Table 2.
Isotope ratios and U–Pb ages of zircons from suevite (KR8-004) and meta-graywacke (KR8-032 and KR8-109) samples from the LB-08A drill core in the Bosumtwi crater (Ghana).
| Sample and spot no. | Isotope ratios and errors |
Apparent ages (Ma) and errors |
Discordance (%) | ||||
|---|---|---|---|---|---|---|---|
| 207Pb/206Pb 1σ | 207Pb/235U 1σ | 206Pb/238U 1σ | 207Pb/206Pb 1σ | 207Pb/235U 1σ | 206Pb/238U 1σ | ||
| Sample KR8-004 | |||||||
| SB-04 | 0.11142 ± 0.00114 | 5.82762 ± 0.04045 | 0.37873 ± 0.00219 | 1823 ± 18 | 1951 ± 6 | 2070 ± 10 | − 14 |
| Sample KR8-032 | |||||||
| LB-01 | 0.13746 ± 0.00282 | 7.64273 ± 0.08625 | 0.40337 ± 0.00404 | 2196 ± 35 | 2190 ± 10 | 2185 ± 19 | 1 |
| LB-02 | 0.13676 ± 0.00281 | 6.96431 ± 0.07872 | 0.36943 ± 0.00372 | 2187 ± 35 | 2107 ± 10 | 2027 ± 18 | 7 |
| LB-03 | 0.13955 ± 0.00285 | 8.00911 ± 0.08880 | 0.41636 ± 0.00419 | 2222 ± 35 | 2232 ± 10 | 2244 ± 19 | − 1 |
| LB-04-a | 0.13019 ± 0.00259 | 8.00371 ± 0.08064 | 0.44599 ± 0.00434 | 2101 ± 35 | 2231 ± 9 | 2377 ± 19 | − 13 |
| LB-04-b | 0.13394 ± 0.00266 | 6.62879 ± 0.06542 | 0.35900 ± 0.00347 | 2150 ± 34 | 2063 ± 9 | 1977 ± 16 | 8 |
| Sample KR8-109 | |||||||
| LC-06 | 0.15313 ± 0.00303 | 8.36005 ± 0.08279 | 0.39597 ± 0.00388 | 2381 ± 33 | 2271 ± 9 | 2151 ± 18 | 10 |
| LC-08-a | 0.13636 ± 0.00276 | 7.51715 ± 0.08200 | 0.39981 ± 0.00404 | 2182 ± 35 | 2175 ± 10 | 2168 ± 19 | 1 |
| LC-08-b | 0.14090 ± 0.00294 | 8.22268 ± 0.09961 | 0.42323 ± 0.00448 | 2238 ± 36 | 2256 ± 11 | 2275 ± 20 | − 2 |
| LC-09 | 0.12833 ± 0.00254 | 6.54637 ± 0.06552 | 0.36991 ± 0.00365 | 2075 ± 34 | 2052 ± 9 | 2029 ± 17 | 2 |
| LC-12 | 0.12926 ± 0.00264 | 7.11928 ± 0.08094 | 0.39930 ± 0.00415 | 2088 ± 36 | 2127 ± 10 | 2166 ± 19 | − 4 |
| LC-15 | 0.12812 ± 0.00262 | 6.49731 ± 0.07367 | 0.36764 ± 0.00381 | 2072 ± 36 | 2046 ± 10 | 2018 ± 18 | 3 |
| LC-20 | 0.13122 ± 0.00265 | 7.09600 ± 0.07776 | 0.39194 ± 0.00406 | 2114 ± 35 | 2124 ± 10 | 2132 ± 19 | − 1 |
| SA-15 | 0.14392 ± 0.00174 | 7.47611 ± 0.06254 | 0.37700 ± 0.00232 | 2275 ± 21 | 2170 ± 7 | 2062 ± 11 | 9 |
| SA-18 | 0.13003 ± 0.00143 | 7.39368 ± 0.04926 | 0.41262 ± 0.00228 | 2098 ± 19 | 2160 ± 6 | 2227 ± 10 | − 6 |
| SA-19 | 0.13039 ± 0.00148 | 7.31758 ± 0.05417 | 0.40710 ± 0.00236 | 2103 ± 20 | 2151 ± 7 | 2202 ± 11 | − 5 |
| SA-24-a | 0.13316 ± 0.00155 | 6.41118 ± 0.05079 | 0.34910 ± 0.00209 | 2140 ± 20 | 2034 ± 7 | 1930 ± 10 | 10 |
| SA-24-b | 0.13183 ± 0.00152 | 6.56971 ± 0.05149 | 0.36129 ± 0.00214 | 2123 ± 20 | 2055 ± 7 | 1988 ± 10 | 6 |
| SA-31-a | 0.13732 ± 0.00171 | 7.05102 ± 0.06611 | 0.37218 ± 0.00246 | 2194 ± 22 | 2118 ± 8 | 2040 ± 12 | 7 |
| SA-31-b | 0.13430 ± 0.00157 | 6.69865 ± 0.05548 | 0.36152 ± 0.00223 | 2155 ± 20 | 2072 ± 7 | 1989 ± 11 | 8 |
| SA-31-c | 0.13095 ± 0.00150 | 6.93734 ± 0.05521 | 0.38395 ± 0.00233 | 2111 ± 20 | 2103 ± 7 | 2095 ± 11 | 1 |
| SA-34 | 0.12622 ± 0.00139 | 6.23961 ± 0.04622 | 0.35822 ± 0.00209 | 2046 ± 19 | 2010 ± 6 | 1974 ± 10 | 4 |
| SA-52-a | 0.12874 ± 0.00137 | 6.28391 ± 0.04359 | 0.35362 ± 0.00202 | 2081 ± 19 | 2016 ± 6 | 1952 ± 10 | 6 |
| SA-52-b | 0.13043 ± 0.00155 | 6.39534 ± 0.05675 | 0.35522 ± 0.00228 | 2104 ± 21 | 2032 ± 8 | 1960 ± 11 | 7 |
| SA-52-c | 0.12231 ± 0.00130 | 6.18633 ± 0.04341 | 0.36640 ± 0.00211 | 1990 ± 19 | 2003 ± 6 | 2012 ± 10 | − 1 |
| SA-59-a | 0.12749 ± 0.00141 | 6.66062 ± 0.05225 | 0.37843 ± 0.00230 | 2064 ± 19 | 2067 ± 7 | 2069 ± 11 | 0 |
| SA-59-b | 0.12310 ± 0.00135 | 6.65573 ± 0.05131 | 0.39163 ± 0.00236 | 2002 ± 19 | 2067 ± 7 | 2130 ± 11 | − 6 |
| SA-59-c | 0.12634 ± 0.00141 | 7.11392 ± 0.05691 | 0.40782 ± 0.00252 | 2048 ± 20 | 2126 ± 7 | 2205 ± 12 | − 8 |
| SA-67-a | 0.13168 ± 0.00146 | 6.25155 ± 0.04995 | 0.34381 ± 0.00212 | 2121 ± 19 | 2012 ± 7 | 1905 ± 10 | 10 |
| SA-67-b | 0.12189 ± 0.00130 | 6.81589 ± 0.05075 | 0.40496 ± 0.00242 | 1984 ± 19 | 2088 ± 7 | 2192 ± 11 | − 10 |
| SA-69 | 0.13536 ± 0.00135 | 6.17312 ± 0.03968 | 0.33026 ± 0.00187 | 2169 ± 17 | 2001 ± 6 | 1840 ± 9 | 15 |