Journal of South American Earth Sciences最新文献_第5页

Unusual number of large tectonic earthquakes before and during the birth of the Paricutin monogenetic volcano. Did they trigger, maintain, and boost the volcanic long-lasting activity from 1943 to 1952? 在Paricutin单生火山诞生之前和期间发生了异常数量的大构造地震。它们触发、维持并促进了1943年至1952年的火山长期活动吗？

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-29 DOI: 10.1016/j.jsames.2025.105895

D. Legrand , M. Perton , M.G. Gómez-Vasconcelos , P. Larrea

Volcanoes can be described as falling somewhere a large spectrum ranging from polygenetic systems, which are constructed through multiple, long-lived eruptive phases, to monogenetic systems, which usually form during a single eruptive event. Within this context, several decades of observations on Earth have shown that close and strong tectonic earthquakes can precede large eruptions of polygenetic volcanoes. In contrast, only a few close and large earthquakes have been reported before the birth of new monogenetic volcanoes, since the latter are rare. Here, we describe the unusually high number of large tectonic earthquakes that preceded the birth of the Paricutin monogenetic volcano in Mexico in 1943. Thirteen large tectonic earthquakes occurred in the near field during the 20-year period spanning the decade before the birth of Paricutin to the end of its eruption, whereas only one earthquake occurred within ten years after the eruption ended. This clustering of large tectonic earthquakes in space and time before and during the eruption of Paricutin is unusual for this region of Mexico. The significant difference in the number of tectonic earthquakes before, during, and after the eruption strongly suggests that Paricutin's birth and growth are related to these earthquakes. They may have changed the stress tensor near Paricutin's location, facilitating magma to migrate towards the surface and sustaining Paricutin's eruption for nine years - an unusually long period for a monogenetic volcano. We propose that changes in static and quasi-static stress fields, resulting from local faults, local tectonics, and static displacement fields generated by near-field earthquakes, may have triggered and boosted the Paricutin's eruption. In addition, we suggest that the dynamic stress field generated by the waves emitted by earthquakes may have altered magma pathways towards the surface prior to and during the Paricutin's eruption.

火山可以被描述为落在一个很大的光谱范围内，从多成因系统，这是通过多个，长期的喷发阶段，单成因系统，通常形成于一次喷发事件。在这种背景下，对地球几十年的观测表明，在多成因火山大爆发之前，可能会发生近距离的强烈构造地震。相比之下，在新的单基因火山诞生之前，只有几次近距离的大地震被报道，因为后者是罕见的。在这里，我们描述了1943年墨西哥Paricutin单生火山诞生之前的异常高数量的大型构造地震。在Paricutin火山诞生前到喷发结束的20年间，近场发生了13次大型构造地震，而在喷发结束后的10年内仅发生了一次地震。在Paricutin火山喷发之前和期间，在空间和时间上聚集的大型构造地震在墨西哥这一地区是不寻常的。火山喷发前、喷发中、喷发后构造地震次数的显著差异，有力地表明Paricutin的诞生和发育与这些地震有关。它们可能改变了Paricutin火山附近的应力张量，促进了岩浆向地表迁移，并使Paricutin火山的喷发持续了9年——对于一个单成因火山来说，这是一个不同寻常的长时间。我们认为，局部断裂、局部构造和近场地震产生的静态位移场可能导致了静态和准静态应力场的变化，从而触发并促进了Paricutin火山的喷发。此外，我们认为地震波产生的动态应力场可能改变了Paricutin火山喷发前和喷发期间岩浆流向地表的路径。

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引用次数: 0

Early craniides (Brachiopoda, Craniiformea) from the Tremadocian of NW Argentina (Central Andean basin) 阿根廷西北部（安第斯盆地中部）Tremadocian的早期颅类动物（腕足目，颅形目）

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-27 DOI: 10.1016/j.jsames.2025.105888

