The development of in-situ Lu-Hf LA–ICP–MS/MS geochronology has opened avenues to dating garnet, apatite, xenotime, calcite and epidote-group minerals. Of these phases, garnet and apatite are particularly relevant to provenance analysis, as both can be dated in situ by the U–Pb, Sm–Nd and Lu–Hf systems, are often present in sediments, and retain geochronological as well as geochemical information during erosion, transport and sedimentation. Garnet and apatite also have the benefit of forming in different geological settings to minerals more widely used in provenance analysis, such as zircon. Zircon usually forms during high-temperature processes such as anatexis and magmatic crystallisation, and has a bias towards more felsic rock compositions. Conversely, garnet is a dominantly metamorphic mineral, and usually retains information about the prograde (and sub-anatectic) history of metamorphic rocks, but may also form in hydrothermal settings, and is stable across a wide variety of lithological compositions. Apatite also forms in a wide variety of rock lithologies during metamorphism and magmatism, and therefore can represent more intermediate and mafic magmatic events which are not sampled by zircon. In situ Lu–Hf geochronology therefore provides an excellent tool to understand the timing and conditions of mountain building and magmatic events from the detrital record, but not without methodological and geological caveats and limitations. The application of the method itself, data handling and analytical interpretations will be presented and discussed.
How to cite: Tamblyn, R., Gillespie, J., and Simpson, A.: In-situ Lu-Hf for provenance analysis – a methodological perspective , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14070, https://doi.org/10.5194/egusphere-egu25-14070, 2025.
The Balearic Promontory (BP) is a NE-SW oriented continental block located in the centre of the Western Mediterranean that corresponds to the northern prolongation of the Betic-Balearic front. The BP represents a unique case study, as it records two distinct compressive periods from the Alpine orogeny, as well as exhibits evidences of volcanism and back-arc extension related to the opening of the Western Mediterranean. Mallorca is the only island of the BP that preserves an almost complete Cenozoic sedimentary record, which encompasses a significant shift in the geodynamic evolution, evolving from northern derived deposits during the Paleogene (“Catalanide-Pyrenean”) to a southern source area during the Early Miocene (“Betic”). As both source areas currently correspond to marine basins, the Cenozoic detrital deposits therein represent the only remnants whose provenance study can contribute to decipher the hinterland tectonic evolution. Nevertheless, the majority of these deposits are carbonate-dominated, and thus, techniques such as detrital geochronology and thermochronology may prove useful in instances where traditional provenance analysis are challenging. The present study seeks to provide a new perspective on the provenance evolution of Mallorca for the first time from two different timings and settings. By using detrital zircon (DZ) double dating we characterized the Paleogene and Neogene provenance and exhumation history. Our findings suggest an evolution from predominantly Mesozoic-derived DZ during the Paleogene, to a mixed Mesozoic and late Palaeozoic DZ during the Neogene. The presence of only two Eocene ZHe ages in early Miocene DZ may suggest a gradual exhumation process within the hinterland rather than a fast dismantling related to the “Betic” compression. Furthermore, the identification of Oligo-Miocene aged zircons related with synsedimentary volcanism enabled us to establish a maximal depositional age (MDA) for some samples, thus providing a more precise chronostratigraphic constraint.
How to cite: Peris, S., Griera, A., Gómez-Gras, D., Roigé, M., Stockli, D., and Teixell, A.: Reconstructing the Cenozoic provenance evolution of Mallorca (Balearic Promontory): insights from detrital zircon U-Pb and (U-Th)/He double-dating, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-962, https://doi.org/10.5194/egusphere-egu25-962, 2025.
Detrital zircon geochronology is becoming increasingly popular in provenance studies relying on the growing availability of accurate techniques and extensive datasets. This large amount of data is currently employed in ancient settings to describe source-to-sink scenarios deriving tectonic and (eventually) climatic implications. The study of modern sediments of African river systems offers the opportunity to observe how the zircon signal is propagated along these vast sediment highways and how the mere interpretation the zircon signal in the deep sea may lead to a significant misfit of interpretations in the source-to-sink system.
One of the factors linking major river systems is the highly segmented nature of sediment transport. Even though this phenomenon is currently enhanced by effect of dams, geomorphic barriers prove to be highly effective. In Niger River, for example, the exclusively Archean-Paleoproterozoic age signal from Leo-Man Shield in Guinea is unable to cross the natural barrier of sand dunes of the Inner Delta. Similarly, old zircons characterising the sands of the Victoria Nile and Albert Nile sink in Lake Victoria and the Sudd marshes. The recent evolution of the Zambezi River demonstrates that zircon geochronology alone is insufficient for depicting the routing system. Paired observations of bulk petrography, elemental, and isotope geochemistry effectively reveals that provenance signals are extremely segment along the river course.
Undoubtedly, the high durability of zircon through sedimentary cycles is effective in indicating the major episodes of crustal growth at continental scale. However, it simultaneously highlights the pitfall of not considering recycling as one of the main features for zircon provenance. In the Orange River, the Pan-African age cluster is dominant from the headwaters all the way to the mouth and transported by ocean currents as far as Angola. This occurs even though the Pan-African basement is only minimally exposed in the catchment, whereas zircon signal is stored in the Karoo Supergroup sandstones.
How to cite: Pastore, G., Garzanti, E., Vermeesch, P., Resentini, A., and Vezzoli, G.: Detrital zircons in modern African rivers: does the Sink truly reflect the Source?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18786, https://doi.org/10.5194/egusphere-egu25-18786, 2025.
Northern Calabria, situated at the southern end of the Italian Peninsula, is geologically complex due to its position at the convergence of the Eurasian and African plates. This complexity arises from significant deformation processes, including thrusting, folding, and extensive faulting associated with the closure of the Tethys Ocean and subsequent collisional and extensional tectonics. Thrusting during the Alpine orogeny resulted in a series of extensive nappe stacking, followed by structural reorganization and exhumation of these stacks during the Oligocene to Miocene, reflecting ongoing tectonic activity. Along the eastern margin of northern Calabria, fore-arc basins developed in response to the retreating subduction zone and evolution of the Calabrian arc. From north to south these are termed Rossano, Ciro, Crotone, and Catanzaro sub-basins. Analysing the stratigraphic record of these basins in terms of provenance shifts and changing drainage patters, will aid in further characterising the main exhumation phase of the northern Calabrian Massif, encompassing the Sila Massif and the Coastal Chain (Catena Costiera).
