Precambrian Research最新文献

{"title":"Petrological and geochemical insights into the genesis and geothermal potential of Late Neoarchean granitoid rocks in the Matouying Uplift, North China Craton","authors":"Quan Gan ,&nbsp;Luming Song ,&nbsp;Shuantong Shangguan ,&nbsp;Xiaofei Qi ,&nbsp;Zhiwei Liao ,&nbsp;Jianye Chen ,&nbsp;Zhili Yang ,&nbsp;Guiling Wang ,&nbsp;Guangyao Xin ,&nbsp;Chongyuan Zhang","doi":"10.1016/j.precamres.2025.107763","DOIUrl":"10.1016/j.precamres.2025.107763","url":null,"abstract":"<div><div>The Matouying geothermal area, located in the eastern region of the North China Craton, is a significant site for hot dry rock (HDR) geothermal exploration. However, the petrogenesis and tectonic setting of the granitoid reservoir remain unclear. This study provides a comprehensive analysis of petrographic, geochemical, Sm-Nd isotopic, zircon Hf isotopic, and U-Pb geochronological data from granitoid samples obtained through deep drilling in the Matouying. The granitoid rocks are classified into three distinct groups based on geochemical characteristics. Group #1 samples exhibit high Sr/Y and (La/Yb)_N ratios, along with ε_Hf(t) values ranging from −0.75 to + 3.34 and ε_Nd(t) from −0.39 to + 1.54, suggesting they were similar to adakitic rocks which originated from partial melting of juvenile subducted oceanic crust. Group #2 samples show weaker LREE/HREE fractionation, LILE enrichment and HFSE depletion (e.g., Nb, Th, Ti), accompanied by negative Eu anomalies. Isotopic data reveal more negative ε_Hf(t) (−8.87 to −4.13) and ε_Nd(t) (−2.34 to + 0.40), indicating formation from partial melting of ancient lower crust under low-pressure conditions. Group #3 samples display variable LREE/HREE fractionation and stronger LILE enrichment, with a smaller degree of depletion in HFSEs compared to Group #1, and show weaker or no Eu anomalies. Isotopic analyses show ε_Hf(t) values from −6.02 to −2.99 and ε_Nd(t) from −14.10 to −4.90, suggesting medium-pressure partial melting of ancient lower crust. Zircon U-Pb dating yields ages of 2495–2502 Ma for Group #1, 2514 Ma for Group #2, and 2534 Ma for Group #3, indicating their formation during the Late Neoarchean (∼2.5 Ga) in a subduction-related arc. The calculated heat generation rates for the Matouying reservoir range from 0.40 to 2.11 μW/m³, with an average arithmetic value of 0.84 μW/m³, indicating a relatively subdued radiogenic heat production potential for geothermal sources. Instead, cumulative evidence suggests that heat derived from the mantle, potentially sourced from deep-seated magma chambers, is the primary contributor. This contribution offers a rational understanding on the HDR reservoir mechanism in Matouying from petrological and geochemical aspects, aiding geothermal potential assessment and estimation.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"421 ","pages":"Article 107763"},"PeriodicalIF":3.2,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eoarchean to Paleoproterozoic crustal growth and evolution of the southern North China Craton revealed by detrital zircon in the Paleoproterozoic Songshan Group","authors":"Bowen Si ,&nbsp;Chunrong Diwu ,&nbsp;Rongjun Si","doi":"10.1016/j.precamres.2025.107752","DOIUrl":"10.1016/j.precamres.2025.107752","url":null,"abstract":"<div><div>Precambrian continental crust is window into Earth’s early history. The North China Craton (NCC) is one of the key regions worldwide to investigate the continuous crustal growth mechanism during early Earth. The Songshan Group is one of the best-preserved Paleoproterozoic sedimentary strata in the southern NCC, which is an ideal target to reveal the Precambrian continental crustal growth and evolution. However, the Songshan Group has received limited scientific scrutiny, both its depositional time and tectonic setting have not been well constrained. In this study, we present U-Pb detrital zircon ages and