Jamaican Caving Notes
June 9, 2004
BONNET BUSH CAVE
Position: WGS84 - 18 22' 31.2" N, 77 51' 19.0" W, +/- 5 m
Field notes: R. S. STEWART
Cavers: R. S. Stewart, M. Taylor, D. K. Roggy
Time in: 12:00 EST, Time out: 12:30 EST
THREAT VULNERABILITY: Low
This cave was found as part of the St James assessment project. The plan is to find every cave and sinkhole in the parish, now about two-thirds done, then georeference and record current conditions. While searching the Welcome Hall district, two caves were found this day. Biologically, both supplied habitat for Eleutherodactylus cundalli, but because of limited dark zones cannot be considered conservation targets. Their main interest was geological, the two caves appearing to both be in a transitional zone between Cretaceous and Tertiary, but with different degrees of bedding and hardness of limestone. Neither of the caves is all twilight zone, the morphology is interesting, so we are listing both of them. The first cave visited was in a little district called Bonnet Bush, and this has been assigned as the name of the cave. Notes for it follow, with a link at the bottom of the page to the second cave. It should be noted that one of our listed targets, Welcome Hall Cave, has not yet been found, but the JU position plots at 200 m NE from the second cave, currently assigned the name Miss Henney. More on this follows in the notes for that cave.
Bonnet Bush Cave was shown to us by Steven Durie, a local man who had in the past assisted us in visits to Mafoota River Cave, and Belly-Full Cave. The entrance is wider than high, about 5 m wide and 3 high, faces 60 deg true in the side of a small hill, and is flanked on both sides by magnificent fluted columns. These columns, located several metres inside of the drip-line, attracted our attention as soon as we were scrambling into the entrance. They rise several metres, ranked along the wall in series, on either side. Calling the columns fluted does not do justice but is the best that we came up with at the time. Rather, think of a limestone column, about 1 metre across, with a second layer attached on the circumference, consisting of many irregularly formed cylinders, about 6-8 cm across, the whole thing resembling fluting but much more beautiful. Sections of broken stals, observed somewhat further into the cave, suggest a mechanism for the formation of this fluting: the fluted formations had small empty cylinders at the centre, such as soda-straws do. It looks as though the fluting didn't form outwards from the columns, but instead began some centimetres way and then grew into the column. Whatever the formation process was, it has resulted in the creation of very unusual speleothems.
A passage, trending about 240, extends from the entrance for about 20 m, becoming apx 10 wide and 8 m high in sections. Dark zone is found in the furthest part.
The cave appears to be an old, stranded, stream-passage cave, that once dry, continued to grow by breakdown. The rock is lightly-bedded and moderately hard. It is softer than the Montpelier limestone found further west, and less bedded. It is also softer and less bedded than the caves of Vaughansfield where we find rudists, or the Cretaceous limestone of Niagara, all on the other side. Perhaps, it managed to pick up a little more of the upper-level yellow limestone, tertiary rock while it was rising, sinking, and rising again above the waves.
Biologically, evidence of occasional occupation by fruit-bats was noted, (seeds sprouting and small amounts of guano), but no bats were seen. Much of the cave is twilight zone; no true cave beasties were observed. A decent GPS WAAS position was taken and we hiked back to the car to visit the next cave that Steven knew of.
|Jamaican Cave Notes - Main Page||June 2004 Caving Notes - Main Page|