Interpretation of Vibroseis reflections from within the Catoctin Formation of central Virginia

Large amplitude seismic reflections from within the Catoctin Formation of central Virginia are interpreted to originate from acoustically thin beds of interlayered metabasalts and metasediments. Large acoustic impedance contrasts exist between epidotised layers ( epidosites and volcanic breccia) and non-epidotised layers (greenstones and phyllites) within the Catoctin Formation. Acoustic impedance contrasts also exist between greenstones (metabasalts) and phyllites (metasediments). Constructive interference of small amplitude reflections from thin beds result in large amplitude, reverberating reflections. Thin bed reflections that approximate the first derivative of the source wavelet constructively interfere to give even larger amplitude reflections than those originating by conventional tuning. Computer modeling based on two geologic sections of thin beds of epidosites interlayered with greenstones and of greenstones interlayered with phyllites and epidosites indicates that large amplitude reflections result from constructive interference of thin bed reflections.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Geophysics

Department dc:contributor.department

Geophysics

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1985

Author dc:creator

• Brennan, Jeanne L.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/76030

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/76030