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Las partículas magnéticas como indicadoras de contaminación en el Valle de Aburrá (Colombia) 在aburra山谷(哥伦比亚),磁性颗粒作为污染指标
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2023-04-15 DOI: 10.18268/bsgm2023v75n1a181122
Alexander Sánchez-Duque, F. Bautista, Rubén Cejudo, M. Cervantes-Solano, Avto Goguitchaichvili
En el presente trabajo se reportan los resultados de un estudio de magnetismo ambiental realizado en el Área Metropolitana del Valle de Aburrá (Colombia) con el objetivo de determinar la variación espacial de la contaminación en la zona urbana. Se diseñó un muestreo bidimensional en el que se definieron 99 sitios de muestreo, cada uno de los sitios fue georreferenciado y descrito por factores categóricos de uso de suelo, jerarquía vial, superficie vial, grupo de suelo o unidad geológica, especie vegetal recolectada y ciudad o municipio. En total se recolectaron 307 muestras ambientales de las cuales, 110 fueron de suelo urbano superficial, 99 de polvo urbano y 98 hojas de plantas de ornato público. Se emplearon técnicas de magnetismo de rocas para determinar la naturaleza de los minerales magnéticos presentes en las muestras. Se realizó un análisis de varianza no paramétrico para relacionar los valores de los parámetros magnéticos con los factores categóricos y revelar las posibles fuentes de las partículas magnéticas. Posteriormente, mediante el factor de aumento magnético en las muestras de polvo y suelo superficial, se definieron los valores de referencia de la contaminación específicos para cada zona y cada tipo de muestra. A partir de los valores calculados y georreferenciados se diseñaron mapas que muestran modelos descriptivos de la contaminación ambiental para cada área urbana según el tipo de muestra ambiental y los parámetros magnéticos. Los resultados revelan que la señal magnética en los sitios con mayor concentración de minerales magnéticos es dominada por minerales ferrimagnéticos de origen antrópico. Los análisis no paramétricos de la varianza muestran que una mayor concentración relativa de estos minerales tiene una fuerte relación con la jerarquía vial y en menor grado con usos de suelo. Los mapas demuestran que la mayor parte de la superficie urbana estudiada presenta algún nivel de contaminación.
本文报告了在哥伦比亚阿布拉河谷大都市区进行的一项环境磁学研究的结果,目的是确定城市地区污染的空间变化。设计了一个二维抽样,确定了99个抽样地点,每个地点都被地理参考,并由土地利用、道路等级、道路面积、土壤组或地质单位、收集的植物物种以及城市或城市的分类因素来描述。共收集了307份环境样本,其中110份来自城市表层土壤,99份来自城市灰尘,98份来自公共装饰植物叶子。岩石磁性技术用于确定样品中磁性矿物的性质。进行了非参数方差分析,将磁性参数的值与分类因素联系起来,并揭示了磁性颗粒的可能来源。随后,通过灰尘和表土样本中的磁增强因子,确定了每个区域和每种样本类型的特定污染参考值。根据计算和地理参考值,设计了地图,根据环境样本类型和磁性参数,显示每个城市地区环境污染的描述模型。结果表明,磁性矿物浓度较高的地方的磁信号以人为来源的铁磁矿物为主。非参数方差分析表明,这些矿物的相对浓度越高,与道路等级关系越密切,与土地利用关系越小。地图表明,所研究的大多数城市地区都存在一定程度的污染。
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引用次数: 0
First occurrence in life position of two Triassic brachiopod species (Thecideida) from NE Italy: Paleoecological considerations 意大利东北部两种三叠纪腕足动物(脊鱼目)在生命位置上的首次出现:古生态学考虑
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2023-04-15 DOI: 10.18268/bsgm2023v75n1a250822
M. Torres-Martínez, Francisco Sánchez-Beristain, J. Reitner
The San Cassiano Formation from the Dolomites, NE Italy, is a Ladinian–Carnian (Middle – Upper Triassic) lithostratigraphic unit belonging to the Western Tethys domain. In this formation numerous groups of marine invertebrates from reef communities have been reported. In particular, brachiopods are represented by different orders. Thecideids are the most abundant and diverse, with different species of the genus Thecospira. Despite the apparent abundance, only one report exists of a thecideid of the genus preserved in life position: Thecospira tyrolensis. In this study, we describe and discuss the first finding of Thecospira semseyi and Thecospira tenuistriata in life position based on the study of thin sections of Cipit boulders. Seemingly, the Th. semseyi shells were not firmly attached to the substrate by a small cementation surface; therefore, they could have lived embedded into the biogenic matrix. By contrast, Th. tenuistriata displays an umbonal region modified in a cementation area, allowing the attachment to the bio-builder. Most samples don’t show any signal of transport since all specimens are articulated and are still attached to the substrate. Besides, the commissures are partially opened, free of any encrustation of sponge or bryozoan growing. The preservation of brachiopods suggests that the samples of both species were fossilized in life position. Moreover, Th. semseyi and Th. tenuistriata continued to live although the host’s fabric was imbibing the brachiopods’ ventral valve. This shows that thecideids were important components of Tethys reef communities.