Hf-in-zircon isotopic data from sedimentary rocks of the Songshan Group. Based on the youngest single cluster of detrital zircons and the intrusion ages of Paleoproterozoic mafic dykes, the depositional age of the Songshan Group is constrained to the period of ca. 2.20–2.00 Ga. Rutiles from the two quartzite samples define lower intercept U-Pb ages of 1922–1912 Ma, suggesting the Songshan Group had undergone the final assembly of the NCC. U-Pb age spectra of the detrital zircons from the Songshan Group show multi-stage age clusters at ca. 3.84–3.33, 3.03–2.80, 2.80–2.60, 2.60–2.43 and 2.41–2.13 Ga, with two distinct peaks at ca. 2.70 and 2.52 Ga. The Precambrian basement in the southern NCC likely served as a proximal source for the clastics of the Songshan Group. The geochemical characteristics of detrital zircons indicate that they are derived from continental granitoid in a continental arc setting. Based on the sedimentology, provenance, geochronology, and geochemistry of the Songshan Group, we conclude that the group was deposited in a retroarc foreland basin during the period between ca. 2.20 and 2.00 Ga, which was positioned between an “Andean-type” continental margin arc and the Eastern Block. The U-Pb-Hf isotopic compositions of detrital zircons from the Songshan Group unveil two significant periods of continental crustal growth at ca. 2.95–2.60 and 2.60–2.45 Ga in the southern NCC, while the ca. 2.44–2.03 Ga zircons reveal a major episode of crustal reworking. Trace elements of detrital zircons indicate the increase of continental crustal thickness at ca. 2.80–2.70 and 2.58–2.50 Ga, with a maximum thickness at ca. 2.70 Ga, which are similar to that of modern orogenic belts. During and after the two periods, crustal thickness of the southern NCC was obviously shortened.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"421 ","pages":"Article 107752"},"PeriodicalIF":3.2,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled Lu-Hf and U-Pb apatite geochronology of Jatobá orebody supports ∼ 2.5 Ga metamorphism in deep shear zones from southern Copper Belt, Carajás Domain, Brazil","authors":"Yuri Tatiana Campo-Rodriguez ,&nbsp;Cristiana L. Ciobanu ,&nbsp;Sarah Gilbert ,&nbsp;Benjamin Wade ,&nbsp;Nigel J. Cook ,&nbsp;Maria Emilia Schutesky ,&nbsp;Kathy Ehrig","doi":"10.1016/j.precamres.2025.107753","DOIUrl":"10.1016/j.precamres.2025.107753","url":null,"abstract":"<div><div>A multi-isotopic geochronological study of apatite (U-Pb, Lu-Hf) in host basalts and mineralization from the Jatobá orebody, Southern Copper Belt, Carajás Domain, Brazil, constrains the age and setting of mineralization. Combined mineral textural relationships from cathodoluminiscence imaging, and compositional and isotopic data from EPMA and LA-ICP-MS, hint at initiation of an iron-oxide-copper–gold system at ca. 2.5 Ga during a deformation event linked to amphibolite facies metamorphism in deep (up to 20 km) shear zones. The ∼ 2.5 Ga Lu-Hf age is obtained from deformed, REE-rich cores of basalt-hosted apatite and is contemporaneous with metamorphism of a volcanic sequence deposited in a rift active during ca. 2.76–2.73 Ga. Some apatite grains retain a mafic, Cl-rich signature, testifying to a primary igneous origin. The Lu-Hf ages stretching from 2527 to 2384 Ma are obtained from apatite displaying textural diversity and geochemical heterogeneity, consistent with a prolonged event featuring dissolution-reprecipitation in response to fluid release during the retrograde cycle. The U-Pb system displays a younger ∼ 2 Ga U-Pb apatite age indicating later re-equilibration. This age corresponds to post-uplift mylonitization of the host sequences. The newly documented ∼ 2.5 Ga age for mineralization in a deposit from the southern Copper Belt is coeval with Cinzento Shear zone reactivation in the northern copper belt, and the ages of deposits like Salobo. Fluid flow along shears leached metals from the Mesoarchean basement, later deposited as sulphides intimately associated with the reworked apatite. We propose deep-rooted connections between mineralizing systems across the region.