A multi-proxy provenance study was designed combining heavy mineral analysis (via semi-automated Raman spectroscopy), garnet chemistry (via electron microprobe), and apatite trace element analysis and U-Pb geochronology (both via LA-ICP-MS). A collection of siliciclastic samples spanning ~15 Ma from Aquitanian to Messinian in age from the four pre-mentioned sub-basins were selected for measurement. The results present a wide range of both high grade to low grade metamorphics and granitoids, with strong contrasts present spatially and temporally. A high contribution of high-pressure metamorphic phases like lawsonite, glaucophane, and kyanite was identified in samples from the Rossano basin. Paired with the presence of garnets from greenschist/blueschist-facies rocks and apatite derived from mafic igneous rocks, sourcing is likely from Liguride units currently exposed in northern and western regions of northern Calabria (e.g. Catena Costiera, northern Crati valley). Occurrence of andalusite in the Serravallian/ Tortonian samples of the Ciro and Crotone basins points to sourcing directly from the Sila Massif plutonic rocks and/or its high-temperature metamorphic rims. Furthermore, large proportions of Ca-rich garnets in Crotone, and the oldest sample from Ciro, suggest metasomatic host-rocks also reflect this sourcing pattern. Apatite geochronology from Crotone shows one singular significant peak around 300 Ma, referring to the Variscan orogeny and further underlining a significant input from Sila granitoid rocks. The shift in sediment sourcing patterns from the lower to middle Miocene in the Rossano, Ciro, and Crotone basins indicate the exhumation of the Calabrian arc, along with its subsequent increasing and then decreasing relief, played a pivotal role in controlling the timing and direction of sediment transport.
How to cite: Feil, S., von Eynatten, H., Chew, D., Schönig, J., Dunkl, I., Caracciolo, L., and Muto, F.: Provenance and drainage evolution of the Northern Calabria forearc, southern Italy, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18573, https://doi.org/10.5194/egusphere-egu25-18573, 2025.
Provenance Characteristics and Tectonic Implication of the Laiyang Group in Lingshan Island of Riqingwei Basin
JIANG, Yushen and ZHOU, Yaoqi, China University of Petroleum (east)
Abstract: Lingshan Island is located on the suture zone of the Sulu orogenic belt and is an important research area of the Riqingwei Basin. There are turbidites of Laiyang Group of Lower Cretaceous, terrigenous clastic rocks of Qingshan Group and igneous rocks in Lingshan Island from top to bottom. There are significant debates about the sedimentary environment, sediment source, and provenance direction of the Laiyang Group sedimentary strata in the Lingshan Island. The stratigraphic features of Lingshan Island section are investigated in detail and analyzed by various methods, and the following conclusions are drawn:
(1) Analysis of the sandstone detrital components has shown that the predominant rock type in the study area is lithic feldspathic sandstone with overall low maturity, and the grain composition of sandstone shows that the source rocks may have the characteristics of volcanic rocks, granite and metamorphic rocks. The sedimentary source of the Laiyang Group sandstones in Lingshan Island is relatively close with a short transportation distance and fast sedimentation rate, and is mainly from the cutting of arc-island region, which is affected by tectonic uplift to some extent.
(2) The results of paleocurrent analysis show that the ancient water flow in Lingshan Island area is generally oriented in the northwest-southeast direction with an average azimuth of 160 °, suggesting that the sandstone deposits in the study area mainly come from the northern provenance.
(3) Analysis of the principal and trace elements in mudstone has revealed that, from bottom to top, there is a trend of change in properties of the source rock from felsic to intermediate, and a trend of decreasing weathering in the source area; The provenance mainly comes from felsic source area, and the overall chemical weathering and recycling degree is low. It is speculated that the clastic materials of mudstone directly come from the strong weathering and deposition of igneous rocks.
(4) Results of heavy mineral components analysis have shown that the sedimentary strata in the study area are influenced by source rocks such as acid magmatic rocks and metamorphic rocks to a certain extent, and from the change of heavy mineral characteristics in different horizons, it records the first-stage tectonic uplift movement.
Based on the above analysis results and the tectonic position of the study area, it can be concluded that the sedimentary strata of Laiyang Group in Lingshan Island area are influenced to some extent by source rocks such as acid magmatic rocks and metamorphic rocks, and the source rocks are mainly metamorphic sedimentary rocks, intermediate-acid volcanic rocks, metamorphic rocks and sedimentary rocks. The change of provenance reflects a period of tectonic uplift. The main source of provenance in Lingshan Island area is from the Sulu orogenic belt, which may be partly from metamorphic sedimentary rocks of Yangtze platform in the early stage and mainly from Sulu orogenic belt in the later stage.
How to cite: Jiang, Y. and Zhou, Y.: Provenance Characteristics and Tectonic Implication of the Laiyang Group in Lingshan Island of Riqingwei Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1981, https://doi.org/10.5194/egusphere-egu25-1981, 2025.
The Ediacaran to Cambrian transition witnessed a key interval in the Earth’s history for biological revolution, environmental change and tectonic evolution. Wells and seismic data show that a Lower Cambrian thick siliciclastic rock succession occurs in the NW Yangtze Block, South China. The provenance and tectonic setting for the thick Cambrian sedimentary successions are very crucial for understanding the Ediacaran-Cambrian transition. Here, a Cambrian outcrop section (ca. 800-m-thick) in the middle Longmenshan fold-thrust belt, NW Yangtze Block, which is composed of mixed carbonate-siliciclastic strata, was investigated to constrain depositional ages, sedimentary environments, provenance and tectonic settings, through integrating field-based sedimentology, petrography, whole-rock element geochemistry, detrital zircon U-Pb dating, zircon trace elements and Hf isotopes, and carbonate stable C isotope data. The sedimentary succession is thought to accumulate during the Terreneunian to Epoch 2 time (i.e., Age 2 to Age 4, ca. 524-509 Ma) by comparison of our new carbonate stable C isotopic data and the global Cambrian δ13C curve and by the detrital zircon U-Pb age evidence (the youngest age peaks ranging from 538 to 518 Ma). The investigated strata have coarsening-upward trends and indicate complex, variable sedimentary environments (including slope-basin, deep-water shelf and fan delta settings) with hydrothermal inputs. Sandstones from the lower Qiongzhusi Formation have abundant volcanic lithic fragments and detrital zircons therein are dominated by Ediacaran to Cambrian ages. However, sandstones from the upper Canglangpu Formation consist of variable lithic fragments (including chert, metamorphic, volcanic and sedimentary clasts) and indicate diverse detrital zircon U-Pb ages (1000-500 Ma and minor 2600-2100 Ma). Both geochemical data of fine-grained sedimentary rocks and petrographic data of the sandstones reveal the deposits were relatively immature and were derived from proximal sources. Additionally, trace elements of the zircon grains with 650–500 Ma ages indicate a continental arc origin. All the results point to nearby arc-related source terranes for the Cambrian clastic records, rather than distant orogen sources as previously proposed. The geological and geochemical evidence, combining published geophysical data, imply the development of an early Cambrian orogen northwest to the study area. We suggest that the underestimated arc settings were formed in response to the subduction of the Proto-Tethys ocean beneath the NW Yangtze Block, which resulted in continental collision and uplift of northwest microterranes that provided siliciclastic sediments to fill the foreland basin southeastward.
