[BCDP] BCDP - Lake Bosumtwi Drilling Project

ICDP-Topics:
Climate & Ecosystems
Paleoclimate
Impact Structures
Natural Hazards


Year of Application: 2004

Expedition ID: 5023

Current Status: completed

africa
BOSUMTWI
climate change
ghana
global environment
ICDP-2002/08
impact crater
lake drilling
paleoclimatology
Master Data

Prof. Dr. Alexander Deutsch (PI)

Dr. Sabine Hunze (Scientific Participant)
Prof. Dr. Agnes Kontny (Scientific Participant)
Prof. Dr. Bernd Milkereit (Scientific Participant)
Dr. Thomas Wonik (Scientific Participant)
Dr. Louise Coney (Scientific Participant)
Prof. Dr. Uwe Reimold (Scientific Participant)

Projektstart: 8 July, 2004
Projektdauer:
Geologisches Alter: Quartaer

Latitude: 6°31'20''N
Kontinente:

Africa

Regionen & Städte:

Longitude: 1°25'15''W
Länder:

Ghana

Themen:

Drilling Data

Drilling Depth: 428.1
Core Yield: 338.95
Core Length: 430.8
Amount of Drill Holes: 8
Amount of Drill Locations: 8

Core Length-Drill Depth-Ratio: 97.17
Core Yield-Core Length-Ratio: 78.69

Description

This is a multidisciplinary proposal to drill the Bosumtwi impact structure in Ghana, West Africa. The Bosumtwi impact crater in Ghana (centered at 0632'N and 0125'W) is almost completely filled by Lake Bosumtwi. The crater has a rimto- rim diameter of about 10.5 km, while the lake has a diameter of about 8 km and maximum depth of about 80 m. The crater has an age of 1.07 Ma and was excavated in lower greenschist facies metasediments of the 2.1-2.2 Ga Birimian Supergroup. The Ivory Coast tektites and microtektites originated from this crater. Only recently, detailed geophysical studies were done. A first high-resolution aerogeophysical survey was conducted in early 1997. Measurements included: total magnetic field; aeroelectromagnetic; gamma radiation data for U-, Th- and K-contents, and total radiation. These data provide a much more detailed image of the crater structure than any previous data. Several projects have dealt with land- and lake-based geophysical measurements and surface geological and geochemical investigations regarding the subsurface topography of the structure. A shallow drilling project studied the near-surface composition of ejecta and weathered surface rocks for correlation with the aerogeophysical data (Austria/Ghana). Groups from Germany, the US, and Ghana have performed gravity measurements around the crater and over the lake, as well as refraction seismics with the goal to obtain a 3D tomographic model of the crater interior. Highresolution seismic studies were done that led to the discovery of a sediment-covered central uplift. Some shallow cores of lake sediments were also recovered. The results from these studies provided all the background work necessary to characterize the subsurface structure of the Bosumtwi crater that are necessary to define the targets for the deep drilling program proposed here.

Related Publications

Deutsch, A., Pölchau, Michael H., Kenkmann, Thomas (2015). "Impact metamorphism in terrestrial and experimental cratering events." EMU Notes in Mineralogy - volume 15 Planetary Mineralogy p89-127


Coney, Louise, Reimold, Wolf Uwe, Gibson, Roger L, Koeberl, Christian, Ogilvie, Paula (2010). "Melt particle characteristics of the within-and out-of-crater suevites from the Bosumtwi impact structure, Ghana: Implications for crater formation" Geological Society of America Special Papers 465 p411-442


Coney, Louise (2009). "Mineralogy and geochemistry of the impact breccias of the Bosumtwi impact structure, Ghana: genesis and secondary proccesses" Dissertation


Koeberl, Christian, Milkereit, Christian, Overpeck, Jonathan T., Scholz, Christopher A., Amoako, Philip Y.O., Boamah, Daniel, Danuor, Sylvester, Karp, Tobias, Kück, Jochem, Hecky, Robert E., King, John W., Peck John A. (2007). "An international and multidisciplinary drilling project into a young complex impact structure: The 2004 ICDP Bosumtwi Crater Drilling Project—An overview" Meteoritics and Planetary Science 42 p483-511


