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The Carboniferous-mid Permian successions of the Northern Apennines: new data from the Pisani Mts. inlier (Tuscany, Italy) 北亚平宁石炭纪-中二叠世序列:来自意大利托斯卡纳Pisani mst . inlier的新资料
Pub Date : 2020-06-01 DOI: 10.3301/ijg.2019.27
F. Marini, E. Pandeli, M. Tongiorgi, E. Pecchioni, L. Orti
This paper updates and partially modifies the knowledge of the geological-palaeoenvironmental and geodynamic framework of the Tuscan segment of the Variscan Chain in Tuscany during Permian times. Particularly, it adds new data on the contact between the upper Carboniferous-lower Permian San Lorenzo schist (SLs) and the mid-Permian Asciano breccia and conglomerate (Abc) clastic formations in the Pisani Mts. metamorphic inlier which represents one of the pinning point outcrops for the study of the upper Paleozoic sequences in the Northern Apennines. Their sharp unconformable contact is well-documented in the literature at map and outcrop scale and was ascribed to the Saalian phase of the Variscan orogeny that would have occurred in correspondence of a climatic change from equatorial to an semi-arid tropical conditions. New geological investigations on the SLs and Abc allowed us to identify the finding of a continuous stratigraphic section in the Pian della Conserva locality (northwestern Pisani Mts.) where the organic matter-rich SLs conformably passes upwards to the reddish immature, mainly coarse-grained deposits of Abc through a decametric transition zone. The section was studied in detail from a lithological-sedimentological point of view and sampled for petrographic, mineralogic and chemical studies. The data show that the passage from SLs to Abc testifies a main change from an equatorial, wet fluvial-lacustrine environment to a well-drained, alluvial fan systems in a monsoon- like climate. This event can be related to the reactivation of the previous late Carboniferous-lower Permian shear zones during the mid-Permian times that produced morpho-tectonic highs subjected to a rapid erosion and the formation of unconformities, whereas the presence of a few residual fluvial plain areas, characterized by dysoxic conditions, is documented by the gradual passage between SLs and Abc in the Pian della Conserva section. In addition, the presence of a metavolcanoclastic or metaepiclastic layer was also recognized in the uppermost part of the SLs and it represents the first evidence of a late Carboniferous-early Permian volcanic event in the Northern Apennines.
本文对二叠纪托斯卡纳瓦里斯坎链托斯卡纳段的地质古环境和地球动力学格局进行了更新和部分修正。特别是为研究北亚平宁地区上古生界层序提供了新资料,揭示了上石炭统-下二叠统San Lorenzo片岩(SLs)与中二叠统Asciano角砾岩和砾岩(Abc)碎屑岩组的接触。它们尖锐的不整合接触在地图和露头尺度的文献中得到了充分的记录,并被归因于Variscan造山运动的Saalian阶段,该阶段的发生可能与气候从赤道到半干旱热带条件的变化相对应。对SLs和Abc的新地质调查使我们在Pian della Conserva地区(Pisani Mts西北部)发现了一个连续的地层剖面,在那里,富含有机质的SLs通过一个十度过渡带,整合向上进入以粗粒Abc为主的微红色未成熟矿床。从岩性-沉积学的角度对该剖面进行了详细研究,并对其进行了岩石学、矿物学和化学研究。数据表明,从SLs到Abc的通道证明了一个主要的变化,从赤道,潮湿的河流-湖泊环境到季风气候下排水良好的冲积扇系统。这一事件可能与中二叠世晚石炭世-下二叠世剪切带的重新激活有关,该剪切带在快速侵蚀和不整合的形成下产生了形态构造高点,而在Pian della Conserva剖面中,SLs和Abc之间的逐渐通过记录了少数残余的河流平原地区,其特征是缺氧条件。此外,在岩石圈上部还发现了变质火山碎屑或变质碎屑层,这是北亚平宁地区晚石炭世—早二叠世火山事件的第一个证据。
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引用次数: 1
Anatomy and Jurassic evolution of a Hercynian basement high (Caloveto High - Calabria, Southern Italy) 海西期基底高压(Caloveto高压-意大利南部卡拉布里亚)的解剖与侏罗纪演化
Pub Date : 2020-02-01 DOI: 10.3301/IJG.2019.16
M. Santantonio, S. Fabbi
The Caloveto area in North-East Calabria hosts a stratigraphic succession which documents the evolution from shallow water carbonates to deeper-water pelagic and hemipelagic deposits, bearing ample evidence for severe tectonic control on Jurassic and Lower Cretaceous sedimentation. Geological mapping indicates that the shallow-water carbonates, also with coral assemblages, formed a narrow fringe around a high of the Hercynian basement, made of lowgrade metamorphic rock, which remained emergent throughout the Pliensbachian and became an intrabasinal high which stood proud of the Longobucco basin, hosting thin pelagic sedimentation through most of the Jurassic. An extensional phase in the Toarcian disrupted and foundered the benthic carbonate factory, whose drowning isdocumented by a change to Rosso Ammonitico-type deposits. This resulted in a complex network of neptunian dykes (also intruding the basement) and in-situ breccias. Starting in the late Toarcian, the rugged submarine topography was gradually leveled by onlapping marls, radiolarites and pelagic limestone, which sealed the Toarcian fault zones producing a diverse array of unconformities. Colonization by microbial communities characterizes the initial stages ofmarine sedimentation around the cores of Paleozoic basement, as banded polychrome microbialites and “swollen” phyllites, a result of the microbially-influenced/induced displacive growth of calcium carbonate crystals along split cleavage planes, constitute an unexpected field tool for identifying basin margins. Silicified marginal zones in the shallow water limestone characterize, in analogy withother Tethyan regions, the onlap unconformities of chert-rich basinal units on the submerged carbonate fringes.