How to cite: Gu, Z. and Jian, X.: Sedimentary provenance analysis unravels the Early Cambrian orogeny in the NW Yangtze Block, South China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13916, https://doi.org/10.5194/egusphere-egu25-13916, 2025.
Quartz is the most stable and abundant mineral in sedimentary rocks and remains stable during weathering and diagenetic processes [1], thus being a good provenance tracer. Traditional and advanced techniques to determine quartz origin, such as petrography and cathodo-luminescence and laser ablation spectrometry have obtained limited success.
The aim of the study is to implement a new protocol to analyze the oxygen isotopic signatures of single detrital grains of quartz, with primary application in source-to-sink studies, and to assess their role as a provenance fingerprint of different magmatic, metamorphic and sedimentary domains. While single grain approach is standard in detrital thermochronology [e.g. 2,3], it has not been applied on major minerals using classic isotopic tracers.
This new protocol is tested on modern sediments of Ganga-Brahmaputra rivers and turbidites from the Bengal Fan (IODP Expedition 354). Single grain isotopic fingerprint allows us to define oxygen isotopic signature of magmatic and metamorphic source rocks of different Himalayan tectonic domains (Greater Himalaya, Lesser Himalaya, Tethys Himalaya and Trans-Himalayan Batholiths) and to detect and quantify their relative contribution in Bengal turbidites and to highlight sediment mixing from specific sources thus enhancing provenance resolution with respect to bulk approaches.
Around 200 quartz grains in each sand sample from rivers draining exclusively a single Himalayan tectonic domain have been analyzed by ion microprobe LG-SIMS to better characterize their oxygen isotopic variability, thus providing a good fingerprint of the source rocks in the detrital record. Around 150 quartz grains from each Bengal Fan turbiditic sample have been analyzed to quantify the contribution of different Himalayan tectonic domains in Bengal Fan turbidites through time.
The new data, combined with data obtained with other bulk-sediment to single-mineral approaches, allow us to enhance provenance resolution and highlight the erosional evolution of the Himalayan-Tibetan orogen through time.
This new method can be profitably applied in any sediment-provenance study as a precious complement to traditional methods applied to the same quartz grains (luminescence, OH-defects, and petrographic characteristics) as well as classic techniques (e.g., petrography, heavy minerals, elemental geochemistry, isotope geochemistry) to discriminate detrital quartz derived from felsic igneous, metamorphic, or sedimentary sources.
Key words: Oxygen isotopes, Ion Probe LG-SIMS, Provenance analysis, Single-grain techniques, Himalayan orogen, Bengal fan
[1] Clayton, Jackson & Sridhar (1978), Geochimica et Cosmochimica Acta 42(10), 1517-1522.
[2] Blum, Rogers, Gleason, Najman, Cruz & Fox (2018), Scientific Reports 8(1), 7973.
[3] Chew, Najman, Mark, Barfod, Carter, Parrish, & Gemignani (2019), Bulletin of the Geological Society of America 131; 9-10.
How to cite: Limonta, M., France-Lanord, C., Galy, A., Gurenko, A., Bouden, N., and Garzanti, E.: Single quartz δ18O: a new proxy in sediment provenance studies (Bengal Fan, IODP Expedition 354)., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6282, https://doi.org/10.5194/egusphere-egu25-6282, 2025.
Quartz optically stimulated luminescence (OSL) sensitivity as well as some electron spin resonance (ESR) and cathodoluminescence (CL) signals have been empirically proposed as provenance indicators. Sensitivity is defined as luminescence emitted in response to a given dose per unit mass. While it is largely believed to be acquired by earth surface processes, recent studies bring evidence that sensitisation processes depend on source geology.
Here we combine OSL and thermoluminescence (TL), ESR and CL analyses to understand the mechanisms of quartz OSL sensitisation. We investigate granites and their derived sediments from catchments draining simple lithologies of known age that display contrasting OSL sensitisation behaviour both in nature and during irradiation and light exposure laboratory experiments. The sample displaying increased OSL sensitisation is characterised by TL emission at intermediate temperatures (150-250 °C), Ti-related signals in CL, and Ti and Ge lithium compensated signals in ESR. The insensitive samples either lack or exhibit very weak such characteristics and contain several times less amount of trace titanium measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).
We demonstrate that the OSL sensitisation results as an effect of the existence of certain defects and impurities in the quartz crystal in the parent rock, such as titanium and germanium. However, the degree of sensitisation reached in nature is significantly higher than in the laboratory. As such, the existence of this precursor represents the potential for sensitisation, which can later be amplified by environmental factors during sedimentary history.
This study is funded by the European Research Council Consolidator Grant - PROGRESS, (ERC-CoG-101043356) awarded to Prof. Alida Timar-Gabor.
How to cite: Constantin, D., Dave, A., Grecu, Ș., Kabacińska, Z., Antuzevics, A., Barla, A., Urdea, P., Ducea, M., and Timar-Gabor, A.: Tracing quartz provenance: a multi-disciplinary investigation of luminescence sensitisation mechanisms of quartz from granite source rocks and derived sediments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1479, https://doi.org/10.5194/egusphere-egu25-1479, 2025.
