SETI Evidence Of Earliest Ecosystems Retrieved From West Australian Outback


Bob Cutter (bcutter@teal.csn.net)
Thu, 2 Sep 1999 14:46:58 -0600


>X-Sender: lklaes@pobox3.bbn.com
>Date: Thu, 02 Sep 1999 16:01:33 -0400
>To: "META@onelist.com" <META@onelist.com>, carlsagan@craigerware.avalon.net,
> "seti@onelist.com" <seti@onelist.com>, setitalk@klx.com
>From: Larry Klaes <lklaes@bbn.com>
>Subject: Evidence Of Earliest Ecosystems Retrieved From West Australian
> Outback
>Cc: bcutter@teal.csn.net, "Dr. Stuart A. Kingsley" <skingsley@coseti.org>,
> Andrew LePage <lepage@visidyne.com>,
> "AllenTough@aol.com" <AllenTough@aol.com>
>X-UIDL: 936304915.003
>
>>Date: Thu, 2 Sep 1999 19:23:39 GMT
>>From: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
>>To: ASTRO-L@uwwvax.uww.edu
>>Subject: Evidence Of Earliest Ecosystems Retrieved From West Australian
>Outback
>>
>>Department of Minerals and Energy
>>East Perth, Western Australia
>>
>>Evidence of earliest ecosystems retrieved from West Australian outback
>>
>>MEDIA CONTACT: James Bowie, (08) 9222 3527 or 0417 923 297
>>
>>2 September, 1999
>>
>>Fossil evidence of what is believed to be the world's earliest ecosystems
>>has been found and retrieved from the Western Australian outback and was
>>today handed over to the Western Australian Museum for safekeeping.
>>
>>The structures, which look like egg cartons, represent a small area of
>>exceptionally well-preserved fossil stromatolites (structures built by
>>microbes) that existed around 3.46 billion years ago.
>>
>>The stromatolites probably existed in a volcanic environment at a time
>>when the red and dusty Pilbara looked more like the hot-spring environment
>>of the North American Yellowstone National Park.
>>
>>The fossilised stromatolites were recently scrutinised by a group of
>>international experts in palaeobiology and associates of the NASA
>>Astrobiology Institute which joined an excursion arranged by the
>>Department of Minerals and Energy to study the structures.
>>
>>Director of the Department's Geological Survey Division, Dr David Blight,
>>said the focus stemmed from an article published in last month's Geological
>>Society of America Bulletin claiming that the fossils provide the best
>>evidence so far discovered of early ecosystems on Earth
>>
>>The scientific paper was jointly written by University of Montreal's
>>Professor Hans Hofmann, Dr Kath Grey and Dr Arthur Hickman of the
>>Department's Geological Survey and Dr Ralph Thorpe of the Geological
>>Survey of Canada.
>>
>>Professor Hofmann said that most of the scientists and palaeontologists
>>accompanying the excursion agreed that the highly complex shapes of the
>>structures were the result of biogenic activity, but they would carry out
>>further tests to try and establish the nature of the structures beyond all
>>reasonable doubt.
>>
>>"Unfortunately, studying the fossils wasn't the only motivating factor
>>behind the expedition," co-author Dr Grey said.
>>
>>Dr Grey said it was necessary to remove the slab containing the fossils
>>from their bush setting because the ancient stromatolites would surely
>>have become one of the 'hottest' items on the international fossil black
>>market.
>>
>>"As these stromatolites were located in a remote area they could not be
>>kept under surveillance and would be easy pickings for an unscrupulous
>>fossil dealer," she said.
>>
>>"Once the article was published we knew that people would be able to
>>narrow down the location of the fossils so we decided the best option
>>was to carefully remove the stromatolites to guarantee their preservation."
>>
>>Dr Grey pointed out that the theft this decade of 360 million-year old
>>fossil fish remains and fossilised dinosaur footprints near Broome
>>highlighted the need to protect the State's fossils.
>>
>>She also said that the intrinsic value of the fossils was demonstrated by
>>the interest that NASA was showing in studying ancient stromatolites.
>>
>>"Stromatolites are of great interest to the new field of exobiology and are
>>being used by NASA as a model for its search for fossilised life on Mars,"
>>Dr Grey said.
>>
>>"Studying early forms of life on Earth could provide the clues needed for
>>the next Mars Lander mission, which sets out in 2003, to find evidence
>>that life once existed on the Red Planet."
>>
>>The fossil locality was initially discovered by a former Director of the
>>Department's Geological Survey Division, Alec Trendall. He visited the area
>>in 1984 with Doctors Hickman and Thorpe searching for rocks suitable for
>>isotopic dating.
>>
>>However, it was not until 1997, when the site was investigated in more
>>detail by Professor Hofmann (who was financially supported by the Natural
