LE3 .A278 2010

2010

Pufahl, Peir

Acadia University

Bachelor of Science

Honours

Geology

Earth & Environmental Sciences

The Joggins Fossil Cliffs of Nova Scotia, Canada, is one of the best- exposed Carboniferous successions in the world. Intense study over the past 150 years has provided important information about coal- forming and fluvial processes in well preserved strata. A longstanding question is the extent to which marine conditions influenced sedimentation. Understanding this influence is important because seawater salinity is a primary control on vegetation type, and thus coal production in coastal environments. The investigation of limestone beds in the Joggins Formation provides a new perspective on the depositional environments in which coal was produced. Limestone beds are 15 to 100 cm thick and contain ostracodes, bivalves, and echinoderm fragments. They occur primarily within cyclothems at the base of the Joggins Formation interbedded with coal and flood plain deposits. The antithetic relationship in the abundance of ostracodes and bivalves through the thickness of the Joggins Formation, as well as the presence of echinoderms, is interpreted to reflect a gradual transition from marine to fluvial conditions with time. Examination of limestone with cathodoluminescence further reveals that maximum burial depths were probably no more than 60 to 80 m, which is much shallower than recent published estimates. Future work should couple these new findings with vitrinite reflectance data from coals to more completely understand burial history.

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https://scholar.acadiau.ca/islandora/object/theses:702