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The Terminos Lagoon is a region of great environmental and economic importance, due to its biodiversity, abundance of natural resources and proximity to the Campeche Sound. These characteristics encourage the development of numerous human activities in its surroundings, including oil, agricultural, industrial, urban and sanitary activities. We evaluated the concentration of Cr, Ni, Pb and V in surface sediment samples from Laguna de Terminos, Campeche, Mexico. The results obtained show that the concentrations of Cr and Pb remained below the ecological criteria of the minimum and maximum adverse ERL and ERM conditions for the biota, as well as within the ranges reported for other coastal lagoons in the Gulf of Mexico, with the exception of Pb, which decreased by almost 100%. Ni recorded values above the ERL and ERM, which have shown fluctuations in concentrations depending on the rainy and dry seasons. V maintained its concentrations below 27.73 mg/kg. High correlations were found between metals Cr – V, Cr – Ni and Ni – V, suggesting that these elements share the same source of origin. The statistics show that there are significant differences between the sampling sites PLZ and C, and PLZ and CDL. The reduction may be due to a decrease in urban, tourist, fishing and agricultural activities.

Beach sediment samples collected along the central part of the Littoral zone of Cameroon were geochemically analyzed using ICP–MS to investigate the distribution characteristics and to identify trace metal concentrations. The textural characteristics of these sediments revealed that they are dominated by sand. Metal concentrations are distributed in the following decreasing order: Fe ˃ Mn ˃ Cr ˃ V ˃ Ni ˃ Co ˃ Cs. Indices of pollution, such as enrichment factor values are generally less than 1.5, except for Cr; index of geo-accumulation, where values of all metals in the sediments were

The spatial and vertical distribution of heavy metals (Fe, Ni, Cr, Co, Sc and V) and radionuclides (Th and U) and the sediment characteristics of Lobe River, south–west Cameroon were assessed in this study to determine the possible source of pollutants and evaluate the level of pollution. Cores sediments were analyzed to measure grain size parameters, organic matter and geochemical composition. To understand the vertical distribution, tree strata were chosen (surface, middle and bottom). The main constituent of studied sediment is sand (82.06%). In these sediments, low content was recorded for organic matter (2.87%). The average concentration (mg/kg) of selected elements are in the order Fe (23,112.84) > Cr (447.62) > Ni (109.93) > V (47.04) > Th (23.70) > Co (7.74) > Sc (5.10) > U (2.78). The maximum concentration of most selected chemical elements was recorded in the middle, followed by surface and bottom, respectively. Enrichment factor (EF > 1.5), Geo-accumulation index (Igeo > 0) and contamination factor (CF > 1) revealed a moderate to severe pollution of Cr, Ni and Th in all strata. The pollution load index (PLI) show that surface and middle sediments (1.08 and 1.14, respectively) are polluted, while bottom sediments (0.88) are unpolluted. Pearson correlation, cluster analysis and component principal analysis confirmed that heavy metals (Fe, Sc, V, Cr, Ni and Co) have common anthropogenic sources where grain size parameters (sand, silt and clay) were associated with them while radionuclides (Th and U) have a natural source. The presence of human activities such as household wastes, intensive agriculture and the result of the processing of the industries products could be possible sources of the anthropogenic pollution, threatening for the environmental related issues in the region.

Cadmium is a toxic element and its effects are well understood for human health, but its biogeochemical behaviour is still poorly studied and understood in natural ecosystems. This work addresses knowledge gaps concerning its presence, biogeochemical behaviour and impacts in mangrove ecosystems. Through geochemical data and multivariate analysis (i.e., factor and cluster analysis) of data from mangroves of Isla del Carmen, one of the largest extents in Mexico we explored the biogeochemical behaviour of Cd, a potentially toxic element, to identify its anthropogenic sources and interactions with sediments. Pollution indices, including enrichment factor (EF), geo-accumulation index (Igeo), sediment quality guidelines (SQG) and toxicological studies were used to assess the biological impacts of Cd and infer the natural levels tolerated by mangrove trees that form the basis of this natural ecosystem. Our results highlighted that Cd accumulation is driven by interactions between organic matter (OM), sulphur and fine particles; whereas enrichment factor showed values of 6.9 (EF) and 3.5 (EF) associated with point sources and ranged between 2 and 2.9 (EF) in relation to non-point sources. Finally, our geochemical approach revealed that Cd enrichment originates from urban activities and from the poor management of urban residuals.