意大利东北部多洛米蒂地区的圣卡西亚诺组是一个Ladinian-Carnian(中-上三叠纪)岩石地层单元,属于西特提斯域。据报道,在该地层中,有许多来自珊瑚礁群落的海洋无脊椎动物。特别是腕足类动物有不同的目。苹果虫是最丰富和多样化的,有不同的种类的Thecospira属。尽管有明显的丰富性,但只有一份关于该属的一种被保存在生命位置上的化石的报告:tyrolensis锥皮蛛。在本研究中,我们描述并讨论了在Cibit巨石薄片研究的基础上首次发现的处于生命位置的Thecospira semseyi和Thecospia tenuistriata。看起来,Th.semseyi壳没有通过小的胶结表面牢固地附着在基底上;因此,它们可能生活在生物基质中。相比之下,Th.tenuistriata显示了一个在胶结区修饰的脐部区域,允许附着在生物构建剂上。大多数样本没有显示出任何运输信号,因为所有样本都是铰接的,并且仍然附着在基底上。此外,连合部分开放,没有任何海绵或苔藓虫生长的外壳。腕足类动物的保存表明,这两个物种的样本都是生命位置的化石。此外,尽管宿主的组织吸收了腕足动物的腹侧瓣膜,但Th.semyi和Th.ttenuistriata仍然存活。这表明该类是特提斯礁群落的重要组成部分。
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引用次数: 0
Interpretación de datos aeromagnéticos y gravimétricos satelitales para la identificación de zonas con potencial acuífero en la porción oeste de la cuenca Grijalva, México 解释航空磁和卫星重力数据,以识别墨西哥格里哈尔瓦盆地西部有潜在含水层的地区
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2023-04-15 DOI: 10.18268/bsgm2023v75n1a031122
Marco Rogelio Bustamante-Orozco, Ojilve Ramón Medrano-Pérez, Iris Neri-Flores, Edgar Ángeles-Cordero
El objetivo de esta investigación es interpretar las respuestas magnéticas y gravimétricas del subsuelo en la porción oeste en la cuenca Grijalva, México, para identificar y delimitar las áreas de unidades de rocas con potencial acuífero. Para ello, se realizó el procesamiento de datos aeromagnéticos y gravimétricos satelitales con el propósito de delimitar las características geológicas de mayor interés. Los resultados muestran que la parte centro-norte de la porción de estudio representa la zona con mayor potencial acuífero, y coincide con las áreas de mayor espesor sedimentario, de menor altitud y donde se concentran las concesiones de agua subterránea. Por tanto, el cambio de gradientes entre las respuestas magnéticas y gravimétricas favorecen el conocimiento del marco estructural (fallas, fracturas, bordes y contactos geológicos) y la inferencia de las áreas con potencial acuífero. En detalle, de las trasformaciones o filtros utilizados la Derivada Tilt (TDR, por sus siglas en inglés) presenta las tendencias lineales asociadas al marco estructural con particular interés hídrico. Se busca favorecer la toma de decisión y la investigación en los temas geohidrológicos, ordenamiento territorial y políticas públicas relacionadas.
