February 26, 2013
PCRG COMPLETE AGAIN
I am glad to say that after almost two months out of the office running around with 8 bags of equipment, Frazer and I have finished our tour of the Americas. As the work has been so diverse, we would like to split our comments and impressions into two different posts, we hope you enjoy them!
October 10, 2012
One of the key goals of the fieldtrip to Ecuador (August-September) was to sample organic and volcanic (tephra) layers from sedimentary exposures with the aim of obtaining new information about past envrionmental change in the region. Our Ecuadorian collaborator, Dr Patricia Mothes (Instituto Geofisico), had identified four of sites she thought might be useful too us: El Fatima Dique, Mera “2” Dique, El Rosol and Vinillos.
At the Fatima site, near Puyo, a thin organic bed was sampled sandwiched between volcanic ash deposits. Wood macrofossils from this deposit have been dated to the last glacial period.
For further descriptions of what we found and field photos read on…
September 15, 2012
The second part of our Ecuadorian expedition took in lakes and sections close to the towns of Papallacta and Cosanga. The variation in climatic conditions was marked as we experienced first hand the transition from freezing fog and driving rain to burning sun and heat within a few tens of kilometers as we travelled from >4000 m down to around 1000 m elevation.
Sampling the sedimentary section at Vinillos was hampered by a tropical downpour. Sediments recovered from here include volcanic ash, mud slide deposits including large wood macrofossils and fine grained organic sediments probably deposited in still water environments.
Preparing to recover a short core from a pond near the antenas at Cujuca. Short cores will be used for Chironomid analysis.
Tomorrow we will attempt to recover short cores from two more lakes. Then our final few days here in Ecuador will be spent visiting partners and packing up.
September 8, 2012
The first half of our field work expedition to Ecuador has now been completed. We had a very successful visit to Mera collecting samples from three new sections and recovered short cores from four lakes.
The sediment sections have yielded many wood macrofossils and samples for pollen analysis. It is anticipated that these will shed light on the nature of tropical vegetation during the last glacial period and before. Some of these samples will be analyzed by Hayley as part of her PhD research.
The sedimentary section found near Mera contained layers of crushed forest beneath volcanic ash. These “forest beds” provide a snapshot of vegetation in the landscape at the time of eruption. Part of plants growing on the landscape thousands of years ago are clearly preserved in the sediment.
September 3, 2012
Mera (Ecuador)
We have now spent two days in sampling sedimentary sections near the Rio Tigre close to Mera in Ecuador. The sections are peat deposits interspersed with volcanic ash and contain many wood macrofossils. It seems likely that the depositional environment was a shallow water swamp or bog. Although we will have to wait for the analysis of the fossil record to know the composition of the vegetation at the site.
Sediment Hunting near Mera
August 2, 2012
I whish I could start with “ Once upon a time…” because that would be the easiest way to begin this paragraph (or a paper). Besides, to some extend, “Once upon a time” can be appropriate because this is a story related to the OLD friends of the Paddington Bear. By that, I mean a story about the mega fauna in South America.
Macrauchenia drawn by Kobrina Olga (Photo credit: Wikipedia)
Ecology of the past 