This study was conducted on the Ngaoundaba Crater Lake sediments to infer provenance, weathering conditions, organic matter accumulation, and trace metal concentrations. Ngaoundaba Lake sediments were collected using a manual core sampler at 5 to 8 m water depth. Two sediment cores from the littoral and center of the lake were analyzed for grain size distribution, water content (WC), organic matter content, mineralogy, and major and trace element concentrations. The Ngaoundaba sediments were classified as silt and sandy silt. Sediments show high content in organic matter, which is more to the littoral than to the center of the lake, varying from 14.6% to 24% and 21.2% to 40.8%, respectively. The grain surface features identified by Scanning Electron Microscopy (SEM) show both chemical and mechanical microtextures with sub-rounded to angular shape suggesting both proximal and distal sources. The lake sediments are composed of quartz, kaolinite, and hematite, with low amounts of feldspars, rutile, calcite, illite, and ilmenite. Weathering indices such as the chemical index of alteration (CIA), chemical index of weathering (CIW), and index of compositional variability (ICV) indicate moderate to intense chemical weathering in the source area and immature to mature sediments. The geochemical composition indicates that the sediments were derived from felsic to intermediate igneous rocks, such as granitoids, and mafic alkali lavas like basanites. The environmental risk assessment of trace metals obtained by enrichment factor (EF) and geo-accumulation index (I-geo) shows low contamination of the lake sediments.

Beach sediments collected along Atlantic Ocean of Cameroon were geochemically analysed using ICP–MS techniques to determine their contamination of heavy metal and related ecological risks. In this study, the selected metals displayed a declining trend of Fe > Mn > Ni > Cu > Co > Zn > Cr > Cd. Indices of pollution, such as factor of enrichment (EF) which values are generally more than 1.5, except for Mn; index of geo-accumulation (I-geo), where values of Co, Ni and Cu in sediments of the studied area were > 0, and other metals (Zn, Cr, Fe and Mn) were

The mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons retrieved from the Barra del Tordo (Tordo) and Tesoro beach sediments in the northwestern Gulf of Mexico were analyzed to determine their provenance. The beach sediments are mainly composed of quartz, ilmenite, magnetite, titanite, zircon, and anorthite. The weathering proxies such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA), reveal a moderate-to-high intensity of weathering in the source area. The chondrite-normalized rare earth element (REE) patterns are similar to felsic igneous rocks, with large negative europium anomaly (Eu/Eu* = ~ 0.47–0.80 and ~ 0.57–0.67 in the Tordo and Tesoro beach sediments, respectively).Three major zircon U–Pb age groups are identified in the Tordo and Tesoro beach sediments, i.e., Proterozoic (~ 2039–595 Ma), Mesozoic (~ 244–70.3 Ma), and Cenozoic (~ 65.9–1.2 Ma). The differences of the zircon age spectrum between the Tordo and Tesoro beach sediments are not significant. The comparison of zircon U–Pb ages in this study with ages of potential source terranes suggests that the Mesozoic and Cenozoic zircons of the studied Tordo and Tesoro beach sediments were derived from the Eastern Alkaline Province (EAP) and Mesa Central Province (MCP). Similarly, the likely sources for the Proterozoic zircons were the Sierra Madre Oriental (SMOr) and Oaxaquia in the northwestern Gulf of Mexico. The results of this study further indicate that the sediments delivered to the beaches by rivers and redistributed by longshore currents were crucial in determining the sediment provenance.

