Doklady Earth Sciences最新文献_第4页

Vegetation and Climate in the North of the Minusinsk Basin in the Late Holocene: A Record from Shira Lake Resolved by Decade 全新世晚期米努辛斯克盆地北部的植被和气候：按年代划分的希拉湖记录

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x2460316x

E. V. Bezrukova, S. A. Reshetova, N. V. Kulagina, A. A. Shchetnikov, I. A. Filinov, M. I. Kuzmin

{"title":"Vegetation and Climate in the North of the Minusinsk Basin in the Late Holocene: A Record from Shira Lake Resolved by Decade","authors":"E. V. Bezrukova, S. A. Reshetova, N. V. Kulagina, A. A. Shchetnikov, I. A. Filinov, M. I. Kuzmin","doi":"10.1134/s1028334x2460316x","DOIUrl":"https://doi.org/10.1134/s1028334x2460316x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>The results of studying the bottom sediments of meromictic Shira Lake, located in the northern part of the Minusinsk Basin, are presented. The sediments are represented by varves, annual layered series, which make it possible to reconstruct the history of the regional natural environment with a high resolution. The age model is based on seven 14C dates. The proposed new palynological record from the upper part of the Shira-2021-II-1 core extends the previous record by 530 years, providing the reconstruction of the regional natural environment for the past 2980 calibrated years with an average resolution of 21 years. The reconstructions show a humid regional climate 2980–2650 BP, with the climate of the basin itself being more arid, providing the existence of steppe and meadow–steppe assemblages around Shira Lake for the past 2980 years. The trend of changes in the Artemisia/Chenopodiaceae pollen ratio, considered as an indicator of available moisture for plants, suggests a slight increase in the moisture level in the Minusinsk Basin in 2980‒70 BP and a noticeable decrease in the past 70 years. However, the increase was interrupted by short-term intervals of increased climate aridization. The reconstructions have shown that changes in vegetation around Shira Lake in the Late Holocene were mainly caused by large-scale circulation processes that changed the regional moisture balance. The steppe assemblages were the most sensitive to moisture changes on a decadal scale. Like the previous pollen record, the new one does not have clear pollen indicators of anthropogenic influence on vegetation. Only a noticeable increase in the birch pollen content in the past 50 years may indicate planting of greenery around the resort areas.","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"66 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Age of Rocks and Peculiarities of the Formation of the Dariganga Volcanic Field, Southeastern Mongolia 蒙古东南部达里干嘎火山岩场的岩石年龄和形成特征

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24602839

V. V. Yarmolyuk, A. M. Kozlovsky, V. M. Savatenkov, E. A. Kudryashova

{"title":"Age of Rocks and Peculiarities of the Formation of the Dariganga Volcanic Field, Southeastern Mongolia","authors":"V. V. Yarmolyuk, A. M. Kozlovsky, V. M. Savatenkov, E. A. Kudryashova","doi":"10.1134/s1028334x24602839","DOIUrl":"https://doi.org/10.1134/s1028334x24602839","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>The results of systematic geochronological (K–Ar) studies of rocks of the Dariganga volcanic field (DVF) composed of Late Cenozoic mafic lavas are presented. Four stages of its evolution are distinguished: the Middle–Late Miocene (>10 Ma), Late Miocene–Early Pliocene (7.8–3.5 Ma), Late Pliocene (2.8–2.6 Ma), and Pleistocene (<1.7 Ma). The products of these stages are regularly distributed within the volcanic field. The main volume of eruptions was related to the Late Miocene–Early Pliocene and Pleistocene stages. The northwestern part of the lava field as a lava plateau formed during the Late Miocene–Early Pliocene. The eruptions are related to a local structural depression, which originated under extension accompanying volcanism. The southeastern part of the DVF formed during the Pleistocene volcanic eruption. Volcanism accompanied the formation of the Khukhot-Ein-Nuru Ridge in the Nukut-Daban Uplift and was responsible for the morphological peculiarities of the volcanic cover. A typical feature of it includes the large multicentered shield volcanoes related to the axial zone of the ridge, as well as the elongated valley flows along both slopes. The peculiarities of the formation of the DVF and other volcanic areas of the Late Cenozoic intraplate volcanic province of Central and East Asia are compared. Their consistent evolution indicates that the formation of the DVF was controlled by the same geodynamic mechanisms as the formation of other volcanic areas of the province, namely, by the activity of a small mantle plume.","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"6 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variability of Ephedra dahurica Turcz. Pollen as an Indicator of Humidity for the Modern Climate of Southeastern Transbaikalia 作为外贝加尔地区东南部现代气候湿度指标的麻黄花粉变异性花粉作为外贝加尔东南部现代气候的湿度指标

