Rathlin was a popular venue for the Society in the 1970s and 1980s - we had some seven memorable trips back then, mostly led by Harold Wilson of GSNI but also by Jack Preston. So it's appropriate to return there in our 50th anniversary year.

Please let the Hon.Sec. Peter Millar know a few days in advance if you are coming, so that he can reserve places on the ferry. This isn't a booking as such - you won't have to pay if you don't turn up. But if it looks like being a fine day, they get a lot of casual trippers, so if we can tell them how many places we want in advance, they'll hold those for us.

The ferry time is 10.00am from Ballycastle Harbour, though you should aim for 9.30am to allow time to get your ticket, as there may be a queue. The fare is £8.60 return for adults. Holders of Translink Senior Citizens cards go free. If disaster strikes and you miss the boat, there's another one at 12.00am. The plan is to return at 5.30pm but if it's really wet we could retreat at 3.30pm.

We shall be working entirely on the Rue Peninsula (the bit that points south towards the mainland). There will be quite a bit of walking - about 10 km (two-thirds of this on roads). The terrain is undulating rather than mountainous. We may traverse a bit of rough ground along the shore. A portable lunch will be needed - you should be able to buy something in the island shop if you're stuck.

Obviously if the weather is really stormy we will have to find something to do on the mainland but the current ferry is a Caledonian MacBrayne drive-on, the Canna, and should be able to sail in much choppier seas than the tiny open boats some members may recall getting soakings in back in the 1970s! In contrast with the old days, the island now boasts a small shop, a teashop, an information centre and toilets - all near the harbour. And, of course, there is the all-important watering hole.

DIRECTIONS

To get to Ballycastle Harbour, you drive into the town from the Belfast direction and keep going until you reach the shore. You turn left past the Marine Hotel and then fork right, coming in a short distance to a very large parking area. The Rathlin office is the small building on your left opposite the big slipway.

Peter will start at Church Bay and follow the shore south, examining folding in the White Limestone. He will then lead us inland, walking south along the main road to Rue Point, on the way seeing the Interbasaltic Bed, columnar jointed Lower and Middle Basalt and 'trap topography' which is much better developed on Rathlin than on the mainland. For Quaternary buffs, Rue Point has superb raised beaches at two different levels. Rue Point is also a nice place for a picnic lunch on a good day.

Returning north we shall descend to the east coast to examine the dolerite/tuff Maddygalla Dyke, and then skirt Doon Bay to see the remarkable fan-shaped jointing at Doon Point. If time permits, we shall also descend to the coast further north, near Arkill Point, to see Haughton's 'Little Causeway'. There is spectacular jointing here - just as sharp as at the Giant's Causeway. Interestingly, the lavas with good columnar jointing hereabouts are actually olivine-tholeite Lower Basalts, not the quartz-tholeite Middle Basalts, which are the ones that show good jointing on the mainland. Also, there is something seriously wrong with the Interbasaltic Bed.

If we have time to kill on returning to the harbour, there is an intrusion almost within a stone's throw of the ferry and if anybody still hasn't had enough exercise, a very clean exposure of vesicle cylinders up the hill behind the bay. Or we could just go to the pub.....