Juan L. Benedetto, Fernando J. Lavié

Only a few representatives of the Order Craniida have been described from the lower Paleozoic so that its early evolutionary history remains poorly understood. So far, the oldest known craniids are from the upper Tremadocian of the Bohemian Massif and Bavaria. Here, we describe new craniid material from siliciclastic rocks of the Coquena Formation exposed in the Cordillera Oriental of northwestern Argentina. The material consists of some well-preserved dorsal valves belonging to two different forms whose morphological features do not fit into any known genus, but available specimens are insufficient to formally erect new taxa. The fossil-bearing horizon has been confidently dated as early late Tremadocian (Tr2) based on conodonts of the Paltodus deltifer Zone and associated trilobites, making this the oldest record of the Craniida worldwide. This discovery supports previous hypothesis that the origin and early diversification of Craniida took place in the cold-water shelves of western Gondwana, then spreading to temperate waters (Baltica, Kazakhstan, Iran, Cuyania terrane) by the Mid Ordovician.

从下古生代开始，只有少数颅目的代表被描述过，因此对其早期进化史的了解仍然很少。到目前为止，已知最古老的头盖骨来自波西米亚山脉和巴伐利亚的上特雷马多西亚。在这里，我们描述了来自阿根廷西北部科迪勒拉东部Coquena组硅质岩石的新颅类物质。这些材料包括一些保存完好的背瓣，属于两种不同的形态，其形态特征不属于任何已知的属，但现有的标本不足以正式建立一个新的分类群。根据Paltodus deltifer带的牙形刺和相关的三叶虫，有信心地将含化石层确定为晚Tremadocian （Tr2）早期，使其成为世界上最古老的颅目记录。这一发现支持了先前的假设，即克拉尼达的起源和早期多样化发生在冈瓦纳西部的冷水大陆架，然后在中奥陶纪传播到温带水域（波罗的海、哈萨克斯坦、伊朗、古巴地）。

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引用次数: 0

Isotope-informed water sources and recharge mechanisms in a tropical karst environment of the Talgua River Basin, Honduras 洪都拉斯塔尔瓜河流域热带喀斯特环境中同位素指示的水源和补给机制

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-27 DOI: 10.1016/j.jsames.2025.105891

Jorge Cardona-Hernández , Germain Esquivel-Hernández , Lucilena Rebelo Monteiro , Ricardo Sánchez-Murillo , Marycel E.B. Cotrim , Rolando Sánchez-Gutiérrez , Christian Birkel , Tania Peña-Paz , Laura Benegas-Negri

Understanding groundwater recharge mechanisms in karst zones is critical for preserving water supply, establishing water-use policies, and monitoring water pollution. In this study, we analyzed the isotope composition (δ²H and δ¹⁸O) of rainfall, surface water, and groundwater in the Talgua River basin in northeastern Honduras between August 2019 and December 2023. The main goal was to study the relationship between rainfall inputs and recharge mechanisms in a complex karstic environment, characterized by high rainfall seasonality and variable land use. The δ¹⁸O and δ²H relationship in rainfall resulted in a significant local meteoric water line of δ²H = 7.68 ± 0.08·δ¹⁸O + 9.47 ± 0.42 (N = 223, r² = 0.97, p < 0.001). HYSPLIT air mass trajectory and cluster analysis using δ¹⁸O and deuterium excess (d-excess) revealed that moisture sources in the Talgua River basin originated mainly from the Caribbean Sea (89 %) with minimal contributions from the Pacific Ocean and the Gulf of Mexico (11 %). Recharge is mainly driven by heavy, isotopically depleted rainfall during the May–November (wet season), as indicated by the rainfall to groundwater (P/GW) ¹⁸O/¹⁶O ratios. d-excess and the line-conditioned excess (LC-excess) values indicate substantial meteoric inputs during the wet season, reflecting a recycled-moisture signal that contributes to recharge, with only minor evapoconcentration effects. This study systematically provides essential insights into rainfall, surface water, and groundwater interactions in the poorly understood karstic regions of Central America. It advances our understanding of tropical karst hydrological processes, such as moisture transport and recharge mechanisms, and provides valuable information for water resource evaluation and management.

