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Integrated 3‐D model from gravity and petrophysical data at the Bosumtwi impact structure, Ghana
Author(s) -
UGALDE Hernan,
DANUOR Sylvester K.,
MILKEREIT Bernd
Publication year - 2007
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2007.tb01081.x
Subject(s) - geology , petrophysics , impact structure , breccia , borehole , scientific drilling , drilling , basement , petrology , geochemistry , seismology , impact crater , geotechnical engineering , porosity , mechanical engineering , physics , astronomy , engineering , civil engineering
— The Bosumtwi impact structure of central Ghana was drilled in 2004 as part of the International Continental Scientific Drilling Program (ICDP). A vast amount of geoscience data is available from the pre‐site surveys and the actual drilling phase. A 3‐D gravity model was constructed and calibrated with the available data from the two ICDP boreholes, LB‐07A and LB‐08A. The 3‐D gravity model results agree well with both the sediment thickness and size of the central uplift revealed by previously collected seismic data, and with the petrophysical data from the LB‐08A and LB‐07A core materials and the two borehole logs. Furthermore, the model exhibits lateral density variations across the structure and refines the results from previous 2.5‐D modeling. An important new element of the 3‐D model is that the thickness of the intervals comprising polymict lithic impact breccia and suevite, monomict lithic breccia and fractured basement is much smaller than that predicted by numerical modeling.