TY - JOUR
T1 - Provenance of mineral phases in the Cretaceous-Tertiary boundary sediments exposed on the southern peninsula of Haiti
AU - Kring, David A.
AU - Hildebrand, Alan R.
AU - Boynton, William V.
N1 - Funding Information:
We thank F.J.-M.R. Maurrasse for letting one of us (ARH) visit his laboratory to examine samples of K/T boundary sediments from Haiti and for providing information to aid in our field studies; G. lzett for letting another one of us (DAK) visit his laboratory to study his spindle stage techniques; G. Izett and B. Bohor for helpful information on preparing mineral separates; F. Kyte and A. Basu for their constructive reviews of the paper; and M. Kastner for her editorial assistance. This work was supported in part by NASA (NAGW 3373) and NSF (EAR-9206520). This is Geological Survey of Canada Contribution No. 19494. [MK]
PY - 1994/12
Y1 - 1994/12
N2 - Acid-insoluble mineral residua of tektite-bearing Cretaceous-Tertiary boundary sediments in the Beloc Formation of Haiti contain abundant shocked quartz and lesser amounts of shocked plagioclase. The shocked quartz grains typically have 2 or 3 sets of planar deformation features, although grains with up to 15 sets were observed. The proportion of shocked quartz in the boundary sediments increases with stratigraphic height; at least 70 ± 11% of the quartz grains are shocked in the uppermost stratigraphic interval. The proportion of shocked quartz throughout the boundary sediments indicates that these grains were excavated primarily from crystalline silicate units, which may have been covered with a small amount of porous quartz-bearing sediments. Polyhedral and moderately sutured margins in shocked polycrystalline quartz grains, the size of the crystal units in these grains and the presence of shocked plagioclase, indicate these ejecta components were excavated from a target with continental affinities, containing quartzites or metaquartzites and a sialic metamorphic and/or igneous component. Other evidence suggests the target may also have contained a significant amount of calcium carbonate and/or sulfate. The large size and amount of shocked quartz grains deposited in Haiti indicate the crater from which they were excavated was produced in the proto-Caribbean region.
AB - Acid-insoluble mineral residua of tektite-bearing Cretaceous-Tertiary boundary sediments in the Beloc Formation of Haiti contain abundant shocked quartz and lesser amounts of shocked plagioclase. The shocked quartz grains typically have 2 or 3 sets of planar deformation features, although grains with up to 15 sets were observed. The proportion of shocked quartz in the boundary sediments increases with stratigraphic height; at least 70 ± 11% of the quartz grains are shocked in the uppermost stratigraphic interval. The proportion of shocked quartz throughout the boundary sediments indicates that these grains were excavated primarily from crystalline silicate units, which may have been covered with a small amount of porous quartz-bearing sediments. Polyhedral and moderately sutured margins in shocked polycrystalline quartz grains, the size of the crystal units in these grains and the presence of shocked plagioclase, indicate these ejecta components were excavated from a target with continental affinities, containing quartzites or metaquartzites and a sialic metamorphic and/or igneous component. Other evidence suggests the target may also have contained a significant amount of calcium carbonate and/or sulfate. The large size and amount of shocked quartz grains deposited in Haiti indicate the crater from which they were excavated was produced in the proto-Caribbean region.
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U2 - 10.1016/0012-821X(94)90175-9
DO - 10.1016/0012-821X(94)90175-9
M3 - Article
AN - SCOPUS:0028564542
VL - 128
SP - 629
EP - 641
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
IS - 3-4
ER -