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24603158

S. A. Reshetova, E. V. Bezrukova, M. I. Kuzmin

引用次数: 0

Petrological Features of Neogene Ulukale Porphyritic Dome and Çağlarca Radial Dykes in the Tunceli Volcanic, Eastern Turkey 土耳其东部通杰利火山岩新近纪乌卢卡莱斑岩穹丘和恰拉尔卡放射状岩脉的岩石学特征

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24601470

Sevcan Kürüm, Abdullah Sar, Muhammed Yasir Yurt, İsmail Yıldırım

{"title":"Petrological Features of Neogene Ulukale Porphyritic Dome and Çağlarca Radial Dykes in the Tunceli Volcanic, Eastern Turkey","authors":"Sevcan Kürüm, Abdullah Sar, Muhammed Yasir Yurt, İsmail Yıldırım","doi":"10.1134/s1028334x24601470","DOIUrl":"https://doi.org/10.1134/s1028334x24601470","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>This study presents new analytical data for the Ulukale porphyritic dome located within the Neogene Tunceli volcanic rocks, as well as whole rock geochemistry and Sr–Nd isotope data for the Çağlarca radial dykes for the first time. The Ulukale porphyritic dome and the Çağlarca radial dykes, have trachyandesite composition. On trace element diagrams normalized to primitive mantle, samples from the dome and dykes have similar features. Whole-rock geochemistry data for the investigated volcanic rocks indicate they formed from low-degree of partial melting of spinel lherzolite at shallow depths. Accordingly magmatism forming the dome appears to have more acidic composition. Sr–Nd isotope data (εNd(T) value –2.0 and –1.7) for both rock groups indicate a lithospheric subcontinental mantle source. All geochemical data indicate these volcanic rocks had source magma with lherzolitic features which underwent low-degree of partial melting; however, fractional crystallization, magma mixing, contamination in the form of continental crust effects and the effect of subduction-linked sediment melts were shown to be important during magma differentiation. Additionally, all this data shows that these volcanic rocks have the same petrological features as the Tunceli Volcanics, the main product of this magmatism.","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"6 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Depositional Environment, Diagenesis and Source Rock Characterization of Middle Jurassic Carbonates, North Waziristan, Khyber Pakhtunkhwa, Pakistan 巴基斯坦开伯尔巴图克瓦省北瓦济里斯坦中侏罗统碳酸盐岩的沉积环境、成因和源岩特征

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x2460244x

Emad Ullah Khan, Maryam Saleem, Syed Muhammad Wasim Sajjad, Saif Ullah Khan

{"title":"Depositional Environment, Diagenesis and Source Rock Characterization of Middle Jurassic Carbonates, North Waziristan, Khyber Pakhtunkhwa, Pakistan","authors":"Emad Ullah Khan, Maryam Saleem, Syed Muhammad Wasim Sajjad, Saif Ullah Khan","doi":"10.1134/s1028334x2460244x","DOIUrl":"https://doi.org/10.1134/s1028334x2460244x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>This study marks the first detailed depositional, diagenetic and organic geochemical investigation of Jurassic Isha Formation in North Waziristan, Khyber Pukhtunkhuwa, Pakistan. Detailed systematic sampling was carried out from exposed outcrop along the Mirali road in North Waziristan for microfacies analysis and diagenetic studies to unravel the depositional environment and diagenetic alterations. The oraganic maturity and hydrocarbon generation potential were assessed by total organic content and Rock-Eval pyrolysis. Outcrop analogue revealed that the formation predominantly comprises of thick to thin bedded oolitic fractured limestone, bioclastic and dolomitic limestone. In the petrography, a total of eight microfacies (MF1–MF8) were constructed and were directed different depositional enviroments. Based on the integrated field data and microfacies analyses, the Isha Formation is interpreted to be deposited on a homoclinal ramp particularly in peritidal, lagoon, and carbonate shoals. Sequences stratigraphic setup shows intervallic Transgressive and Regressive Systems Tracts. The TSTs are mostly grainstone and packstone facies whereas the RSTs are wackestone and mudstone microfacies which demonstrates a single 2nd order cycle and then multiple 3rd order transgressive and regressive cycles for the deposition of Isha Formation. The total organic content and Rock-Eval pyrolysis results were ploted on VanKerevlen diagram which indicate that the source rock potential fall within the type III kerogen. The HI versus Tmax and PI versus Tmax cross plots indicate that the formation lies within the zone of maturation, generation potentiality indicate that the formation has fair to poor potential and hydrocarbons are indigenous.","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"27 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New Data on the Regional Stratigraphic Scale of the Paleoproterozoic of the Fennoscandian Shield (Isotope Geochemistry and Age of Supracrustal Rock Complexes of the Inari Terrane, Kola Peninsula) 关于芬诺斯堪地盾古近纪区域地层尺度的新数据（科拉半岛伊纳里地层超岩体的同位素地球化学和年龄）

