Article in Science / Natural Resources
This paper reports the continuation of a long-term project examining fossil evidence from the Permian to Triassic at selected sites in northern Tasmania, Australia. While the finds reported in this paper confirm those made during the author’s earlier expeditions, there remain questions regarding...
 
 
 

Some Interesting Fossil Finds from the Non-Marine Permian and Triassic Sequences in Northern Tasmania, Australia

Part 3: The Permian and the Triassic at 4 sites

Philip J. Tattersall,

8 Lenborough St,

Beauty Point,

Tasmania

AUSTRALIA 7270

Email: soiltechresearch@bigpond.com

ABSTRACT

This paper reports the continuation of a long-term project examining fossil evidence from the Permian to Triassic at selected sites in northern Tasmania, Australia. While the finds reported in this paper confirm those made during the author’s earlier expeditions, there remain questions regarding possible conditions that guaranteed the survival of species beyond the end of Permian extinction. An arthropod fossil find from late Permian-early Triassic sediment in the Poatina area, made during a past expedition suggests that further fossil evidence may exist confirming an emerging hypothesis, namely that ecological enclaves may have remained intact ensuring the continued survival of species such as Anaspides tasmaniae to the present day.

Introduction

This paper is a continuation of a long-term project looking at fossil finds in the non-marine sequences in Permian and Triassic sedimentary rocks at selected sites in northern Tasmania.

Tasmania is situated some 240km south of the Australian mainland at around 42 degrees latitude. Tasmania has a rich and diverse geology containing many fossil-bearing areas of marine and non-marine origin.

The author’s interest in the non-marine sedimentary sequences began in the early

1970’s when he made a number of interesting plant finds in what he believed at the time were Permian sediments. Geographically his area of interest spanned sites along the Great Western Tiers (Figure 1), taking in sites from Drys Bluff at Liffey (Figure 2) to sites at Poatina (Figure 3) as well as those near Projection Bluff (Figure 4). The author has spent several years exploring fossil sites in areas bordering the central highland plateau in central northern Tasmania.

Banks (n.d., p.25) describes the geology of the Plateau as “…consisting of two main, nearly horizontal, layers of rock resting on a basement of older steeply tilted rocks. The surface layer, a few hundred meters thick, is dolerite about 165 million years old. This was injected into marine and non-marine sedimentary rocks deposited during a span of about 90 million years beginning about 290 million years ago.”

Over the past 2 years the author has been working at 4 main sites, the first at Liffey (near Drys Bluff, see Fig. 1), in non-marine (Pike 1973, p.27) sandstone formations. Exploration of this site has been ongoing over a number of years. Stratigraphically the upper Permian and Triassic groups are part of what is known as the Upper Parmeener Supergroup (Forsyth 1987), which is characterized as upper Permian (Jackey Formation 43 meters thick – see Table 1) through to several formations of Triassic Sandstone (588 meters thick). The Upper Permian-Triassic deposits at Site 1 are located at the base of the scree slopes on Drys Bluff (see Fig 2.). The Late Permian rock (also known as Jackey formation) is described as cross-bedded quartz sandstone feldspathic sandstone and shale. Here this will be referred to here as late Permian-early Triassic ‘Jackey Formation’ (see Table 1). The red arrows on Fig. 2 show the location of the late Permian-early Triassic deposits in the upper Liffey on the north-western slope of Drys Bluff).

The second site is located at Poatina in northern Tasmania (see red arrow on Figure 3). The early Permian sedimentary sandstone was deposited under non-marine conditions and contains abundant plant fossils (Pike, 1973). The sandstone at the site

belongs to the Liffey Formation deposited in the early Permian (Sakmarian-Artinskian) and is described as a lower member of the Parmeerner Supergroup. Its age is estimated to be around 270 to 290 Ma (Fielding et al, 2010).

The third site is also located at Poatina, (see the blue arrows in Figure 3). Finds from this site were reported in an earlier paper (Tattersall, 2014). Sub site 2 consists of sandstones and silt/mudstones deposited in non-marine conditions during the mid to late Triassic (Table 1). There is clear evidence of plant fossils as well as arthropod finds (e.g. Triops) (Tattersall, 2014). Sub site 1 is an area of younger Triassic sandstone, known locally a Brady formation (See Table 1).

The forth site is located along the Highland Lakes Highway in northern Tasmania. Figure 4 shows the general area as well as sites of interest (marked as black arrows). The areas marked (sub sites 2&3) at the lower elevations appear to correlate with the Jackey formation (Pike, 1973) at the Drys Bluff Liffey site. The areas higher-up appear to be Triassic (sub site 1).