了解喀斯特地区地下水补给机制对保护供水、制定用水政策和监测水污染至关重要。在这项研究中，我们分析了2019年8月至2023年12月洪都拉斯东北部Talgua河流域降雨、地表水和地下水的同位素组成（δ2H和δ18O）。主要目的是研究在高降雨季节性和多变土地利用特征的复杂岩溶环境中，降雨输入与补给机制之间的关系。降水δ18O与δ2H的关系导致了显著的局地大气水线δ2H = 7.68±0.08·δ18O + 9.47±0.42 （N = 223, r2 = 0.97, p < 0.001）。HYSPLIT气团轨迹及δ18O和氘过量（d-excess）的聚类分析表明，Talgua河流域的水汽源主要来自加勒比海（89%），太平洋和墨西哥湾贡献较小（11%）。从降水对地下水（P/GW）的18O/16O比值可以看出，补给主要是由5 - 11月（雨季）大量的、同位素耗尽的降雨驱动的。d-excess和线条件过剩（LC-excess）值表明雨季有大量的大气输入，反映了有助于补给的再循环水分信号，只有轻微的蒸散效应。这项研究系统地提供了对中美洲喀斯特地区降雨、地表水和地下水相互作用的基本见解。该研究促进了我们对热带喀斯特水文过程的认识，如水分输送和补给机制，并为水资源评价和管理提供了有价值的信息。

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引用次数: 0

Application of the hyperextended rift model to Campos Basin, offshore Brazil: Implications for tectonic evolution and hydrothermal processes 超伸展裂谷模型在巴西Campos盆地的应用：构造演化和热液作用的意义

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-26 DOI: 10.1016/j.jsames.2025.105890

Rodrigo Alberti , Emanuele Francesco La Terra , Marcos Fetter , Gilmar Bueno , Sergio Fontes , Renata Alvarenga , Gerson José Salamoni Terra , Almério Barros França , Cosme Ferreira Ponte-Neto

Recent development of rifted margins studies brings new concepts and changed the way that continental margins are interpreted. While several recent studies have applied hyperextension concepts to Campos Basin at margin scale, this study provides a detailed local-scale integration centered on the BM-C-33 exploratory block (Raia Manta and Raia Pintada fields), focusing on the link between crustal structure and hydrothermal processes. We apply the protracted rift model (stretching–thinning–hyperextension) to the southern Campos Basin, offshore Brazil, integrating 2D seismic interpretation and forward gravity modeling to investigate the structural evolution and its role in sustaining hydrothermal circulation during continental breakup. Three seismic-constrained gravity models reveal a coherent transition from stretching to thinning of the continental crust, characterized by a main low-angle detachment fault, pronounced crustal attenuation, and mantle uplift to depths shallower than 20 km. The position of this detachment was refined and placed slightly farther basinward than in previous regional interpretations, improving the correlation between crustal thinning and the BM-C-33 block. This sector represents the area of maximum crustal attenuation, where fault-controlled permeability, elevated geothermal gradients, and mantle-induced heat flow sustained a long-lived hydrothermal system. Petrographic evidence from well 3-REPF-15DA-RJS, including pervasive silicification, hydraulic breccias, saddle dolomite, quartz veining, and bitumen infill, confirms the diagenetic imprint of this tectono-thermal regime. These findings establish a link between crustal-scale architecture and reservoir-scale hydrothermal alteration, demonstrating that the hyperextended rift framework can explain both the margin-scale evolution and localized hydrothermal systems of the Campos Basin.

近年来裂谷边缘研究的发展带来了新的概念，改变了对大陆边缘的解释方式。虽然最近的一些研究将超伸展概念应用于Campos盆地边缘尺度，但本研究以BM-C-33勘探区块（Raia Manta和Raia Pintada油田）为中心，提供了详细的局部尺度整合，重点关注地壳结构与热液过程之间的联系。本文以巴西南部Campos盆地为研究对象，采用延伸性裂谷模型（拉伸-变薄-超伸展），结合二维地震解释和正演重力模拟，探讨了该盆地在大陆分裂过程中的构造演化及其在维持热液循环中的作用。三个地震约束的重力模型揭示了大陆地壳从拉伸到变薄的连贯过渡，其特征是主要的低角度拆离断层，地壳衰减明显，地幔抬升深度小于20 km。与之前的区域解释相比，这一拆离的位置得到了改进，向盆地内的位置略远，从而提高了地壳变薄与BM-C-33块体之间的相关性。该板块代表了地壳衰减最大的区域，断层控制的渗透率、升高的地热梯度和地幔诱导的热流维持了一个长期存在的热液系统。3-REPF-15DA-RJS井的岩石学证据，包括普遍的硅化作用、水力角砾岩、鞍状白云岩、石英脉纹和沥青充填，证实了这一构造-热机制的成岩印记。这些发现建立了地壳尺度构造与储层尺度热液蚀变之间的联系，表明超伸展裂谷格架既可以解释坎波斯盆地边缘尺度演化，也可以解释局部热液系统。

