Geomorphology最新文献_第7页

The variation of particle concentration with height of wind-blown coral sand 风吹珊瑚沙颗粒浓度随高度的变化

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-15 DOI: 10.1016/j.geomorph.2024.109455

Jianjun Qu , Caizhi Hu , Xiang Xiao , Yimeng Wang , Benli Liu

Wind-blown coral sand movement is common in the marine coral sand island environment but received much less research attention compared to desert and coastal sands. We used the particle image velocimetry technique with wind tunnel experiments to determine the decay trends of the particle number density, nominal particle area density, and actual particle area density with height for wind-blown coral sands from the South China Sea. Then, a new morphology factor F_M that consists of volume V, density ρ_s, drag coefficient C_D, and projected area A of sand particles, was defined to evaluate the influences of particle characteristics on wind-blown sand movement and the results were compared with those of quartz sands from an inland desert. We found that the average F_M of coral sands is more comparable to that of coarse quartz sands than smaller size groups. Coral sands tend to move nearer the surface during aeolian processes compared to smaller quartz ones due to their larger F_M. The decay rate of particle number density of coral sands with height is similar to that of coarse (0.8–1 mm) quartz sands, but significantly larger than that of smaller quartz ones. The decay rate of the actual particle area density of coral sands with height is larger than that of their nominal particle area density, so that significant deviations may exist if a fixed particle size and spherical shape are assumed to study wind-blown particle movement. The present work contributes to understand the effect of particle characteristics on the wind-blown sand movement from a physical mechanism perspective for both desert quartz sands and marine coral sands.

风吹珊瑚沙运动在海洋珊瑚沙岛环境中很常见，但与沙漠和海岸沙相比，其研究关注度要低得多。我们利用颗粒图像测速技术和风洞实验，确定了南海风吹珊瑚沙的颗粒数密度、名义颗粒面积密度和实际颗粒面积密度随高度变化的衰减趋势。然后，定义了由沙粒体积 V、密度 ρs、阻力系数 CD 和投影面积 A 组成的新形态因子 FM，以评估颗粒特征对风吹沙运动的影响，并将结果与内陆沙漠石英沙的结果进行了比较。我们发现，珊瑚沙的平均调频与粗石英沙相比更接近。与较小的石英砂相比，珊瑚砂由于其较大的调频，在风化过程中往往更靠近地表。珊瑚砂的颗粒数密度随高度的衰减率与粗石英砂（0.8-1 毫米）相似，但明显大于小石英砂。珊瑚沙的实际颗粒面积密度随高度的衰减率大于其名义颗粒面积密度的衰减率，因此，如果假定研究风吹颗粒运动的颗粒大小和球形是固定的，则可能存在显著偏差。本研究有助于从物理机制的角度理解沙漠石英砂和海洋珊瑚砂的颗粒特征对风吹砂运动的影响。

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引用次数: 0

Rainfall characteristics and magnitude control the volume of shallow and deep-seated landslides: Inferences from analyses using a simple runoff model 降雨特征和降雨量控制着浅层和深层滑坡的体积：使用简单径流模型进行分析得出的推论

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-12 DOI: 10.1016/j.geomorph.2024.109453

Tadamichi Sato , Yasuhiro Shuin

Landslide volume plays a pivotal role in controlling landslide movement and potential damage. Although rainfall is widely recognized as one of the most important factors underlying landslide occurrence worldwide, its impact on landslide volume has been investigated only for individual landslide types. In this study, we show that rainfall characteristics and magnitude control the volume produced by both shallow and deep-seated landslides. A total of ten shallow and deep-seated landslides in Japan were compiled with volume, occurrence time, and rainfall data. Rainfall characteristics that triggered landslides were identified using the Soil Water Index and the three-layer tank model, which is a simple runoff model, and magnitude was quantified based on lag time. A strong positive correlation was found between lag time and landslide volume, indicating that landslide volume increases with increasing magnitude of rainfall to induce landslides. This study is the first attempt to suggest a relationship between rainfall magnitude and the volume produced by shallow and deep-seated landslides systematically and will promote the development of landslide risk management strategies.

