Claim CC373:
Mud springs near Swindon, Wiltshire, England produce fossils, supposedly about 165 million years old, of remarkable preservation. Some bivalves still have their original organic ligaments, and ammonites are irridescent and still have their original shells of aragonite, a metastable form of calcium carbonate.Source:
Snelling, Andrew A. 1997. A '165 million year surprise. Creation
19(2): 14-15.
http://www.answersingenesis.org/creation/v19/i2/surprise.asp
Response:
- The ammonites are well preserved but still consistent with an age of
165 million years. Although the microstrucure of the bivalve ligaments
is preserved, their organic material is not. Irridescent fossils are
not uncommon from mudrocks of that age. Dr. Hollingworth, cited
secondhand in the source for this claim, wrote,
The bivalves found at the Wootton Bassett Mudspring come from the Upper Jurassic, Oxfordian Ampthill Clay Formation and are very well preserved. Several specimens of the bivalve Myophorella have been found articulated with the ligament still preserved and retaining original microstructure. The organic material has been replaced by hydroxyapatite. Aragonite is metastable but in mudrocks is sometimes still preserved due to the impermeable nature of the sediment, especially when compacted. (Hollingworth 2005; see also Harding et al. 2000)
References:
- Harding, I. C., J. Armitage, N. Hollingworth, and N. Ainsworth. 2000. Sourcing mudsprings using integrated palaeontological analyses: An example from Wootton Bassett, Wiltshire, England. Geological Journal 35: 115-132.
- Hollingworth, 2005. Letter to Jon Fleming. In: Preservation of 165 Mya organic ammonite ligaments?, talk.origins, May 2, 2005.
created 2005-5-2