GEOLOGY OF AND CLIMATIC INDICATORS IN THE WESTPHALIAN A NEW GLASGOW FORMATION, NOVA-SCOTIA, CANADA - IMPLICATIONS FOR THE GENESIS OF COAL AND OF SANDSTONE-HOSTED LEAD DEPOSITS

By the Late Carboniferous, Late Paleozoic northward drift of the conti nent Laurentia had carried Nova Scotia from the southern dry climate b elt into the equatorial rainy belt. Carboniferous amalgamation of Laur entia with the southern continent Gondwana enclosed the area within th e new supercontinent Pangea, imposing a gradually drying seasonal trop ical climate. Disagreement exists on whether the early Pennsylvanian c limate of the Euramerican coal province was everwet or seasonal. Abund ant paleopedological evidence, including calcrete-bearing vertisols, s hows that during formation of Westphalian C to Stephanian coals in Nov a Scotia, the climate was tropical and seasonal with a pronounced dry season, but interpretation of Westphalian A-B coal-bearing sequences l acks this form of evidence. Development of calcrete-bearing vertisols in alluvial fan deposits of the Westphalian A New Glasgow formation in dicate that a tropical climate with a pronounced dry season was alread y in force by early Westphalian time. During the dry season, the coal swamps of the early Westphalian Joggins and Springhill Mines formation s were fed by groundwater from coeval alluvial fan deposits of the Pol ly Brook Formation at the basin margin. Sedimentological evidence indi cates that, similarly, groundwater flowed northward from the toe of th e New Glasgow alluvial fan, but correlative palustrine sediments have not been found on land in the New Glasgow area. The possibility remain s of an early Westphalian coalfield associated with the New Glasgow fo rmation to the north under the Northumberland Strait and Gulf of St. L awrence. Formation of the Yava sandstone-hosted lead deposit in the fl uvial Silver Mine Formation of Cape Breton Island, a stratigraphic equ ivalent of the Cumberland Basin coal swamps, indicates that such depos its can form in fluvial strata deposited under a tropical seasonal cli mate with a pronounced dry season.