, Vezzoli, G, GARZANTI, EDUARDO, ANDO', SERGIO, VEZZOLI, GIOVANNI, Blayney, T, Najman, Y, Dupont Nivet, G, Carter, A, Miller, I, Garzanti, E, Sobel, E, Rittner, M, Ando', S, Guo, Z, Vezzoli, G, GARZANTI, EDUARDO, ANDO', SERGIO, and VEZZOLI, GIOVANNI
- Abstract
The Pamirs represent the indented westward continuation of the northern margin of the Tibetan Plateau, dividing the Tarim and Tajik basins. Their evolution may be a key factor influencing aridification of the Asian interior, yet the tectonics of the Pamir Salient are poorly understood. We present a provenance study of the Aertashi section, a Paleogene to late Neogene clastic succession deposited in the Tarim basin to the north of the NW margin of Tibet (the West Kunlun) and to the east of the Pamirs. Our detrital zircon U-Pb ages coupled with zircon fission track, bulk rock Sm-Nd, and petrography data document changes in contributing source terranes during the Oligocene to Miocene, which can be correlated to regional tectonics. We propose a model for the evolution of the Pamir and West Kunlun (WKL), in which the WKL formed topography since at least ~200 Ma. By ~25 Ma, movement along the Pamir-bounding faults such as the Kashgar-Yecheng Transfer System had commenced, marking the onset of Pamir indentation into the Tarim-Tajik basin. This is coincident with basinward expansion of the northern WKL margin, which changed the palaeodrainage pattern within the Kunlun, progressively cutting off the more southerly WKL sources from the Tarim basin. An abrupt change in the provenance and facies of sediments at Aertashi has a maximum age of 14 Ma; this change records when the Pamir indenter had propagated sufficiently far north that the North Pamir was now located proximal to the Aertashi region.
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- 2016
92. The Euphrates-Tigris-Karun river system: Provenance, recycling and dispersal of quartz-poor foreland-basin sediments in arid climate
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Garzanti, E, Al Juboury, A, Zoleikhaei, Y, Vermeesch, P, Jotheri, J, Akkoca, D, Obaid, A, Allen, M, Ando', S, Limonta, M, Padoan, M, Resentini, A, Rittner, M, Vezzoli, G, GARZANTI, EDUARDO, ANDO', SERGIO, LIMONTA, MARA, PADOAN, MARTA, RESENTINI, ALBERTO, VEZZOLI, GIOVANNI, Garzanti, E, Al Juboury, A, Zoleikhaei, Y, Vermeesch, P, Jotheri, J, Akkoca, D, Obaid, A, Allen, M, Ando', S, Limonta, M, Padoan, M, Resentini, A, Rittner, M, Vezzoli, G, GARZANTI, EDUARDO, ANDO', SERGIO, LIMONTA, MARA, PADOAN, MARTA, RESENTINI, ALBERTO, and VEZZOLI, GIOVANNI
- Abstract
We present a detailed sediment-provenance study on the modern Euphrates-Tigris-Karun fluvial system and Mesopotamian foreland basin, one of the cradles of humanity. Our rich petrographic and heavy-mineral dataset, integrated by sand geochemistry and U–Pb age spectra of detrital zircons, highlights the several peculiarities of this large source-to-sink sediment-routing system and widens the spectrum of compositions generally assumed as paradigmatic for orogenic settings. Comparison of classical static versus upgraded dynamic petrologic models enhances the power of provenance analysis, and allows us to derive a more refined conceptual model of reference and to verify the limitations of the approach. Sand derived from the Anatolia-Zagros orogen contains abundant lithic grains eroded from carbonates, cherts, mudrocks, arc volcanics, obducted ophiolites and ophiolitic mélanges representing the exposed shallow structural level of the orogen, with relative scarcity of quartz, K-feldspar and mica. This quartz-poor petrographic signature, characterizing the undissected composite tectonic domain of the entire Anatolia-Iranian plateau, is markedly distinct from that of sand shed by more elevated and faster-eroding collision orogens such as the Himalaya. Arid climate in the region allows preservation of chemically unstable grains including carbonate rock fragments and locally even gypsum, and reduces transport capacity of fluvial systems, which dump most of their load in Mesopotamian marshlands upstream of the Arabian/Persian Gulf allochemical carbonate factory. Quartz-poor sediment from the Anatolia-Zagros orogen mixes with quartz-rich recycled sands from Arabia along the western side of the foreland basin, and is traced all along the Gulf shores as far as the Rub' al-Khali sand sea up to 4000 km from Euphrates headwaters.