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24602773

A. B. Vrevsky, A. B. Kuznetsov, P. A. Lvov

引用次数: 0

Thermodynamic Model of the H2O–LiCl–NaCl System for Study of Fluid Inclusions: Calculations Using the Pitzer Equations 用于研究流体夹杂物的 H2O-LiCl-NaCl 系统热力学模型：使用皮策方程进行计算

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24603389

M. A. Misyura, S. A. Bushmin, O. V. Aleksandrovich, M. E. Mamykina, E. V. Savva

{"title":"Thermodynamic Model of the H2O–LiCl–NaCl System for Study of Fluid Inclusions: Calculations Using the Pitzer Equations","authors":"M. A. Misyura, S. A. Bushmin, O. V. Aleksandrovich, M. E. Mamykina, E. V. Savva","doi":"10.1134/s1028334x24603389","DOIUrl":"https://doi.org/10.1134/s1028334x24603389","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>A thermodynamic model of the ternary fluid system H2O–LiCl–NaCl is proposed for the temperature range from –77 to +300°C. This model incorporates low-temperature phase transitions of freezing products of water–salt inclusions. The model is based on the Pitzer equations using new interaction parameters of Na, Cl, and the corresponding equilibrium constants of reactions involving the solid and liquid phases. Based on microthermometry data of fluid inclusions (T of phase transitions during heating after freezing), the model allows determination of the salt concentrations. The characteristics (T, wt %, LiCl and NaCl) of triple points with solid phases including the eutectic ({text{E}}{kern 1pt} '') (ice + LiCl · 5H2O + NaCl · 2H2O), peritectic ({text{P}}_{1}^{{{text{''}}}}) (LiCl · 5H2O + NaCl · 2H2O + NaCl) and ({text{P}}_{2}^{{{text{''}}}}) (LiCl · 5H2O + LiCl · 3H2O + NaCl), and the cotectic, peritectic curves separating the phase fields (ice + L, NaCl · 2H2O + L, NaCl + L), as well as solubility isotherms of ice, hydrohalite, and halite calculated by the model, showed good agreement with the experimental data. As an example of the application of a model to a natural object, we determined the salt contents in lithium-bearing brine inclusions in late quartz veins of the Bolshie Keivy area (Fennoscandian Shield).","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"29 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

He Isotopic Composition and 4He/20Ne Ratio of Pyrite and Magnetite of Explosive Carbonatite Breccia of the Sallanlatva Massif, Kola Region 科拉地区萨兰拉特瓦地块黄铁矿和磁铁矿的 He 同位素组成和 4He/20Ne 比率