卡拉布里亚东北部Caloveto地区的地层演替记录了从浅水碳酸盐岩到深水远洋和半远洋沉积的演化过程,为侏罗纪和下白垩世沉积的严重构造控制提供了充分的证据。地质填图表明,浅水碳酸盐岩和珊瑚组合在海西期基底的一个高地周围形成了一条狭窄的边缘,该高地由低级变质岩组成,在整个普林恩巴氏期一直出现,并成为一个盆地内高地,矗立在Longobucco盆地之上,在侏罗纪的大部分时间里都有薄的远洋沉积。托拉纪的一个伸展期破坏并摧毁了底栖碳酸盐工厂,其淹没由罗索氨型矿床的变化记录下来。这导致了一个复杂的海王星岩脉网络(也侵入了基底)和原位角砾岩。从晚陶拉纪开始,崎岖不平的海底地形逐渐被重叠的泥灰岩、放射石和远洋石灰岩夷平,这些岩石封闭了陶拉纪断裂带,形成了各种不整合面。微生物群落的定植是古生代基底核心周围海洋沉积的初始阶段的特征,如带状多色微生物长岩和“膨胀”千层岩,这是微生物影响/诱导碳酸钙晶体沿分裂解理面置换生长的结果,构成了一个意想不到的野外识别盆地边缘的工具。与其他特提斯地区类似,浅水灰岩硅化边缘带的特征是淹没碳酸盐岩边缘上富燧石盆地单元的上覆不整合面。
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引用次数: 3
Drowning of microbial mounds on the slopes of the Latemar platform (middle Triassic) 中三叠世Latemar地台斜坡上微生物丘的淹没作用
Pub Date : 2020-02-01 DOI: 10.3301/ijg.2019.23
M. Franceschi, N. Preto, M. Caggiati, Giovanni Gattolin, A. Riva, P. Gianolla
Two microbial mound-shaped carbonate bodies buried below the slope deposits of the middle Triassic Latemar platform (Dolomites, Italy) have been studied. The two sedimentary bodies, after having reached different stages of evolution, drowned and were covered by the slopes of the Latemar carbonate platform. The estimation of the depth and time at which they were located when they were buried made it possible to infer the average rates of relative sea-level rise to which they were subjected, revealing that these latter exceeded the growth rate of the main Latemar buildup. Given the estimated rates of sea-level rise, the two satellite bodies reached a critical depth at which microbial carbonate production stops, or it is significantly reduced, before being buried. As extensional tectonics was active in the area of the Dolomites during the Anisian, subsidence is the more likely cause of sea level rise. It is therefore hypothesized that the cause of the ultimate drowning of the “mounds” were subsidence rates exceeding their aggradation potential and inducing a progressive deepening that brought them below the lower depth threshold of microbial carbonate production.
研究了埋藏于中三叠统Latemar地台(Dolomites, Italy)斜坡矿床下的两个微生物丘状碳酸盐体。这两个沉积体经过不同的演化阶段后,被拉特玛碳酸盐台地的斜坡所淹没和覆盖。对它们被埋时所处的深度和时间的估计,使人们有可能推断出它们受到的相对海平面上升的平均速度,揭示出后者超过了拉特玛尔主要沉积物的增长速度。考虑到海平面上升的估计速度,这两个卫星体达到了一个临界深度,微生物碳酸盐的生产在被掩埋之前停止或显著减少。由于阿尼西期白云岩地区的伸展构造活动,沉降是海平面上升的主要原因。因此,我们假设“土丘”最终被淹没的原因是沉降速度超过了它们的沉积潜力,并导致逐渐加深,使它们低于微生物碳酸盐生产的较低深度阈值。
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引用次数: 3
Non-condensed shell beds in hiatal successions: instantaneous cementation associated with nutrient-rich bottom currents and high bivalve production 裂孔序列中的非凝聚壳层:与营养丰富的底流和高双壳类产量相关的瞬时胶结
Pub Date : 2020-02-01 DOI: 10.3301/ijg.2019.21
A. Tomašovỳch, J. Schlögl, J. Michalík, Lenka Donovalová
Pelagic carbonate deposits formed by the thin-shelled, epifaunal, originally bimineralic bivalve Bositra buchi were geographically widely distributed in the Tethyan basins during the Middle Jurassic. Here, to evaluate conditions that allowed the formation of peculiar, metre-scale, densely-packed shell beds primarily formed by Bositra, we assess size distributions and preservation of this bivalve in thin sections at ten sites in the Pieniny Klippen Belt and Peri-Klippen units (Western Carpathians), representing a bathymetric transect from pelagic-platform tops with shell beds up to slope environments where small filaments occur with spicules and radiolarians. Although Bositra shell beds are modulated by transport and winnowing, three types of evidence indicate that they primarily reflect high bivalve productivity. First, we find that size distributions of this species form a bathymetric gradient, from the dominance of remains smaller than 0.5 mm in low- energy slope environments, to 0.5-2 mm on muddy platform edges, up to lensoid shell beds with large valves (~2-15 mm) occurring on platform tops exposed to bottom currents. Although sediment winnowing from shell beds contributed to the rarity of small-sized specimens in platform-top environments, the bathymetric shift in the shape of size distributions is not purely driven by fragmentation and by size-selective transport of small specimens into slope environments because the average valve thickness declines with depth and thick fragments do not occur in slope environments. High abundances of