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- 2016
93. Brachiopods from the Cisuralian–Guadalupian of Darvaz, Tajikistan and implications for Permian stratigraphic correlations
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Angiolini, L, Campagna, M, Borlenghi, L, Grunt, T, Vachard, D, Vezzoli, G, Vuolo, I, Worthington, J, Nicora, A, Zanchi, A, VEZZOLI, GIOVANNI, ZANCHI, ANDREA MARCO, Angiolini, L, Campagna, M, Borlenghi, L, Grunt, T, Vachard, D, Vezzoli, G, Vuolo, I, Worthington, J, Nicora, A, Zanchi, A, VEZZOLI, GIOVANNI, and ZANCHI, ANDREA MARCO
- Abstract
In this paper, we describe the upper Cisuralian Safetdara and Gundara formations of the Darvaz mountains, North Pamir, which were part of the Kunlun Arc, developed along the active Eurasian margin. The Safetdara Formation comprises massive limestones (mainly cyanobacterial, Tubiphytes and Archaeolithoporella boundstones) alternating with well-bedded bioclastic and oncoidal limestones and an interval of recessive shales. The formation crops out above the Chelamchi Formation consisting of turbiditic siltstones and sandstones with bioclastic silty limestones yielding massive limestone olistoliths. The Gundara Formation consists of fine sandstones at the base, followed by well-bedded marly bioclastic, oncoidal and microbial limestones, bearing a rich silicified brachiopod fauna in life-position. Two new taxa have been identified in this association: the cemented coralliform Gundaria insolita n. gen. n. sp. and the pedicle attached Hemileurus politus n. sp. The inferred environmental setting is that of shoal deposits of warm, shallow, high energy, clear marine waters for the Safetdara Formation. The agglutinated microbial reefs to cluster reefs of the Gundara Formation were probably growing in a muddier, quieter and probably slightly deeper setting. The foraminifers of the Brevaxina Zone suggest a Bolorian age for the top of the Chelamchi Formation, the Safetdara Formation and the base of the Gundara Formation. Kungurian conodonts have been found in the lower part of the Safetdara Formation. The biostratigraphic data from the sedimentary succession of North Pamir, integrated with those already obtained from Southeast Pamir, allow to refine the correlations between the Tethyan regional scale and the International Time Scale. In particular, it seems now clear that the Bolorian and the lower part of the Kubergandian correlate to the Kungurian.
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- 2016
94. The provenance of Taklamakan desert sand
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Rittner, M, Vermeesch, P, Carter, A, Bird, A, Stevens, T, Garzanti, E, Ando', S, Vezzoli, G, Dutt, R, Xu, Z, Lu, H, Lu, H., GARZANTI, EDUARDO, ANDO', SERGIO, VEZZOLI, GIOVANNI, Rittner, M, Vermeesch, P, Carter, A, Bird, A, Stevens, T, Garzanti, E, Ando', S, Vezzoli, G, Dutt, R, Xu, Z, Lu, H, Lu, H., GARZANTI, EDUARDO, ANDO', SERGIO, and VEZZOLI, GIOVANNI
- Abstract
Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run-o
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- 2016
95. Erosion in the Western Alps (Dora Baltea Basin)2. Quantifying sediment yield
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VEZZOLI, GIOVANNI and Vezzoli, G
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bed load fluxe ,denudation rates ,M. Bianco Massif ,glacier ,Stratigraphy ,Dora Baltea basin ,GEO/02 - GEOLOGIA STRATIGRAFICA E SEDIMENTOLOGICA ,Geology ,relief ,lithology - Abstract
The present work shows how sediment composition can be used to constrain bed load sediment budgets in mountain catchments. A database of high-resolution petrographic and dense-mineral analyses of detritus carried by the Dora Baltea River and its tributaries allowed us to partition bed-load sediment budgets, obtained from data available from a public authority, between two different sets of sediment sources (major tributaries and major geological units). Relative and absolute budgets of sediment bed-load thus obtained are more robust than those derived from traditional empirical methods alone. Total detrital flux in the Dora Baltea drainage basin is 1,000,000 ton/year (bed-load 590,000 ton/year, suspended load 410,000 ton/year), with denudation rates of 0.12 mm/year (data from Italian public authority-Progetto di piano stralcio per l'assetto idrogeologico (PAI). Parma, Supplemento Straordinario della Gazzetta Ufficiale 166). More than 75% of the Dora Baltea total bed-load (453,000 9000 ton/year) is derived from tributaries (Dora di Ferret, Dora di Veny, Savara, Grand Eyvia, Buthier, Lys) sourced from the highest granitoid peaks (>4000 m a.s.l.: M. Bianco, M. Rosa, M. Cervino, Gran Paradiso massifs), which drain 36% of the whole catchment. The M. Bianco Massif, with its granitoid lithology, extreme relief and heavily glaciated drainage basins, occupies only 3% of total basin area, but it produces 294,000 +/- 6000 tons of arkosic sands per year, which represents 50% of total Dora Baltea bed-load. The Dora di Veny (2% of total Dora Baltea mountain catchment) exhibits the highest denudation rate of the whole Dora Baltea mountain basin (0.73 mm/year). The values calculated in this study compare well with measured modem river loads of pardy glaciated m:id-latitude mountain regions. (C) 2004 Elsevier B.V. All rights reserved.