Relief degradation and drainage evolution in the aftermath of major orogenies have been extensively studied for young mountain belts. For ancient orogenic settings such reconstructions often remain enigmatic with respect to, e.g., exhumation and erosion rates, sediment dispersal paths and sediment budgets as well as associated paleolandscapes and sediment routing systems. Sedimentary provenance analysis provides an essential tool to constrain these complex systems in space and time.
Here we present a multi-method provenance study from the Black Forest, the Palatinate Forest and the Vosges (SW Germany and NE France) that includies heavy mineral assemblage data from 100 sandstone samples as well as detrital zircon U-Pb geochronology and grain-size measurements from 40 selected samples. The samples cover approximately 10 to 15 Myrs from Zechstein to Upper Bundsandstein strata (Wuchiapingian to early Anisian). Additional data comprise detrital tourmaline and garnet geochemistry as well as detrital monazite geochronology.
The heavy mineral assemblages are rather uniform, dominated by the stable phases zircon, tourmaline and rutile (along with other TiO2-polymorphs) and complemented by variable apatite content as well as minor monazite. Zircon U-Pb ages range from ~0.25 to 3.5 Ga, showing prominent Variscan (30%), Caledonian (23%) and Cadomian (28%) age components, along with older ages (19%). Grain-size data indicate an overall decrease of zircon size with increasing U-Pb age. The zircon age distributions suggest an increase of Cadomian and older ages at the expense of Variscan ages with decreasing stratigraphic age of the samples. This observation is independent of zircon grain size. It is interpreted to reflect a change from more local sources in Late Permian time to a significantly enlarged catchment area in the Early Triassic that includes tapping new source regions. This comes along with a homogenization of sediment composition across the entire drainage and depositional area in the late Olenekian to early Anisian. Our study serves as an example of heavy-mineral based fingerprints for regional-scale drainage basin widening due to relief planation in the aftermath of major orogenic phases.
How to cite: von Eynatten, H., Sass, K., Dunkl, I., and Schönig, J.: Permo-Triassic sediment provenance and paleodrainage in Central to Western Europe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15518, https://doi.org/10.5194/egusphere-egu25-15518, 2025.
Mercury (Hg), a highly volatile metal, is capable of tracing volcanism through geological history as LIP events transiently emit large amounts of Hg. There are two indicators that make Hg a unique tool for geochemistry, the Hg to total organic carbon ratio (Hg/TOC) and mass-independent fractionation (Hg-MIF, defined as Δ199Hg). Owing to the affinity of Hg to organic matter, anomalous high Hg/TOC ratios in sediments can better reveal large volcanic eruptions. The anomaly of Hg-MIF is mainly observed in Hg photoreactions, providing a fingerprints of specific reaction pathways of Hg. Volcanic Hg usually has Δ199Hg ~ 0, but photochemical processes in the surface environment can alter this signal, resulting in positive Δ199Hg in marine systems (e.g., seawater and marine sediments) and negative Δ199Hg in terrestrial systems (e.g., soil and vegetation).
Here, we examined the Hg records in Ediacaran cap carbonates in South China and Upper Cretaceous oceanic red beds (ORBs) in southern Tibet and the North Atlantic, to obtain their sedimentary material sources and the cause of the termination of Marinoan glaciation and Cretaceous oceanic anoxic events.
(1) The cap carbonates show higher Hg concentrations (4.9 to 405 ppb), most of which are comparable to that observed in carbonates deposited during non-LIPs periods. The lack of Hg/TOC anomalies in these cap carbonates suggests that background volcanic activity, rather than a short-term large igneous province event, drove the Marinoan deglaciation. The cap carbonates show positive Δ199Hg values (0.18 to 0.34 ‰) in slope settings and slightly negative to slightly positive Δ199Hg values (0.16 to 0.11 ‰) in shelf settings, suggesting a binary mixing of seawater- and terrestrial-derived Hg in early Ediacaran Ocean. We infer that the accumulation of greenhouse gases, due to ongoing volcanic emissions of CO2 and enhanced release of gas hydrates, triggered global warming. This warming led to melting of sea ice cover, enhanced terrestrial inputs, and large-scale dissolution of atmospheric CO2 into seawater, driving widespread deposition of Ediacaran cap carbonates.
(2) In southern Tibet and the North Atlantic, black/gray shales (typical deposition of oceanic anoxic events) show much higher Hg concentrations and Hg/TOC values than ORBs, indicating enhanced Hg flux to global oceans during time of black/gray shale deposition. Black/gray shales show lower Fe3+/Fe2+ and positive Δ199Hg, suggesting a significant input of Hg into the anoxic/dysoxic ocean via atmospheric deposition. The isotope values are consistent with a volcanic source for this excess Hg. ORBs show high Fe3+/Fe2+ and negative shifts of Δ199Hg, suggesting that the dominant source of Hg into the oxic oceans was via terrestrial runoff. These results suggest that volcanism was an important driver of the climate/ocean dynamics during the Late Cretaceous.
To sum up, in addition to indicating short-strong volcanic activities, Hg can also trace the source of sedimentary materials under weak magmatism. Moreover, Hg offers a more accurate depiction of the interactions and exchanges among the Earth’s atmosphere-ocean-land system.
How to cite: Sun, R. and Yin, R.: Mercury Isotope Geochemistry in Ediacaran Cap Carbonates and Cretaceous Oceanic Red Beds, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-167, https://doi.org/10.5194/egusphere-egu25-167, 2025.
Detrital petrochronology is a powerful method of characterizing sediment and potentially sediment sources. The recently developed Tucker-1 decomposition method holds promise of using detrital petrochronology to identify both sediment-source characteristics and the proportions in which sources are present in sink samples even when sediment sources are unknown or unavailable for sampling. However, the correlation between endmember characteristics and lithological sources or proportions and sedimentary processes has not been established. Herein we present a case study of the recently developed Tucker-1 decomposition method to a multivariate geochemical data set from detrital zircons in till samples collected above the Cu-bearing Guichon Creek Batholith (GCB) in southern British Columbia, Canada. Data include a suite of eleven variables, including age, Ce anomaly, CeN/NdN, DyN/YbN, ΔFMQ, Eu anomaly, ΣHREE/ΣMREE, Hf, Th/U, Ti temperature, and YbN/GdN, from 12 samples from collected at a range of distances in the down ice-flow direction from the GCB.