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"421 ","pages":"Article 107753"},"PeriodicalIF":3.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin of Neoproterozoic anorthosites in the Wadi El Dib ultramafic-mafic layered intrusions, Egypt","authors":"H.A. Eliwa ,&nbsp;R. Deevsalar ,&nbsp;N.M. Mahdy ,&nbsp;Y. Pan ,&nbsp;Kh. El-Gameel ,&nbsp;H.A. El-Desouky ,&nbsp;H. Khamis ,&nbsp;M. Murata ,&nbsp;A. Andresen ,&nbsp;D. Chew ,&nbsp;H. El Sundolly ,&nbsp;M.M. Fawzy ,&nbsp;Y. Kato ,&nbsp;K. Fujinaga ,&nbsp;K.-C. Shin ,&nbsp;R. Shinjo","doi":"10.1016/j.precamres.2025.107750","DOIUrl":"10.1016/j.precamres.2025.107750","url":null,"abstract":"<div><div>The Neoproterozoic ultramafic–mafic intrusions (NUIs) in the Wadi El Dib (WED) region of the Northeastern Desert, Egypt, consist of a gabbro-serpentinite sequence overlain by anorthosite intrusions. The WED anorthosites show two texturally distinct types of framework-dominated and intercumulus-rich and made of cumulus plagioclases (anorthite percentage: An_60-45) and intercumulus mafic minerals along with granophyric materials. They are associated with rock types typically found alongside anorthosites within layered mafic intrusions. Zircon U-Pb age dating yielded Concordia age of 591.5 ± 3.5 Ma for both types of WED anorthosites. The measured crystallization age of the WED anorthosites matches the post-collisional stage of the Pan-African orogeny and coinciding with the emplacement of A-type granites in the Arabian Nubian Shield. The geochemical evidence suggests that gabbros and anorthosites likely formed from a common mafic parental magma. This is indicated by progressive decreases in concentrations of highly compatible elements and Mg^# from gabbros to anorthosites, relatively high total REE contents in anorthosites, chondrite-normalized REE patterns with positive versus negative Eu anomalies, and the crystallization of transitional magmatic to metamorphic orthopyroxene in anorthosites. The low (⁸⁷Sr/⁸⁶Sr)_i ratios and strongly positive εNd_(t) values of the WED gabbros and anorthosites validate their genesis from an isotopically depleted mantle source. Trace-element geochemical modelling suggests that the older gabbros are denser mafic cumulates segregated from partially crystallized high alumina (high-Al) basaltic parent magma originated from low degree partial melting of mantle peridotite, whereas anorthosites settle out of the cooling residual melt through imperfect fractional crystallization process. The Sr-Nd systematics of the anorthosites coupled with distinct An% variations of cumulus plagioclases and the existence of both magmatic and inherited zircon in the granophyric materials verify a small contribution of lower crustal melts through the entrapment of felsic melt pockets within intercumulus spaces. The data and models indicate that the formation of WED anorthosites at the top of NUIs is triggered by post-collisional crustal thickening and asthenosphere upwelling consistent with previously proposed tectono-magmatic model for the NED.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"421 ","pages":"Article 107750"},"PeriodicalIF":3.2,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detrital zircon data suggest multiple Cryogenian–Cambrian active margins along northern and western Baltica and close ties with Siberia","authors":"Kine Tangvik Størdal ,&nbsp;Trond Slagstad ,&nbsp;Maarten Felix ,&nbsp;Silje Funderud ,&nbsp;Evgeniy Kulakov ,&nbsp;Bjørn Eske Sørensen ,&nbsp;Kerstin Saalmann ,&nbsp;Magdalena H. Huyskens ,&nbsp;Stefanie Lode","doi":"10.1016/j.precamres.2025.107749","DOIUrl":"10.1016/j.precamres.2025.107749","url":null,"abstract":"<div><div>Deciphering the