这项研究的目的是解释墨西哥格里哈尔瓦盆地西部底土的磁和重力响应,以识别和划定具有潜在含水层的岩石单位区域。为此,对卫星航磁和重力数据进行了处理,目的是划定最感兴趣的地质特征。结果表明,研究区中北部是含水层潜力最大的地区,与沉积厚度最大、海拔较低、地下水特许权集中的地区相吻合。因此,磁和重力响应之间梯度的变化有助于了解结构框架(断层、裂缝、边缘和地质接触),并推断具有含水层潜力的地区。具体而言,在所使用的转换或过滤器中,倾斜导数(TDR)显示了与具有特殊水利益的结构框架相关的线性趋势。旨在促进地质水文、领土管理和相关公共政策问题的决策和研究。
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引用次数: 1
El yacimiento de Zn-Pb de Castellanos (Cuba): un depósito sedimentario-exhalativo finijurásico-cretácico 卡斯特利亚诺斯(古巴)的Zn-Pb矿床:一个沉积-喷流-晚侏罗世-白垩纪矿床
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2023-04-15 DOI: 10.18268/bsgm2023v75n1a161122
David Gómez-Vivo, Fernando Gervilla, A. Azor, Rebeca Hernández-Díaz, R. Piña, C. Alvarez
El yacimiento de Zn-Pb de Castellanos, situado al noroeste de la isla de Cuba, encaja en un paquete de pizarras negras intercalado en la parte superior de una potente secuencia siliciclástica (>4km), constituida principalmente por areniscas y limolitas de edad Jurásico Inferior y Medio (Formación San Cayetano). El yacimiento es estratiforme, se orienta en dirección NE-SO concordantemente con la estratificación de las pizarras encajantes y está constituido por dos bloques (el bloque Farallones al NE y el bloque Susana al SO) separados por una zona de falla con rumbo N120ºE; una zona de falla con la misma dirección limita también el bloque Farallones en su contacto NE. Este bloque se superpone a un complejo filoniano constituido por filones de pirita±calcopirita y cuarzo, de <10cm de espesor, y orientados también en dirección N120ºE. El cuerpo estratiforme principal está constituido por pirita, esfalerita y galena, con ganga de carbonatos (principalmente dolomita-ankerita y calcita), cuarzo, barita y, y menores proporciones de sericita, biotita parcialmente alterada a clorita y apatito criptocristalino. Muestra una estructura zonal con una zona basal discontinua rica en pirita y una zona superior heterogénea en la que varían tanto las proporciones modales de sulfuros+carbonatos (localmente con cuarzo), como la abundancia relativa de esfalerita+galena respecto a pirita. En conjunto, presenta una textura groseramente bandeada en la que alternan irregularmente bandas ricas en pirita, bandas con esfalerita y galena, y bandas de dolomita-ankerita (±sericita, biotita-clorita y apatito criptocristalino), mejor definida hacia el SO del cuerpo mineral. En este sentido, y hacia el techo de la mineralización., tiende a aumentar la proporción modal de cuarzo y localmente de barita. De NE a SO también se observa una variación en la composición química de la esfalerita, la cual se hace progresivamente más rica en Zn, a la vez que cristaliza una generación más tardía de esfalerita extremadamente pobre en Fe (<1% en peso). En los límites de bloques, la mineralización está afectada por varios episodios de fracturación y brechificación durante los cuales precipitaron y/o se movilizaron diversas generaciones de calcita, barita, cuarzo y galena. En los episodios más tardíos de esta etapa precipita también calcopirita rellenando fracturas y huecos intersticiales entre los fragmentos de sulfuros previos. La interpretación genética de la mineralización de Castellanos que se propone está basada