In this study, we analyzed the mineralogy and bulk chemical composition of 20 sediment samples, as well as trace, rare earth element (REE) concentrations and U–Pb ages of 400 detrital zircons retrieved from the Bosque (PB) and Paseo del Mar (PM) coastal sediments, southwestern Gulf of Mexico, to investigate the provenance. The XRD study revealed that the PB sediments are associated with quartz, muscovite, cordierite, albite, and anorthite. The PM sediments are associated with calcite, aragonite, and biogenic materials, which derived probably within the coastal environment. The weathering indices like Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA) revealed a moderate intensity of weathering for the PB sediments. The chondrite normalized REE patterns of the PB and PM sediments are with negative and positive europium anomalies (Eu/Eu*), suggesting that the sediments were derived by the combination of felsic and mafic source rocks. The Th/U ratios (>0.3) of the PB and PM zircons indicated an igneous origin. The chondrite normalized REE patterns of the PB and PM zircons are depleted in low REE (LREE) and enriched in heavy REE (HREE) with positive cerium and negative europium anomalies. A wide variation in chondrite normalized REE patterns of zircons with respect to ages was observed. The PB is dominated by Proterozoic (~551–2500 Ma) and Paleozoic zircons (~445–480 Ma; Ordovician), whereas PM is dominated by Cenozoic zircons (~5–21 Ma; Miocene), indicating that the zircons were derived from different source terranes. The Chiapas Massif (CMC) and Chuacus complexes are identified as the potential source areas, which contributed Proterozoic zircons to PB. On the other hand, Cuicateco terrane (CUI) and Tuxtla Volcanic Field (TVF) are considered as the potential source areas, which supplied significant number of Cenozoic zircons to the PM coastal area. The zircon U–Pb ages and the bulk sediment geochemistry together indicate that the source terranes, which supplied sediments to the PB and PM coastal areas, consist of mafic and felsic rocks. The results of this study further illustrated the importance of littoral currents in distributing sediments, although rivers are considered as a carrier and agent of distributing sediments along the coastal areas.

The Mesozoic Qiangtang Basin is investigated to reconstruct the tectonic evolution of the Paleo- and Meso-Tethys Oceans. We present a detailed sedimentary facies analysis of the Nadi Kangri and Quemoco formations and the systematic zircon U Pb ages of the volcanoclastic rocks in the Nadi Kangri Formation to understand the onset and nature of the Mesozoic Qiangtang Basin. The Nadi Kangri Formation, consisting of volcanic-volcanoclastic facies associated with alluvial-diluvial facies association, which represents continental volcanic succession. The Quemoco Formation, consisting of braided fluvial, restricted platform and tidal flat facies associations, represents continental siliciclastic and marine carbonate successions. The deepening-upward transgressive sequences reconstructed from the two formations are indicative of a rift basin. Zircon U Pb ages of the volcanoclastic rocks in the bottom, middle, and upper sections of the Nadi Kangri Formation in the Fanghu area are 221.7 ± 1.3 Ma, 217.0 ± 1.5 Ma, and 207.1 ± 1.3 Ma, respectively. Combined with the previous zircon ages of the Nadi Kangri Formation, we interpreted that 221.7–220.4 Ma is the initial age for the onset of the Mesozoic rift basin. An evolution pattern for the Tethys Ocean and Mesozoic Qiangtang Basin has been proposed based on the magmatism, metamorphism, sedimentary sequence, and deformation data obtained from the Kunlun (KLT), Hoh Xil–Bayan Har (HBT), North Qiangtang (NQS), Central Uplift Belt (CUB), South Qiangtang (SQS), and North Lhasa subterranes/terranes (NLS) during the Early Triassic–Middle Jurassic. Based on the new data, we interpret a double-sided subduction and subsequently a collision of the Paleo-Tethys Ocean beneath the KLT to north and NQS to south, probably occurring at ca. 252-237 Ma and 237-227 Ma, respectively. This interpretation is consistent with the Late Triassic residual sea (ocean) model that attributed to the origin of the Hoh Xil–Bayan Har Basin. The QT and NLS experienced a strong extension between ca. 225 and 201 Ma owing to the rapid expansion of the Bangong Lake–Nujiang Ocean (Meso-Tethys Ocean), which is consistent with the massive volcanic eruption and deposition of volcanic sediments in the QT and NLS. In addition, the QT and NLS experienced a stabilized subsidence during 201–166 Ma, due to the existence of the mature Bangong Lake–Nujiang Ocean.

