The technique of lineaments and linears analysis and its application in the Minerogenic Province of Southeast Missouri

Current terminology in the field of lineaments and linears (lineations) analysis was reviewed and quantitative definitions of the common terms offered. A general classification of lineations is herein proposed. Characteristics of drainage and airphoto lineations were reviewed and the procedure used in their analysis discussed. An area about 1880 square miles was analyzed for lineations based on drainage networks and the resulting patterns showed preferred orientation. These drainage lineations were later compared with the airphoto lineations of the same area and a limited degree of similarity was observed. The airphoto lineations of an area approximately 7000 sq. mi. covering the Minerogenic Province of southeast Missouri were analyzed using airphoto indexes compiled to a scale of 1 inch:1 mile. To check the consistency of the resulting lineation pattern an area in and adjacent to the Province was similarly studied, based on a high altitude airphoto index sheet. A regional pattern of airphoto lineations was recognized as well as several local interferences. The regional pattern is characterized by a prominent diagonal system and a less significant axial system. The diagonal system includes a northeasterly and a northwesterly set and the axial system a northerly and an easterly set. The diagonal sets are distinct over all the area but the axial system is recognized locally and frequently only one set (the northerly trending) is present. Significant causes of and variables affecting the local patterns are believed to be: local structural disturbances, primary and diagenetic structures in the Paleozoic sediments, buried knobs and ridges, and collapse structures and sink holes. The maximum density of lineation is found in the Precambrian St. Francois Mountains, and the value drops gradually in all directions outside of this area. Major fault trends coincide with major lineation trends in most cases. Repeating lineation pattern in areas of sub-continental to continental scale (Sondar\u27s regmatic shear pattern ) is advocated by many writers. Four major trends, similar to those of he regional pattern of southeast Missouri, are commonly recognized,.The writer reviewed current theories of their origin and concludes that the major fracture pattern of the earth is caused by extra-terrestial forces, such as oscillatory earth tides, and intra-terrestial (tectonic) forces. Internal forces explain the local intensification of the pattern (along all or some of its trends) in some geologic environments. The following conclusions are reached regarding lead deposits in the Minerogenic Province: 1) the lead mineralization was of an epigenetic-hypogene origin, 2) channelways for mineralization followed one or more directions of the four regional lineations of the Precambrian complex. These trends also affected the shape of the basins of sedimentation, and the trends of the linear primary and diagenetic features of the sediments, 3) the lead deposits are controlled by: a) the primary and diagenetic linear structural features which reflect the lineation pattern of the basement, b) buried Precambrian knobs (with their local fracture patterns), and c) the regional fracture pattern of the sediments which is essentially similar to that of the Precambrian basement, and 4) ore shoots and extensions of known ores are likely to be aligned parallel to one or more of the four regional lineation sets. This condition applied also for the Precambrian iron ores and the rich runs of the residual barite deposits in the Province --Abstract, pages i-ii