We demonstrate that endmember modelling using the Tucker-1 decomposition method successfully deconvolves the multivariate data sets into two endmembers in which the geochemical distributions are consistent with derivation from either non-oxidized and relatively anhydrous (i.e., low ore potential, Source 1) or oxidized and hydrous (i.e., potential ore bodies, Source 2) igneous rocks. Furthermore, we demonstrate that the proportions of the Source 2 endmember decrease with increasing distance from the ore bodies, as expected due to downstream zircon mixing and dilution.
Finally, we attribute each of the zircon grains to either the Source 1 or 2 endmember based on maximization of the likelihood that their measured multivariate geochemistry was drawn from one or the other of the learned multivariate endmembers. We compared these grain attributions to the results of an independent Classification and Regression Tree (CART) analysis designed to characterize zircon grains as either “fertile” or “barren” with respect to copper based on their geochemistry. We find that there is ~80% overlap between the source attributions based on the CART analysis and the grain-source identification based on the Tucker-1 decomposition.
We conclude that the novel Tucker-1 decomposition approach provides a flexible, precise, and accurate method of characterizing multivariate sediment sources even when those sources are unknown. It thus provides a basis for future petrochronological interpretations with applied and pure geoscience applications. All of the analyses presented herein can be freely accessed through a web application (https://dzgrainalyzer.eoas.ubc.ca/) or open-source Julia code (https://github.com/MPF-Optimization-Laboratory/MatrixTensorFactor.jl).
How to cite: Saylor, J. E., Richardson, N., Graham, N., Lee, R. G., and Friedlander, M. P.: Endmember modelling of detrital zircon petrochronology data via multivariate Tucker-1 tensor decomposition, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4081, https://doi.org/10.5194/egusphere-egu25-4081, 2025.
Thirty-three surface sediment samples were collected from the Hupo Basin including Hupo Bank, located offshore along the East Coast of Korea, to investigate the provenance of fine-grained sediments using geochemical elements, particularly focused on REEs compositions. Cluster analysis of the surface sediments identified three distinct groups: (1) the inner offshore area of the northwestern Hupo Bank, (2) the area extending from the inner offshore of the southwestern Hupo Basin to the eastern slope of the Hupo Bank, and (3) a single sediment deposit on the eastern slope of the Hupo Bank.
Additionally, the sediments from the southwestern Hupo Basin to the eastern slope of the Hupo Bank were further classified into two subgroups based on their UCC-normalized (Upper Continental Crust-normalized) REE patterns. A comprehensive analysis of the UCC-normalized REE patterns, combined with satellite imagery, suggested that most of the sediments on the northwestern Hupo Bank were predominantly supplied by small nearby streams during typhoon seasons. However, some sediments covered on southern Hupo Basin were likely transported from the southern area via the East Korea Warm Current during the heavy rainy season.
How to cite: Um, I.: Provenance and Transport Mechanisms of Fine-Grained Sediments in the Hupo Basin, Offshore East Coast of Korea, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5457, https://doi.org/10.5194/egusphere-egu25-5457, 2025.
In northwestern Croatia, synorogenic clastic formations record important events in the evolution of the Dinarides, including the Dinaride-Alpine transitional area, a region characterized by considerable geological complexity resulting from a severe and long-lasting Mesozoic and Cenozoic deformational history. Our study concentrates on the provenance of Cretaceous sandstones which occur on Mt. Ivanščica, Mt. Medvednica, and Žumberak Mts, with the intent of providing new insights into the evolution of the orogen and possible paleogeographic connections with neighboring tectonic units. Uranium-lead ages of detrital zircon populations place new constraints on the nature of source terrains being exhumed and eroded during the early stage of convergence of the Adria plate margin. Construction of the nascent mountain belt in this stage involved obduction of Neotethyan ophiolites and inclusion of basement units within propagating nappe structures. Zircon age spectra of Early Cretaceous sandstones from Mt. Ivanščica reveal Permo-Triassic, Variscan, Caledonian and Pan-African populations, and one grain with concordant Middle/Late Jurassic age. In Late Cretaceous sandstones from Mt. Medvednica and Žumberak Mts the spectra are dominated by Variscan, Caledonian and Pan-African ages, but in different proportions. Permo-Triassic zircons are completely absent in Mt. Medvednica sandstones, and reflected by only one grain in Late Cretaceous Žumberak Mts sandstone. Permo-Triassic zircons with a mode at ~240 Ma were probably derived from volcano-sedimentary sequence outcropping in northwestern Croatia, while Variscan and pre-Variscan zircons could have been derived both from reworked igneous/metaigneous or sedimentary/metasedimentary sources. The absence of Permo-Triassic zircons in Late Cretaceous clastic sequences precludes the resedimentation of Early Cretaceous sandstones. Significant variations in the age spectra of Late Cretaceous zircon populations point to diverse catchment areas. These results hint towards change in predominant source rocks from Early to Late Cretaceous, as well as local variability during the Late Cretaceous. The presented work is supported by the Croatian Science Foundation project SECret (HRZZ IPS-2023-02-2683).
How to cite: Šuica, S., Lužar-Oberiter, B., Olić, I., and Zeh, A.: U-Pb ages of detrital zircons from synorogenic clastic sedimentary rocks in the Dinarides (Croatia), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8608, https://doi.org/10.5194/egusphere-egu25-8608, 2025.