滑坡体积在控制滑坡运动和潜在破坏方面起着关键作用。尽管降雨被公认为是全球滑坡发生的最重要因素之一，但人们只研究了个别滑坡类型的降雨对滑坡体积的影响。在这项研究中，我们发现降雨特征和降雨量控制着浅层和深层滑坡产生的体积。我们汇编了日本总共 10 个浅层和深层滑坡的体积、发生时间和降雨量数据。利用土壤水分指数和三层水槽模型（一种简单的径流模型）确定了引发滑坡的降雨特征，并根据滞后时间量化了滑坡的规模。研究发现，滞后时间与滑坡量之间存在很强的正相关性，表明滑坡量随着降雨量的增加而增加，从而诱发滑坡。这项研究首次尝试系统地提出降雨量与浅层和深层滑坡体积之间的关系，将促进滑坡风险管理策略的制定。

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引用次数: 0

Giant landslide, hidden caldera structure, magnetic anomalies and tectonics in southern Tyrrhenian Sea (Italy) 意大利第勒尼安海南部的巨型滑坡、隐藏的火山口结构、磁异常和构造作用

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-09 DOI: 10.1016/j.geomorph.2024.109445

Riccardo De Ritis , Luca Cocchi , Salvatore Passaro , Massimo Chiappini

Phlegraean Fields and Ischia Island are large, densely populated, active volcanic structures located in the Campanian Tyrrhenian margin between the onshore and offshore sectors. While the emerged landforms provide significant insights into a series of intense volcano-tectonic events of the last 60 ka, our understanding of the sub-marine portion of these volcanoes remains limited due to its inaccessibility to direct exploration. In the last decades, the use of magnetic methods has proven to be useful in volcanic context, given the presence of large magnetization contrasts, whereas the implementation of a high-resolution Digital Elevation Model (DEM) has allowed the integration of detailed morphological analyses into the geophysical studies. In this work, we present two new high-resolution airborne and shipborne magnetic surveys, carried out by the National Institute of Geophysics and Volcanology (INGV) in the marine sector of the Phlegraean Fields caldera (Pozzuoli Bay) and surrounding sea sectors. Moreover, the new datasets have been integrated with older marine surveys carried out by the National Research Council (CNR) to extend the resulting magnetic anomaly map embracing the whole Campanian offshore volcanic structures, excluding Ischia Island. As a result, we present here three new magnetic anomaly maps used for an integrated interpretation of magnetic, morphological, and tectonic features. The study results provide valuable insights into the relationship between volcanic, magmatic, and tectonic activity, which may be useful for further investigations. Among the most notable findings are: the identification of the magnetic signatures of regional faults, previously unknown caldera structures, and a massive rock avalanche. Consequently, our research provides a significant contribution to seabed exploration aimed at identifying potential hazard factors in the study area.

菲勒格拉埃火山区和伊斯基亚岛是位于坎帕尼亚-第勒尼安海边缘的大型、人口稠密的活火山结构，处于陆地和近海区域之间。虽然新出现的地貌为了解过去 60 ka 年间一系列强烈的火山构造事件提供了重要信息，但由于无法直接勘探，我们对这些火山的海底部分的了解仍然有限。在过去的几十年中，由于存在较大的磁化对比，磁力方法的使用已被证明在火山环境中非常有用，而高分辨率数字高程模型（DEM）的实施则使详细的形态分析得以融入地球物理研究中。在这项工作中，我们介绍了国家地球物理和火山学研究所（INGV）在菲格拉耶火山口海洋区（波祖利湾）和周边海区进行的两次新的高分辨率机载和船载磁力勘测。此外，新数据集还与国家研究委员会（CNR）开展的旧海洋勘测相结合，以扩展所绘制的磁异常图，使其涵盖整个坎帕尼亚近海火山结构，但不包括伊斯基亚岛。因此，我们在此展示了三幅新的磁异常图，用于综合解释磁性、形态和构造特征。研究结果为火山、岩浆和构造活动之间的关系提供了有价值的见解，可能有助于进一步的研究。其中最显著的发现包括：确定了区域断层的磁性特征、以前未知的火山口结构以及大规模岩崩。因此，我们的研究为旨在确定研究区域潜在危险因素的海底勘探做出了重大贡献。

