Report on geological exploration and calculation of reserves of brown ferrous deposits of the Khalilovskoye field: on September 1. 1931", prepared by the team of authors, is a unique and detailed document that reveals the wealth and prospects of one of the important iron ore deposits of Russia of the early XX century. This work is not just a report, but an important historical source that allows us to understand the stages of development of geological exploration and resource assessment in the era of active industrial growth of the country. The focus of this book is the Khalilovskoye field, which at the beginning of the 20th century attracted the attention of specialists for its potential importance for the metallurgical industry. The authors describe in detail the geological exploration work carried out, the methods of research, the results of field research and laboratory analyzes, and also give accurate calculations of brown iron deposits. The book traces all the complex and painstaking work on the identification and assessment of rich deposits, which makes it a valuable source for historians of geology, specialists in mineral resources and enthusiasts of industrial history. This book may be of interest to a wide range of readers - from professional geologists and mineral engineers to students of specialized universities, researchers of the history of industry and lovers of domestic geology. Its content is perfect for those who are looking for a deep understanding of the methods of exploration and evaluation of reserves at the beginning of the XX century, as well as for those who are interested in the history of the development of the mining industry in Russia. This work is especially valuable for those who appreciate the accurate data, historical reports and analytical approaches used in an era when the country's industrial development was on the rise. The topics raised in the report cover a wide range of issues, from the geological features of the field and exploration methods to the assessment of reserves and their economic significance. The book describes in detail the structure and composition of the ironclads, the geological history of the formation of the field, as well as the features of exploration in the 1930s. Particular attention is paid to the accuracy of stock calculations, which emphasizes the professional approach of the authors and their desire for the most objective assessment of resources. The style of presentation in the book is characterized by strict scientific accuracy, while the authors tried to make the text available to a wide audience interested in history and geology. This work is not only a technical report, but also a kind of historical document reflecting the level of knowledge and methods of the time. For those who are familiar with other works in the field of geological exploration and mineral resources, the book will be an excellent addition to their library, and for beginners - a fascinating journey into the past of Russian industry. Of particular importance is the fact that the team of authors, when creating this report, used advanced research and analysis methods at the time, which makes it a valuable source for studying the development of geological sciences in Russia. In General, "Report on geological exploration and calculation of reserves of brown iron deposits of the Khalilovskoye field: 1 Sept. 1931" is not just a technical document, but a living testimony to an era when the industrial future of the country largely depended on the accuracy and professionalism of geologists. If you are looking for a book that combines historical significance, scientific accuracy and a wealth of factual material, then this work will be a real discovery for you. It is perfect for those who appreciate in-depth research, historical reports and are interested in the development of the mining industry in Russia. Inspiring and informative, it will help to understand how stocks were formed, which in the future could become the basis for the development of the metallurgical industry and industry as a whole.