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24603183

E. N. Kozlov, E. N. Fomina, M. Yu. Sidorov, A. V. Gudkov, V. V. Kolobov

{"title":"He Isotopic Composition and 4He/20Ne Ratio of Pyrite and Magnetite of Explosive Carbonatite Breccia of the Sallanlatva Massif, Kola Region","authors":"E. N. Kozlov, E. N. Fomina, M. Yu. Sidorov, A. V. Gudkov, V. V. Kolobov","doi":"10.1134/s1028334x24603183","DOIUrl":"https://doi.org/10.1134/s1028334x24603183","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>The He isotopic composition and the He and Ne ratio of fluid inclusions in magnetite and pyrite from carbonatite breccias of the Sallanlatva alkali-ultramafic complex of the Kola alkaline province (Northwest Russia) are studied using the step-crushing method. The results indicate the highly likely involvement of fluids from several sources trapped in various proportions during the formation of the Sallanlatva explosive carbonatite breccias. The R/Ra ratio, where R is the measured 3He/4He ratio and Ra of 1.382 × 10–6 is the same ratio of atmospheric air, reaches 2.3, which is a reliable indicator of the presence of mantle gases. A low (1–44) 4He/20Ne ratio allows us to suggest the involvement of atmospheric gases dissolved in paleometeoric waters. A combination of these two facts favors a hypothesis of the phreatomagmatic nature of the studied breccias, i.e., their formation at the expense of interaction between the intruding hot orthomagmatic fluids and meteoric waters with dissolved atmospheric gases.","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"4 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

First Assessment of Soil Cover Pollution with Polycyclic Aromatic Hydrocarbons in the City of Ulan-Ude 首次评估乌兰乌德市土壤覆盖层的多环芳烃污染情况

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24602888

N. E. Kosheleva, N. B. Zhaxylykov, Yu. A. Zavgorodnyaya, N. S. Kasimov

引用次数: 0

Ag-Bearing Tetrahedrite-(Cd), (Cu,Ag)6(Cu4Cd2)Sb4S13, from the Galena–Fluorite Kon-Dara Mineral Deposit (Southwestern Pamirs): The First Discovery in Tajikistan 来自方铅矿-萤石 Kon-Dara 矿藏（帕米尔西南部）的含银四面体-(Cd)，(Cu,Ag)6(Cu4Cd2)Sb4S13：塔吉克斯坦的首次发现

IF 0.9 4区地球科学

Doklady Earth Sciences Pub Date : 2024-08-11 DOI: 10.1134/s1028334x24603286

N. G. Lyubimtseva, N. S. Bortnikov, V. M. Gekimyants, S. E. Borisovsky, P. Yu. Plechov

{"title":"Ag-Bearing Tetrahedrite-(Cd), (Cu,Ag)6(Cu4Cd2)Sb4S13, from the Galena–Fluorite Kon-Dara Mineral Deposit (Southwestern Pamirs): The First Discovery in Tajikistan","authors":"N. G. Lyubimtseva, N. S. Bortnikov, V. M. Gekimyants, S. E. Borisovsky, P. Yu. Plechov","doi":"10.1134/s1028334x24603286","DOIUrl":"https://doi.org/10.1134/s1028334x24603286","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3>Tetrahedrite-(Cd), Cu10Cd2Sb4S13, is a member of the tetrahedrite series of the tetrahedrite group with a predominance of Cd at the C position typically occupied by divalent metals. Cadmium end-members from the tetrahedrite group are rare: they have been described in 15 deposits and ore occurrences. This work reports on a new discovery site of Ag-bearing tetrahedrite-(Cd) at the Kon-Dara mineral deposit (Southwestern Pamirs, Tajikistan) and summarizes the known data on rare Cd-bearing fahlores with a Cd content from 1 to 12.31 wt %. Ag-bearing tetrahedrite-(Cd) at the Kon-Dara deposit occurs as xenomorphic segregations 10–35 μm in size in association with tetrahedrite-(Fe), tetrahedrite-(Zn), galena, polybasite, and chalcopyrite, calculated which replace bournonite. According to the EPMA data, its composition averaged over seven analyses (in wt %) is as follow: Ag 16.17, Cu 25.19, Cd 10.09, Fe 0.38, Zn 0.09, Pb 0.13, Sb 25.55, As 0.18, and S 22.34. The empirical formula calculated based on 29 atoms per unit is (Cu7.40Ag2.80)Σ10.20(Cd1.68Fe0.13Zn0.03Pb0.01)Σ1.84(Sb3.92As0.04)Σ3.96S13.00. The composition of the tetrahedrite-(Cd) from Kon-Dara is similar to those from the Tyndrum Pb–Zn mineralization in Scotland, the Clara baryte–fluorite–(Ag,Cu) mine in Germany, and the Xitieshan Pb–Zn deposit in China. The formation temperature of Ag-bearing tetrahedrite-(Cd) at the Kon-Dara deposit is estimated to have been at about (170–140) ± 20°C.","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"20 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0