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引用次数: 0

Shallow subsurface structure of the late pleistocene sudoeste volcano using shear-wave velocity models from ambient seismic noise in the san quintín volcanic field, Baja California 下加利福尼亚san quintín火山场环境地震噪声剪切波速度模型研究晚更新世sudoeste火山浅层地下结构

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-26 DOI: 10.1016/j.jsames.2025.105887

Ismael Yarbuh , Luis A. Yegres-Herrera , Lenin Ávila-Barrientos , Miguel A. Santa Rosa-Del Rio

The San Quintín Volcanic Field (SQVF), located on the Baja California Peninsula, comprises a set of Quaternary monogenetic cones whose eruptive and structural evolution remains only partially constrained. This study focuses on the Late Pleistocene Sudoeste Volcano to investigate its shallow subsurface structure and evaluate how pre-existing crustal features influence magma ascent and conduit emplacement. Ambient seismic noise measurements were conducted along two orthogonal profiles across the Sudoeste cone. The Horizontal-to-Vertical Spectral Ratio (HVSR) method, combined with 1D inversion, was applied to derive shear-wave velocity (Vs) models. The results reveal a vertically coherent high-Vs anomaly (>2700 m/s) extending from approximately 200 to 800 m depth, showing a consistent NW–SE elongation that aligns with adjacent cones Pescador 1 and 2. This structure is interpreted as a shallow, consolidated intrusive body, while lower Vs values (<800 m/s) surrounding the anomaly likely correspond to unconsolidated volcanic deposits and saturated sediments. These observations support the presence of a structurally guided feeder system and highlight the role of pre-existing crustal discontinuities in controlling magma pathways. The well-preserved morphology of the Sudoeste cone, its structural alignment with nearby cones, and the interpreted intrusive body provide new constraints on magma ascent within an active plate boundary setting. This study demonstrates the effectiveness of HVSR-based shear-wave velocity models from ambient seismic noise for imaging shallow volcanic architecture and contributes valuable insights into the tectono-magmatic evolution of the SQVF.

圣Quintín火山场（SQVF）位于下加利福尼亚半岛，由一套第四纪单成因锥体组成，其喷发和构造演化仅受到部分限制。本研究以晚更新世Sudoeste火山为研究对象，研究其浅层地下结构，并评价已有地壳特征对岩浆上升和导管侵位的影响。环境地震噪声测量沿着Sudoeste锥体的两条正交剖面进行。采用水平-垂直谱比（HVSR）方法，结合一维反演，推导出横波速度（Vs）模型。结果显示，垂直相干高v异常（>2700 m/s）从大约200到800 m深度延伸，显示出一致的NW-SE延伸，与相邻的锥体Pescador 1和2对齐。该构造被解释为一个浅层固结侵入体，而异常周围较低的v值（<800 m/s）可能对应于松散的火山沉积物和饱和沉积物。这些观测结果支持了构造导向的补给系统的存在，并强调了预先存在的地壳不连续在控制岩浆通道方面的作用。Sudoeste锥体保存完好的形态、与附近锥体的构造排列以及解释的侵入体为岩浆在活动板块边界环境下的上升提供了新的约束条件。该研究证明了基于hvrr的环境地震噪声剪切波速模型在浅层火山构造成像中的有效性，并为SQVF的构造-岩浆演化提供了有价值的见解。

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引用次数: 0

Interseismic strain accumulation along the Chilean segment of the Magallanes – Fagnano fault zone recorded by continuous GNSS 连续GNSS记录的Magallanes - Fagnano断裂带智利段地震间应变累积

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-26 DOI: 10.1016/j.jsames.2025.105889