en la precipitación repetitiva (multifásica) de los sulfuros+carbonatos como consecuencia de la interacción de fluidos/salmueras mineralizantes ascendentes a lo largo de las fracturas que dieron lugar al complejo filoniano con los sedimentos ricos en materia orgánica depositados en el fondo de una subcuenca anóxica desarrollada en la cuenca de margen pasivo donde se depositó la Formación San Cayetano. Las salmueras fueron oxidantes, saturadas en sulfato, y se habrían generado en la
卡斯特利亚诺锌铅矿床位于古巴岛西北部,位于一个强大的硅质碎屑岩序列(>4km)顶部的一组黑色页岩中,主要由下侏罗纪和中侏罗纪的砂岩和粉砂岩(圣卡耶坦组)组成。该矿床呈层状,与燕尾页岩的分层一致,呈NE-SO方向,由两个区块(东北部的法拉隆区块和苏珊娜区块)组成,两个区块被N120°E的断层带隔开;一个方向相同的断层带也限制了法拉隆地块的东北接触。该地块与一个由黄铁矿±黄铜矿和石英脉组成的菲隆杂岩重叠,厚度<10cm,也向N120ºE方向。主要层理由黄铁矿、闪锌矿和方铅矿组成,含碳酸盐脉石(主要是白云石-安克雷石和方解石)、石英、重晶石和少量绢云母、部分蚀变为绿泥石的黑云母和隐晶质磷灰石。它显示出一种带状结构,基底区域不连续,富含黄铁矿,上部区域不均匀,硫化物+碳酸盐(局部含石英)的模式比例以及闪锌矿+方铅矿相对于黄铁矿的相对丰度都有所不同。总体而言,它呈现出一种粗糙的带状结构,其中富含黄铁矿的条带、与闪锌矿和方铅矿的条带以及白云石-安克雷石(±绢云母、黑云母-绿泥石和隐晶质磷灰石)条带不规则地交替出现,更好地定义为矿体的SO。从这个意义上说,朝着矿化的屋顶。,它倾向于增加石英和局部重晶石的模态比例。从Ne到So,闪锌矿的化学成分也发生了变化,锌含量逐渐增加,同时结晶出一代后来的铁含量极低的闪锌矿(<1 wt%)。在区块边界上,矿化受到几次压裂和角砾化事件的影响,在此期间,几代方解石、重晶石、石英和方铅矿沉淀和/或动员起来。在这一阶段的后期,黄铜矿也沉淀下来,填充了以前硫化物碎片之间的裂缝和空隙。提出的对卡斯蒂利亚人矿化的遗传解释是基于硫化物+碳酸盐的重复(多阶段)沉淀,这是由于沿断裂上升的成矿流体/盐水相互作用,导致菲隆杂岩与沉积在被动边缘盆地底部的富含有机质的沉积物沉积在San地层沉积的缺氧亚盆地中卡耶塔诺。盐水是氧化的,饱和为硫酸盐,本应在碳酸盐台地产生,蒸发岩在上侏罗纪-下白垩纪期间在盆地边缘发育。这些卤水通过强大的砂岩和粉砂岩序列的渗透将其温度提高到100-200ºC,有利于形成主要矿化所需的锌和铅的溶解和动员。压裂/角砾化阶段还促进了还原液的上升,这些还原液与硅质碎屑岩序列中插层的黑色页岩水平相平衡,为成矿提供了金和钡。在最后阶段,压裂使更深更热的流体(~350ºC)上升,导致黄铜矿晚期沉淀。
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引用次数: 0
Biostratigraphy of Yazdanshahr No.2 section in Kerman area, Central Iran, based on conodont communities 伊朗中部克尔曼地区Yazdanshahr 2号剖面基于牙形石群落的生物地层学
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2023-04-15 DOI: 10.18268/bsgm2023v75n1a300822
Ehsanollah Nasehi, Mohammad Amin Nasehi
Yazdanshahr No.2 section, which consists mostly of Bahram and Sibzar formations is located in the Zarand city, northern Kerman province (Central Iran). Five biozones have been identified based on the conodont community. The first biozone, which includes Padehat (15 meter) and Sibzar formations (75 meter), was distinguished based on genera Bipennatus and Icriodus and the probable corresponding age was considered to span Emsian to Eifelian. The second biozone is recognized by the first appearance of index taxon Polygnathus varcus (varcus Zone: early to middle Givetian). The third biozone starts with the firth appearance of the index genus Icriodus expansus (expansus zone: middle Givetian). The base of the Fourth biozone is recognized by the first appearance of the genus I. subterminus (subterminus Zone: middle to late Givetian) and the last biozone was distinguished with the first appearance of genera Ancyrodella and Polygnathus incompletes in the Givetain-Frasnian boundary (falsiovalis to crepida Zone?: Frasnian to Famenian?). Bahram Formation (94 meter) consists of Fossiliferous limestone (varcus to subterminus Zone) at the lower part, and alternation of dolomite and sandstone (falsiovalis to crepida Zone?) at the upper part. Sibzar Formation consists of Middle Devonian dolomite and limy dolomite containing intercalation of sandstone and limestone layers.