history of active continental margins is of key importance for paleogeographic reconstructions, but the low preservation potential of such margins commonly hampers such attempts and may introduce unrecognized biases. Here, we present new sedimentological observations and detrital zircon U–Pb and Hf isotopic data from the Ediacaran–Cambrian Vestertana Group in Finnmark, Arctic Norway. The data are consistent with derivation from the Fennoscandian Shield and the appearance of an Ediacaran source at the Ediacaran–Cambrian transition. However, the new paleocurrent observations dispute that this influx is related to a change in paleocurrent direction from northerly to southerly. Instead, we argue for the possibility of an alternative source represented by the Kalak Nappe Complex, which we suggest may be a remnant of a Neoproterozoic accretionary margin outboard of western Baltica that was thrust onto Baltica during the Ediacaran rather than during the Silurian Caledonian Orogeny. Further work focusing on detrital minerals other than zircon may provide a more comprehensive understanding of the character of these potential sources. Comparisons with detrital zircon data from Ediacaran–Cambrian sedimentary rocks around the North Atlantic show that both Baltica and Siberia are characterized by large Neoproterozoic populations, while such ages are all but absent from Laurentia. The apparent link between Baltica and Siberia during the Ediacaran–Cambrian is consistent with fossil data and suggests that the two continents were separated from Laurentia by this time.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"421 ","pages":"Article 107749"},"PeriodicalIF":3.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking detrital zircon record and supercontinent over the past 3.5 billion years","authors":"Dongchuan Jian ,&nbsp;Simon E. Williams ,&nbsp;Guochun Zhao ,&nbsp;Shan Yu","doi":"10.1016/j.precamres.2025.107680","DOIUrl":"10.1016/j.precamres.2025.107680","url":null,"abstract":"<div><div>Ideas on the history of supercontinents on Earth have moved beyond the most recent and well understood – Pangea – to establish the concept of supercontinent cycles over a much longer span of Earth history. A series of supercontinents including Rodinia and Nuna are proposed to have existed before the Phanerozoic, but many disagreements persist on their detailed history due to the limited, ambiguous geological record surviving from the Precambrian. One step towards resolving these issues is to integrate extensive databases of geological information within a global, quantitative reconstruction framework. Previous work demonstrated how samples with distinct zircon age spectra characteristics form coherent patterns in space across the past 400 Myr that delineate the periphery and core of Pangea. Here, we investigate the spatial and temporal characteristics of detrital zircon samples deposited over the past 3.5 Ga, and evaluate consistency between different reconstruction models and our expectations based on younger, more well-constrained periods. We find that the preference for detrital samples dominated by young zircons to be located closer to reconstructed subduction zones differs significantly between different reconstruction models, providing a basis for favoring some models over others. Although the number of available samples becomes sparser back in time, the patterns of the categorized samples in Proterozoic reconstructions are broadly consistent with previous results for Pangea, though reconstructed sample distributions indicate spatial bias towards sampling of Proterozoic supercontinent interiors not apparent for Pangea sampling. Global temporal trends reveal that, as supercontinents assemble, the proportion of samples characteristic of subduction tectonic settings increases while the proportion of samples from settings distal from subduction zones decreases, while the opposite trend defines periods of supercontinent dispersal. Together, these results show that quantitative reconstruction of global zircon databases holds important information related to past paleogeographic change.