Degradation, diagenesis, and mineralogical changes in foraminiferal tests are recognized as mechanisms that control their preservation and destruction under the subaquatic/aerial conditions, commonly influenced by processes such as dissolution, abrasion, breakage, and mineralogical replacement. In this paper, we discuss test degradation and early diagenesis on the large benthic foraminifera Archaias angulatus from the Yucatan Peninsula beach sands, a region absent in surficial rivers and terrigenous input seawards. Two main sites of Yucatan beach were selected: the high-energy environment of the Gulf of Mexico coast (GOMC) and the low-wave-energy environment of the Mexican Caribbean coast (MCC). Test degradation in the GOMC and MCC is affected by chemical dissolution, bioerosion, and physical abrasion. Among other factors, we found the effects of the bacterial microboring and dissolution by lowering pH in seawater (i.e., nearshore springs discharging seaward), as well as longshore currents and waves, depending on the prevailing conditions before transport and resuspension of the tests landwards. The observed degradation features in the tests are wall loss, chamberlet exposure, surface pits, and highly abraded edges. However, we explain the presence of pristine A. angulatus tests in the MCC beach through its association with Thalassia seagrass patches. Very low Mg/Ca ratios were found, which suggest the early diagenesis in the foraminiferal tests and the absence of recrystallized processes. Rare-earth element analyses suggest reduced authigenic precipitation of Mn–Fe coatings in the tests, and the absence of freshwater discharges or terrigenous inputs in the beach sands.

The present investigation is focused on the forecasting visual observation of the impact of anthropogenic activity on the pilgrimage places located along the coastal environments in Tamil Nadu, India. Devotees performing the unregulated ritual ceremonies, open defecation, waste materials dumping and local municipality discharging wastewater contamination levels were assessed from direct visual surveillance, and by taking photographs and baseline information collected from five different pilgrimage sites. Results showed that ritual ceremonies, wastewater discharges and debris highly contaminated site-III, and found open defecation at site-I. The lack of coastal regulation, pollution awareness, insufficient sanitation facilities and failure to control the commercial and recreational activities have major deleterious effects on the present and future environments of the coastal areas. This is the first attempt conducted by visual assessment of the coastal pollution in pilgrimage places. The results immensely support the recommendation for proper regulation of ritual activities, arrangement of basic sanitation facilities and prohibition of wastewater discharges to prevent waterborne diseases as well as to strictly follow the regional and national level of coastal regulation policy to protect the biological resources of the Gulf of Mannar marine ecosystems.