Yazdanshahr 2号部分主要由Bahram和Sibzar地层组成,位于克尔曼省北部(伊朗中部)的Zarand市。根据牙形石群落划分出5个生物带。第一个生物带包括Padehat组(15米)和Sibzar组(75米),根据Bipennatus属和Icriodus属进行了区分,并认为可能对应的年龄跨越emian到Eifelian。第二个生物带以指数分类群Polygnathus varcus首次出现为标志(varcus带:早至中Givetian)。第三个生物区开始于索引属鸢尾花的第五次出现(鸢尾花区:middle Givetian)。第四个生物带的基础是首次出现的I. subterminus属(subterminus带:Givetian中晚期),最后一个生物带是在givetin - frasnian边界首次出现的Ancyrodella属和Polygnathus in完成属(pseudoovalis to crepida Zone?从弗拉斯尼亚语到法曼尼亚语?)Bahram组(94米)下部为化石灰岩(varcus - subterminus带),上部为白云岩-砂岩(pseudoovalis - crepida带?)西扎尔组由中泥盆统白云岩和灰质白云岩组成,含砂岩和灰岩夹层。
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引用次数: 0
Late Pleistocene paleoenvironment at a Middle Stone Age archaeological site in Equatorial Guinea: a paleopedological approach 赤道几内亚中石器时代考古遗址的晚更新世古环境:古学方法
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2022-12-13 DOI: 10.18268/bsgm2022v74n3a200622
T. Cruz-y-Cruz, Alejandro Terrazas-Mata, L. Pogosyan, S. Sedov, T. Pi-Puig, Irán Rivera-González, Beatriz Menéndez-Iglesias, Jorge Rodríguez-Rivas, H. Cabadas-Báez
Key evidence of human occupation in Africa during the Middle Palaeolithic (Middle Stone Age [MSA]) is available from the south and east of the continent, where semi-arid climate prevails. Rare evidence of MSA human occupation in the humid tropical region was recently reported from Equatorial Guinea. To identify if paleolithic human occupation occurred in the tropical forest, the stratigraphy of the recently discovered archaeological site “Mabewele I” was analyzed using a paleopedological approach. The properties evaluated along a vertical profile are: granulometry, magnetic susceptibility (K), free iron extractable with sodium dithionite (Fed), total organic carbon (TOC), chemical composition by X-ray fluorescence (XRF), X-ray diffraction mineralogy (XRD), ternary plot of the three main oxides (SiO2-Al2O3-Fe2O3), phytoliths and micromorphology. The predominant fraction is sand, with a significant clay content (> 30 %). The K and the Fed presented low values, as well as the TOC. XRF showed few variations along the sequence and XRD showed that the clays are mainly kaolinites, with a very low component of vermiculites. The phytoliths correspond to tropical vegetation with few changes in the vegetal composition between the deep and superficial zones. A charcoal from the lower part of the profile was dated between 12.57-12.24 ka cal BP, while the main artifact horizon was located at the bottom. The analytical results appear contradictory: on the one hand, there is evidence of intense chemical weathering under a humid tropical climate, but the clay cutans in the pores are very scarce and incipient and the iron nodules are mostly anorthic. This indicates that the sequence is composed of pedosediments associated with a high environmental dynamism, with short periods of erosion-sedimentation-pedogenesis. The results allow us to propose that humans inhabited the tropical forest during the MSA and that erosion-sedimentation processes could be related to anthropization processes.
人类在旧石器时代中期(中石器时代[MSA])居住在非洲的关键证据来自非洲大陆的南部和东部,那里普遍存在半干旱气候。最近从赤道几内亚报告了湿润热带地区MSA人类活动的罕见证据。为了确定旧石器时代的人类是否曾在热带森林中居住过,研究人员使用古学方法分析了最近发现的考古遗址“Mabewele I”的地层学。沿着垂直剖面评估的性质是:粒度测定、磁化率(K)、二亚硫酸钠(Fed)可提取的游离铁(游离铁)、总有机碳(TOC)、x射线荧光(XRF)化学成分、x射线衍射矿物学(XRD)、三种主要氧化物(SiO2-Al2O3-Fe2O3)的三元图、植物岩和微观形貌。主要组分为砂,粘土含量显著(约30%)。K和Fed的值较低,TOC也较低。XRF沿序列变化不大,XRD显示粘土以高岭石为主,蛭石含量极低。植物岩与热带植被相对应,深层和浅层植被组成变化不大。剖面下部的木炭的年代在12.57-12.24 ka cal BP之间,而主要的人工制品层位于底部。分析结果似乎是矛盾的:一方面,在潮湿的热带气候下,有强烈的化学风化的证据,但孔隙中的粘土岩屑非常稀少且处于初期阶段,铁结核大多是植物性的。这表明该层序是由具有高环境动力的土壤沉积物组成,具有短时间的侵蚀-沉积-成土作用。这些结果使我们能够提出人类在MSA时期居住在热带森林,并且侵蚀-沉积过程可能与人类化过程有关。
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引用次数: 0