The fossil finds reported in this paper confirm finds reported in earlier papers. As will be discussed, the palaeontological contexts of fossil finds reveal important clues relating to climatic and ecological conditions, as well as habitat structures. While the majority of fossil finds made during the course of this research have been floral there are indications that arthropod species were present at certain times during the late Permian to late Triassic (Tattersall, 2014; Tattersall, 2015).

Arthropod finds are of particular significance as they may provide clues regarding the survival of species in to the Triassic through to the present day. The presence of the crustacean Anaspides tasmaniae in present day rock pools and tarns at higher elevations in the Tasmanian highlands is one example of such a species. An earlier paper reports a discovery believed to be a possible relative of A. tasmaniae (Tattersall, 2015). The find was located in late Permian-early Triassic indicating that environmental conditions must have been favorable, despite the traumatic events associated with the late ‘Permian die-off’ during which many species perished. The nature of the environmental conditions that led to the survival of the species is therefore of much interest. Indeed, the same can be said regarding the survival of the branchiopod Triops (a member of the order Notostraca) and the other conchostracan finds reported by other researchers (Tasch, 1975).

As important as individual finds are, the present project also places considerable emphasis on the palaeoecological contexts in which finds have been made. This approach may well provide insights into the conditions that guaranteed species survival. Therefore the identification of co-surviving floral species is also of interest.

Specimen collection and handling

Removal of specimen from in situ

Rock samples were carefully removed from the field with minimal disturbance of each site. Location details were recorded on a map and a field log was completed at the time of sampling along with photographs.

Transport, clean-up and storage

Many of the specimens were quite fragile as many originated from siltstone materials. This required special handing and transport methods. Specimens were wrapped in high strength tissue and then wrapped in bubble wrap to prevent breakage or damage. Specimen fragility also presented challenges for handling and cleanup back at the laboratory. Specimens were carefully brushed and cleaned and dried prior to storage in tissue line plastic boxes.

Each specimen was given a unique identification number from a register held at the laboratory.

Digital image capture (macro)

Unless specified images presented herein were taken using a Sony® Cyper-Shot, 14.1 Mega Pixels DSC-W530 digital camera. Raw images were then processed using Microsoft® Office Picture Manager Software.

Digital image capture (micro)

Images were taken with a Digitech USB Microscope. Low power UV was used to improve resolution. Images were then sharpened using Microsoft® Office Picture Manager Software.

Site Locations and finds

Site 1: Upper Permian –Early Triassic Formation at Drys Bluff, Liffey

The track area shown by the red arrows in Figure 2. The former logging track provides useful access to sites as well as useful cuttings where sedimentary material (upper Permian-early Triassic) is exposed.

Specimen 426 found at the side of the logging track in the area marked by red arrows in Figure 2. The impressions appear to be root channels or worm burrowing’s.

Specimen 429 found at the side of the logging track in the area marked by red arrows in Figure 2.The fossil is believed to be that of Paracalamites. The sedimentary material is sandstone.

Specimen 436 contains a plant fossil, possibly a fern species. The specimen was found in the same general area as the previous 2.

Site 2: Lower Permian Poatina

The site is located near the township of Poatina in northern Tasmania. The site has been described in earlier reports (Fielding et al, 2010). The site is marked by a red arrow in Figure 3 below.

Map source (enlargement): Tasmap, Edn 7: 2011, Meander, 1:100,000 (Base image by TASMAP ( www.tasmap.tas.gov.au), © State of Tasmania)

Figure 3. Location of early Permian sandstone (Liffey Formation (Pike 1973). Markedby a red arrow.

Liffey sandstone outcrop at the Poatina township site. Site location: Red arrow in Figure 3.

Close-up of the Liffey sandstone, note plant fossil impressions. Site location: Red arrow in Figure 3.

Further finds at the Poatina township site. Plant fossils evident. Site location: Red arrow in Figure 3.

Specimen 371. Fossil plant stem in Liffey sandstone from track cutting in the Liffey area in the river valley below Drys Bluff (Figure 2). This is the same sedimentary material as that at the Poatina site.

Close-up of plant fossil impression from the Liffey sandstone. Site location: Red arrow in Figure 3.