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引用次数: 0

Spatial distribution and deposits of cliffs along the Brazilian semi-arid coast 巴西半干旱海岸悬崖的空间分布和沉积情况

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-09 DOI: 10.1016/j.geomorph.2024.109451

Antonio Rodrigues Ximenes Neto , Rhaiane Rodrigues da Silva , Davis Pereira de Paula , Melvin Moura Leisner , Abner Monteiro Nunes Cordeiro , Jáder Onofre de Morais , Lidriana de Souza Pinheiro

Cliffed coasts are common landforms found worldwide, but their precise spatial distribution and the nature of associated deposits may present regional gaps. This works presents a geological and geomorphological study of the Brazilian semi-arid coast (∼900 km), which was carried out on coastal cliffs with the aim of addressing three important knowledge gaps: i) spatial distribution of coastal cliffs, analyzed using topographic data from SRTM, LiDAR and field surveys, ii) the lithology and ages of the deposits, investigated through sedimentological analysis and OSL dating, and iii) origin of the cliffs, explored through relations with global and regional sea-level curves. The supply of terrigenous sediments to the western equatorial Atlantic coast was also considered. Coastal cliffs were identified along 235 km of the coastline, represented mainly by inactive cliffs (∼170 km). These cliffed coasts are composed mainly by poorly sorted siliciclastic sandstones and conglomerates, deposited in the Late Pleistocene. The depositional phases correlate with abrupt climate changes, due to pulses of terrigenous supply to the continental margin during the Heinrich Events. The formation of marine cliffs in these deposits occurred in the mid-Holocene, as sea level reached current elevation (msl) in ∼7 ka and 2-4 m above in ∼5.5 ka. This previous higher sea-level supports the widespread occurrence of inactive cliffs. The findings in this work contribute to i) improved mapping of coastal landforms, with higher resolution data demonstrating that previous works underestimated the presence of coastal cliffs; ii) the coastal cliffs are cut in Pleistocene sediments instead of older, Miocene deposits of the Barreiras Formation as previously assumed; iii) cliff formation due to marine erosion occurred in the mid- to- late Holocene; iv) the siliciclastic sediments that compose the cliffs are correlatable to marine sediments found in adjacent offshore areas, highlighting the role of abrupt global climatic changes in the Pleistocene in shaping contemporary coastal landscapes.

悬崖海岸是世界各地常见的地貌，但其精确的空间分布和相关沉积物的性质可能存在区域性空白。这篇论文介绍了对巴西半干旱海岸（900 公里）进行的地质和地貌研究，研究对象是海岸悬崖，目的是解决三个重要的知识空白：i) 海岸悬崖的空间分布，利用 SRTM、激光雷达和实地调查的地形数据进行分析；ii) 沉积物的岩性和年龄，通过沉积学分析和 OSL 测年进行调查；iii) 悬崖峭壁的起源，通过与全球和区域海平面曲线的关系进行探讨。此外，还考虑了向赤道大西洋西部海岸供应陆相沉积物的问题。在 235 公里的海岸线上发现了海岸悬崖，主要是不活跃的悬崖（∼170 公里）。这些悬崖海岸主要由晚更新世沉积的分选较差的硅质砂岩和砾岩组成。沉积阶段与气候突变相关，这是由于海因里希事件（Heinrich Events）期间向大陆边缘提供了大量土著物质。这些沉积物中的海崖形成于全新世中期，海平面在 7 ka ∼ 7 ka 达到目前的海拔高度（msl），在 5.5 ka ∼ 5.5 ka 高出 2-4 m。之前海平面的升高支持了不活动悬崖的广泛出现。这项工作的发现有助于 i) 改进海岸地貌的测绘，更高分辨率的数据表明以前的工作低估了海岸悬崖的存在；ii) 海岸悬崖被切割在更新世沉积物中，而不是像以前假设的那样被切割在更古老的中新世巴雷拉斯地层沉积物中；iii）因海洋侵蚀而形成的悬崖发生在全新世中期至晚期；iv）构成悬崖的硅质沉积物与邻近近海地区发现的海洋沉积物具有相关性，突显了更新世全球气候突变在塑造当代海岸景观中的作用。