Comparative study of pre-Hispanic and colonial adobes in Mexico. Preliminary inferences on the effects of the granulometric distribution and used recycled materials in the state conservation of earth architecture 墨西哥前西班牙裔和殖民地土坯的比较研究。粒度分布和再生材料在土建筑国家保护中作用的初步推断
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2022-12-13 DOI: 10.18268/bsgm2022v74n3a010422
M. J. Puy-Alquiza, Velia Yolanda Ordaz-Zubia, Omar Cruces-Cervantes, Antonio Bello-Sandoval, R. Miranda-Avilés, M. D. C. Salazar-Hernández, G. Carreño-Aguilera, G. Zanor, Yanmei Li
The characterization of the pre-Hispanic and colonial adobes used in the construction of buildings in Mexico was carried out to know the differences between their processes and manufactures. The eight samples obtained correspond to adobe blocks 0.45 m long x 0.35 m wide and 0.12 m thick, which were part of the interiors of houses, the structure of fences, and hacienda galleys. These samples were investigated using X-ray Diffraction, X-ray Fluorescence, and Scanning Electron Microscopy techniques to determine the morphometry of the material and its chemical and mineralogical composition. Likewise, some analyzes were performed to determine their mechanical properties (simple compressive strength), physical properties (granulometry, solid density, cohesion, plasticity index, porosity, and moisture content), and biological (organic matter content). The results obtained in terms of the granulometric distribution indicate that pre-Hispanic adobe has a higher content of sand than silt-clay and gravel, while the colonial adobes present a low or null content of gravel with a higher content of silt-clays. Regarding the organic matter content, the colonial adobe presents the highest percentages compared to those of the pre-Hispanic adobes. Taking into account the above the pre-Hispanic adobes have better resistance and durability than colonial adobes due to their granulometric distribution, low organic matter content, good cohesion, high plasticity index, and the use of materials found in their natural environment, while the colonial used recycled materials, coming from the economic activity to which the hacienda was dedicated, for example, agriculture, mining, livestock, this has given rise to different manufacturing techniques and construction styles that reflect the state of conservation of buildings throughout the pre-Hispanic and colonial times. The granulometric distribution that pre-Hispanic adobe provides favorable physical and mechanical qualities for any construction technique, so it is recommended to use this formula to manufacture resistant and durable adobe.
对墨西哥建筑中使用的前西班牙裔和殖民地土坯进行了表征,以了解其工艺和制造之间的差异。所获得的八个样本对应于0.45米长、0.35米宽、0.12米厚的土坯块,这些土坯块是房屋内部、围栏结构和庄园厨房的一部分。使用X射线衍射、X射线荧光和扫描电子显微镜技术对这些样品进行了研究,以确定材料的形态计量学及其化学和矿物学组成。同样,进行了一些分析,以确定它们的机械性能(简单抗压强度)、物理性能(粒度、固体密度、内聚力、塑性指数、孔隙率和水分含量)和生物性能(有机物含量)。根据粒度分布获得的结果表明,前西班牙裔土坯的沙子含量高于粉质粘土和砾石,而殖民地土坯的砾石含量较低或为零,粉质粘土含量较高。就有机物含量而言,与前西班牙裔土坯相比,殖民时期的土坯所占比例最高。考虑到上述情况,前西班牙裔土坯比殖民地土坯具有更好的抵抗力和耐久性,因为它们的粒度分布、低有机质含量、良好的内聚性、高塑性指数,并且使用了在其自然环境中发现的材料,而殖民地使用的是来自庄园致力于的经济活动的回收材料,例如,农业、采矿业、畜牧业,这产生了不同的制造技术和建筑风格,反映了整个前西班牙裔和殖民时代的建筑保护状况。前西班牙裔土坯的粒度分布为任何施工技术提供了良好的物理和机械质量,因此建议使用该配方制造耐腐蚀、耐用的土坯。
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引用次数: 0
Fire microfacies and pyroresidues tracing atmospheric electrification impacts on the Moche Valley and on the Mochica (North Peru) 火微相和焦渣追踪大气电气化对莫切河谷和莫奇卡(秘鲁北部)的影响
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2022-12-13 DOI: 10.18268/bsgm2022v74n3a060622
M. Courty
