Contents

Doklady Earth Sciences

Vol. 526, No. 2, 2026

GEOLOGY

U–Pb Age of Kimberlite Zircon Grains from Commercial Placers and Placer Occurrences of Diamonds in the Northeastern Siberian Platform

M. N. Goloburdina, S. A. Grakhanov, A. I. Dak, T. N. Zubova, V. F. Proskurnin, N. V. Rodionov, A. V. Tarasov, and Academician V. S. Shatsky p. 22  abstract

U–Pb (ID TIMS) Age of Garnet from Nepheline Syenites of the Yakokutsky Volcano-Plutonic Complex: A New Reference Estimate of Age for Mesozoic Alkaline Magmatism Event of the Aldan Shield

E. B. Salnikova, M. V. Stifeeva, Corresponding Member of the RAS A. B. Kotov, N. V. Vladykin, I. A. Sotnikova, and N. V. Alymova p. 23  abstract

PALEOGEOGRAPHY

Isotope Stage 23 of the Palynological Record of Lake Elgygytgyn, Polar Chukotka

A. V. Lozhkin, P. M. Anderson, Yu. A. Korzun, and E. Yu. Nedorubova p. 24  abstract

SEISMOLOGY

Megathrust Earthquake off the Eastern Coast of Kamchatka on July 30, 2025

A. V. Konovalov, Yu. A. Stepnova, and Academician A. I. Khanchuk p. 25  abstract

OCEANOLOGY

Contourite Drifts in the Romanche Fracture Zone (Equatorial Atlantic)

M. S. Popov, D. G. Borisov, E. V. Ivanova, and O. V. Levchenko p. 26  abstract

GEOLOGY

2.0–2.2 Ga Old Ruined Magmatic Arc in the Lapland–Kola Ocean: U–Th–Pb Data for Zircon from Metasedimentary Rocks of the Tersk Terrane, Eastern Fennoscandia

I. A. Zhitnikova, K. G. Erofeeva, Corresponding Member of the RAS A. V. Samsonov, A. V. Stepanova, and O. A. Maksimov p. 27  abstract

GEOCHEMISTRY

Niobium-Bearing Microbiota in REE–Nb Ores of the Tomtor Deposit (Arctic Siberia, Republic of Sakha (Yakutia))

S. M. Zhmodik, E. A. Zhegallo, L. V. Zaitseva, N. V. Grubova, E. V. Lazareva, and Academician A. Yu. Rozanov p. 28  abstract

PETROLOGY

The Cambrian Metavolcanic Rocks of the Upper Unit of the Maksyutov Complex (South Urals): Results of U–Pb (SHRIMP II) Dating of Zircon

P. M. Valizer, D. A. Zedgenizov, and N. N. Farrakhova p. 29  abstract

Petrogenesis of Sin Quyen Paragneiss, Phan Si Pan Zone, Northwest Vietnam and Geological Significance

Pham Minh and Nguyen Thanh Tung p. 30  abstract

OCEANOLOGY

Annual Variability of CO2 Flux at the Carbon Polygon in the Northeastern Black Sea

A. A. Polukhin, Yu. V. Murzakova, Yu. O. Pronina, A. O. Varvarova, Yu. A. Khoroshilov, E. A. Rebetskaya, V. V. Ocherednik, V. V. Kremenetsky, and Academician S. K. Gulev p. 31  abstract

GEOGRAPHY

The First 5700-Year History of Vegetation and Climate of the North-Minusinsk Basin According to a Decadal-Resolution Palynological Record from the Sediments of Lake Shira

E. V. Bezrukova, S. A. Reshetova, A. A. Shchetnikov, I. A. Filinov, and Corresponding Member of the RAS K. S. Ganzey p. 32  abstract

GEOLOGY

Early Neoproterozoic Island-Arc Volcanogenic Sedimentary Complex of the Ulutau Terrane (Central Kazakhstan): Substantiation of Age and Conditions of Formation

A. A. Tretyakov, N. A. Kanygina, Academician K. E. Degtyarev, A. S. Dubenskiy, K. G. Erofeeva, and V. S. Sheshukov p. 33  abstract

The Age of the Terminal Stage of Magmatism in the Stanovoy Volcano-Plutonic Belt

A. M. Larin, Corresponding Member of the RAS A. B. Kotov, E. B. Salnikova, S. D. Velikoslavinsky, V. P. Kovach, T. M. Skovitina, A. A. Ivanova, Yu. V. Plotkina, and N. L. Alekseev p. 34  abstract

GEOCHEMISTRY

Background Concentrations of Trace Elements in Recent Lake Sediments of the Murmansk Region

Z. I. Slukovskii, V. A. Dauvalter, D. B. Denisov, P. N. Adamskaia, and A. V. Guzeva p. 35  abstract

MINERALOGY

Bismuth Sulfosalt Mineralization in the Ores of the Vladimirskoe Deposit (Eastern Sayan Mountains)

E. V. Airiyants, D. K. Belyanin, S. M. Zhmodik, O. N. Kiseleva, and P. A. Roshchektaev p. 36  abstract

PALEONTOLOGY

The Ancient Sun Bear Helarctos malayanus praemalayanus (Ursidae, Carnivora) from the Middle Pleistocene of Vietnam

Academician A. V. Lopatin, D. O. Gimranov, E. N. Maschenko, and Le Xuan Dac p. 37  abstract

GEOLOGY

Age of Gabbrodolerites of Belarus “Big Dike”: Results of Baddeleyite U–Pb (ID-TIMS) Geochronological Studies

V. N. Burmistrov, O. A. Piskun, Correspondent Member of the RAS A. B. Kotov, E. B. Salnikova, Correspondent Member of the RAS A. V. Samsonov, A. A. Tolkachikova, A. V. Stepanova, M. P. Gurinovich, and K. A. Savko p. 38  abstract

GEOLOGY OF ORE DEPOSITS

Sulfur Isotope Composition of Sulfides from Phoscorite and Carbonatite of the Guli Massif (Maimecha–Kotui Province, Russia): First Results

K. N. Malitch, N. V. Sorokhtina, Corresponding member of RAS A. E. Izokh, A. A. Voitin, I. Yu. Badanina, and V. V. Murzin p. 39  abstract

MINERALOGY

Local Structure of Ba- and F-Dominant Minerals of the Lamprophyllite Structural Family (Based on Vibrational Spectroscopy Data)

S. M. Aksenov, N. V. Chukanov, A. A. Kompanchenko, Yu. A. Mikhailova, G. S. Ilyin, and Corresponding Member of the RAS I. V. Pekov p. 40  abstract

PALEONTOLOGY

First Findings of Fossil Pollen of the Genus Decodon in the Oligocene and Miocene in the South of Western Siberia and Their Paleobiogeographical Distribution Features

O. B. Kuzmina, Yu. D. Vnukovskaya, and Corresponding Member of the RAS B. L. Nikitenko p. 41  abstract

PHYSICS OF THE EARTH

Turbulent Thermal Convection in the Earth’s Liquid Core

V. D. Kotelkin and Academician L. Y. Aranovich p. 42  abstract