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引用次数: 0

Fluvial-lacustrine influences on linear dune erosion at Lake Caroline in the Simpson Desert of Australia 澳大利亚辛普森沙漠卡罗琳湖的冲积-湖积对线性沙丘侵蚀的影响

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-09 DOI: 10.1016/j.geomorph.2024.109438

Rachel Rotz , Adam Milewski , Robert Craddock , Alex Morgan , David S. Leigh

Linear dunes are frequently examined with regard to their formation and maintenance; however, erosion or degradation of these landforms is less commonly addressed, due in part to the lack of observable changes in the geologic record. This study investigates the significant erosion of linear dunes along Lake Caroline, a playa in the northern Simpson Desert of central Australia. Field observations, laboratory analyses, and remote sensing imagery document recent fluvial and lacustrine interactions at Lake Caroline. Compositional and geochemical sediment analyses from three ∼2 m deep hand-augured sample sites indicate that the playa is primarily filled with sand from linear dunes, but also contains evaporite minerals and weathered local bedrock. Satellite images show that the playa has flooded at least 58 times since 2001. Our results indicate that present-day aeolian processes are sufficient to mobilize and transport sediment but are dominated by fluvial-lacustrine processes, resulting in the playa-adjacent dunes becoming isolated and starved of local sediment. As a result, the dunes are currently eroding into the playa which supports the conclusion that long-distance sediment transport is not responsible for the formation or maintenance of linear dunes as suggested by the linear due extension hypothesis. Burial dates from optically stimulated luminescence (OSL) indicate the linear dunes have been eroding for as much as 24 ka, and sediment samples from the playa near one linear dune suggest an onset of dune formation in the area before 58 ka. This work documents an instance in geologic time during the late Quaternary when aeolian, fluvial, and lacustrine processes are competing with one another, offering new insights into the dynamics of linear dunes in the arid Simpson Desert.

人们经常研究线性沙丘的形成和维护问题，但这些地貌的侵蚀或退化问题却较少涉及，部分原因是地质记录中缺乏可观察到的变化。本研究调查了澳大利亚中部辛普森沙漠北部卡洛琳湖沿岸线性沙丘的严重侵蚀情况。实地观察、实验室分析和遥感图像记录了卡罗琳湖近期的河道和湖泊相互作用。从三个 2 米深的手工取样点进行的沉积物成分和地球化学分析表明，该水域主要由来自线性沙丘的沙子填充，但也含有蒸发岩矿物和风化的当地基岩。卫星图像显示，自 2001 年以来，该地区至少被洪水淹没过 58 次。我们的研究结果表明，现今的风化过程足以动员和运输沉积物，但主要由河道-湖泊过程主导，导致与沙丘相邻的沙丘变得孤立，缺乏当地沉积物。因此，沙丘目前正被侵蚀到沙丘区内，这支持了长距离沉积物迁移并不是线性适当延伸假说所提出的线性沙丘形成或维持的原因这一结论。光激发发光（OSL）的埋藏日期表明，线性沙丘被侵蚀的时间已长达 24 ka，而一个线性沙丘附近的沙丘沉积物样本表明，该地区沙丘形成的时间早于 58 ka。这项研究记录了第四纪晚期风化、河流和湖泊过程相互竞争的地质时间，为了解干旱的辛普森沙漠线性沙丘的动态提供了新的视角。

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引用次数: 0

Corrigendum to “Responses of geomorphic indices to the northward migration of the Eastern Himalayan syntaxis” [Geomorphology 465 (2024) 109396] 对 "地貌指数对喜马拉雅山东部综丝北移的响应 "的更正[《地貌学》465 (2024) 109396]

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-09 DOI: 10.1016/j.geomorph.2024.109449

Xuemin Pan , Xiaoming Shen , Zhiyuan He , Xiaoping Yuan , Yukui Ge , Xiong Wu , Yingying Jia , Yanglin Zhao , Xiudang Tang

引用次数: 0

Exploring the inclusion of soil management practices in erosion models towards the improvement of post-fire predictions 探索将土壤管理方法纳入侵蚀模型，以改进火灾后的预测工作

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-08 DOI: 10.1016/j.geomorph.2024.109452

Ana Lopes , Sónia Gouveia , Dalila Serpa , Jacob Keizer , Diana Vieira

Wildfires are recognized for having a strong impact on forest soils, a situation aggravated by inadequate pre-fire land management practices. Land management operations, such as plowing, are routinely carried out for cultural reasons and can impact soils for decades after their implementation. Therefore, it is crucial to take into account the pre-fire land management history when predicting post-fire sediment losses in burnt areas. This consideration is critical for a realistic assessment of soil erosion risk and, consequently, for effectively implementing emergency stabilization and/or rehabilitation measures.

The aim of the study was to integrate pre-fire land management practices into erosion models, to enhance post-fire sediment losses predictions at slope scale. To accomplish this goal, both Multiple Linear Regression (MLR) and the revised-Morgan-Morgan-Finney model (revised-MMF) were applied in the Colmeal burnt area (Central Portugal). These models were adapted to account the impacts of different management options, specifically no plowing, downslope-plowing and contour-plowing, on the erosive response following a wildfire.

The results revealed fluctuations in the performance of both models across different soil management, and over time since the wildfire. Despite the observed variability, it is important to highlight the positive outcomes achieved with the revised-MMF model over the three monitoring years where contour-plowing was applied. These results demonstrate that the best model performances are achieved when soil management is individualized and analyzed independently. Similarly, the MLR model exhibited improved performance when incorporating management practices into its predictions. This study confirms that disturbances on topsoil, whether caused by wildfires or soil management operations, play key roles in driving change in soil erosion. Hence, integrating these factors into models is essential for providing relevant information for the development of mitigation and/or restoration strategies in areas at high risk of erosion.

野火对森林土壤的影响是公认的，而火前不适当的土地管理措施则加剧了这种情况。耕地等土地管理作业通常是出于文化原因而进行的，在实施后的几十年里都会对土壤产生影响。因此，在预测烧毁地区火灾后的沉积物损失时，考虑火灾前的土地管理历史至关重要。这项研究的目的是将火灾前的土地管理实践纳入侵蚀模型，以提高斜坡尺度的火灾后沉积物损失预测。为实现这一目标，在科尔米尔焚烧区（葡萄牙中部）应用了多元线性回归模型（MLR）和修订版摩根-摩根-芬尼模型（修订版-MMF）。这些模型经过调整，以考虑不同管理方案（特别是不耕作、下坡耕作和等高耕作）对野火后侵蚀反应的影响。尽管观察到了这些变化，但必须强调的是，在采用等耕耕作的三个监测年中，修订后的 MMF 模型取得了积极成果。这些结果表明，如果对土壤管理进行个性化和独立分析，就能实现最佳的模型性能。同样，当将管理措施纳入预测时，MLR 模型的性能也有所提高。这项研究证实，无论是野火还是土壤管理作业造成的表土扰动，都对土壤侵蚀的变化起着关键作用。因此，将这些因素纳入模型对于为高侵蚀风险地区制定缓解和/或恢复策略提供相关信息至关重要。

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引用次数: 0

An inception framework hypothesis for karst development in the Burren, Ireland 爱尔兰伯伦岩溶发展的初始框架假设

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-05 DOI: 10.1016/j.geomorph.2024.109450

Robert A. Watson , Colin Bunce , David Drew , Simone Fiaschi , Caoimhe Hickey , John Walsh , Eoghan P. Holohan

The Inception Horizon Hypothesis (IHH) postulates that certain stratigraphic horizons in a limestone sequence, combined with structural surfaces such as joints, provide a framework for cave development. Although subsurface and surface karst landforms are fundamentally linked, the IHH has not yet been extended to surface karstification. We tested this extension of the IHH in the world-renowned Burren karst due to its stratigraphic and structural simplicity. We used very high-resolution remote sensing datasets and detailed fieldwork to develop an updated map of the Burren's surface karst features, combined with a 3D geological model containing over 60 km of mapped cave passages.