Ocean drill cores recovered by IODP Expedition 354 Bengal Fan (BF) shed light on the world’s largest source-to-sink (S2S) sedimentary system, providing insight into its geodynamic history during the Late Cenozoic. Here, we investigate Hf isotopic compositions of detrital zircon (DZ) grains (N = 1300) by laser ablation multi-collector ICP-MS in Miocene through Pleistocene age turbidites from the middle BF. Prominent DZ age populations in BF turbidites at ca. 25 Ma, 50 Ma and 120 Ma are a close match for modern DZ ages obtained from Brahmaputra River sands, suggesting strong ties to Tibetan sources within the paleo-Brahmaputra drainage area. Previous studies documented increased proportions of young U-Pb DZ age populations (< 300 Ma) in BF turbidites, showing they nearly double in abundance starting in the Late Pliocene (ca. 2.7 Ma). We obtained Hf isotope compositions on individual U-Pb dated DZ grains, with an emphasis on placing further constraints on the provenance of the < 300 Ma DZ age group. BF turbidite sands all contain DZ showing a wide range of hafnium isotopic compositions (εHf = +20 to -30); however, Pleistocene turbidites contain a higher proportion (by 2:1) of more negative εHf DZ signatures compared to Miocene/Pliocene-age turbidites. This is reflected in the εHf signatures of the ca. 25, 50 and 120 Ma DZ U-Pb age groups, which all trend more negative in Pleistocene turbidites compared with Miocene/Pliocene -age turbidites. The effect is most pronounced for the ca. 50 Ma DZ age group; comparison with published zircon U-Pb and zircon Hf isotope data from bedrock sources indicate that the ca. 50 Ma DZ age group is derived from the Gangdese or Bomi Chayu batholiths of the Lhasa Terrane, whilst the ca. 120 Ma DZ age group is primarily sourced from the Bomi Chayu batholith; the ≤25 Ma DZ age group carries the signature of sources in the Namche Barwa massif (eastern Himalayan syntaxis portion of the Brahmaputra drainage). We hypothesize that greater integration of the Lhasa Terrane into the Yarlung-Brahmaputra river drainage system changed the dynamics of paleo-sediment transport to the Bengal Fan starting in the Late Pliocene. A growing U-Pb age and Hf isotope database from modern Himalayan river sands will help place further constraints on sediment routing, tectonic and climatic influences in the Himalaya-Bengal Fan S2S system since the mid-Miocene when delivery of turbidite sands to the middle Bengal Fan rapidly intensified.
How to cite: Gleason, J., Najman, Y., Orme, D., Sundell, K., and Blum, M.: Himalayan source-to-sink dynamics and the detrital zircon Hf isotope record in Bengal Fan Turbidites (IODP Exp. 354), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13697, https://doi.org/10.5194/egusphere-egu25-13697, 2025.
The Gyeongsang Basin, situated in the southeastern part of the Korean Peninsula, is a non-marine sedimentary basin that formed as a result of the subduction of the Paleo-Pacific Plate beneath the East Asian continent during the Cretaceous. While numerous studies of the basin fill (Gyeongsang Supergroup) of the Gyeongsang Basin have revealed the tectonic history of East Asia, most of them have focused on the western part of the basin, with less attention paid to the strata in the eastern part of the basin. However, the geological units currently consisting the Japanese islands originally developed along the eastern margin of the Korean Peninsula during the Cretaceous. The Icheonri Formation, distributed in the southeastern part of the Gyeongsang Basin, probably records the composition and tectonic settings of the provenance along the continental margin. This study investigates the provenance and tectonic history of the Icheonri Formation based on sandstone petrography, detrital mineral chemistry, and whole-rock geochemistry of sandstones and mudrocks. The analyzed sandstone samples of the Icheonri Formation are very fine- to coarse-grained, subangular, and poorly sorted. They are mainly composed of quartz, plagioclase, and rock fragments, with minor grains including chromian spinel, pyroxene, and epidote. Based on the modal composition, the sandstones are classified as feldspathic litharenite, derived from a transitional arc provenance. In addition, volcanic rock fragments are nearly absent in the studied samples, indicating weak volcanic activity in the southeastern part of the Gyeongsang Basin during deposition of the Icheonri Formation, contrary to previous interpretations from the western part of the basin. Whole-rock geochemistry suggests that the source rock composition is felsic to intermediate, derived from a continental arc. Furthermore, the occurrence of detrital Cr-spinels suggests the presence of ultramafic bodies exposed in the provenance. The composition of Cr-spinel grains from the Icheonri Formation indicates that they were originated from mantle-wedge peridotites. Together with the occurrence of highly weatherable pyroxene, this suggests that forearc peridotite containing Cr-spinels and pyroxene-bearing mafic rocks were exposed near the Icheonri depocenter. Previous studies have reported Cr-spinels from forearc peridotite in sandstones from the western Gyeongsang Basin and interpreted that the peridotite was exposed along at least two fault zones that developed in the west of the basin as a result of oblique convergence. In conclusion, while subduction zones and volcanic arcs developed around the basin, the Icheonri sediments were derived from eroded volcanic arc or basement during the cessation of volcanism rather than from active volcanoes. Moreover, the forearc peridotite is interpreted to have been exposed by protrusion along fault zones that probably formed around the eastern part of the basin as a result of subduction tectonics. Our result contributes to a better understanding not only of the Cretaceous tectonic developments along the East Asian continental margin, but also of the nature of arc-related sedimentary basins and basin fills.
How to cite: Yang, H., Kim, K., Kim, H. J., Chae, Y.-U., Lim, H. S., and Joo, Y. J.: Sandstone petrography and geochemistry of the Icheonri Formation in southeast Korea: Implications for provenance and tectonic setting, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14108, https://doi.org/10.5194/egusphere-egu25-14108, 2025.
Turbiditic sediments found in accretionary complexes (ACs), originally deposited in a trench environment, document processes and environmental conditions governing sediment production and deposition in a subducting continental margin, including tectonic setting and paleogeographic configuration. Along the East Asian continent, subduction of the Paleo-Pacific plate has continued since the late Paleozoic, resulting in the development of numerous ACs containing Paleozoic and Mesozoic sediments that now make up a large part of the Japanese Islands. The Ashio terrane, distributed in central Japan, consists of Upper Paleozoic-Jurassic pelagic and turbiditic sediments and is considered equivalent to the Mino-Tamba terrane, the AC covering a large area of the main island. This study examines the sandstone petrography and whole-rock geochemistry of turbiditic sandstone and shale of the Ashio terrane to interpret their provenance and tectonic history. The sandstones of the Ashio terrane, classified as lithic arkose to feldspathic litharenite, are sub-angular to sub-rounded and poorly sorted. The major framework grains are quartz, plagioclase, K-feldspar, and lithic fragments (metamorphic and sedimentary, including chert), with minor amounts of mica, garnet, and heavy minerals. In the Qt-F-L diagram of provenance tectonic setting, they are all interpreted to have been derived from a recycled orogen provenance. Based on the presence of chert grains, we hypothesize that at least part of the pre-Jurassic ACs was probably uplifted and exposed in the hinterland during deposition of the Ashio terrane sediment. Furthermore, the presence of easily weatherable feldspar and metamorphic lithic fragments suggests that not only the ACs sediment but also metamorphic and/or igneous rocks were exposed in the source area. The detrital garnet assemblages in the Ashio terrane sandstones are characterized by a pyrope-rich almandine garnet with low grossular content, reflecting their origin in granulite-facies metamorphic rocks. Such detrital garnets have been previously reported from Jurassic to Cretaceous sandstones of Japan with rare occurrences in Permian sandstones, suggesting that the Ashio terrane garnets were likely first-cycle detritus from a nearby high-grade metamorphic basement. Based on their rare earth element patterns, the source rock composition of the Ashio terrane sediments seems felsic and more fractionated than the upper continental crust (UCC), which is known to be similar to granodiorite. In the A-CN-K compositional space, the Ashio terrane sediments suggest weathering from granodioritic source rocks, and the scatter of the samples along the weathering trend indicates that non-steady-state weathering conditions in the source area. In a tectonic discrimination diagram based on chemistry, their composition resembles sediments derived from a passive continental margin, which is consistent with the sandstone modal composition. Previous studies of Cretaceous Japanese ACs suggested sediment recycling and supply from uplifted pre-existing ACs, supporting our interpretation of the Ashio terrane provenance. Additionally, the compositional difference between the sandstones of the Mino terrane (arkosic) and Ashio terrane (lithic) infer a heterogenous nature of depositional conditions in a subduction zone. These findings provide paleogeographic information and more comprehensive interpretations of the environmental conditions surrounding the subduction zone along the East Asian continental margin during the Mesozoic.