suspension-feeding Bositra preferentially associated with indicators of bottom currents at oligophotic or aphotic depths indicate that plankton productivity was probably sourced by nutrient-rich internal waves that intersected platform tops, leading to low juvenile mortality in Bositra populations. In contrast, populations in deeper environments with the limited input of particulate organic matter failed to achieve maturity. Second, the inner, originally nacreous shell layer of Bositra is now represented by neomorphic calcite that is luminescent, enriched in Mn and depleted in Mg, indicating that this layer was not dissolved in the taphonomic active zone. Third, fibrous- acicular low-Mg calcite cements that characteristically coat Bositra in shell beds show blotchy luminescence and highly irregular Mg distribution, indicating that they were precipitated as high-Mg calcite cements. Fibrous-acicular cements in shell beds do not coat upward- facing sides of valves covered by a first phase of micrite whereas they fully coat elevated portions of the same valves. Therefore, they were precipitated at very high rates concurrently with micrite deposition in shelters. Nutrient-rich bottom currents thus simultaneously increased (1) Bositra survivorship by enhancing primary productivity and (2) cementation rate by renewal of saturation of pore waters in the taphonomic active zone at platform tops. In spite of the associati
中侏罗统时期,特提斯盆地中广泛分布着由原双矿物双壳类Bositra buchi形成的薄壳、下底、双壳类Bositra buchi沉积的远洋碳酸盐岩矿床。在这里,为了评估主要由Bositra形成的特殊、米尺度、密集堆积的壳层形成的条件,我们在Pieniny Klippen带和periklippen单元(西喀尔巴阡山脉)的10个地点的薄片中评估了这种双壳类动物的大小分布和保存情况,代表了从具有壳层的上层平台顶部到具有针状体和放射虫的小细丝的斜坡环境的等深样带。尽管Bositra贝壳床受到运输和筛选的调节,但有三种证据表明它们主要反映了高双壳类动物的生产力。首先,我们发现该物种的尺寸分布形成了一个等深梯度,从低能量斜坡环境中小于0.5 mm的残留物占主导地位,到泥质平台边缘的0.5-2 mm,再到暴露于底流的平台顶部出现的具有大阀(~2-15 mm)的透镜状壳床。尽管壳层沉积物的筛分导致了平台顶部环境中小尺寸标本的稀缺性,但尺寸分布形状的水深变化并不完全是由破碎和小标本向斜坡环境的尺寸选择性迁移驱动的,因为平均阀厚随着深度而下降,斜坡环境中不会出现厚的碎片。高丰度的悬浮食性Bositra优先与寡聚或无聚深度的底流指标相关,这表明浮游生物的生产力可能来自于与平台顶部相交的营养丰富的内波,导致Bositra种群的幼鱼死亡率低。相比之下,在颗粒有机质输入有限的较深环境中,种群未能达到成熟。(2) Bositra内部原珍珠质壳层由富锰贫镁的发光新晶方解石代表,表明该层未溶解于埋藏活跃区。③包覆在壳层Bositra上的纤维状针状低镁方解石胶结物,其发光呈斑点状,且Mg的分布高度不规则,表明其为高镁方解石胶结物析出。壳床中的纤维针状胶结物不覆盖由第一相泥晶覆盖的阀门的朝上侧面,而完全覆盖同一阀门的凸起部分。因此,它们与遮蔽物中的泥晶沉积同时以非常高的速率沉淀。因此,富含营养的底流同时增加了(1)通过提高初级生产力来提高Bositra存活率,(2)通过更新平台顶部埋藏活动性带孔隙水饱和度来提高胶结速率。尽管Bositra壳层与主要裂孔表面有关,但(1)纤维针状胶结物的快速沉淀,(2)壳层中铁染色Bositra阀的罕见,以及(3)富壳泥中的铁浓度明显低于贫壳泥,这表明壳层不代表长期的裂孔或滞后浓度。它们代表了复合壳床,记录了这些双壳类动物在生态时间尺度上的高种群密度。由断块形成的海底洋流强度和海底地形的空间变化导致(1)在高能洋流扫过的地点形成了带有矿化硬地面的裂孔表面,(2)在强度较小但持续洋流的地点保留了厚达1米的透镜状壳层。因此,Bositra壳层最终具有斑块状的水平和地层分布。
{"title":"Non-condensed shell beds in hiatal successions: instantaneous cementation associated with nutrient-rich bottom currents and high bivalve production","authors":"A. Tomašovỳch, J. Schlögl, J. Michalík, Lenka Donovalová","doi":"10.3301/ijg.2019.21","DOIUrl":"https://doi.org/10.3301/ijg.2019.21","url":null,"abstract":"Pelagic carbonate deposits formed by the thin-shelled, epifaunal, originally bimineralic bivalve Bositra buchi were geographically widely distributed in the Tethyan basins during the Middle Jurassic. Here, to evaluate conditions that allowed the formation of peculiar, metre-scale, densely-packed shell beds primarily formed by Bositra, we assess size distributions and preservation of this bivalve in thin sections at ten sites in the Pieniny Klippen Belt and Peri-Klippen units (Western Carpathians), representing a bathymetric transect from pelagic-platform tops with shell beds up to slope environments where small filaments occur with spicules and radiolarians. Although Bositra shell beds are modulated by transport and winnowing, three types of evidence indicate that they primarily reflect high bivalve productivity. First, we find that size distributions of this species form a bathymetric gradient, from the dominance of remains smaller than 0.5 mm in low- energy slope environments, to 0.5-2 mm on muddy platform edges, up to lensoid shell beds with large valves (~2-15 mm) occurring on platform tops exposed to bottom currents. Although sediment winnowing from shell beds contributed to the rarity of small-sized specimens in platform-top environments, the bathymetric shift in the shape of size distributions