Version 10/03/2007 MOUNTAIN OCCUPATION PROJECT MIRES OF THE AUSTRALIAN CAPITAL TERRITORY Figure 1. Nursery Swamp: The Carex gaudichaudiana fen is often frozen in winter. Core collection by Ben Keaney and Matiu Prebble May 2002. Stratigraphy Two main cores from the same site have been analysed, but dating samples also came from an 1982 core. Core 02/1 (prob same location as 82/2) Depth cm Material 0-4 Loose rootlet mat of Carex fen 4-36 Firm black fibrous mat with Carex roots and some clay-silt 36-94 Yellow brown fibrous sedge peat 94-185 Black clayer fibrous peat, possible Phragmites stems @ 95-110. 185-230 Black peaty clay 230-274 Dark grey compact fibrous peat with slight clay 274-280 Black sandy peaty clay 280-314 Grey clayey fine sand 314-317 Grey clayey fine sand 317-319 Grey clayey coarse sand with sedge stems 319-345 Dark grey clayey fine sand with sedge remains 345-365 Pale grey sandy clay with sedge roots 365-395 Green-grey medium sandy clay with very occ vertical sedge stems 10 March 2007 Coring and probing. 1.05km from head of swamp. Core 2007/1: GPS: 148° 57.966’E 35° 40.5997’S Composite Core 2007/1 (28m from western edge- hole not completed below 250cm) I have integrated the sed description for the two spots we sampled in 2007. I used the description 0-150cm from core 1 and 150-450 from the second spot, which had deeper inorganic sediments. Core 2007/2 (15m from western edge) GPS: 148° 57.9593’E 35° 40.611’S Depth cm Material -Description Colour 0-20cm Sedge mat, fibrous peat Brown 20-52cm Black stiff clayey peat with fine rootlets Black 52-61 Organic sands, gritty feel Rusty brown grading to black 61-93 Fibrous sedge peat Dark brown 93-97 Gritty, maybe charcoal/silt, mealy peat with roots Black 97-110 Clayey peat, large amounts of clay Dark brown 110-150 Darker brown peat, more clay Dark brown 150-154 Fibrous peaty clay Brown 154-157 Pale yellow clay Yellow 157-161 Peaty clay Dark brown 161-163 Medium brown peaty clay Brown 163-189 Coarsening down from peaty clay 189-192 Sandy layer, fine sand, made of angular gravel from 1mm-3mm Black/grey 192-200 Slightly sandy clay with some root material Black 185-215 Clay Grey/Black 215-223 Coarse grey sand 223-250 Fibrous peat 250-275 Large sand grains, fibrous peat 275-277 Organic layer, more textured, mealy peat (sand sized organic particles, more like inwashed organics from a soil) 277-301 Clayey fibrous peat (at 289 and 293 there are yellow clay bands) Dark brown (with yellow bands) 301-305 Peaty clay Black 305-340 Dark grey silty clay (black band at 330) Dark grey 340-350 Sandy silty clay Grey 343-400 Fine sandy clay Very dark grey (Black) 400-420 Fine sandy clay, abundant mica Grey/Black 420-450 Very sandy Pale grey SAMPLES 150-350 duplicate D Section, 225-325, 325-425, 420-450(Base) Livingstone. Dark brown Dating Core Depth cm Date Lab No Cal Age BP Cal median Material 82/1 25-30 100.5M ± 2.1% ANU 3354A M 82/1 25-30 240 ± 110 ANU 3354B 260-450 355 Fines <0.25mm 82/1 145-150 5610 ± 240 ANU 3355 6161- 6702 6430 Fines <0.25mm from organic clays 82/2 55-60 107.4 ± 2.4%M ANU 3356A M Coarse sedge remains 82/2 55-60 99.1.4 ± 1.9%M ANU 3356B M Fines <0.25mm 02/1 170-176 2910 ± 80 ANU 11640 2946- 3183 3065 Coarse peaty debris in clay 82/2 295-300 8200 ± 250 ANU 3357A 8908- 9464 9185 Coarse peaty debris in clay 82/2 295-300 8140 ± 340 ANU 3357B 8646- 9443 9045 Fines <0.25mm from fibrous peat 02/1 345 12300 ± 120 OZI 144 14009-14500 14255 Organic ABA insol in grey sandy cl Coarse sedge remains I have used the calibrated ages based on the dates given in red above together with the advent of pine pollen at 15 cm= 50BP to create an age model for the diagrams. Note that only two dates come from the pollen analysed core and none from our 2007 core. To estimate the age of the 2007 core I presumed that the age at 345cm in core 02/1 applies to the deepest organic rich sandy clay in core 07/2 at ca 400cm. The transition from sandy clay to significantly more organic –rich material occurs around 300cm in all three cores, hence the date ANU 3357A is assumed to be valid for all. Note that that level was dated on fines and on sedge debris, yielding identical ages, which suggests that intrusion by younger sedge has been minimal. A pollen diagram (Figure 4). at 20cm interval has been prepared from the 02/1 core (by John Rogers in 2003 using standard HF and acetolysis methods, with pollen identification based on MacPhail. and Hope (2003). Macro-charcoal occurs at several levels and carbonised particles are abundant throughout the deposit, with a noteable peak at 25cm depth, again reflecting burning of the bog by leaseholders or recent bushfires. I have presented Johns and your results in several diagrams. Feel free to use some in your reports. One is the analyses made on the 2007 cores. Then there are three using pollen and extrapolated physical data. NURSALL1 has a complete set of data. NURS-VEG has a summary diagram and data from plants that either do not grow in the swamp itself or which (like some herbs and grass) often do not. NURSSWAMP repeats the data for Swamp margin herbs and ferns and the aquatics and mosses. The diagram has been zoned into five zones on the basis of a classification based on the wetland and local plants. Note that the basal zone has very low pollen counts and is not very reliable. I have put the pollen data up as EMF files which you can paste into the report. However TILIAGRAPH tgx files print much more clearly and you may wish to have some special features added. Feel free to come over and we can prepare and print these. You have the class data as well. Macphail, M. K. and Hope, G. S. 1985. Late Holocene mire development in montane southeastern Australia: a sensitive climatic indicator, Search 15, 344-349. Macphail, M.K. and Hope, G.S. 2003. Pollen flora for subalpine south eastern Australia. Department ANH, Canberra. Rogers, J. 2003. A pollen study at Nursery Swamp, ACT. Unpublished report. Rosenfeld and Winston-Gregson 1983. Excavations at Nursery Swamp 2, Gudgenby Nature Reserve, Australian Capital Territory. Australian Archaeology 17, 48-58