The effects of environmental events on living conditions during occupation periods are studied by comparing alluvial soils and occupation floors that formed during the late Holocene in the Moche valley (North Peruvian coast). The microcontextual study comprises (1) microsurface identification in the field; (2) micromorphological analysis of thin sections; (3) multi-scale characterization of soil components based on digital stereo microscope and scanning electron microscope analysis. The alluvial sequence consists of a 6 m thick alternation of organic silty-clay, fine sandy strata with well-preserved ashy charcoal strata and massive grey sandy beds. This cyclical pattern reflects alternation of stable episodes with a dense reed-bed vegetation, regularly affected by wildfires and drought marked by sand invasions from coastal dunes during El Niño events. The 14C dates show that these contrasting conditions lasted for one millennium up to establishment of the Mochica empire at the Huaca at 300 years cal. BC. Vesicular slags produced by flash-melting of the soil components, biosourced quartz and nanostructured polymers formed from flash-ionization of the reed vegetation, all with FeCrNi metals coatings, were retrieved in the fired surfaces. They trace impact at the soil surface of electrically charged particles, lightning-flashes, nanoaerosol production by enhanced atmospheric electrification, i.e., flash-heating, shock vaporization, plasma-polymerization of the vegetation and the host matrix. The study shows the occurrence in the basal Uhle platform occupation deposits at the foot of the Huaca de la Luna of similar cemented ashy microfacies associated with a funerary deposit with food offerings in ritual vessels and an intriguing scoriaceous slag. The evidence for ritual disposal of imperishable offerings to deaths is interpreted as the memorial record of the Mochica knowledge of long-lived materials produced by lightning-triggered plasma processes. This integrated study of the environmental and cultural contexts refutes previous assumptions of long-term engineering of the arable alluvial plain to counteract sand invasion and torrential floods. In contrast, the establishment of the Moche pyramids is shown to have occurred during a period of floodplain stability marked by high-energy natural events and lightning processes that offered access to durable soil resources of important social values.
通过比较莫切河谷(秘鲁北部海岸)全新世晚期形成的冲积土和占领层,研究了占领期间环境事件对生活条件的影响。微观上下文研究包括(1)现场微观表面识别;(2) 薄片的微观形态分析;(3) 基于数字立体显微镜和扫描电子显微镜分析的土壤成分多尺度表征。冲积序列由6 m厚的有机粉质粘土、细砂质地层和保存完好的灰炭层以及块状灰色砂层组成。这种周期性模式反映了稳定期的交替,芦苇床植被茂密,经常受到野火和干旱的影响,在厄尔尼诺事件期间,海岸沙丘的沙子入侵是其特征。公元前14世纪的日期表明,这些对比鲜明的条件持续了一千年,直到公元前300年在华卡建立了莫奇卡帝国。在烧制表面回收了土壤成分闪速熔化产生的气泡状炉渣、生物源石英和芦苇植被闪速电离形成的纳米结构聚合物,所有这些都带有FeCrNi金属涂层。它们追踪了带电粒子对土壤表面的影响、闪电、通过增强大气带电产生的纳米气溶胶,即闪光加热、冲击蒸发、植被和宿主基质的等离子体聚合。研究表明,在Huaca de la Luna山脚下的基底Uhle平台占用矿床中,出现了类似的胶结灰微相,与带有礼器中的食物和有趣的焦渣的陪葬矿床有关。仪式上处理不朽的死亡祭品的证据被解释为莫奇卡人对闪电触发等离子体过程产生的长寿材料的认识的纪念记录。这项对环境和文化背景的综合研究驳斥了以前对可耕地冲积平原进行长期工程以抵御沙子入侵和暴雨的假设。相比之下,Moche金字塔的建立被证明是在洪泛平原稳定时期发生的,其特点是高能自然事件和闪电过程为获得具有重要社会价值的耐用土壤资源提供了途径。
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引用次数: 0
Subducted iron and glassy spherules in the upper mantle? 上地幔的俯冲铁和玻璃球?
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2022-12-13 DOI: 10.18268/bsgm2022v74n3a200722
J. González-Jiménez, I. Sergeeva, T. Kerestedjian, F. Gervilla
Spherules are documented in ophiolitic mantle rocks such as peridotites and associated chromitites. They consist of: (1) native iron having variable amounts of Ni with/without inclusions of silicate glass or oxides (wüstite), (2) dendritic intergrowth of oxides (magnetite, wüstite and hematite) with/without silicate glass and, (3) silicate glass. Consensually, they are interpreted as indigenous to chromitites and related with high-temperature processes operating in the Earth’s upper mantle. However, their similarity with terrestrial and extraterrestrial spherules found in other settings of the geological record is remarkable. We raise the question on such indigenous origin, relating them to volcanic and cosmic material recycled back to the mantle wedge where chromitites form during subduction.