Ferrière, Ludovic, Koeberl, Christian, Reimold, Wolf Uwe, Mader, Dieter (2007). "Drill core LB-08A, Bosumtwi impact structure, Ghana: Geochemistry of fallback breccia and basement samples from the central uplift" Meteoritics & Planetary Science 42 (4/5) p689-708


Ferrière, Ludovic, Koeberl, Christian, Reimold, Wolf Uwe (2007). "Drill core LB-08A, Bosumtwi impact structure, Ghana: Petrographic and shock metamorphic studies of material from the central uplift" Meteoritics & Planetary Science 42 (4/5) p611-633


Coney, Louise, Reimold, Wolf Uwe, Gibson, Roger L., Koeberl, Christian (2007). "Geochemistry of impactites and basement lithologies from ICDP borehole LB-07A, Bosumtwi impact structure, Ghana" Meteoritics & Planetary Science 42 (4/5) p667-688


Hunze, Sabine, Wonik, Thomas (2007). "Lithological and structural characteristics of the Lake Bosumtwi impact crater, Ghana: Interpretation of acoustic televiewer images" Meteoritics & Planetary Science 42 (Nr. 4/5) p779-792


Coney, Louise, Gibson, Roger L., Reimold, Wolf Uwe, Koeberl, Christian (2007). "Lithostratigraphic and petrographic analysis of ICDP drill core LB-07A, Bosumtwi impact structure, Ghana" Meteoritics & Planetary Science 42 (4/5) p569-589


Kontny, Agnes, Elbra, Tiiu, Just, Jana, Pesonen, Lauri J., Schleicher, Anja M., Zolk, Jochen (2007). "Petrography and shock-related remagnetization of pyrrhotite in drill cores from the Bosumtwi Impact Crater Drilling Project, Ghana" Meteoritics & Planetary Science 42 (4/5) p811-827


Karikari, Forson, Ferrière, Ludovic, Koeberl, Christian, Reimold, Wolf Uwe, Mader, Dieter (2007). "Petrography, geochemistry, and alteration of country rocks from the Bosumtwi impact structure, Ghana" Meteoritics & Planetary Science 42 (4/5) p513-540


Elbra, T., Kontny, A., Pesonen, L. J., Schleifer, N., Schell, C. (2007). "Petrophysical and paleomagnetic data of drill cores from the Bosumtwi impact structure, Ghana" Meteoritics & Planetary Science 42 (4/5) p829-838


Goderis, S., Tagle, R., Schmitt, R. T., Erzinger, J., Claeys, Ph (2007). "Platinum group elements provide no indication of a meteoritic component in ICDP cores from the Bosumtwi crater, Ghana" Meteoritics & Planetary Science 42 (4/5) p731-741


McDonald, Iain, Peucker-Ehrenbrink, Bernhard, Coney, Louise, Ferrière, Ludovic, Reimold, Wolf Uwe, Koeberl, Christian (2007). "Search for a meteoritic component in drill cores from the Bosumtwi impact structure, Ghana: Platinum group element contents and osmium isotopic characteristics" Meteoritics & Planetary Science 42 (4/5) p743-753


Deutsch, Alexander, Luetke, Sabine, Heinrich, Volker (2007). "The ICDP Lake Bosumtwi impact crater scientific drilling project (Ghana): Core LB-08A litho-log, related ejecta, and shock recovery experiments" Meteoritics & Planetary Science 42 (4/5) p635-654


Koeberl, Christian, Brandstätter, Franz, Glass, Billy P., Hecht, Lutz, Mader, Dieter, Reimold, Wolf Uwe (2007). "Uppermost impact fallback layer in the Bosumtwi crater (Ghana): Mineralogy, geochemistry, and comparison with Ivory Coast tektites" Meteoritics & Planetary Science 42 (4/5) p709-729


Koeberl, Christian, Reimold, WU, Moon, PA (2005). "Bosumtwi impact crater, Ghana (West Africa): An updated and revised geological map, with explanations" Jahrbuch der geologischen Bundesanstalt (Buch) Band 145, Heft 1 p31-70