- Published
- 2004
96. Indentation of the Pamirs with respect to the northern margin of Tibet: Constraints from the Tarim basin sedimentary record
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Blayney, Tamsin, primary, Najman, Yani, additional, Dupont‐Nivet, Guillaume, additional, Carter, Andrew, additional, Millar, Ian, additional, Garzanti, Eduardo, additional, Sobel, Edward R., additional, Rittner, Martin, additional, Andò, Sergio, additional, Guo, Zhaojie, additional, and Vezzoli, Giovanni, additional
- Published
- 2016
- Full Text
- View/download PDF
97. Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment
- Author
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Nie, Junsheng, Stevens, Thomas, Rittner, Martin, Stockli, Daniel, Garzanti, Eduardo, Limonta, Mara, Bird, Anna, Ando, Sergio, Vermeesch, Pieter, Saylor, Joel, Lu, Huayu, Breecker, Daniel, Hu, Xiaofei, Liu, Shanpin, Resentini, Alberto, Vezzoli, Giovanni, Peng, Wenbin, Carter, Andrew, Ji, Shunchuan, Pan, Baotian, Nie, Junsheng, Stevens, Thomas, Rittner, Martin, Stockli, Daniel, Garzanti, Eduardo, Limonta, Mara, Bird, Anna, Ando, Sergio, Vermeesch, Pieter, Saylor, Joel, Lu, Huayu, Breecker, Daniel, Hu, Xiaofei, Liu, Shanpin, Resentini, Alberto, Vezzoli, Giovanni, Peng, Wenbin, Carter, Andrew, Ji, Shunchuan, and Pan, Baotian
- Abstract
Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river/'s upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records., Supplementary information available for this article at http://www.nature.com/ncomms/2015/151009/ncomms9511/suppinfo/ncomms9511_S1.html
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- 2015
- Full Text
- View/download PDF
98. Loess plateau storage of northeastern Tibetan plateau-derived yellow river sediment
- Author
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Nie, J, Stevens, T, Rittner, M, Stockli, D, Garzanti, E, Limonta, M, Bird, A, Ando', S, Vermeesch, P, Saylor, J, Lu, H, Breecker, D, Hu, X, Liu, S, Resentini, A, Vezzoli, G, Peng, W, Carter, A, Ji, S, Pan, B, GARZANTI, EDUARDO, LIMONTA, MARA, ANDO', SERGIO, RESENTINI, ALBERTO, VEZZOLI, GIOVANNI, Pan, B., Nie, J, Stevens, T, Rittner, M, Stockli, D, Garzanti, E, Limonta, M, Bird, A, Ando', S, Vermeesch, P, Saylor, J, Lu, H, Breecker, D, Hu, X, Liu, S, Resentini, A, Vezzoli, G, Peng, W, Carter, A, Ji, S, Pan, B, GARZANTI, EDUARDO, LIMONTA, MARA, ANDO', SERGIO, RESENTINI, ALBERTO, VEZZOLI, GIOVANNI, and Pan, B.
- Abstract
Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO 2 and erosion records.
