Twenty-first Annual Meeting
Organic Matter Down Under

Sydney, Australia
26 September - 1 October, 2004

Departure from Sydney: Approximately 14.00h on Thursday, 30th September

The field trip is designed to introduce the participants to some of the unique geological features of the Newcastle Coalfield that can be seen in outcrop. These include the changing pattern from predominantly bright coal lithotypes and fine-grained interseam sediments near the base of the Permian coal measures to the dull coal lithotypes and interbedded conglomerates in the upper portion. Evidence will be shown of some of the volcanic eruptions that caused the violent cessation of coal formation in the middle portion of the coal measures, and, finally, a comparison will be made between a modern coastal swamp and one of its Permian equivalents.

Some traversing of moderate length over loose beach sand and uneven ground will be required.

Cost, including overnight accommodation (twin share), dinner, breakfast, cut lunch and field trip notes is $275.

Hat, sunscreen and suitable walking shoes.

Thursday, 30th September

The excursion will leave Sydney around 14.00h and travel north along the Sydney - Newcastle Expressway for approximately 270 km.

Expected Arrival: 17.00h; expected departure: 17.30h.

After reaching Newcastle, a stop is made at the only non-coastal outcrop of the excursion which shows the contact between the Waratah Sandstone and the overlying Borehole Seam, the lowermost coal in the Newcastle Coal Measures. Both are the product of the southward progradation of a barrier beach and its back-swamp into the Sydney Basin. A smaller-scale modern example of the palaeo-environmental setting of this contact will be shown on the following day.

Expected Arrival: 18.00h

The hotel selected for the overnight stop is located at Newcastle Beach, one of the main surfing beaches in the Newcastle area. Nearby rock outcrops and headlands belong to the lower Newcastle Coal Measures. Given enough daylight, a walk to Nobby's Head at the harbour entrance will show a splendid outcrop of 25 m of a silicified tuff underneath the Victoria Tunnel Seam at the base of the lighthouse.

After breakfast, the excursion will leave the hotel at 09.00h and proceed south along the coastline back to Sydney with several stops en route.

Expected Arrival: 09.15h; expected departure: 09.35h

This stop will give an overview of the geological setting of the Newcastle and Hunter Valley Coalfields close to the orogenic margin of the Sydney Basin.

Expected Arrival: 09.45h; expected departure: 10.25h

This stop provides an opportunity to look at some of the vitrinite-rich coals and their associated fine-grained sediments in the stratigraphically lower portion of the Newcastle Coal Measures. The Dudley and Yard seams can be studied at close range, as well as point-bar and other fluviatile sedimentary structures.

Expected Arrival: 11.10h; expected departure: 11.25h

An example of the massive conglomerates from the upper portion of the Newcastle Coal Measures can be inspected at this locality. Over-steepened fore-set beds provide evidence of peat compaction due to the lateral accretion of gravel sheets over the Lower Fern Valley Seam.

Expected arrival: 11.40h; expected departure: 12.30h

Jewell's Swamp is a modern, small-scale example of the kind of coastal mire that produced the Waratah Sandstone/Borehole Seam couplet visited the day before. The first stop (6) is located near reed-fringed open water and some exposed peat just behind the present barrier beach. The second stop (7) is near the heavily vegetated landward end of the lagoon.

Expected arrival: 13.00h; expected departure: 13.45h

Lunch. There are shops for those wishing to supplement their packed lunch.

Expected Arrival: 14.00h; expected departure: 14.40h

The middle portion of the Newcastle Coal measures contains the largest proportion of pyroclastic intercalations in the form of interseam tuffs and intraseam tonsteins. The Reids Mistake Formation, situated below the pilot station, is an 8m-thick deposit of volcanic ash that terminated peat formation in the Lower Pilot Seam. The tuff/coal contact is littered with both downed trees and upright stumps.

Expected Arrival: 15.10h; expected departure: 16.00h

This last stop of the field trip is close to the stratigraphic top of the Newcastle Coal Measures. The dull but clean coal of the Great Northern Seam is exposed close to sea level between the coarse Teralba Conglomerate above and the Bolton Point Conglomerate below. Pebble imbrication, cross-bedding, erosion surfaces and dolerite dykes are exposed on the wave-cut platform.

http://www.minerals.ns w.gov.au/geosurvey/coal/newcastle.htm

http://www.noahsonthebeach.com.au/

Coal seams and interseam strata outcropping at Susan Gilmour Beach

Outcrop of Great Northern seam, Catherine Hill Bay

Outcrop of the Yard seam on the Newcastle coast

Upright Permian tree stump preserved in tuff, Swansea Head