is not purely driven by fragmentation and by size-selective transport of small specimens into slope environments because the average valve thickness declines with depth and thick fragments do not occur in slope environments. High abundances of suspension-feeding Bositra preferentially associated with indicators of bottom currents at oligophotic or aphotic depths indicate that plankton productivity was probably sourced by nutrient-rich internal waves that intersected platform tops, leading to low juvenile mortality in Bositra populations. In contrast, populations in deeper environments with the limited input of particulate organic matter failed to achieve maturity. Second, the inner, originally nacreous shell layer of Bositra is now represented by neomorphic calcite that is luminescent, enriched in Mn and depleted in Mg, indicating that this layer was not dissolved in the taphonomic active zone. Third, fibrous- acicular low-Mg calcite cements that characteristically coat Bositra in shell beds show blotchy luminescence and highly irregular Mg distribution, indicating that they were precipitated as high-Mg calcite cements. Fibrous-acicular cements in shell beds do not coat upward- facing sides of valves covered by a first phase of micrite whereas they fully coat elevated portions of the same valves. Therefore, they were precipitated at very high rates concurrently with micrite deposition in shelters. Nutrient-rich bottom currents thus simultaneously increased (1) Bositra survivorship by enhancing primary productivity and (2) cementation rate by renewal of saturation of pore waters in the taphonomic active zone at platform tops. In spite of the associati","PeriodicalId":55341,"journal":{"name":"Bollettino Della Societa Geologica Italiana","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87316458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Mass-transport deposits from the Toarcian of the Umbria-Marche-Sabina Basin (Central Italy) 意大利中部翁布里亚-马奇-萨比纳盆地托瓦西亚地区的大块搬运沉积
Pub Date : 2020-02-01 DOI: 10.3301/IJG.2019.14
A. Cipriani, C. Zuccari, Giulia Innamorati, M. Marino, F. M. Petti
Mass-transport deposits (MTDs) intercalated in slope/basinal successions, produced by submarine collapses and mass flows, are generally constituted of allochthonous elements sourced from platform margins. Here we present a noticeable exception where Toarcian calciclastic deposits made of pelagic carbonate elements are embedded in other pelagic carbonates. Selected outcrops pertaining to the Rosso Ammonitico Fm of three different pelagic carbonate platform (PCP)-basin systems were studied. The pelagic successions of the study areas onlap Early Jurassic structural highs. These clastic bodies partially replace the typical Toarcian reddish marls and shales of the Umbria-Marche-Sabina palaeogeographic Domain at different stratigraphic levels. The clasts range from blocks to megablocks; extraclasts of Corniola facies (Pliensbachian) and, sporadically, of Calcare Massiccio peritidal carbonates (Hettangian) are associated with Rosso Ammonitico intraclasts.The internal architecture of the MTDs and their emplacement processes, as well as their source and accumulation areas, were identified. Three distinct lithofacies characterise the clastic bodies, each one corresponding to a different emplacement process or to a different portion of the flow. The occurrence of lithified megablocks (>20 m across) of Corniola Fm suggests the exhumation of the buried portion of the unit. Synsedimentary extensional tectonics is the most likely triggering mechanism.Sedimentological analysis, coupled with geological mapping of the study areas, reveals the key role played by PCPs in the genesis of these MTDs. The early Toarcian reactivation of Hettangian palaeofaults bounding the structural highs is inferred. These faults, characterised by moderate offsets, crosscut the onlap wedges of the hangingwall successions, exhuming the older and lithified portion of Corniola Fm. Once become inactive, the fault planes were then eroded producing palaeoescarpments. Their backstepping, coupled with seismic shocks, produced the accumulation of the study clastic bodies.
嵌入斜坡/盆地序列的体运沉积(MTDs)是由海底崩塌和体流形成的,通常由来自台地边缘的异域元素组成。在这里,我们提出了一个明显的例外,即由上层碳酸盐元素构成的托阿西钙质沉积物被嵌套在其他上层碳酸盐中。选取了3个不同的远洋碳酸盐岩台地-盆地体系的Rosso氨组露头进行了研究。研究区中上层层序上覆早侏罗世构造高点。这些碎屑体在不同地层水平上部分取代了翁布里亚-马尔切-萨宾纳古地理域典型的陶拉西亚红泥灰岩和页岩。碎屑从块到兆锁不等;Corniola相(Pliensbachian)和Calcare Massiccio潮外碳酸盐岩(Hettangian)的萃取物与Rosso amonitico内碎屑有关。确定了MTDs的内部结构及其就位过程,以及它们的来源和积累区域。碎屑体具有三种不同的岩相特征,每一种岩相对应于不同的侵位过程或流的不同部分。Corniola Fm的石化巨型岩块(>20 m)的出现表明该单元的埋藏部分已被发掘。同沉积伸展构造是最可能的触发机制。沉积学分析和研究区的地质填图揭示了pcp在这些MTDs成因中的关键作用。推断鹤塘期古断裂在构造高点附近的早陶拉纪复活。这些断层以中等偏移为特征,横切了上盘序列的上覆楔,发掘出了Corniola组较老的岩化部分。一旦不活动,断平面就会受到侵蚀,形成古峭壁。它们的后退,加上地震冲击,产生了研究碎屑体的堆积。
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引用次数: 5
Elemental and Sr-isotope characterization of the high-altitude Bosa vineyard in the Apuan Alps UNESCO Global Geopark (Italy) 联合国教科文组织世界地质公园(意大利)Apuan Alps高海拔Bosa葡萄园元素和sr同位素特征
Pub Date : 2020-02-01 DOI: 10.3301/IJG.2019.20
L. Ghezzi, R. Petrini, F. Castorina, C. Scotti, G. Ottria, A. Bartelletti
The Sr-isotope systematics and trace element analysis were applied to vine and wine collected during the 2015 harvest from the Bosa vineyard, a high-altitude farm in the Apuan Alps UNESCO Global Geopark in Italy, in order to investigate the links with geology in vineyards facing with a hostile environment. The results indicate a correspondence between the 87Sr/86Sr ratio in wine and must [87Sr/86Sr = 0.70843(1) and 0.70846(1), respectively] and the NH4OAc extractable Sr from soil [87Sr/86Sr = 0.70847(1)]. However, detailed investigations reveal that Sr-isotope data on grape juice collected in different vines vary in the range between 0.70833(1) and 0.70844(1), reflecting a small-scale vineyard variability and indicating that the root system explores heterogeneous soil resources for nutrient uptake. Grape seeds and stems from one single vine both show identical 87Sr/86Sr of 0.70820(1), significantly lower with respect to corresponding juice [87Sr/86Sr=0.70844(1)]: this finding is unexpected and reflects the uptake from isotopically different reservoir during the evolved dynamic of vine and fruit development. In particular, the lower 87Sr/86Sr ratio is attributed to the minor contribution of an unradiogenic carbonate component. These effects, however, do not mask the existing isotopic relationship between soil and wine at the vineyard scale. Trace elements in wine show a characteristic pattern that roughly mimics bedrock, suggesting a minor role of bedrock chemical weathering in developing the soil profile. Relatively high Fe and Mn contents are measured in wine, inherited from bedrocks, and high Zn, possibly applied to grapevines. Elements that are considered potentially toxic (As, Cd, Cu, Pb, Zn) are below the maximum acceptable limits established by OIV.Despite preliminary, these data represent the first characterization for traceability of the high-altitude Bosa vineyard, giving some track of weathering and elemental availability in a particular microclimate setting and underlying the link between bedrock geology and element uptake in vines at high elevations with respect to valley grown grapes.
在意大利阿普安阿尔卑斯联合国教科文组织世界地质公园的高海拔农场Bosa葡萄园,研究人员对2015年收获的葡萄和葡萄酒进行了sr同位素系统分析和微量元素分析,以研究面临恶劣环境的葡萄园与地质的联系。结果表明,酒中87Sr/86Sr的比值[87Sr/86Sr分别= 0.70843(1)和0.70846(1)]与土壤中NH4OAc可萃取Sr的比值[87Sr/86Sr = 0.70847(1)]基本一致。然而,详细的研究表明,不同葡萄藤采集的葡萄汁sr同位素数据在0.70833(1)~ 0.70844(1)之间变化,反映了小规模的葡萄园变异,表明根系探索异质土壤资源来吸收养分。同一株葡萄藤的葡萄种子和茎的87Sr/86Sr相同,均为0.70820(1),而葡萄藤汁的87Sr/86Sr显著低于葡萄藤汁[87Sr/86Sr=0.70844(1)],这一发现是出乎意料的,反映了葡萄藤和果实发育过程中不同同位素库的吸收。87Sr/86Sr比值较低是由于非放射性成因的碳酸盐岩组分的少量贡献。然而,这些影响并不能掩盖葡萄园尺度上土壤和葡萄酒之间存在的同位素关系。葡萄酒中的微量元素表现出一种近似基岩的特征模式,表明基岩化学风化在土壤剖面的形成中起着次要作用。葡萄酒中铁和锰含量相对较高,遗传自基岩,锌含量较高,可能适用于葡萄藤。被认为具有潜在毒性的元素(砷、镉、铜、铅、锌)均低于OIV规定的最高可接受限度。尽管是初步的,但这些数据代表了高海拔博萨葡萄园可追溯性的第一个特征,给出了在特定小气候环境下的风化和元素可用性的一些轨迹,并揭示了基岩地质与高海拔山谷种植葡萄的葡萄元素摄取之间的联系。
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引用次数: 2
Mesozoic tectono-sedimentary evolution of the Trapanese SouthernTethyan margin (NW Sicily) integrating facies and stratigraphic analysis with subsidence history 特拉帕尼斯-南特提斯边缘(西西里岛西北部)中生代构造-沉积演化:相、地层分析与沉降史
Pub Date : 2020-02-01 DOI: 10.3301/IJG.2019.19
L.uca Basilone
Several Mesozoic successions of the Southern Tethyan margin were accumulated on a carbonate platform evolving to pelagic plateau depositional systems. Rifting paleotectonics was the main process conditioning their tectono-sedimentary evolution. The well-exposed outcrops in the NW Sicilian fold and thrust belt of the so-called Trapanese carbonate platform to pelagic succession highlight the occurrence of lateral facies and thickness changes, paleofaults, volcanics, and resedimented deposits. The integration of facies analysis, stratigraphic data, and subsidence history have permitted to decipher the polyphase tectono-sedimentary evolution and to distinguish different depositional settings. Structural lows, filled with up to 100m of pillow lavas and reworked deposits, appear as intraplatform basins bordered by structural highs, as horst ridges, characterised by condensed sedimentation, and isolated seamounts. These sectors were linked among them by stepped fault margins, scalloped margins and depositional slopes. The tectonic history, highlighted by the backstripped sections, reveals superimposed evolutionary stages reflecting rifting and rapid tectonic subsidence, leading to continental break-up (Late Triassic-Early Jurassic stage); the Middle Jurassic stage reflects slow thermal subsidence in the basin shoulders and higher rates in the intervening depressions; the Late Jurassic-Early Cretaceous regional uplift interrupts the thermal subsidence curve trend. The tract of the Late Cretaceous-Eocene curve suggests again slow thermal post-rift subsidence, also influenced by sediment load. The different subsidence curves, reconstructed from different positions in the sedimentary basin, demonstrate that its evolution could be driven by the identified syn-sedimentary faults that were formed and/or re-activated during several tectonic events encompassing the whole Jurassic-Cretaceous time period. The regional significance of this tectonics indicates that the Sicilian sector of the Southern Tethyan continental margin was tectonically active for the whole Mesozoic.The reconstructed paleophysiography of the Trapanese continental margin, during the Mesozoic, appears characterised by a segmented and drowned carbonate platform with morphostructural highs separated by deep channels. The comparison with the present-day morphostructural setting of some regions of the Atlantic continental margins (e.g. Caribbean, Brazilian equatorial margin), suggests also for the study region that the occurrence of transcurrent/transform faults and stretching of the continental lithosphere can have played an important role in determining the physiographic conformation.
南特提斯边缘的几个中生代序列是在碳酸盐岩台地上形成的,并演化为中古高原沉积体系。裂谷古构造作用是该区构造-沉积演化的主要调节作用。北西西西里褶皱和特拉帕尼斯碳酸盐岩台地逆冲带的出露突出了侧向相和厚度变化、古断裂、火山岩和再沉积的存在。结合相分析、地层资料和沉降史,可以破译多期构造-沉积演化,区分不同的沉积背景。构造低岩充填了长达100米的枕状熔岩和改造过的矿床,形成了以构造高点为边界的地内盆地,形成了以凝聚沉积为特征的地脊和孤立的海山。这些区段之间由阶梯式断层边缘、扇贝状边缘和沉积斜坡相连接。构造史上,以背带剖面为重点,揭示了反映裂陷和快速构造沉降的叠加演化阶段(晚三叠世—早侏罗世);中侏罗统表现为盆地肩热沉降缓慢,中间凹陷热沉降速率较高;晚侏罗世—早白垩世区域隆升中断了热沉降曲线趋势。晚白垩世-始新世曲线的范围再次显示出缓慢的热后裂谷沉降,也受沉积物负荷的影响。在沉积盆地不同位置重建的不同沉降曲线表明,沉积盆地的演化可能受到侏罗纪-白垩纪期间多次构造事件形成或重新激活的同沉积断裂的驱动。这一构造的区域意义表明,南特提斯大陆边缘的西西里板块在整个中生代都是构造活动的。重建的特拉帕尼斯大陆边缘中生代古地貌表现为一个以深沟道分隔的形态构造高点为特征的分段淹没式碳酸盐岩台地。通过与大西洋大陆边缘某些地区(如加勒比海、巴西赤道边缘)现今的形态构造背景的比较,也表明研究区域的横流/转换断层的发生和大陆岩石圈的伸展在决定地理构造方面可能起着重要作用。
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引用次数: 14
Seismic imaging of the shallow and deep structures in the Ancona landslide area 安科纳滑坡区浅部和深部构造的地震成像
Pub Date : 2020-02-01 DOI: 10.3301/ijg.2019.22
F. Accaino, L. Baradello, R. Nicolich, Alessandro Affattato
Following the large 1982 Ancona landslide, which affected a densely populated district with many man-made infrastructures, a big effort was made by the scientific community to study the area and a great amount of geophysical and geotechnical data were acquired. The region is part of the external domain of Central Apennine resulted by Neogene compressive deformations. The tectonic processes have resulted in instabilities along the entire central Adriatic coasts of Italy, marked today by large-scale gravitational phenomena. An early Pleistocene regional uplift formed a slope subject to glacioeustatic sea-level oscillations, with erosion and water infiltration, favouring instability and movements under the action of gravitational driving forces. Sliding surface formation and roto-translational displacements have occurred until the recent reactivations of earth-flows and chaotic mounds at the slope break in correspondence with the formation of the Peri-Adriatic basin. In this paper, we present images of seismic sections obtained from the processing of two sea-land reflection profiles and offshore very high-resolution prospecting. Our paper intends to reinforce the importance of a multi-disciplinary approach integrating geophysical data to geological, morphological and engineering methods. The seismic survey of the two sea-land sections considered a joint land–sea acquisition to image the subsurface in the transitional zone. Composite sections were obtained from the processing of differently recorded sub-datasets, which depended on the type of land and marine sources and sensors in combination with the unique frequency content, source strength and noise, such as the propagation of surface-waves or air-gun bubbles. The properly acquired and processed data yielded post-stack migrated depth converted seismic sections, reflecting interfaces down to approximately 1400 m depth, where the top of Messinian evaporites has been encountered. The final sections reveal the deep structural settings and the importance of the still active anti-Apennine transfer faults.The offshore Boomer high-resolution profiles show only the near sea-bottom sequences. These fluvio-deltaic Plio-Quaternary deposits represent the final filling phase of the foreland basins, exposed to sub-aerial erosion during the last glacial period and to submersion during the subsequent sea-level rise of approximately 120 m.The final sections reveal the deep structural settings and the importance of the still active anti-Apennine transfer faults.
1982年的安科纳大滑坡影响了一个人口稠密的地区,那里有许多人工基础设施。在那次滑坡之后,科学界对该地区进行了大量的研究,并获得了大量的地球物理和岩土工程数据。该地区是新近纪挤压变形形成的亚平宁中部外域的一部分。构造过程导致了意大利整个亚得里亚海中部海岸的不稳定,今天以大规模的引力现象为标志。早更新世区域隆起形成的斜坡受冰川上升海平面振荡的影响,具有侵蚀和水入渗作用,在重力驱动下有利于不稳定和运动。滑面形成和旋转平移位移一直持续到最近与亚得里亚海沿岸盆地形成相对应的坡折处土流和混沌丘的重新激活。本文介绍了两个海陆反射剖面处理和海上高分辨率勘探所获得的地震剖面图像。本文旨在强调将地球物理数据与地质、形态和工程方法相结合的多学科方法的重要性。两个海陆剖面的地震测量考虑了陆海联合采集,以对过渡带的地下进行成像。根据陆地和海洋源和传感器的类型,结合独特的频率含量、源强度和噪声(如表面波或气枪气泡的传播),对不同记录子数据集进行处理,获得复合剖面。正确获取和处理的数据产生了叠后偏移深度转换的地震剖面,反映了约1400 m深度的界面,在那里遇到了墨西尼亚蒸发岩的顶部。最后部分揭示了深部构造背景和仍在活动的反亚平宁转移断裂的重要性。海上婴儿潮时期的高分辨率剖面只显示了近海底的序列。这些河流三角洲沉积代表了前陆盆地的最后填充阶段,在末次冰期暴露于地面侵蚀,并在随后海平面上升约120米期间被淹没。最后部分揭示了深部构造背景和仍在活动的反亚平宁转移断裂的重要性。
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引用次数: 3
Esperienze educative alla mostra Cristalli ai Raggi X: il gesso di Vezzano sul Crostolo (RE) X射线晶体展览的教学经验:玻璃上的石膏(RE)
Pub Date : 2018-07-01 DOI: 10.3301/rol.2018.26
M. Scacchetti, Milena Bertacchini
The General Assembly of the United Nations declared 2014 the International Year of Crystallography, after 100 years from the awarding of the first Nobel Prize for the discovery of X-ray diffraction by crystals. On this occasion, the Department of Chemical and Geological Sciences of Modena and Reggio Emilia University (Italy)and its Museum “Gemma 1786”, organized an exhibition named Cristalli ai raggi X (Modena, 24 Jan.-29 Mar. 2015). The initiative involved the cooperation of many public and private partners and the active participation of twenty schools of different types and levels. An innovative aspect was the planned participation of highschool students to the fifty collateral events organized during the exhibition. The main purpose of Cristalli ai raggi X was to introduce non-specialists to the world of crystals and their properties, and to show how crystallography plays a role in the development of scientific disciplines. The display ended with the appreciation of 9,000 visitors and a hundred of guided tours for regional and extra-regional schools.The activity developed by the Manini Middle School of Vezzano sul Crostolo (Reggio Emilia province) involved 27 students of 13thyear-old. During an exhibition event opened to the public, they presented a study on the features of gypsum and the extraction history of the land where they come from and where, in the past, the gypsum was an important economic resource.