How to cite: Kim, K., Lee, Y. I., and Joo, Y. J.: Sandstone petrography and whole rock geochemistry of the Ashio terrane, a Jurassic accretionary complex in Japan: Implications for provenance and tectonic setting, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14110, https://doi.org/10.5194/egusphere-egu25-14110, 2025.
Rutile belongs to the group of ultra-stable minerals during processes of the sedimentary cycle, along with zircon and tourmaline. While detrital zircon mostly derives from felsic igneous rocks and tourmaline is hardly datable, rutile is mainly sourced from metamorphic rocks and routinely datable by U−Pb chronology. Thus, combining detrital rutile age information with trace-element based discrimination of different metamorphic source rocks has a high potential to gain time-resolved insights into the geodynamic evolution of the hinterland. However, trace-element based approaches are so far limited to (i) bivariate discrimination of mafic and felsic metamorphic source rocks by considering Cr and Nb concentrations (Zack et al. 2004a; Meinhold et al. 2008; Triebold et al. 2007, 2012), (ii) temperature information by considering Zr concentrations (e.g., Zack et al. 2004b; Kohn 2020) and assuming the same pressure conditions for all detrital grains, (iii) identification of fluid alteration based on e.g., W, Sn, V, Sb, Cr, Nb, Fe (Agangi et al. 2020; Pereira et al. 2021; Pereira & Storey 2023); and (iv) identifying very specific sources like mafic low-temperature/high-pressure rocks by considering H2O concentrations in combination with Zr, Nb, W, and Sn (Lueder et al. 2024).
Here we compiled a dataset of 2,335 rutile trace-element analyses (16 elements) from 110 metamorphic rock samples of a wide range of pressure−temperature conditions. Using a modified version of the original random forest algorithm (Breiman 2001) for dealing with the hierarchically structured data, we trained three multivariate discrimination models. Under the assumption of a metamorphic source, the first model discriminates felsic and mafic rutile with a classification success rate of >90 %, which is a strong improvement compared to Cr versus Nb plots (72−86 % success on the same dataset). The second and third models discriminate rutile from rocks that formed under low and high temperature/pressure gradients (≤ 350 °C/GPa versus >350 °C/GPa) for felsic (>91 % success) and mafic rocks (>93 % success), respectively. We are currently integrating the three models to achieve a simultaneous prediction of composition and temperature/pressure gradients of the metamorphic source rock, taking rutile provenance analysis to a new level.
How to cite: Schönig, J., Zack, T., Rösel, D., Marschall, H., von Eynatten, H., Lünsdorf, K., Lueder, M., Konrad-Schmolke, M., and Walters, J.: Chemical discrimination of rutile from different metamorphic source rocks, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14755, https://doi.org/10.5194/egusphere-egu25-14755, 2025.
The collision between Europe and Alcapa (a segment of Adria) led to the formation and subsequent erosion of high-pressure rocks in the Carpathian and Alpine arcs. Metamorphic rutile, which forms under relatively high pressures, is a reliable indicator of subduction environment during orogeny. To enhance our understanding of the Alpine Tethys Ocean's closure in the Western Carpathians, U-Pb geochronology was performed on detrital rutile from medium-grained sandstones within the Magura and Silesian Nappes.
Twelve samples were collected along a transect in the Magura Nappe, with an additional three samples from the Silesian Nappe serving as a reference. An additional profile of three samples was collected from the Altengbach-Formation of the Rhenodanubian Flysch in the Greifensteiner-Decke for comparison. From each sandstone, approximately 200 rutile grains were extracted, and about half were selected for detailed analysis. The dated rutile grains exhibit significant variation in age and physical characteristics, indicating multiple source origins.
In the Magura transect the most prominent age peaks align with the Variscan (c. 400–280 Ma) and Alpine (c. 160–90 Ma) tectonic events, both of which are well-represented except oldest dated sample. Notably in the Magura transect, four distinct Alpine maxima were identified in the rutile dataset. Among these, the two dominant peaks at 137–126 Ma and 115–105 Ma appear in most samples. Two additional samples, deposited during the Eocene–Oligocene and the Late Cretaceous–Paleocene, reveal the youngest age peak at 94–90 Ma. A peak at 193–184 Ma is observed in these two samples and in another sandstone dated between the Paleocene and Eocene.
The Silesian samples consistently exhibit a prominent Variscan peak. Only the sample deposited in the Oligocene reflects Alpine tectonic events, with one dominant peak at 95 Ma and two minor peaks at 26 Ma and 180 Ma.
In the Altlengbach-Formation the Alpine peaks appear in the two youngest samples, whereas the Variscan peaks are prominent in all samples. The oldest sample is Lower Cretaceous whhereas the other two are Upper Cretaceous–Paleocene.