Surface features of quartz and zircon grains in the Barra del Tordo (PBT) and Tesoro (PT) beaches, NW Gulf of Mexico (GoM), were analyzed. The microtextures in the PBT and PT beaches were classified into mechanical, chemical, and mechanical/chemical origin. The quartz grains from the two beach areas were subrounded to rounded in shape. Rounded zircon grains in PT suggest that the sediments were derived by wind, long transport distance, and long residence time relative to PBT. Rounded quartz grains with the combination of bulbous and broken edges indicated a recycled provenance. Mechanical features such as V-shaped marks, impact scars, conchoidal fractures, and straight-curved grooves indicated a fluvial environment. Chemical features such as solution pits, crystal overgrowth, and adhering particles in quartz and zircon grains indicated a diagenetic environment and silica re-precipitation in a coastal environment. The association of mechanical (bulbous edge) and chemical (silica overgrowth, small and large solution pits) features in a single grain suggested a dual environment, that is, the combination of littoral and coastal environments. The sediments were also partly supplied by the coastal dunes located along the GoM coastal region and were redistributed by wave energy and littoral currents. Euhedral, subhedral, and unetched zircon grains in PBT and PT were mixed with rounded and etched grains, indicating a diverse provenance from crystalline rocks. In general, the microtextures identified on zircon and quartz grains reveal that sediments are influenced by wind, fluvial, and subaqueous marine environment and derived by nearby and distal sources.

This study examines textural characteristics, carbonate, organic carbon and chemical composition of sediment samples recovered in the nearshore region (~3–19 m water depth) at the Grijalva River mouth, southern Gulf of Mexico. The aim of this study is to assess the heavy metal contamination and provenance variations in sediments between the dry and northers (rainy) seasons. The proportion of sand, carbonate, and organic carbon contents were abundant at sites located near to the Grijalva River mouth, principally in northers season. Silt content is dominant in the dry season, especially in the sites located away from the Grijalva River mouth. The Chemical Index (CIX) values obtained for the dry (~76–84) and northers (~75–87) seasons indicated a moderate to high intensity of weathering and a humid climate in the source area. The low K2O/Al2O3 ratio values (

This study investigates the provenance, paleoweathering, and paleoclimate of the Ossa lake sediments, based on the mineralogy and geochemistry data. Ossa lake sediments are characterized by silt and clay with high content of total organic carbon (TOC). Clay minerals are identified as kaolinite and illite types. Other dominant minerals identified are quartz, zircon, rutile, goethite, gibbsite, feldspar, and accessory vivianite. The major, trace, and rare earth element concentrations indicate that the sediments were derived from felsic rocks, such as gneisses and granitoids. The tectonic discrimination diagrams revealed an active margin setting. Weathering indices such as the chemical index of alteration (CIA), the plagioclase index of alteration (PIA), and chemical index of weathering (CIW) suggest intense chemical weathering in the source area. K2O/Na2O ratio and index of compositional variation (ICV) are consistent with high maturity of the sediments. The mineral assemblages and trace elemental ratios and climatic index “C” of the Ossa Lake sediments suggest a warm to semi-humid climate and deposition in an oxic shallow environment.

Microtextures of quartz and zircon grains from the Bosque and Paseo del Mar beaches in the Gulf of Mexico were examined using a Scanning Electron Microscopy (SEM), to infer their provenance and palaeoenvironment. A total of 16 microtextures from 200 grains were identified and were grouped into mechanical, chemical, and mechanical/chemical origin. Microtextures of mechanical origin represent parallel striations (ps), cracks due to collision (ck), conchoidal fractures (cf), v-shaped marks (vs), abrasion fatigue (af), meandering ridges (mr), chattermarks (ch), curved (cg) and straight grooves (sg), which are attributed to a high-energy fluvial and sub-aqueous marine environment. Solution pits (sp), crystal overgrowth (cro), and silica globules (sgl) of chemical origin indicated precipitation and dissolution in a silica saturated marine environment. Adhered particles (ap), elongated depressions (dp), and relief are grouped as mechanical/chemical origin, suggested a sub-aqueous nearshore marine environment. Although zircon is considered as a resistant mineral, the frequency of microtextures observed was higher in zircon than in quartz. The results of this study revealed that the Los Tuxtlas volcanic field, Chiapas Massif and Oaxacan Complexes in the SW Gulf of Mexico are the potential source areas, which supplied sediments to the Paseo del Mar and Bosque beach areas.