Site 3. Upper Triassic Poatina (Sub site 1 shown by blue arrow in Figure 3)

Specimen 474. Brady Formation material from Triassic recovered from the site shown by the blue arrow number 1 in Figure 3. The Triassic deposits at this sub-site age from about 208.5 – 228 Ma (known locally as Brady Sandstone, Pike, 1973). The Impression is believed to be that of a plant fossil. Specimen width approximately 75mm.

View of the Triassic sub-site marked by the number 2 blue arrow in Figure 3. The Triassic sediment is believed to be around ~228 – ~235Ma, known locally as Tiers-Cluan Formation (Pike, 1973) (See Table 1).

Specimen 461. Appears to be a drag-mark/trackway located at the Triassic site marked by the number 2 blue arrow in Figure 3. Matrix : sand stone.

Specimen 462. Ripple impression located at the Triassic site marked by the number 2 blue arrow in Figure 3. The impressions indicate possible quiet pool conditions Matrix: Siltstone/mudstone.

Specimen 463. Impressions (possibly Conchostracan) located at the Triassic site marked by the number 2 blue arrow in Figure 3. Matrix: siltstone/mudstone. Diameters of impressions 7mm to 10mm. Some faint striations (marked with arrows) in the impressions suggest shells? The relief of the impressions suggests quiet pool or pond conditions at the time of fossilization. That said, Tasch (1975) has reported a conchostracan fossil (Palaeolimnadia poatinis) in Triassic sandstone (Ross Sandstone at Poatina), but the specimen appears to have been flattened and does not exhibit the relief of those reported here. Accordingly the find reported is conjectured to be conchostracan.

Specimen 465. Plant fossil impression located at the Triassic site marked by the number 2 blue arrow in Figure 3. Matrix: siltstone/mudstone. Note also carbon and other plant remains. The broken and mixed nature of the fossil fragments indicates a degree of physical turbation.

Site 4. Highland Lakes Road (Late Permian-Triassic)

Map source (enlargement): Tasmap, Edn 7: 2011, Meander, 1:100,000 (Base image by TASMAP ( www.tasmap.tas.gov.au), © State of Tasmania)

Figure 4. Location of sub-sites at the Site 4 study area.

Quamby Bluff. A prominent resistant dolerite peak in the immediate area

Road cutting show by arrow 3 in Figure 4, this is Triassic material.

Section road cutting located at sub-site 2 in Figure 4.The material appears to be similar to Jackey (seeTable 1) Formation sandstone with layers of crumbly siltstone and mudstone (Pike , 1973).

Specimen 441. Plant impressions found in Triassic sandstone shown by arrow 1 in Figure 4.

Specimen 442 (Plant impression - Equisetum?) found in the Triassic at sub-site 1 in Figure 4. The finds at this site are not dissimilar to those found at the Triassic site at Poatina (Site 2, subsite 2, Figure 3).

Table 1. Approximate ages of the Permian-Triassic formations at the Poatina site.

IUGS SYSTEM Local names of Formations
System Series Stage
Age (Ma) Formation at Poatina (Pike 1973, pp.31-32)
Triassic Late Rhaetian 201.3–208.5 Brady (Feldspathic sandstone and dark
grey shale. Carbonaceous shale and coal
bands are common)
Norian 208.5–~228 Brady – Tiers (Tiers alternating grey-
green shale and non-carbonaceous
feldspathic sandstone and occasional
siltstone)
Carnian ~228–~235 Tiers - Cluan
Middle Ladinian ~235–~242 Cluan (Quartz sandstone interbedded
with dark grey shale.
Anisian ~242–247.2 Cluan-Ross
Early Olenekian 247.2–251.2 Ross (impure, medium-grained quartz
sandstone)
Induan 251.2–252.2 Ross-Jackey
Permian Lopingian Changhsingian older Jackey (siliceous sandstone with mud
pellets and dark grey to brown shale.
Plant fragments and carbonaceous
material is evident)

Discussion

While the finds in this report largely confirm earlier findings (Banks, nd; Fielding et al, 2010; Forsyth, 1987; Pike 1973; Tasch, 1975; Tattersall, 2014; Tattersall 2015), further arthropod finds are yet to be made.

Site 1. Field expeditions to the late Permian - early Triassic site (Upper Permian-early Triassic: Figure 2) at the Drys Bluff, Liffey site continue to yield plant fossils, many of which are quite interesting (see specimen numbers 426, 429 and 436). The Paracalamites fossil find was significant and further interpretation will assist inunderstanding the ecological conditions. The species is usually associated with Lower Gondwanan deposits, suggesting lower Permian (Rigby, 1969). Tasmania of course was associated with the Gondwanan landmass. As the deposits at the Drys Bluff, Liffey site are believed to be late Permian it is clear that Paracalamites were present up until that time. In any case, further studies of the fossil and the find area will be made.

