HR: 0800h
AN: MR11A-0920    [Abstracts]
TI: Radiogenic Heat Production in the Cretaceous Sediments of Yola Arm of Nigeria Benue Trough: Implications for Thermal History and Hydrocarbon Generation
AU: * Ehinola, O A
EM: oa.ehinola@mail.ui.edu.ng
AF: University of Ibadan, Department of Geology, Ibadan, Oyo 20005 Nigeria
AU: Joshua, E O
EM: eo.joshua@yahoo.com
AF: University of Ibadan, Department of Physics, Ibadan, Oyo 20005 Nigeria
AU: Opeloye, S A
EM: adelayo2002@yahoo.com
AF: Federal University of Technology, Yola, Department of Geology, Yola, Ada 20005 Nigeria
AU: Ademola, J A
EM: N/A
AF: University of Ibadan, Department of Physics, Ibadan, Oyo 20005 Nigeria
AB: Yola Arm is an east-west extension of the upper Benue Trough of Nigeria with Cretaceous sediments of Albian to Coniacian ages. Thirteen samples which are mainly sandstone, shale, mudstone, clay, siltstone, limestone and coal were collected from six different geological units namely: Bima Sandstone (BS), Yolde Formation (YF), Dukul Formation (DF), Sukuliye Formation (SF), Numanhan Formation (NF) and Lamja Sandstone (LS). This is to determine their radioactive heat production and implications for thermal history and hydrocarbon generation. The result shows that concentration and rate of heat production of $^{40}$K, $^{232}$Th, and $^{238}$U in the samples varies widely with lithologies and stratigraphic intervals. Three groups of total heat production (HP) were identified and designated as low (LHP), moderate (MHP), and high (HHP). The LHP includes sandstones of BS, limestone of DF and coal of LS with total heat production of $<$750 pW/Kg. Clay of BS, siltstone of YF, limestone of SF and NF, and sandstone of LS belong to MHP with total heat production of between 750 and 1500 pW/Kg. Shale of YF, SF and NF with total heat production of $>$1500 pW/Kg belong to HHP. The HHP group corresponds to shale units at different ages in the study area, and may have produced enough heat for hydrocarbon generation. The total heat production studies have suggested that the Cretaceous sediments experienced complex temperature history with at least two sudden thermal pulses. They could have been related to Cretaceous synsedimentary volcanism or to the emplacement of the basaltic pluton.
UR: http://www.agu.org
DE: 8130 Heat generation and transport
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting