Amber Listserv / Triassic amber

[Tom Buckley]

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. Triassic amber of the Southern AIDS (ItaIV), by 
Guido Roghl, Eugenio Ragazzl, and Plero Glanolla. Palalos, Vol. 21, pp. 143-154, 2006. 
The Southern Alps In northern Italy (the Dolomites) have yielded "a new kind of fossil resin with unique stratigraphical and physical-chemical character- Istlcs." According to researcher Guido Roghl, of the Institute of Geosciences and Earth Resources In Padova, Italy, and colleagues, the amber from th~ Helllgkreuz-Santa Croce formation is one "of the most ancient and substantial Triassic amber 
- deposits In the world." Along with a "consider- 
able amount of amber" In the same formation are found remains of lycopSids, flllCOpSlds, sphenop- slds, pterldosperms, as well as conifers and their spores. This co-occurrence suggests an associa- tion between the resin and the flora present In the area during the TriaSsic. Roghl and his co-workers believe the amber may have "an affinity to the conIfer family Cheirolepidiaceae." 
In their study of the stratigraphy and physical chem- Istry of the small droplet-shaped amber, Roghl and hiS colleagues performed several tests. These Included solid-state fourier-transform Infrared analysis, nuclear magnetic resonance, pyrolysls- gas-chromatography, thermogravlmetry, differen- tial thermogravlmetry and automatized elemental analysis. 
The authors describe the amber as ranging from yellow to reddish-brown In color with "resinous brilliance and conchoidal fracture" and with hard- ness on the Mohs scale of between 2 and 3. If exposed to flame, It burns and produces an odor of resin. The authors' combination of tests allowed for comparison studies with other ambers as well. It Is similar to others In that It has absorption bands typical of all fossil resins but Its spectral "finger- print" differs from all other known resins. 
Roghl and hiS colleagues wondered about the formation and quality of the Dolomite amber. Was this large cache formed all at once? Due to the fact that there was so much of It, they doubted this. Three hypotheses to explain the relative abundance of the amber were generated by this study. The first states that an event stressed the plants and resulted In a massive production of resin. Secondly, a new kind of conifer may have evolved, producing the resin. Or thirdly, "a relative sea-level rise covered the land where the resln- producing plants lived." The authors suggest the possibility that all three scenarios may have occurred at the same time. 

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