Our analysis shows that karstic connectivity between the surface and subsurface is primarily provided by a suite of vertically-persistent calcite and silica-rich veins, which form a non-stratabound fracture system across the Burren. The flow pathways provided by these veins then intersect the following inception horizons: (i) boundaries between distinct lithological units in the limestone sequence; (ii) crinoidal cycle tops, and more sporadically chert lenses, within one of those units (the Slievenaglasha Formation); (iii) thin horizons of non‑carbonates (‘clay wayboards’) within another unit (the Aillwee member). At the surface, the same horizons have been preferentially exploited by glacial processes, creating surfaces from which meteoric waters now recharge the subsurface and form new surface karst depressions and other karst landforms. Our new inception framework for karstification thus provides a new basis for understanding surface and subsurface connectivity in the karst critical zone in the Burren landscape, and it provides new geological insight into the functioning of carbonate critical zones more generally.

地层起始层假说（IHH）认为，石灰岩序列中的某些地层层位与节理等构造面相结合，为溶洞的发育提供了一个框架。虽然地下岩溶地貌和地表岩溶地貌从根本上是相关联的，但 IHH 尚未扩展到地表岩溶。由于地层和结构的简单性，我们在世界闻名的布伦岩溶中测试了 IHH 的扩展。我们利用高分辨率遥感数据集和详细的实地考察，绘制了最新的布伦地表岩溶特征图，并结合三维地质模型绘制了 60 多公里的洞穴通道图。我们的分析表明，地表与地下之间的岩溶连通性主要由一系列垂直存在的方解石和富含二氧化硅的矿脉提供，这些矿脉在布伦形成了一个非层状断裂系统。这些矿脉提供的流动路径与以下起始层相交：(i) 石灰岩序列中不同岩性单元之间的边界；(ii) 其中一个单元（Slievenaglasha Formation）中的板岩周期顶，以及更零星的白垩系透镜体；(iii) 另一个单元（Aillwee 成员）中的非碳酸盐薄层（"粘土路板"）。在地表，同样的地层被冰川过程优先利用，形成了一些地表，现在流星水从这些地表补给地下，形成了新的地表岩溶洼地和其他岩溶地貌。因此，我们新的岩溶化概念框架为了解布伦地貌岩溶临界区的地表和地下联系提供了新的基础，并为更广泛地了解碳酸盐临界区的功能提供了新的地质见解。

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引用次数: 0

Evaluation of geodiversity in the Brazilian Amazon using different quantification methodologies 使用不同的量化方法评估巴西亚马逊地区的地质多样性

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-05 DOI: 10.1016/j.geomorph.2024.109441

Julio Manoel França da Silva , Juliana de Paula Silva , Fernando César Manosso

When one considers geodiversity as the variability of abiotic elements distributed on the earth's surface in an unequal and complex manner, and that the configuration of these elements plays an important role in ecosystem dynamics, it becomes necessary and important to evaluate the different forms by which its spatial organization can be quantified and mapped. A recent academic effort in different countries, scales, and territories aims to evaluate and quantify geodiversity and its spatial variation. Thus, this work aims to apply and compare the spatial distribution of the geodiversity indices derived from four methodologies in the Brazilian Amazon. From this analysis, we seek to understand the distribution of the geodiversity indices in the Brazilian Amazon and organize a cartographic base for future correlations with spatial data representative of biodiversity and human appropriation of the territory. When one considers the tendencies of spatial similarity for each methodology, regardless of the size and shape of the quantification cells, the indices generated with the second methodology have a higher correlation with the basic index. In general, since they consider the same diversity measure (richness), the tendencies of direct spatial similarity are highlighted by the basic index and the products of the second methodology. The Shannon's index in the 250 × 250 km hexagonal grids, besides the high value of positive correlation, is also equivalent to the basic index, regaining the spatial proportion of each class, above all other indices. The indices generated from Shannon's and Simpson's indices tend to differ from the other indices because, besides class richness, they also measure evenness. The comparison between the quantitative indices shows some tendencies in the spatial patterns of geodiversity of the Brazilian Amazon but also presents indications of the limitations imposed by the different measurement criteria of the abiotic variables used.