For the Carpathian samples, we tentatively propose that key tectonic events include the Jurassic subduction of the Meliata Ocean (~180–155 Ma) and the Cretaceous nappes stacking and exhumation of the Veporic and Gemeric megaunits (140–90 Ma). The widespread presence of Alpine-age rutile in all but the oldest sandstone indicates an open sedimentary pathway from the southern and central Alcapa to a basin located north of the alleged Oravic (Czorsztyn) continental sliver within the Alpine Tethys Ocean. The absence of Alpine ages in the oldest sandstone may reflect either a physical barrier separating the basin from the orogen or the unavailability of rutile-bearing rocks at the surface during that time.
More broadly, we suggest that the synorogenic deposits of the Outer Western Carpathians contain detritus derived from previously subducted, exhumed, and imbricated oceanic and continental crustal domains. Age peaks in the ~180–105 Ma range are probably related to the closure of the Neotethys Ocean (Meliata branch), while the youngest peak at 94–90 Ma possibly corresponds to the subduction of the Alpine Tethys beneath Alcapa.
Research is funded by the NSC, Poland, project no. 2021/43/B/ST10/02312.
How to cite: de Doliwa Zieliński, L., Bazarnik, J., Kooijman, E., Kośmińska, K., Potočný, T., Mazur, S., and Majka, J.: Tracing Alpine Tethys Closure: Insights from Detrital Rutile Geochronology in the Outer Western Carpathians and Eastern Alps, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18697, https://doi.org/10.5194/egusphere-egu25-18697, 2025.
To address the controversial and insufficient understanding of the source, sedimentary architecture and reservoir quality differences of the Extension Formation in the Huachi area of the Ordos Basin. This paper is based on the analysis of heavy minerals and their assemblage characteristics, cathodoluminescence imaging of quartz grains, zircon U-Pb geochronology (LA-ICP-MS). It also combines the analyses and test data of core, logging, scanning electron microscope, cast thin section, high-pressure mercury injection (HPMI), constant-rate mercury injection (CRMI) and so on. This basic principles and methods of sedimentology, stratigraphic stratigraphy, sedimentary basin analysis and reservoir sedimentology have been applied to systematically study the relationship between the provenance directions, provenance types, sedimentary system spreading, sedimentary configuration, and reservoir quality in the Chang 3 member of the Yanchang Formation in the study area. The study shows that the Chang 3 of the Huachi area is located in the sedimentary centre of the lake basin, and is influenced by provenance from both the northeast and southwest directions, and is in a mixed-source area along the Qingcheng-Heshui area; The area develops a delta front subfacies, and underwater distributary channel is the main microfacies. The single sand body has three vertical combination modes: downcut superimposed type, superimposed contact type and mudstone separated type, and three lateral combination modes: side cut superimposed type, butt type and mudstone embedded type. The delta front in the study area has an evolutionary pattern of advanced accumulation and backward accumulation, and the single sandbody of the tangential and overlapping relationship developed in the late progradation stage has the best connectivity, with good pore throat structural characteristics and good reservoir quality. In conclusion, under the background of shallow water, low accommodation space, rapid uplift-slow curtain settlement tectonics, the direction, proximity, and type of the source of shallow-water delta are the key factors influencing the distribution of sedimentary micro-phase, and also the material basis for the sedimentary configuration and reservoir quality.
How to cite: Zhang, H.: study on shallow water delta provenance, sedimentary architecture and reservoir quality differences--a case of the Chang 3 member of Yanchang formation in Huachi area of Ordos Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5497, https://doi.org/10.5194/egusphere-egu25-5497, 2025.
The metasedimentary Legoupil Formation, located at Cape Legoupil and the Schmidt Peninsula, antarctica could give a hint for the tectonic evolution of Antarctic Peninsula. In this contribution, we constrain the sedimentary provenance of the Legoupil Formation through geochemistry and detrital zircon U-Pb geochronology. The petrography and geochemical features indicate that the provenance of the Legoupil Formation could be felsic rocks. Detrital zircon grains record a steady supply of Permian and Ordovician material into the Legoupil Formation. The youngest concordant zircon ages of 262 Ma suggest that the depositional time of Legoupil Formation is no older than Late Permian. The detrital zircon age spectrum of Legoupil Formation suggests that the Legoupil Formation sediments should be derived from regional sources endemic to western Gondwana prior to its breakup.
How to cite: Cui, Y. and Wang, X.: Early Triassic Legoupil Formation in Schmidt Peninsula, Antarctic Peninsula, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20283, https://doi.org/10.5194/egusphere-egu25-20283, 2025.
Provenance analysis is a critical connection between the sedimentary basin and the orogenic belt. Methods such as petrological analysis of clastic rocks, heavy mineral analysis, geochemical analysis, and isotopic dating methods are all based on core analysis. However, core analysis is expensive and limited in quantity.
Well logging data are easy to obtain and can reflect much information. Moreover, the logging data has longitudinal continuity, which can record the formation properties continuously. A new quantitative method for provenance analysis based on well logging data is proposed. The new method mainly relies on the assumption that terrigenous clastic rocks are the products of weathering, fragmentation, transport, and deposition of the original rocks in the provenance area, and the composition and combination of clastic minerals in the rocks can reflect the characteristics of the source area. Then, different clastic minerals have different physical properties, and logging responses, so clastic rocks from different provenances may have different logging responses. The difference in logging response can be used to analyze the source-sink system.
A case study is introduced. Jiyang Depression of the Bohai Bay Basin is a faulted lake basin in the Paleogene. The northern part of Dongying sag is the Chenjiazhuang uplift, and the western part is the Binxian uplift, both parts are important provenance areas. Sedimentary systems such as near-shore subaqueous fan and fan delta are widely developed in the steep slope zone of the faulted lacustrine basin. The logging and drilling lithology analysis shows that well A has a 50m conglomerate layer in Shahejie Formation. The logging data show that the logging response of the top 30m conglomerate layer is different from that of the bottom 20m conglomerate layer. The core analysis shows that the top conglomerate is dominated by granitic gneiss rock, while the bottom conglomerate is dominated by carbonate rock. two provenance systems are developed in Dongying Sag.
This method can achieve good results on coarse-grained sediments, but this method may be restricted to deposits mainly composed of fine sandstone, silty, and shale. In the future, multiple methods should be combined to improve the result of provenance analysis.
How to cite: Qiu, T.: A new method for provenance analysis in sedimentary basins based on logging data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15816, https://doi.org/10.5194/egusphere-egu25-15816, 2025.
