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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 63 (1979)

Issue: 3. (March)

First Page: 484

Last Page: 484

Title: Detailed Temperature Logging as Useful Tool for Lithologic Interpretation: ABSTRACT

Author(s): Joseph J. Lambiase, Michael Svetlichny, Samuel S. Dashevsky, Barbara U. Conrad, John K. Costain

Article Type: Meeting abstract

Abstract:

Data from an extensive drilling program conducted on the Atlantic coastal plain by the Department of Energy suggest that detailed temperature logs may be useful for interpretation of subsurface lithology and stratigraphy. Temperature was measured to ±0.01°C and was sampled every 0.5 m. Thermal gradients were computed, and compared to lithologic sequences as derived from drill cuttings collected every 3.0 m.

Examination of a vertical thermal-gradient curve reveals that breaks in the curve correspond to major grain-size changes. Many of these breaks correspond to stratigraphic boundaries that are associated with a grain-size change. However, stratigraphic boundaries that are not defined by a grain-size change are more difficult to recognize.

Preliminary results from the first hole at Fort Monmouth, New Jersey, suggest that the correspondence between thermal gradient and grain size is due to a direct correlation between local thermal gradient and the amount of sediment at that depth that is finer than 4.0 psi. This relation allows detailed interpretation of lithologic sequences. Trends within a stratigraphic unit, such as fining-upward sequences, can be readily identified. Also, thin lithologic units (1 to 2 m thick) that were recovered within sediment cores are recognizable on a thermal-gradient curve. These results suggest that detailed temperature logs can provide valuable, detailed information about subsurface stratigraphy and lithology.

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Copyright 1997 American Association of Petroleum Geologists