Department
Geosciences and Geological and Petroleum Engineering
Major
Geological Engineering
Research Advisor
Hogan, John P.
Advisor's Department
Geosciences and Geological and Petroleum Engineering
Funding Source
Missouri S& T Opportunities for Undergraduate Research Experiences (OURE) Program
Abstract
Jointing present at an outcrop of sandstone in the Roubidoux formation was examined in order to determine the principal stress direction(s) causing the joint formation. The investigation was accomplished with traditional mapping techniques (detailed field sketches, photographs, structural measurements). Seventy-seven attitude measurements of joints and measurement of primary bedding were collected using a Brunton Compass. These measurements were analyzed using stereo nets and rose diagrams. Two major joint sets were present. The more major joint set strikes along the 175° or 355° azimuth and it has a dip averaging from 75° to 80° . The minor joint set strikes along the 115° or 295° azimuth and has a dip averaging from 75° to 80° as well. This spatial pattern of these joints indicates the presence of a conjugate joint set. This indicates an orientation of 325° for s1 and 055° for s3 at the time of joint formation. Major joints from both sets exhibit secondary hematite cement in the sandstone adjacent to the joint, whereas hematite cementation is sparse along the minor joint sets indicating these joints-controlled paleo fluid flow. Understanding how joints in rock form can better constrain numerical computer models to further understand the effect joints may have on groundwater or petroleum reservoir characteristics like secondary permeability and direction of fluid flow. Understanding the conditions in which joints form can also aid exploration geologists in determining the genesis of specific ore bodies. Current spatial orientation of joints and bedding also affect rock face stability and highway safety.
Biography
Evan Stevens is a senior in the geological engineering department at Missouri S& T. He plans to find a job as a geological engineer with an emphasis in geology while working for a mining company. In his spare time, Evan likes to play guitar and spend time with his family and friends.
Research Category
Natural Sciences
Presentation Type
Poster Presentation
Document Type
Poster
Location
Havener Center, Upper Atrium/Hallway
Presentation Date
9 Apr 2008, 1:00 pm - 3:00 pm
Investigation of jointing in the Roubidoux Formation, Rolla, Missouri
Havener Center, Upper Atrium/Hallway
Jointing present at an outcrop of sandstone in the Roubidoux formation was examined in order to determine the principal stress direction(s) causing the joint formation. The investigation was accomplished with traditional mapping techniques (detailed field sketches, photographs, structural measurements). Seventy-seven attitude measurements of joints and measurement of primary bedding were collected using a Brunton Compass. These measurements were analyzed using stereo nets and rose diagrams. Two major joint sets were present. The more major joint set strikes along the 175° or 355° azimuth and it has a dip averaging from 75° to 80° . The minor joint set strikes along the 115° or 295° azimuth and has a dip averaging from 75° to 80° as well. This spatial pattern of these joints indicates the presence of a conjugate joint set. This indicates an orientation of 325° for s1 and 055° for s3 at the time of joint formation. Major joints from both sets exhibit secondary hematite cement in the sandstone adjacent to the joint, whereas hematite cementation is sparse along the minor joint sets indicating these joints-controlled paleo fluid flow. Understanding how joints in rock form can better constrain numerical computer models to further understand the effect joints may have on groundwater or petroleum reservoir characteristics like secondary permeability and direction of fluid flow. Understanding the conditions in which joints form can also aid exploration geologists in determining the genesis of specific ore bodies. Current spatial orientation of joints and bedding also affect rock face stability and highway safety.
