Search Results (9)

Low-altitude palaeoglaciation in Atlantic mountain regions provides important insights into past climatic conditions and moisture dynamics during the Last Glacial Cycle. This study presents the first quantitative reconstruction of palaeoglaciers in Serra da Cabreira (northwest Portugal), a mid-altitude granite massif located along the Atlantic fringe of the Iberian Peninsula. Detailed geomorphological mapping (1:14,000) and field surveys identified 48 glacial and periglacial landforms, enabling reconstruction of two small valley glaciers in the Gaviões and Azevedas valleys using GlaRe numerical modelling. The spatial distribution of palaeoglacial landforms shows a pronounced west–east asymmetry: periglacial features prevail on wind-exposed west-facing slopes, whereas glacial erosion and depositional landforms characterise the more protected east-facing valleys. The reconstructed glaciers covered 0.24–0.98 km², with maximum ice thicknesses of 72–89 m. Equilibrium-line altitudes were estimated using AABR, AAR, and MELM methods, yielding consistent palaeo-ELA values of ~1020–1080 m. These results indicate temperature depressions of ~6–10 °C and enhanced winter precipitation associated with humid, Atlantic-dominated conditions. Comparison with regional ELA datasets situates Cabreira within a clear Atlantic–continentality gradient across northwest Iberia, aligning with other low-altitude maritime palaeoglaciers in the northwest Iberian mountains. The findings highlight the strong influence of the orographic barrier position, moisture availability, valley hypsometry, and structural controls in sustaining small, climatically sensitive glaciers at low elevations. Serra da Cabreira thus provides a key reference for understanding Last Glacial Cycle palaeoclimatic variability along the Western Iberian margin. Full article

Groundwater quality and availability in coastal aquifers have become a serious concern in recent times due to increased abstraction for domestic, agricultural and industrial purposes. (1) Background: Zhuhai city is selected as a representative coastal aquifer in Southern China to comprehensively evaluate the hydrochemical characteristics, spatial distribution and controlling mechanisms of groundwater. (2) Methods: A detailed study utilizing statistical analyses, a Piper diagram, Gibbs plots, and ion ratios was conducted on 114 surface water samples and 211 groundwater samples. (3) Results: The findings indicate that the pH of most groundwater is from 6.06 to 6.52, indicating a weakly acidic environment. The pH of surface water ranges from 5.35 to 9.86, with most values being weakly alkaline. The acidity in the groundwater may be related to the acidic atmospheric precipitation, an acidic unsaturated zone, oxidation of sulphide minerals and tidal action. The groundwater chemical types are predominantly mixed, followed by Ca-Mg-HCO₃ type. Surface water samples are predominantly Na-Cl-SO₄ type. The NO₃⁻ concentration in groundwater is relatively high, with a mean value of 17.46 mg/L. The NO₂⁻ and NH₄⁺ concentrations in groundwater are relatively low, with mean values of 0.46 mg/L and 7.58 mg/L. (4) Conclusions: The spatial distribution of the principal chemical constituents in the groundwater is related to the landform. The chemical characteristics of groundwater in the study area are mainly controlled by the weathering and dissolution of silicate and sulfate minerals, evaporation, seawater mixing and cation exchange. Nitrate in clastic fissure groundwater, granite fissure groundwater and unconfined pore groundwater primarily originates from atmospheric precipitation, agricultural activities of slope farmland and forest land. Nitrate in confined pore groundwater and karst groundwater primarily originates from domestic sewage and mariculture wastewater. Our findings elucidate the processes characterizing the hydrogeology and surface water interactions in Zhuhai City’s coastal system, which are relevant to other catchments with similar geological characteristics. Full article

Geomorphology is the link between natural and cultural heritage, so the geomorphological map is a useful tool for inventorying landforms and its management. In this paper, a Castro de Ulaca geomorphological map at 1:20,000 scale has been designed, focused on granite landforms and based on bibliographical and cartographic review followed by systematic field work in the Ulaca site and around. It shows a mastery of granite landforms and their relationship with cultural elements, as well as the adaptation of the society to the geomorphological conditions. The twelve granite landforms represented are not relevant in a national or regional scale, but they are of local importance as they represent the links between geomorphology and the archaeological elements present in Ulaca. It is essential to incorporate geomorphological elements in the management of cultural spaces, to guarantee their protection from visitors, as well as to ensure the survival and use of this cultural service for local population. Full article

Changsha kilns were exported to more than 20 countries and regions and were an essential part of the culture in the central Yangtze River during the late Holocene. Reconstructing the hydrological landform and sedimentary history of its surrounding areas (Shizhu) is significant for further constraining any links between regional paleoenvironmental change and the human−land relationship in the lager river valley. To examine paleo−hydrological and provenance evolution, the rare earth element (REE) and trace element ratio from the Shizhuping (SZP) section were analyzed. The SZP section records the paleo−hydrological evolution over 1300 years: river network cutting plain landscape—Shizhu Lake—river floodplain—Shizhu Lake reformation—Shizhu flat. This section was labeled as stages IV to I, respectively. The deposition of stages IV was wind and dust accumulation during the Last Glacial. The provenance of stages III (1288–1094 a.BP) was wasted from the ceramic production process. The layer of stage II (1094–380 a.BP) was in two parts. In stage II−2 (1094–890 a.BP), provenance was dominated by granite. Sedimentary rocks became the source of stage II−1 (890–380 a.BP). In stages I (380 a.BP–), the primary material sources were anthropogenic bedding and weathering erosion deposits around the slope. During the Medieval Warm Period, the climate was warm and humid, and the rising water level of the Xiangjiang River led to the emergence of lakes in the Shizhu area. The migration of northern China into Changsha kiln brought new technology and labor. In the late Five Dynasties, the climate turned dry, and the falling water level of the Xiangjiang River caused Changsha kiln to lose its commercial wharf. Full article