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107680"},"PeriodicalIF":3.2,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis of coexisting authigenic ferric illite and glauconite in the Deodongar Sandstones, Chattisgarh Basin, India: Unraveling redox dynamics of a Mesoproterozoic Sea?","authors":"Ayoti Banerjee ,&nbsp;Ashim Kumar Patel ,&nbsp;Sivaji Lahiri ,&nbsp;Pramita Majumder ,&nbsp;Amlan Banerjee ,&nbsp;Somnath Dasgupta","doi":"10.1016/j.precamres.2025.107735","DOIUrl":"10.1016/j.precamres.2025.107735","url":null,"abstract":"<div><div>This study investigates the co-occurrence of ferric illite and glauconite in the Deodongar sandstone of the Mesoproterozoic Chattisgarh Supergroup in India. Forming a Member within the stromatolitic Chandi Formation, these glauconitic arenites were deposited in a shallow marine setting, as revealed by field relationships. Electron Probe Micro Analyzer (EPMA) data shows that these ferric illites and glauconites are rich in magnesium and aluminum, although they exhibit considerable variation in iron and potassium content. Oxide cross-plots indicate that ferric illite and glauconite followed different geochemical pathways of formation. Textural observations indicate that these minerals formed over K-feldspar, quartz and chert fragments as authigenic phases. Mass balance calculations suggest that potassium released during the conversion of K-feldspar to glauconitic minerals may aid in transforming quartz/chert fragments to these minerals, though additional sources for iron, magnesium and aluminum ions are necessary. Thermodynamic calculations show that ferric illite formation is favorable than glauconite at 1 atmospheric pressure and 298 Kelvin temperature. Yet, occurrence of ferric illite and glauconite forming over adjacent substrates suggests that each substrate acted as a closed independent chemical system for mineral authigenesis.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107735"},"PeriodicalIF":3.2,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth and reworking of continental crust: Insights from the Dunhuang Block, NW China","authors":"Tingyi Wang ,&nbsp;Guochun Zhao ,&nbsp;Chunrong Diwu","doi":"10.1016/j.precamres.2025.107739","DOIUrl":"10.1016/j.precamres.2025.107739","url":null,"abstract":"<div><div>The craton margins and small-scale Precambrian blocks are not always with stable lithosphere; they tend to lose their roots and be reworked and isotopically reset by subduction and collision from multiple directions. The Dunhuang Block is one of the microcontinents within the Central Asian Orogenic Belt (CAOB), and has been involved and reworked by tectonics evolution of the southern CAOB, leading to extensive reworking and recycling of continental lithosphere. Therefore, the Dunhuang Block is an excellent example for revealing the growth and reworking of early Precambrian continental crust. Archean–Paleoproterozoic basement rocks in the Dunhuang Block are sporadically exposed and spatially associated with Paleozoic complexes related to the CAOB. Available geochronological data reveal that the Dunhuang Block is a unified Precambrian block that likely formed a coherent crystalline basement prior to ca. 1.79 Ga. In the representative Gangou cross-section of the Dunhuang Block, the early Precambrian rocks were mainly composed of Neoarchean to Paleoproterozoic TTG gneisses with a small amount of late Paleoproterozoic pyroxenite and marble. The protoliths of Neoarchean TTG rocks in the Dunhuang Block were likely originated from a subducted oceanic slab under the garnet-amphibolite- and rutile-eclogite-facies conditions with presence of rutile; whereas the Paleoproterozoic TTG