在因发现晶体x射线衍射而获得诺贝尔奖100周年之际,联合国大会宣布2014年为国际晶体学年。值此机会,意大利摩德纳和雷焦艾米利亚大学化学与地质科学系及其“Gemma 1786”博物馆组织了一场名为Cristalli ai raggi X的展览(摩德纳,2015年1月24日至3月29日)。该倡议涉及许多公共和私人伙伴的合作以及20所不同类型和级别的学校的积极参与。一个创新的方面是计划让高中生参加展览期间组织的50个附带活动。Cristalli ai raggi X的主要目的是向非专业人士介绍晶体及其性质的世界,并展示晶体学如何在科学学科的发展中发挥作用。展览以9,000名参观者的赞赏和100名地区和地区外学校的导游结束。该活动由雷焦艾米利亚省Vezzano sul Crostolo的Manini中学开展,共有27名13岁的学生参加。在一次向公众开放的展览活动中,他们介绍了石膏的特点和石膏产地的开采历史,在过去,石膏是一种重要的经济资源。
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引用次数: 0
Structural setting, kinematics and metamorphism in a km-scale shear zone in the Inner Nappes of Sardinia (Italy) 意大利撒丁岛内推覆带km尺度剪切带的构造背景、运动学与变质作用
Pub Date : 2018-06-01 DOI: 10.3301/IJG.2018.16
C. Montomoli, S. Iaccarino, M. Simonetti, M. Lezzerini, R. Carosi
In continental collisional orogenic belts, the hinterland-foreland transition plays a crucial role in the deformation styles and in the exhumation modes of the middle crustal rocks. The Barbagia Thrust (BT), a regional scale shear zone in the Variscan belt of central Sardinia, represents this transition. The BT, separating nappes withdifferent deformation styles, is still poorly characterized.We present new data of the BT and of the nearby tectonic units, using a multidisciplinary approach. We characterized in detail both meso- and micro-structural features, as well as, the metamorphic conditions with the aid of illite and chlorite “crystallinity” of rocks from the footwall, hanging wall and high-strain zone of the BT. Moreover, combining different palaeopiezometer-wet quartzite flowlaw pairs we characterized the rheological parameters (i.e., flow stress and strain rate) present during the BT activity. Three main deformation phases were recognized. After a D1 contractional deformation, a D2 related to the BT movement was associated to the development of a nearly 100 m thick high-strain zone withthe development of a mylonitic foliation, Sm, at middle crustal conditions, near the brittle-ductile” transition. Metamorphic constrains obtained from the footwall, the hanging wall and the high-strain zone supported an epizonal metamorphism with no unambiguous trend related to the strain intensity.Integrating our new metamorphic, deformation and rheological data, with previous ones in the geological literature helps to better unravel the long-lasting history of the nappe emplacement at hinterland-foreland transition in the Sardinian Variscan Belt.
在大陆碰撞造山带中,腹地—前陆过渡对中部地壳岩石的变形样式和掘出方式起着至关重要的作用。Barbagia逆冲带(BT)是撒丁岛中部Variscan带的一个区域性剪切带,代表了这一转变。不同变形类型推覆体的BT层特征尚不明确。我们采用多学科方法,提出了BT和附近构造单元的新数据。通过对BT下盘、上盘和高应变带岩石中伊立石和绿泥石“结晶度”的分析,详细表征了其细观和微观结构特征以及变质条件,并结合不同的古风化层-湿石英岩流动规律对,表征了BT活动过程中的流变参数(即流动应力和应变速率)。确定了三个主要变形阶段。经过D1收缩变形后,与BT运动相关的D2与近100 m厚的高应变带的发育有关,在地壳中部条件下,在脆-韧“过渡”附近发育糜棱质片理Sm。下盘、上盘和高应变带的变质约束支持层向变质作用,与应变强度没有明确的变化趋势。将我们新的变质、变形和流变学资料与以前的地质文献相结合,有助于更好地揭示撒丁岛瓦里斯坎带腹地-前陆过渡时期推覆体侵位的长期历史。
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引用次数: 12
期刊
Bollettino Della Societa Geologica Italiana
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