Francisco Delgado , Juan Carlos Báez , Pablo León-Ibáñez

We present the first evidence of interseismic strain accumulation along the Chilean segment of the Magallanes Fagnano Fault Zone, the plate boundary between the Scotia and South America plates. We use a network of seven continuous GNSS stations, including two deployed within

\sim

8 km from the fault trace. Despite the low spatial resolution of the network, the data record a variation of

\sim

6 mm/yr in the eastward velocity across a

\sim

100 km long transect. This is compatible with the presence of a likely segmented, locked strike-slip fault. The velocities can be modeled by an infinitely long screw dislocation parallel to the mapped fault trace, with fault-parallel velocity of 5.48 mm/yr and locking depth of 6.45 km. The geodetic fault velocity is similar to that measured elsewhere by previous studies with denser campaign GNSS in Argentina and with post-glacial fault slip rate derived from geomorphic offsets. This suggests a consistency between the long-term fault slip that records the cumulative deformation over many earthquake cycles and the nearly instantaneous strain accumulation. The time series do not show clear evidence for aseismic release of energy such as slow-slip events, fault creep, or other processes such as glacial isostatic adjustment. We speculate that the strain accumulation extends towards the fault segments that are located beneath the fjords in the region.

我们提出了沿Magallanes Fagnano断裂带智利段地震间应变积累的第一个证据，该断裂带是斯科舍板块和南美洲板块之间的板块边界。我们使用由7个连续GNSS站组成的网络，其中两个部署在距离故障轨迹约8公里的范围内。尽管该网络的空间分辨率很低，但数据记录了沿~ 100公里长的样带向东的速度变化约6毫米/年。这与可能存在的分段、锁定走滑断层相一致。速度可以用平行于断层线的无限长螺旋位错来模拟，断层平行速度为5.48 mm/yr，锁定深度为6.45 km。大地测量断层速度与以前在阿根廷使用更密集的运动GNSS和由地貌偏移得出的冰川后断层滑动率进行的研究在其他地方测量的速度相似。这表明记录许多地震周期累积变形的长期断层滑动和几乎瞬时的应变积累之间存在一致性。时间序列没有显示出地震释放能量的明确证据，如慢滑事件、断层蠕变或其他过程，如冰川均衡调整。我们推测，应变积累向位于该地区峡湾下方的断层段延伸。

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引用次数: 0

Stratigraphic characterization of the Atalaia Beach (Pará, Brazil) based on GPR data 基于GPR资料的Atalaia海滩（par<e:1>，巴西）地层表征

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-26 DOI: 10.1016/j.jsames.2025.105885

João Fillipe Sousa Siqueira , Saulo Siqueira Martins , Joelson Lima Soares

The study was conducted at Praia do Atalaia, in Salinópolis (PA), an area of intense coastal dynamics and urbanization. The main objective was to characterize the stratigraphy of sedimentary units using Ground-Penetrating Radar (GPR), a high-resolution geophysical tool for subsurface investigation. For this purpose, survey lines were acquired both parallel and perpendicular to the coastline using a 200 MHz antenna, integrated with digital elevation models (DEM). The interpretation was based on radar facies analysis, considering parameters such as reflection geometry, continuity, internal configuration, and amplitude. Nine GPR profiles were presented, with an average depth of up to eight meters, and nine distinct radar facies sets were identified, highlighting the structural and depositional complexity. The interpreted features indicate the presence of incised tidal paleochannels, clayey or homogeneous zones, dune dynamics, low-energy deposits, and erosional surfaces associated with marine transgression events. Based on these data and the geometry of the reflection sets, stratigraphics models was proposed for the study areas, in which the units were correlated with the Pirabas and Barreiras Formations and Post-Barreiras Sediments, as well as with recent deposits. The models also revealed the thickening of the Pirabas Formation toward the northwest sector of the coastal plain, where this unit outcrops. The integration of geophysical data, topographic information, and sedimentary interpretation was essential for the detailed characterization of coastal depositional systems, significantly contributing to the understanding of the sedimentary dynamics and evolution of the Bragantina coastal plain, serving as a basis for future studies employing complementary geophysical techniques.