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- 2015
99. From rift to drift in South Pamir (Tajikistan): Permian evolution of a Cimmerian terrane
- Author
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Angiolini, L, Zanchi, A, Zanchetta, S, Nicora, A, Vuolo, I, Berra, F, Henderson, C, Malaspina, N, Rettori, R, Vachard, D, Vezzoli, G, ZANCHI, ANDREA MARCO, ZANCHETTA, STEFANO, MALASPINA, NADIA, VEZZOLI, GIOVANNI, Angiolini, L, Zanchi, A, Zanchetta, S, Nicora, A, Vuolo, I, Berra, F, Henderson, C, Malaspina, N, Rettori, R, Vachard, D, Vezzoli, G, ZANCHI, ANDREA MARCO, ZANCHETTA, STEFANO, MALASPINA, NADIA, and VEZZOLI, GIOVANNI
- Abstract
Here, we describe the Permian-Lower Triassic sedimentary succession of South Pamir and the associated biota of conodonts, foraminifers and brachiopods. The studied succession comprises the Carboniferous-Lower Permian siliciclastic Uruzbulak and Tashkazyk formations (Bazar Dara Group), which are unconformably covered by upper Lower to Upper Permian units, deposited both in platform settings (Kurteke Formation), and on the slope and basin (Kochusu Formation, Shindy Formation, Kubergandy Formation, Gan Formation, and Takhtabulak Formation). These formations comprise bioclastic limestones, cherty limestones, shales, volcaniclastic rocks, basalts, sandstones and conglomerates, and are locally very rich in fossils (fusulinids, ammonoids, brachiopods, corals and conodonts). The Permian succession is then overlain by shallow water carbonates of the Induan to Anisian Karatash Group. Subsidence analysis and volcanics of the Permian and overlying Triassic successions constrains the timing of rifting of South Pamir from Gondwana in the Early Permian (=Cisuralian), and its docking to Central Pamir, the Eurasian margin and the interposed volcanic arcs at the end of the Triassic. The sedimentary successions of the Pamirs represent a key-point to refine the correlations between the Tethyan regional scale and the International Time Scale. The analyses of the fusulinids and conodonts of the Kubergandian and Murgabian stratotypes of SE Pamir suggest that: (1) the upper Bolorian and the lower part of the Kubergandian correlate to the upper Kungurian; (2) the upper Kubergandian and the lower Murgabian correlate to the Roadian; (3) the mid-upper Murgabian correlates to the Wordian; (4) possibly the uppermost Murgabian and the lower Midian correlate to the lower Capitanian.The Kubergandian is thus a defined regional stage, based on fusulinids, ammonoids and conodonts and can be correlated to the Kungurian and the Roadian; still problematic remains the Murgabian correlation which needs to
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- 2015
100. What killed the Tertiary Southalpine carbonate platform?
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DI CAPUA, A, Coletti, G, Vezzoli, G, DI CAPUA, ANDREA, COLETTI, GIOVANNI, VEZZOLI, GIOVANNI, DI CAPUA, A, Coletti, G, Vezzoli, G, DI CAPUA, ANDREA, COLETTI, GIOVANNI, and VEZZOLI, GIOVANNI
- Abstract
The carbonate platforms of the Tertiary Alpine basins (Northalpine Molassa and Southalpine Foredeep basin) are shaped by the different geodynamic settings. According to the classification of Bosence (2005-Sed.Geo.), the Northalpine basin hosted a foreland margin platform (Nummulitic Limestones), whereas the Southalpine basin probably hosted a thurst-top platform that supplied the shallow-water carbonate turbidites of the Ternate Formation. Actually, this latter carbonate platform is no more present, rapidly eroded during the Oligo-Miocene evolution of the Southern Alps, but a paleoecological reconstruction have been provided by Coletti et al. (in prep.) through the analysis of pebbles encountered in the Oligo-Miocene siliciclastic turbidite fan of the Gonfolite Lombarda Group. Here, we first reconstructed the suitable conditions of rise and growth of this narrow platform on top of the active thrusts of the Southern Alps during the Eocene and Early Oligocene, and then investigated the geodynamic processes that have contributed to killing it in the Early Oligocene. We envisaged a top-thrust platform grown up in front of gentle relieves of Jurassic to Cretaceous sedimentary covers, as suggested by the abundant and angular Mesozoic pebbles encountered in the turbidite fan of the Ternate Formation. The large presence of mass flow deposits and marly, often plurimetric soft clasts also suggests that a small, instable delta was frequently discharging terrigenous detritus through flash flood events moving across the platform deep into the basin. The abrupt disappearance of re-sedimented shallow-water carbonates probably corresponded to the death of the platform soon after the Early Oligocene, but doubts are still present on the causes that triggered it. The temporal gap (at least 5 Ma) that divides the top of the Ternate Formation and the first clastic inputs of the Gonfolite Lombarda Group (~27 Ma) may indicate that the onset of the major phase of growth of the Alpine belt
- Published
- 2015
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