Gleysol and ferralsol samples were collected at Dimako (Eastern Cameroon) to investigate their use as raw materials in the ceramic industry, using petrological and physicochemical approach. Field and analytical investigations reveal that gleysols are grey-white with sandy clay textures. The organic carbon contents are low in both soil types. These soils are characterized by low cation exchange capacity (CEC) contents (3–5.40 cmol(+)/kg). The mineral assemblage of gleysols comprises quartz and kaolinite with few amounts of anatase and zircon. In ferralsols, the mineralogical composition is quartz, kaolinite, and hematite with accessory anatase, gibbsite, goethite, and zircon. The Fourier-transform infra-red (FT-IR) spectra confirm the presence of kaolinite with ordered structure. Gleysols are richer in SiO2 than ferralsols. However, gleysols are less enriched in Al2O3 than ferralsols. Fe2O3 contents are lower in gleysols (av. = 0.93 wt% at Koba and 1.69 wt% at Dimako) than in ferralsols (6.21–8.79 wt%). The abundance of quartz and kaolinite exhibits low contents in other major elements and several trace elements (including rare-earth elements (REE)) except Zr, Sr, and Ba in some samples. The normalized REE patterns relative to parent rocks (gneisses and granites) and chondrite reveal negative and positive Ce anomalies, strong negative Eu anomalies, and intense REE fractionation. Both soils result from the intense chemical weathering of gneisses and granites under tropical humid climate. Technological properties (color, grain size distribution, linear shrinkage, water absorption, and flexural strength) increase with the firing temperature, from 1000 to 1200 °C. Petrological and technological features highlight that gleysols are inorganic clays appropriate for refractory bodies and white stoneware tiles.

Microtextures on fine to medium-grained quartz grains (65–500 μm) from three sections, i.e., Laboni, Kuakata, and Jhauban points of the Kuakata beach area, Bangladesh, were examined by a scanning electron microscope (SEM) to determine the transport history, provenance, depositional environment, and paleoclimate. Thirty microtextures were observed on 180 quartz grains, which were subsequently classified as mechanical (20 features), chemical (5 features), and combined mechanical and chemical (5 features) origins. The abundance of sub-rounded to rounded quartz grains with smooth outlines, V-shaped pits, straight or curved grooves, crescent-shaped features and straight or arcuate steps, indicates that the quartz grains experienced long-distance transport through fluvial environment (e.g., Himalayan sediments). The angular to sub-angular quartz grains with straight or curved grooves, straight steps, and adhering particles inferred that they were probably derived from adjacent landmasses (e.g., Chittagong-Tripura Folded Belt and/or Indo-Burman Ranges). The well-rounded outlines, low relief with dish-shaped depressions, mechanically upturned plates, and arcuate steps were also observed, indicating aeolian processes in shoreface or beach environment. Etching, solution/irregular pits, and differential relief observed in the quartz grains indicate a subaqueous collision in fluvial and nearshore environments.

We applied both the ordinary linear regression (OLR) and the new uncertainty weighted linear regression (UWLR) models for the calibration and comparison of a XRF machine through 59 geochemical reference materials (GRMs) and a procedure blank sample. The mean concentration and uncertainty data for the GRMs used for the calibrations (Supplementary Materials) (available here) filewere achieved from an up-to-date compilation of chemical data and their processing from well-known discordancy and significance tests. The drift-corrected XRF intensity and its uncertainty were determined from mostly duplicate pressed powder pellets. The comparison of the OLR (linear correlation coefficient r∼0.9523–0.9964 and 0.9771–0.9999, respectively, for before and after matrix correction) and UWLR models (r∼0.9772–0.9976 and 0.9970–0.9999, respectively) clearly showed that the latter with generally higher values of r is preferable for routine calibrations of analytical procedures. Both calibrations were successfully applied to rock matrices, and the results were generally consistent with those obtained in other laboratories although the UWLR model showed mostly narrower confidence limits of the mean (slope and intercept) or lower uncertainties than the OLR. Similar sensitivity (∼2.69–46.17 kc·s−1·%−1 for the OLR and ∼2.78–59.69 kc·s−1·%−1 for the UWLR) also indicated that the UWLR could advantageously replace the OLR model. Another novel aspect is that the total uncertainty can be reported for individual chemical data. If the analytical instruments were routinely calibrated from the UWLR model, this action would make the science of geochemistry more quantitative than at present.