rocks likely originated from partial melting of thickened mafic lower continental crust under amphibolite-facies condition. Hf isotopic compositions in zircons from the Precambrian rocks in the Dunhuang Block reveal that remnants of Hadean-Eoarchean crustal components were still present in the basement of the Dunhuang Block. The Neoarchean rocks in the Dunhuang Block have been mainly extracted from the depleted mantle, whereas the Paleoproterozoic rocks have been primarily reworked from older crustal reservoirs. The Dunhuang Block was an independent Precambrian continental fragment or microcontinent situated between the Tarim Craton and North China Craton. Similar to many other Precambrian blocks within the CAOB, it was significantly involved in Paleozoic orogenic events related to the subduction-accretion processes of the Paleo-Asian Ocean in the southern CAOB.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107739"},"PeriodicalIF":3.2,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The significance of Mesozoic basement uplift for interpreting the NCC’s Precambrian tectonic regime: Evidence from the Paleoproterozoic magmatic rocks along the eastern margin of the Lishi Fault","authors":"Qingsong Duan ,&nbsp;Mingguo Zhai ,&nbsp;Xiyan Zhu ,&nbsp;Yanyan Zhou ,&nbsp;Yuhong Fan","doi":"10.1016/j.precamres.2025.107737","DOIUrl":"10.1016/j.precamres.2025.107737","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study offers the first comprehensive geochronological and geochemical results for the Paleoproterozoic magmatic rocks exposed along the eastern margin of the Lishi Fault in the North China Craton (NCC). Their emplacement age, petrogenesis, and relationship with the basement provide critical constraints for inferring the subdivisions and tectonic evolution of the NCC basement. The U-Pb ages, Hf-O isotopes, in combination with whole-rock major and trace element data, identify three episodes of magmatism along the eastern margin of the Lishi Fault at ca. 2.33–2.29 Ga, 2.20–2.17 Ga and 1.97–1.94 Ga. The magmatic rocks include the 2.33–2.29 Ga granites, 2.20–2.17 Ga tonalites, granodiorites, granites and &lt;em&gt;meta&lt;/em&gt;-gabbros, and 1.97–1.94 Ga granites. The 2.33–2.29 Ga granites are characterized by high SiO&lt;sub&gt;2&lt;/sub&gt;, K&lt;sub&gt;2&lt;/sub&gt;O contents, and Ce/Pb and Nd/Sm values ranging from 2.50 to 5.62 and 4.74–7.61, respectively. The zircon Hf isotope compositions (&lt;em&gt;ε&lt;/em&gt;&lt;sub&gt;Hf&lt;/sub&gt;(&lt;em&gt;t&lt;/em&gt;) = -1.71-+3.0, &lt;em&gt;T&lt;/em&gt;&lt;sub&gt;DM2&lt;/sub&gt; = 3.0–2.6 Ga), suggest their origin through a recycled Archean crustal. The 2.20–2.17 Ga felsic rocks (SiO&lt;sub&gt;2&lt;/sub&gt; = 63.83–74.30 wt%) show relatively high Mg# values, large variation in Cr and Ni abundances, and low (La/Yb)&lt;sub&gt;N&lt;/sub&gt; value. These characteristics and zircon Hf isotope compositions (&lt;em&gt;ε&lt;/em&gt;&lt;sub&gt;Hf&lt;/sub&gt;(&lt;em&gt;t&lt;/em&gt;) = -4.24-+2.69, &lt;em&gt;T&lt;/em&gt;&lt;sub&gt;DM2&lt;/sub&gt; = 2.8–2.6 Ga) suggest their evolution through high-temperature melting of a Neoarchean mafic source and a significant role of mantle-derived materials. The 2.20–2.17 Ga gabbros (subsequently metamorphosed) with high K (K&lt;sub&gt;2&lt;/sub&gt;O = 0.91–2.20 wt%) and depleted Nb-Ta-Ti, were derived from an enriched lithospheric mantle source. The 1.97–1.94 Ga granites are moserately peraluminous (A/CNK = 1.02–1.12) and display high zircon δ&lt;sup&gt;18&lt;/sup&gt;O values (5.51–8.15 ‰, Ave. 6.72 ‰). Such characteristics underline their S-type nature and derivation from partial melting of (meta)sedimentary source. The 2.33–2.29 Ga granite and 2.20–2.17 Ga tonalite show variably low zircon δ&lt;sup&gt;18&lt;/sup&gt;O values of 3.29–6.07 ‰ and 2.94–6.27 ‰ respectively, which are below the normal mantle zircon values. A general increase in zircon δ&lt;sup&gt;18&lt;/sup&gt;O