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Title: Floristic and ecological significance of coal balls from late Middle Pennsylvanian strata of western Pennsylvania, USA

Thesis/Dissertation ·
OSTI ID:5786295

342 coal balls or pieces of coal balls, representing a single concretionary mass occupying the full thickness of the original peat mass of a thin Allegheny Formation coal seam, were collected at the Derringer Corners locality, Lawrence County, western Pennsylvania, late Middle Pennsylvanian age. In the study of systematics of pteridosperms, two stem species (Schopfiastrum decussatum and Sutcliffia insignis), two leaf species (Alethopteris lesquereuxii and Alethopteris sullivantii), and one seed species (Pachytesta noei) are described and illustrated; the concentric leaf traces of Sutcliffia has been proved; one new stem species (Heterangium crossii) is designated. Morphological and anatomical variance of medullosan roots are also discussed. The technique transferring the entire epidermal tissue and cuticle of alethopterid pinnules from coal ball specimens, macerated by using EDTA solution, has been illustrated. Such preparations provide three-dimensional structure. The coal ball flora was composed of four major plant groups comprising about 30 genera common in the Pennsylvania Euramerican coal swamps. The abundance of lycopods found in the coal balls is generally recognized as an indicator of a wet environment or habitat. However, the low shoot/root ratio determined infers relatively dry conditions in the coal-forming peat swamps at the Derringer Corners. The discrepancy of these two environmental indicators is discussed, and it is suggested that the regional climate was relatively dry, compared to that of some earlier coal-forming environment, but edaphic and perhaps geomorphic conditions resulted in local areas of wet habitat.

Research Organization:
Michigan State Univ., East Lansing (USA)
OSTI ID:
5786295
Resource Relation:
Other Information: Thesis (Ph.D)
Country of Publication:
United States
Language:
English