Field Guide to Joint Patterns and Geomorphological Features of Northern Ohio

Author Institution: Department of Geology, University of Toledo, Department of Geological Sciences, Wright State University, Department of Geology, Bowling Green State University and France Stone CompanyBedrock in northern and northwestern Ohio consists of Middle Paleozoic carbonates and shales and is pervasively jointed. The regional joint pattern and chronology, established by the characteristics of joint traces, mineralization, and surfaces, reveal a complex history of fracture development. Joint studies along the north-south trending Bowling Green fault zone indicate that northwest-trending joints formed first in response to extensional stresses associated with differential dip-slip movement in this fault zone, or by left lateral movement along this zone

Applications of Fractography to Core and Outcrop Investigations

Purpose of this paper is to introduce geologists to the principles of fractography, especially those principles that govern the formation of fracture surface structures commonly observed in rocks. A knowledge of the inception mechanics governing the formation of a fracture\u27s tendential and transient structures should provide geologists with a method to distinguish natural from coring-induced and handling-induced fractures in oriented core samples, and show how coring-induced fractures may be assisted in their formation by stresses that can be attributed to the drilling process

Applications of Fractography to Core and Outcrop Investigations

Purpose of this paper is to introduce geologists to the principles of fractography, especially those principles that govern the formation of fracture surface structures commonly observed in rocks. A knowledge of the inception mechanics governing the formation of a fracture\u27s tendential and transient structures should provide geologists with a method to distinguish natural from coring-induced and handling-induced fractures in oriented core samples, and show how coring-induced fractures may be assisted in their formation by stresses that can be attributed to the drilling process