在蛇绿质地幔岩石中,如橄榄岩和伴生的铬铁矿中记录了球粒。它们由:(1)含有不同数量镍的天然铁(含/不含硅酸盐玻璃或氧化物(w石)),(2)氧化物(磁铁矿、w石和赤铁矿)枝晶共生,含/不含硅酸盐玻璃,(3)硅酸盐玻璃。普遍认为,它们被解释为铬铁矿的原生产物,并与地球上地幔的高温过程有关。然而,它们与在地质记录的其他环境中发现的地球和地外球体的相似性是显著的。我们提出了这种原生起源的问题,将它们与火山和宇宙物质联系起来,这些物质在俯冲过程中被回收到地幔楔中形成铬铁矿。
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引用次数: 0
Identification of materials used for earthwork construction: the semi-circular fortification rampart of Hedeby, Northern Germany 土方施工材料的鉴定:德国北部Hedeby的半圆形防御工事
IF 0.8 4区 地球科学 Q3 Earth and Planetary Sciences Pub Date : 2022-12-13 DOI: 10.18268/bsgm2022v74n3a040422
A. Kurgaeva, S. Khamnueva-Wendt, H. Bork
The protected status of archaeological sites requires using minimally invasive methods of material investigation such as coring. In contrast to excavations, the coring method does not present a complete view of the inner structure, and the limited amount of material in cores represents a small portion of the study object. This complicates the interpretation of material genesis. This problem is particularly relevant for complex structures such as earthworks. Nonetheless, the proper interpretation of the construction materials in earthworks is crucial for geoarchaeological investigations of the anthropogenic transformation of landscapes. We proposed a method for classifying and identifying the earthwork materials, sampled by the coring technique. It was developed using an example of the semi-circular fortification rampart around the former Viking settlement Hedeby, which was an important early medieval international trading center and today is a UNESCO world heritage site. Materials from the coring transect across the semi-circular rampart were described. The physicochemical properties of 139 samples from three cores were determined: grain size distribution, weight percentages of gravel, artefacts, bones, and charcoal, loss on ignition, magnetic susceptibility, and element concentrations. The statistical methods (normalization, correlation, standardization, principal component analysis, cluster analysis) were applied to distinguish and group materials according to their physicochemical properties. The resulting clusters were used as a basis for material classification. Some clusters were mildly transformed according to the morphological properties of the material. Consequently, 20 groups were distinguished based on the physicochemical and morphological properties of the material. The rampart was constructed from soil horizons, cultural deposits, and Pleistocene material, which were used in different proportions along the investigated transect. In addition, the constituents of mixed layers were identified. Overall, the presented method for the statistical classification of the material considerably facilitates and objectifies the identification of material genesis. This is particularly valuable in tackling the challenges of coring-based investigations of earthworks.
考古遗址的保护状态需要使用微创的材料调查方法,如取芯。与挖掘相比,取芯方法并不能完整地观察内部结构,取芯中有限的材料只占研究对象的一小部分。这使对物质起源的解释变得复杂。这个问题与土方工程等复杂结构特别相关。尽管如此,对土方工程中的建筑材料进行适当的解释对于景观人为变化的地质考古调查至关重要。我们提出了一种通过取芯技术对土方材料进行分类和识别的方法。它是以前维京人定居点赫代比周围的半圆形防御工事为例开发的,赫代比是中世纪早期的一个重要国际贸易中心,今天是联合国教科文组织世界遗产。描述了半圆形斜坡取芯样带的材料。测定了来自三个岩芯的139个样品的物理化学性质:粒度分布、砾石、人工制品、骨骼和木炭的重量百分比、灼烧失重、磁化率和元素浓度。采用统计学方法(归一化、相关、标准化、主成分分析、聚类分析),根据材料的理化性质对其进行区分和分组。所得的簇被用作材料分类的基础。根据材料的形态特性,对一些团簇进行了温和的转化。因此,根据材料的物理化学和形态特性,区分了20个组。城墙是由土层、文化沉积物和更新世材料建造的,这些材料在调查的样带上以不同的比例使用。此外,还鉴定了混合层的成分。总的来说,所提出的材料统计分类方法极大地促进了材料成因的识别并使其客观化。这对于解决土方工程取芯调查的挑战尤其有价值。
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引用次数: 1
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Boletin De La Sociedad Geologica Mexicana
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