Site 2. Over a period of several years, sustained field studies of non-marinesedimentary rocks (Liffey Formation, Pike, 1973) lower down in the Permian (around 284Ma) found only plant fossils. Figure 3 shows one location (see specimen 371) where finds are plentiful. Earlier work undertaken at a different site revealed similar finds (Tattersall, 2015). To date, no arthropod finds have been made.

Site 3. Finds in the mid to late Triassic at Poatina (sub-site 2, Figure 3) have revealedboth plant and arthropod finds. The impressions on Specimen 463 appear to be conchostracan fossils and have been noted in similar rocks by Tasch (1975). The earlier find of a Triops fossil (Tattersall, 2015) in late Triassic rocks at the Poatina site boosted efforts to continue searches of that site (Poatina – sub-site 2, Figure 3). Associated fossils at that site are plant and confirm earlier finds and conclusions that the environmental context was estuarine (see specimens 465, 461 and 462). Specimen 461 is particularly interesting as it indicates either a drag mark or a trackway. The surface weathering makes positive identification very difficult. The lines show evidence of cutting into the surface and also evidence of furrow residue to the sides of the trackways.

Site 4. The Highland Lakes (Figure 4) so far has revealed only plant material in whatappears to be river/swamp or possibly estuarine conditions (see specimens 441 and 442).

Recent efforts have concentrated on the late Permian to early Triassic sites (Figure 2 and sub-site 2 in Figure 4). Extended field expeditions to a number of sites are planned for this coming spring-summer period.

Conclusions

The finds reported here extend the knowledge of the Permian-Triassic. Except for one find of a suspected Syncarid (Tattersall, 2015), arthropod finds in the late Permian appear to be rare in the areas studied. On the other hand arthropod finds in the mid to late Triassic have confirmed those made by other researchers (Tasch, 1975).

Further Permian sites will be examined, particularly those at around ≈260 to ≈250Ma (Capitanian to Changhsingian age) (Tattersall, 2014). Identification of marine arthropod fossil species and associated fossils in those sediments would be of immense value in shedding light on the survival pathways taken by those species, particularly those still present today. At the same time, associated fossil finds will continue to be invaluable in helping to better understand the ecological conditions prevailing at those earlier times. In terms of the present areas of interest (late Permian-Early Triassic), such finds would assist in identifying the conditions coming out of the Permian, especially during the period of the ‘great extinction’ and whether ecological enclaves might have existed guaranteeing the continued survival of certain arthropod species.

The semi-marine conditions during the early Triassic that gave way to estuarine/freshwater scenarios over many millions of years led to environmental conditions that were favorable to arthropod species. The Triassic saw the prevalence of non-marine conditions in which a range of arthropod species flourished (e.g. Syncarida and Conchostracans), possibly due to their presence in ecological enclaves.

Acknowledgements

I thank Dr. Thomas A. Hegna, (Assistant Professor, Department of Geology, Western Illinois University, USA) for his helpful suggestions and advice during the drafting of this paper.

References

Banks, M. R. (n.d.) General Geology, Department of Geology, University of Tasmania, downloaded from University of Tasmania website www.eprints.utas.edu.au/14567/1/General_geology.pdf, December 14th, 2013.

Fielding, C.R., Frank, T.D., Isbell, J.L., Henry, L.C. and Domack, E.W. 2010, Stratigraphic signature of the late Palaeozoic Ice Age in the Parmeener Supergroup of Tasmania, SE Australia, and inter-regional comparisons, Palaeogeography, Palaeoclimatology, Palaeoecology 298, pp.70-90.

Forsyth, S. M. 1987, Review of the Upper Parmeener Supergroup, Tasmanian Department of Mines Report 1987/01, Department of Mines, Hobart, Tasmania.

Pike, G. P. 1973, Geology Survey Explanatory Report, Geological Atlas 1 Mile Series, Zone 7, Sheet No, 46 (8219N), Quamby, T. J. Hughes. Government Printer, Hobart,Tasmania.

Rigby, J.F., 1969, Permian Sphenopsids from Antarctica, Geological Survey Professional Paper 613-F, U.S. Department of the Interior. Accessed from

https://pubs.usgs.gov/pp/0613f/report.pdf

Tasch, P. 1975, Non-marine Arthropoda of the Tasmanian Triassic, Papers and Proceedings of the Royal Society of Tasmania, vol. 109.