New investigations in the Western Caucasus contribute to the understanding of granite pseudokarst (sensu lato) and megaclasts linked to river erosion. A plot on the bank of the Belaya River (Mountainous Adygeya, Western Caucasus) was selected to examine diverse and abundant pseudokarst features (small rock basins, hollows, potholes, and channels) and large clasts. Morphological analysis of these features clarifies their general characteristics and genetic interpretations. Pseudokarst features can be classified into two major categories, namely the relatively small (<1 m) and large (>1 m) features. Potholes, which are usually 1–3 m in size, are the most characteristic features occurring on two levels, i.e., on steep walls of the gorge (half-filled with river water) and on slightly inclined surfaces of a terrace-like landform (subaerial exposure). In both cases, their walls from the side of the river are broken. Apparently, these potholes were formed on the river bottom. Subsequent incision of the gorge elevated potholes and the river has eroded them from one side. Apparently, some pseudokarst features are related to macroturbulent flood flows and granite weathering. Due to its scientific uniqueness and aesthetic attractiveness, this granite pseudokarst constitutes geoheritage, which can be exploited for the purposes of geoscience research and geotourism development. Full article

Geoheritage is not necessarily linked genetically to “purely” geological processes. Investigations in two urban areas of Russia allowed us to find essentially artificial objects demonstrating certain geological uniqueness. The huge balls sculptured from rapakivi granite and installed in Saint Petersburg represent cultural, historical, and stone heritage. These are also artificial megaclasts with perfect sphericity. The coal waste heaps situated in Shakhty and its vicinity represent industrial, historical, and urban heritage. These are also artificial landforms creating a kind of pseudo-mountainous landscape. These examples permit us to question the importance of the co-occurrence of heritage categories for geosite assessment. Full article

Granite geomorphological sceneries are important components of global geoheritage, but international awareness of their significance seems insufficient. Based on existing literature, ten distinctive types of relief are identified, along with several sub-types, and an overview of medium-size and minor landforms characteristic for granite terrains is provided. Collectively, they tell stories about landscape evolution and environmental changes over geological timescale, having also considerable aesthetic values in many cases. Nevertheless, representation of granite landscapes and landforms on the UNESCO World Heritage List and within the UNESCO Global Geopark network is relatively scarce and only a few properties have been awarded World Heritage status in recognition of their scientific value or unique scenery. Much more often, reasons for inscription resided elsewhere, in biodiversity or cultural heritage values, despite very high geomorphological significance. To facilitate future global comparative analysis a framework is proposed that can be used for this purpose. Full article

Geological heritage (geo-heritage) is a resource for geoscience, geo-education, and geo-tourism. Geo-tourist attractions differ in their physical visibility, interpretation (clarity), and aesthetic attractiveness. These three characteristics determine perception of visitors and, thus, the importance of attractions. An integrative parameter, namely specific visibility, is proposed for qualitative geo-tourism resource evaluation. This parameter is examined for all geo-heritage types, and some relevant examples from southwest Russia are considered. The geo-heritage types differ in their specific visibility. For instance, when landforms like the Granite Gorge in the Western Caucasus (geomorphological type) are well-visible, geochemical processes like the heavy metal cycling in the Don River delta and the Pelenkino mud lake (geo-chemical type) are not as visible. Such a difference should be taken into account when geo-tourism resources of any area or a geopark are evaluated. The lower the specific visibility, the higher the costs for professional interpretation and demand for advanced infrastructure solutions. Full article

This study focuses on the granite mountain known as Monte Pindo (627 m above sea level) in the Autonomous Community of Galicia (NW Spain). This territory is included in the area classified as “Costa da Morte” in the “Politica de Ordenación Litoral” (POL) (Coastal Planning Policy) for the region of Galicia. This coastal unit, located between “Rías Baixas” and “Cape Fisterra” has great potential for demonstrating geological processes and its geomorphological heritage is characterized by a high degree of geodiversity of granite landforms. The main objective of our work is to assess the geomorphological heritage of the site, thus revealing its wide geodiversity. We shall analyze and highlight: its scientific value, developing an inventory of granite landforms; its educational valuel and its geotouristic potential. It must be ensured that the Administration understands that natural diversity is composed of both geodiversity and biodiversity. Only then will the sustainable management of Monte Pindo become possible by integrating natural and cultural heritage values. The goal is to ensure that Monte Pindo and its immediate surroundings become a geopark with the aim of promoting local development projects based on the conservation and valorization of its geological heritage. Full article