这项研究是在Salinópolis （PA）的Praia do Atalaia进行的，这是一个沿海动态和城市化强烈的地区。主要目的是利用探地雷达（GPR）来描述沉积单元的地层特征，这是一种用于地下调查的高分辨率地球物理工具。为此，使用200 MHz天线，结合数字高程模型（DEM），获取平行和垂直于海岸线的测量线。该解释基于雷达相分析，考虑了反射几何形状、连续性、内部结构和振幅等参数。绘制了9条平均深度达8米的探地雷达剖面，识别了9组不同的雷达相，突出了构造和沉积的复杂性。解释特征表明，古潮汐河道、粘土或均质带、沙丘动力学、低能沉积物和与海侵事件有关的侵蚀面存在。根据这些数据和反射集的几何形状，提出了研究区域的地层模型，其中单元与Pirabas和Barreiras组和后Barreiras沉积物以及最近的沉积物相关联。该模型还揭示了皮拉巴斯组在沿海平原西北部分的增厚，该单元在那里露头。地球物理数据、地形信息和沉积解释的整合对于海岸沉积体系的详细表征至关重要，有助于理解布拉干蒂纳海岸平原的沉积动力学和演化，为未来采用互补的地球物理技术进行研究奠定基础。

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引用次数: 0

The Chanic orogeny revisited: What have we learned about the Early Paleozoic evolution of SW Gondwana? 再看Chanic造山运动：我们对SW Gondwana早古生代的演化有什么了解？

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-26 DOI: 10.1016/j.jsames.2025.105886

F.L. Boedo , J.P. Ariza , S. Pérez Luján , G.G. Voldman , V. Zaccaria , M.V. Sánchez , G.I. Vujovich

The Chanic orogeny, originally proposed by Ramos et al. (1984) as the result of collision between the Chilenia terrane and Gondwana during the Late Devonian, remains a key yet debated event in the Early Paleozoic evolution of SW Gondwana. Over four decades, multidisciplinary research in the Argentine Precordillera and adjacent units has refined and challenged this proposal, revealing a more complex basin evolution between 30 and 33°S. Mafic–ultramafic rocks, long considered the suture zone between Cuyania and Chilenia and initially interpreted as a single Famatinian-aged ophiolite, are now recognized as products of multi-stage rifting magmatism from the Late Neoproterozoic to the Devonian. The earliest rifting stage that separated both terranes is documented south of 32°S and involved deposition of continental margin sequences linked to Late Neoproterozoic MORB magmatism. This stage may be related to Rodinia break-up and separation from Laurentia. Rifting persisted through the Cambrian and expanded north of 32°S during the Middle Ordovician–Early Devonian, producing passive margin successions and MORB magmatism emplaced on thinned continental crust. A ductile deformation phase (D₁) and high-pressure units occur south of 32°S, whereas a second deformation phase (D₂) is recorded along the entire western margin of the Precordillera and is associated with the closure of the basin in the Middle–Late Devonian due to the collision of the Chilenia terrane with Gondwana. Although substantial progress has been made, several questions still remain unanswered, and at the same time alternative interpretations are supported by new data. This scenario will be shaping the direction of future research.

拉莫斯等人（1984）最初提出的Chanic造山运动是晚泥盆世智利地体与冈瓦纳碰撞的结果，至今仍是冈瓦纳西南早古生代演化中的一个关键事件，但仍有争议。在过去的40年里，阿根廷Precordillera和邻近单元的多学科研究已经完善并挑战了这一建议，揭示了30 - 33°S之间更复杂的盆地演化。镁铁质-超镁铁质岩石长期以来被认为是贵州和智利之间的缝合带，最初被解释为一个单一的法马汀期蛇绿岩，现在被认为是晚新元古代至泥盆世多期裂谷岩浆作用的产物。分离两块地体的最早裂谷期记录在32°S以南，涉及与晚新元古代MORB岩浆作用有关的大陆边缘层序沉积。这一阶段可能与Rodinia的分手和与Laurentia的分离有关。裂谷作用贯穿寒武纪，在中奥陶世—早泥盆世扩展至32°S以北，形成被动边缘序列和MORB岩浆作用，侵位在变薄的大陆地壳上。在32°S以南出现了韧性变形阶段（D1）和高压单元，而在整个前科迪勒拉西缘记录了第二次变形阶段（D2），并与中晚泥盆世由于Chilenia地块与Gondwana地块的碰撞而导致盆地闭合有关。虽然取得了重大进展，但仍有几个问题没有得到解答，同时，新的数据支持了不同的解释。这种情况将决定未来研究的方向。