>>Sciences and Engineering Research Council of Canada) and Dr Grey, that the
>>patch of well-preserved fossils was discovered beneath an overlying rock.
>>
>>The fossils were handed over to the Western Australian Museum by Dr David
>>Blight and are now on display at the Museum's Discovery Centre.
>>
>>A website based on the story of the stromatolites and print quality
>>photographs of their removal can be viewed at
>>
>> www.dme.wa.gov.au/ancientfossils
>>
>>Background of the fossil recovery mission
>>
>>The new stromatolite locality was originally discovered in 1984 in Western
>>Australia's Pilbara, by Dr Alec Trendall, former Director of the Geological
>>Survey Division (GSD) of the Department of Minerals and Energy in Western
>>Australia.
>>
>>Dr Kath Grey visited the outcrop later that year, but unable to find the
>>exact site, was not convinced that the structures she saw were fossils and
>>consequently, interest in the outcrop declined.
>>
>>The stromatolite site was visited again by Drs Trendall and Hickman,
>>together with Dr Ralph Thorpe from the Geological Survey of Canada, in
>>1990, when photographs were taken of one metre high conical stromatolites
>>embedded in the rock surfaces.
>>
>>Dr Thorpe later showed these photographs to Professor Hans Hofmann of
>>the University of Montreal and a few samples of the conical structures
>>were made into thin sections.
>>
>>The photos and material convinced Prof. Hofmann that the structures might
>>be biogenic.
>>
>>Between 1992 and 1995 several papers were published questioning the
>>biogenicity of previously discovered 3.4 billion year old 'fossils' from
>>the Pilbara and the whole question of early Archaean stromatolites was
>>thrown into doubt.
>>
>>Prof. Hofmann recognised that the Trendall locality, as the area became
>>known, would be significant in resolving the controversy about the
>>biogenicity of early Archaean stromatolites and referred to the conical
>>structures in a draft publication reviewing the oldest known fossils.
>>
>>This led to extended discussions between Prof. Hofmann and Dr Grey, until
>>a new GSD mapping program in the area finally provided an opportunity in
>>1997 for both of them to examine the structures in the field, accompanied
>>by Dr Hickman.
>>
>>Once at the outcrop, it didn't take long for Drs Hofmann[1] and Grey to agree
>>that the cones (missed by Dr Grey in 1984) were probably biogenic, or for
>>them to discover other complex structures associated with the cones.
>>
>>While working in the area, the three scientists noticed a tiny patch of
>>well-formed cones poking out beneath an overlying rock. Upon removal
>>of the overlying slab, the 'egg-carton' surface (a series of small cones
>>preserved three dimensionally) was revealed.
>>
>>Field study was followed by laboratory examination carried out by
>>Professor Hofmann at the University of Montreal, culminating in the
>>publication, in August 1999, of a scientific paper (authored by Hofmann,
>>Grey, Hickman and Thorpe) describing the find.
>>
>>The Trendall locality is of particular significance because of the
>>exceptional preservation and because it exhibits complex shapes
>>consistent with biologic activity at beginning of the fossil record.
>>
>>The structures are of great interest to the new field of exobiology (life
>>on other planets), because NASA's Mars Lander will search for similar
>>structures as part of its mission to the red planet, leaving Earth in 2003,
>>to look for evidence of life on other worlds.
>>
>>After assessing the risk of losing the fossils through theft or erosion if
>>they were left at the locality and mindful that the structures needed to be
>>studied in context, GSD decided to organise an excursion for specialists so
>>they could examine the structures before they were removed.
>>
>>The 1999 visitors (including five associates of NASA's Astrobiology
>>Institute) reacted in much the same way as Drs Grey, Hofmann and Hickman
>>towards the coniform structures.
>>
>>Most agree that the evidence for biogenicity is very strong based on the
>>shape of the fossils, however, they will now try to find other evidence
>>(such as chemical signatures) that support the claim that the structures
>>were built by living organisms.
>>
>>Because these structures are so significant and because removing them
>>from the locality to protect them was a contentious scientific decision,
>>GSD invited the ABC television science program Quantum to document the
>>removal of the slab to the Western Australian Museum for safekeeping.
>>
>>Footnote:
>>[1] Prof. Hofmann was funded by the Natural Sciences and Engineering
>>Research Council of Canada
>>
>>
>
>



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