Tattersall, P.J. 2014, Some interesting fossil finds from the non-marine Permian and Triassic sequences in northern Tasmania – Part 1, accessed from

https://www.bestthinking.com/articles/science/biology_and_nature/some-interesting-fossil-finds-from-the-non-marine-permian-and-triassic-sequences-in-northern-tasmania-australia-part-1

Tattersall, P.J. 2015, Some Interesting Fossil Finds From the Non-Marine Permian and Triassic Sequences in Northern Tasmania Part 2: The Permian-Triassic Interface – Part 2, accessed from

https://www.bestthinking.com/articles/science/earth_and_ocean_science/geology_and_land_forms/some-interesting-fossil-finds-from-the-non-marine-permian-and-triassic-sequences-in-northern-tasmania-part-2-the-permian-triassic-interface

Bibliography

Brandt, D. 1997, Help me I’m molting…, accessed from

http://www.cccbiotechnology.com/WN/SUA10/trilo597.php

Chilton, C. 1929, Note on a fossil shrimp from Hawkesbury sandstone, Journal of the Royal Society of New South Wales, 62: 366-368.

Clarke, M.J., Farmer, N. and Gulline, A.B. (n.d.), Parmeener Supergroup (Lower Part, Poatina, Downloaded from http://eprints.utas.edu.au/14598/1/The_parameener_supergroup.pdf, December 14th, 2013.

Forsyth, S. M., Farmer, N., Gulline, A. B., Banks, M. R., Williams, E. and Clarke, M. J. 1974, Status and Subdivision of the Parmeener Super-Group, Papers and Proceedings of the Royal Soc. of Tasmania, vol. 108.

Rogala, B. 2008, Deposition and Diagenesis of the Early Permian Lower Parmeener Supergroup Limestones, Tasmania. Ph.D thesis, Queen’s University, Kingston,

Ontario, Canada.

Royal Soc. Of Tasmania.1973, Excursion notes Lake Country, Papers and Proceedings of the Royal Soc. of Tasmania. The Lake Country of Tasmania: A symposium conducted by the Royal Soc. of Tasmania at Poatina, November 11-12, 1972, Royal Soc. Of Tasmania

White, Mary E., 1981. Cylomeia undulata (Burges) gen.et comb. nov., a lycopod of the Early Triassic strata of New South Wales. Records of the Australian Museum 33(16): 723–734. [31 July 1981].

Paper accepted by Best Thinking for publication in August 2017

 

BestThinking.com to Shut Down Permanently on December 31, 2017

If you want to save a copy of your content, you must do so before the website shuts down on December 31, 2017. We will NOT be able to provide any assistance after the website shuts down. We are available at support@thinkermedia.com only until the shutdown to provide more information and assistance.

It was a noble 10-year experiment, but it turns out that the writers with the best content are the least adept at the tech required to publish under our model, which in hindsight, makes perfect sense. If you are dedicating your life to becoming an expert in your specialty, you don’t have a lot of time left for figuring out publishing tech.

It hasn't helped that we have entered an age of unprecedented polarization and antagonism which doesn't foster demand for a website dedicated to the respectful engagement of diverse views.

Thank you, everyone!

Close
Philip J Tattersall Identity Verified

About the Author 

Philip J Tattersall
Phil holds qualifications in analytical chemistry, applied chemistry and sustainable agriculture. His research interests include sustainabl

Recent Content by Philip J Tattersall

Some Interesting Fossil Finds from the Non-Marine Permian and Triassic Sequences in Northern Tasmania, Australia Part 3:...

This paper reports the continuation of a long-term project examining fossil evidence from the Permian to Triassic at selected sites in northern Tasmania, Australia. While the finds reported in this paper confirm those made during the author’s earlier expeditions, there remain questions regarding...

Some Interesting Fossil Finds From the Non-Marine Permian and Triassic Sequences in Northern Tasmania Part 2: The...

The brief paper presents fossil finds from those non-marine sedimentary deposits in the late Permian to early Triassic Formations from the Poatina and Liffey areas in northern Tasmania, Australia. Several fossils of floral and faunal origin are presented and discussed.

On the Nature of Space and the Emergence of the New Physics - Some Speculations and Reflections

In reflecting on the emergent ideas of Stochastic Electrodynamics (SED) the author suggests that the zero point activity, also termed ‘vacuum noise,’ is not only a fundamental aspect of space, but is space itself.

 
 
Latest Ebooks