Buck Island Reef National Monument Geologic Resources Inventory

Contents
List of Figures ................................................................................................................ iv
List of Tables ................................................................................................................. iv
Executive Summary ....................................................................................................... v
Acknowledgements ...................................................................................................... vi
Credits ........................................................................................................................................................................ vi
Introduction ................................................................................................................... 1
Purpose of the Geologic Resources Inventory ............................................................................................................... 1
Establishment of Buck Island Reef National Monument ................................................................................................. 1
Regional Information ................................................................................................................................................... 1
Geologic Setting .......................................................................................................................................................... 2
Geologic Issues .............................................................................................................. 7
Oceanographic and Meteorological Variables ............................................................................................................... 7
Sea Level Rise............................................................................................................................................................... 9
Sediment Characteristics and Distribution ..................................................................................................................... 9
Erosion ...................................................................................................................................................................... 10
Windblown Particulates ............................................................................................................................................. 10
Seismic Activity .......................................................................................................................................................... 11
Hurricanes ................................................................................................................................................................. 11
Geologic Features and Processes ................................................................................ 19
Caledonia Formation .................................................................................................................................................. 19
Benthic Habitats ......................................................................................................................................................... 19
Reefs ......................................................................................................................................................................... 19
Seagrass Beds ............................................................................................................................................................ 22
Paleontological Resources .......................................................................................................................................... 22
Geologic History .......................................................................................................... 27
Upper Cretaceous Period: Island-Arc Setting ............................................................................................................... 27
Miocene and Pliocene Epochs: Deep-Marine Rocks to Shoaling in the Basin ................................................................ 27
Pliocene and Pleistocene Epochs: Development of Reefs around St. Croix ................................................................... 28
Pleistocene and Holocene Epochs: Reef Formation around Buck Island ........................................................................ 28
Geologic Map Data ...................................................................................................... 33
Geologic Maps ........................................................................................................................................................... 33
Source Maps .............................................................................................................................................................. 33
Geologic GIS Data ...................................................................................................................................................... 33
Geologic Map Overview ............................................................................................................................................. 34
Map Unit Properties Table .......................................................................................................................................... 34
Use Constraints .......................................................................................................................................................... 34
Geologic Map Overview Graphics .............................................................................. 35
Map Unit Properties Table .......................................................................................... 37
Glossary ........................................................................................................................ 43
Literature Cited ............................................................................................................ 47
Additional References ................................................................................................. 53
Appendix: Scoping Session Participants .................................................................... 54
Attachment 1: Geologic Resources Inventory Products CD
BUIS Geologic Resources Inventory Report iii