Foraminifera species distribution, 14C ages, and geochemistry data of sediment cores GM33 and GM34 recovered from the southwestern Gulf of Mexico were investigated to infer the age, sedimentation rate, provenance, heavy metal contamination, and depositional environment. Core GM34 (490 cm interval) reached an age of 34,346 ± 280 cal Yrs. BP and the average sedimentation rate was calculated as 0.014 cm/yr. The weathering indices like Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA) revealed a moderate intensity of weathering in the source area. The trace elemental ratios and rare earth element (REE) patterns indicated the derivation of sediments from intermediate rocks like andesite. The trace element based bivariate (La/Sc and Co/Th) and ternary (Ni Th V) diagrams revealed that the sediments were derived mostly from andesite located along the Gulf of Mexico coastal areas. The enrichment factor and geo-accumulation index suggested the absence of heavy metal contamination in sediment cores. The redox proxy trace elemental ratios like V/Cr, Ni/Co, Cu/Zn, and (Cu + Mo)Zn suggested an oxic depositional condition. The benthic foraminiferal assemblages, Mn and Mo concentrations indicated that the late Pleistocene abyssal waters in the Gulf of Mexico were more oxygenated than the present. An absence of significant compositional variations between the core sediments revealed that the depositional condition in the southwestern Gulf of Mexico was probably similar for the last 34,346 cal Yrs. BP.

The Qiangtang Basin is the largest Mesozoic marine basin in the Tibetan Plateau. The Upper Triassic black mudstones are among the most significant hydrocarbon source rocks in this basin. Here, we present geochemical data for the Upper Triassic black mudstones to determine their paleoenvironment conditions, provenance, and tectonic setting. To achieve these, 30 black mudstones formed in various sedimentary environments were collected from the Zangxiahe, Zana, and Bagong formations. The results show that the total REE concentrations of mudstones from these formations range from 169 to 214 ppm, 204 to 220 ppm, and 141 to 194 ppm, respectively. All samples have chondrite-normalized REE patterns with enrichment of LREE, depletion of HREE and negative Eu and Ce anomalies. Specifically, mudstones from the Bagong Formation exhibit higher negative Eu anomalies and lower REE contents than those from the Zangxiahe and Zana formations. Mudstones from the Zangxiahe and Zana formations with low Sr/Ba and Sr/Cu ratios indicate the humid climate, whereas the high Sr/Ba and Sr/Cu ratios of rocks from the Bagong Formation suggest the arid climate. The low U/Th, (Cu + Mo)/Zn, V/Cr and Ni/Co ratios of rocks from the Zangxiahe, Zana, and Bagong formations are indicators of oxidized conditions. The bivariate diagrams (TiO2 vs. Al2O3, TiO2 vs. Zr, La/Th vs. Hf, and Co/Th vs. La/Sc) reveal that mudstones from the Zangxiahe and Zana formations were potentially derived from intermediate igneous rocks, whereas mudstones from the Bagong Formation were probably sourced from felsic igneous rocks. Their source rocks are mostly deposited in the collisional setting. REE of mudstones from the Zangxiahe, Zana, and Bagong formations were possibly originated from terrigenous detritus, with minor non-terrigenous contributions into the Zana samples. The REE contents of these mudstones are controlled mainly by terrigenous detrital minerals, rather than by the paleoclimate, paleoredox conditions, or organic matter. However, calcite minerals could dilute REE. Therefore, the REE contents of the Bagong Formation mudstones are significant lower than those of the Zangxiahe and Zana formations mudstones.