当我们认为地质多样性是以不平等和复杂的方式分布在地球表面的非生物元素的变异性，并且这些元素的配置在生态系统动态中发挥着重要作用时，对其空间组织进行量化和绘图的不同形式进行评估就变得非常必要和重要。最近，不同国家、不同规模和不同地区的学术界都在努力评估和量化地质多样性及其空间变化。因此，这项工作旨在应用和比较巴西亚马逊地区由四种方法得出的地质多样性指数的空间分布情况。通过分析，我们试图了解巴西亚马逊地区的地质多样性指数分布情况，并为今后与代表生物多样性和人类对该地区的占用的空间数据相关联建立一个制图基础。如果考虑到每种方法的空间相似性趋势，无论量化单元的大小和形状如何，第二种方法生成的指数与基本指数的相关性更高。一般来说，由于它们考虑的是相同的多样性度量（丰富度），基本指数和第二种方法的产品都突出了直接空间相似性的趋势。在 250 × 250 千米的六边形网格中，香农指数除了具有较高的正相关值外，还与基本指数相当，重新获得了每一类的空间比例，高于所有其他指数。由香农指数和辛普森指数生成的指数往往与其他指数不同，因为除了类别丰富度外，它们还测量均匀度。定量指数之间的比较显示了巴西亚马逊地区地质多样性空间模式的一些趋势，但也表明了所使用的非生物变量的不同测量标准所带来的局限性。

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引用次数: 0

Pulsed uplift of the South Tianshan since the Late Miocene indicated by the linear inversion on river longitudinal profiles 河流纵剖面线性反演显示南天山自晚中新世以来的脉冲式隆起

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-03 DOI: 10.1016/j.geomorph.2024.109448

Jiangang Li , Wentian Liang , Yizhou Wang , Shida Song , Qi Shen , Sihua Yuan

The early Cenozoic collision and subsequent continuous convergence between the Indian and Eurasian plates reactivated the Tianshan orogen in the Central Asia and caused multistage uplift of the mountain range. The modern Tianshan, with high mountain peaks of >7000 m, forms very prominent topography that profoundly affects the regional tectonics and climate. However, the late Cenozoic uplift process and topography growth of the South Tianshan remain controversial. River longitudinal profile inversion provides a distinctive way to reveal rock uplift history since the late Cenozoic. In this study, we presented linear inversion on river longitudinal profiles of four drainage basins originating from high mountains in the South Tianshan. The inversion results from two basins in the northern flank show fast and continuous increases in the uplift rates from about 0.1–0.2 mm/a to 0.6–1.0 mm/a since 4 Ma. While in the southern flank, the uplift rates of the two basins increased gradually from about 0.1 mm/a to 0.2 mm/a before 10 Ma and from 0.2 mm/a to 0.4 mm/a around 10 Ma and 6 Ma, respectively. Our results combined with recently published chronological data in this region indicate that the South Tianshan experienced a pulsed tectonic uplift process since the Late Miocene. Moreover, the pulsed tectonic uplift should lead to an elevated South Tianshan during 6–4 Ma, coinciding well with the ∼5.3 Ma extreme aridification in the Tarim Basin, thus supporting that the rain shadow effect caused by high topography of South Tianshan is a critical reason for aridification.

新生代早期印度板块和欧亚板块之间的碰撞以及随后的持续辐合重新激活了中亚地区的天山造山带，并造成了该山脉的多级隆升。现代天山的山峰高达 7000 米，形成了非常突出的地形，对区域构造和气候产生了深远的影响。然而，新生代晚期南天山的隆升过程和地形发育仍存在争议。河流纵剖面反演为揭示新生代晚期以来的岩石隆升史提供了一种独特的方法。在本研究中，我们对发源于南天山高山的四个流域的河流纵剖面进行了线性反演。北翼两个盆地的反演结果表明，自4Ma以来，隆升速率从约0.1-0.2 mm/a快速持续增加到0.6-1.0 mm/a。而在南翼，两个盆地的隆升速率在10Ma以前从约0.1 mm/a逐渐增加到0.2 mm/a，在10Ma和6Ma左右分别从0.2 mm/a增加到0.4 mm/a。我们的研究结果与该地区最近发表的年代学数据相结合，表明南天山自晚中新世以来经历了一个脉冲式的构造抬升过程。此外，脉冲式构造抬升应导致南天山在6-4Ma期间抬升，这与塔里木盆地5.3Ma∼5.3Ma的极端干旱化非常吻合，从而支持了南天山高地形造成的雨影效应是干旱化的关键原因。

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