GeologyRocks

• Location: Quarry near Coco Bay Hotel, Antigua, Caribbean
• Date Taken (dd-mm-yy): 17/01/2008

I think this is an altered limestone reef (Oligocene) that formed at the same time that the main volcano of Antigua was forming. As the volcano became less active, small reefs - only 10s of metres in size would form along the sides. As the volcano was active, the relative sea level would rise and fall rapidly, causing drowning or emergence of the reefs. However, later eruptions would occur, covering the reefs and altering them. This may be one such reef (the lighter grey area, whereas the red/brown rock is basalt).

• Location: Quarry near Coco Bay Hotel, Antigua, Caribbean
• Date Taken (dd-mm-yy): 17/01/2008

Small cubes of galena (lead sulphide) formed in a Oligocene limestone reef during alteration by volcanic activity. The matrix is heavily altered limestone.