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引用次数: 0

Main factors influencing the pore structure development of late mature organic-rich shales: A case study based on La Peña and Eagle Ford Formations, Sabinas Basin, NE Mexico 影响晚成熟富有机质页岩孔隙结构发育的主要因素——以墨西哥东北部Sabinas盆地La Peña组和Eagle Ford组为例

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-26 DOI: 10.1016/j.jsames.2025.105880

J. Ortiz-Treviño , I. Flores-Vivián , E. Padilla-Ortega , L.F. Camacho-Ortegón , G. Chávez-Cabello , F. Núñez-Useche , E. Chacón-Baca , C.G. Aguilar-Madera

The Aptian La Peña and the Cenomanian-Turonian Lower Member of the Eagle Ford Formations in the Sabinas Basin are organic-rich source rocks that represent unconventional petroleum resources in northeastern Mexico. In this study, we explore the formation and evolution of shale pores in these source rocks through a combination of mineralogy, geochemistry, organic petrography, scanning electron microscopy (SEM), and low-pressure nitrogen adsorption techniques. Results show that the samples are carbonate, quartz, and clay-rich. Geochemical and petrographic analyses indicate a post-oil and wet gas maturation stage, with limited petroleum generation potential. SEM imaging revealed that the more abundant pore types are intergranular, intragranular, intercrystalline, and dissolution pores. In addition, micropores, mesopores, and macropores are all present, with mesopores being the most dominant pore size (avg. 22.7 nm). Correlation analysis revealed that the microscopic pore structure of the shale samples is positively controlled by OM abundance and maturity, and negatively affected by clay minerals. These attributes are also controlled by the structural configuration on samples location, affected by regional folds, faults, areas of salt withdrawal and vicinity with igneous bodies in the Sabinas basin. Overall, the interaction of these factors conditioned the pore types, sizes, and morphology, affecting the gas content and network connectivity of these source rocks.

Sabinas盆地的Aptian La Peña和Eagle Ford组的Cenomanian-Turonian下段是墨西哥东北部非常规油气资源的富有机质烃源岩。本研究通过矿物学、地球化学、有机岩石学、扫描电镜、低压氮吸附技术等综合手段，探讨了这些烃源岩中页岩孔隙的形成与演化。结果表明，样品中碳酸盐、石英和粘土含量丰富。地球化学和岩石学分析表明，该区处于后油气成熟阶段，生烃潜力有限。扫描电镜（SEM）成像显示孔隙类型较多的是粒间孔、粒内孔、晶间孔和溶蚀孔。此外，微孔、中孔和大孔均存在，其中中孔是最主要的孔径，平均孔径为22.7 nm。相关分析表明，页岩微观孔隙结构受有机质丰度和成熟度的正向控制，受粘土矿物的负向影响。这些属性还受样品位置上的构造构造控制，受区域褶皱、断裂、盐退区及火成岩附近的影响。总体而言，这些因素的相互作用决定了孔隙类型、大小和形态，影响了烃源岩的含气量和网络连通性。

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引用次数: 0

Retraction notice to “Spatiotemporal dynamics and transformation of the Parana State coastline: A 34-year analysis using RS, GIS, and machine learning” [SAMES 148 (2024) 105162] 对“巴拉那州海岸线的时空动态和转变：使用RS， GIS和机器学习的34年分析”的撤回通知[SAMES 148 (2024) 105162]

IF 1.5 4区地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY

Journal of South American Earth Sciences

Pub Date : 2025-11-25 DOI: 10.1016/j.jsames.2025.105845

M.R Raja Ramesh , Nageswara Rao Aramanda , Nallabariki Praveen Kumar , Phani Babu K , Dammu Venkata Ravi Kumar

引用次数: 0