values in the Paleoproterozoic magmatic rocks along the eastern margin of the Lishi Fault underlines a change in the tectonic regime from extension to collision setting. The zircon U-Pb age and Lu-Hf isotope data of the early Precambrian basement rocks reveal a close similarity in the tectono-thermal regime and crustal growth between OB and other tectonic domains of NCC, such as the northern Khondalite Belt and Yinshan Block (KB + YB), Trans-North China Orogen (TNCO), and the Eastern Block (EB). We propose that the lithosphere of the NCC was significantly thinned since the Mesozoic and was accompanied by extensive magmatic activities. The geomorphology of present day NCC was shaped by multiple stages of uplift-den","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107737"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis of a newly discovered ∼1.1 Ga aillikite, carbonate-rich kimberlite, and carbonatite association on the northern margin of the Mid-continental Rift System, Ontario, Canada","authors":"Irmak Yılmaz ,&nbsp;Ali Polat ,&nbsp;Joel Gagnon ,&nbsp;Robert Frei ,&nbsp;Peter Jobin","doi":"10.1016/j.precamres.2025.107736","DOIUrl":"10.1016/j.precamres.2025.107736","url":null,"abstract":"<div><div>In this study, we present new field, petrographic, and whole-rock major and trace element, and Nd–Pb–Sr radiogenic isotope data for a newly discovered aillikite, carbonate-rich kimberlite, and carbonatite association on the northern shore of Lake Superior, Canada.<!--> <!-->The aillikite, carbonate-rich kimberlite, and carbonatite association is exposed as sills and dykes in the Neoarchean Schreiber-Hemlo greenstone belt in the Ripple Bay area, Ontario. The carbonatite and carbonate-rich kimberlite occur in the same dykes and sills, whereas the aillikite occurs in separate dykes and sills. Boundaries between the carbonatite and carbonate-rich kimberlite are mostly sharp, with some gradational outcrops. Field relationships, near 1.1 Ga Pb–Pb and Rb–Sr errorchron ages, and Nd depleted mantle model ages (T_DM = 1.14–1.46 Ga) reported in this study, collectively suggest that the Ripple Bay aillikite, carbonate-rich kimberlite, and carbonatite association formed as part of the late Mesoproterozoic Mid-continental Rift System in North America. New geochemical data are used to constrain the petrogenesis of the Ripple Bay aillikite, carbonate-rich kimberlite, and carbonatite association and address the long-standing debate on the co-genetic relationship of aillikite, kimberlite, and carbonatite occurrences worldwide. Each rock type displays distinct major and trace element characteristics. On the chondrite-normalized REE diagram, all three rock types exhibit subparallel trends characterized by large enrichments of LREEs over HREEs (La/Yb_cn = 33–62), with the carbonatite displaying the most enriched patterns and carbonate-rich kimberlites showing the least enrichment, and aillikites plot between the carbonatites and carbonate-rich kimberlites. Aphanitic texture and flow patterns in the carbonatite indicate that it solidified from a carbonatite melt. All three rock types resulted from small degrees of partial melting in different parts of the same mantle source region, which had different proportions of metasomatic minerals, and represent near-primary melt compositions. The carbonate-rich kimberlite and carbonatite melts were transported simultaneously to the surface through the same magma conduits, with minimal mixing, indicating that their sources were spatially associated. Initial Nd (εNd=+0.6 to + 7.0) and Sr (Sr_i = 0.700309–0.704111) compositions and ²⁰⁶Pb/²⁰⁴Pb (17.83–40.23) and ²⁰⁸Pb/²⁰⁴Pb (37.66–62.88) isotope ratios reflect heterogeneous asthenospheric mantle sources containing strongly depleted to enriched components.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107736"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}