《THE STRATIGRAPHIC SUCCESSION OF THE FOSSIL FLORAS OF THE POTTSVILLE FORMATION IN THE SOUTHERN ANTHRA》

Introduction755

Application of the term " Pottsville formation "755

Agency of fossil plants in the correlation of the terranes756

Purpose and scope of this paper757

General description of the Southern field759

Form and extent of the field759

General geologic structure759

Description of the Pottsville formation in the type region762

Composition of the formation763

Conglomeratic nature of the Coal Measures766

The Lykens or Pottsville coals766

Nomenclature of the coals768

The type paleobotanic section of the Pottsville formation769

Fossil-plant collections769

Species and their observed distribution within the formation and field771

Paleontologic divisions of the formation773

Floras of the Lower Lykens division790

Flora of the Zero and No. 6 coals790

Flora of Lykens coal No. 5791

Paleontologic features of the roof shales of coal No. 4792

Comparison of the lower portion of the type section with reference to the Lykens coal horizons793

Flora of the Lower Intermediate division794

Brief existence of a transition flora794

Flora of the Upper Lykens division795

Flora of Lykens coals Nos. 3 and 2795

Flora of Lykens coal No. 1798

Upper Lykens zones in the type section798

Flora of the Upper Intermediate division800

Plants of beds M and N in the type section800

Correlations803

Paleontologic relations of coals developed at isolated mines in the Southern Anthracite field803

Horizon of the lower Lykens Valley coal in the Western Middle Anthra- cite field, between Frackville and Shamokin810

Zones of the Pottsville floras in other regions of the Appalachian province812

Clark formation814

Quinnimont formation815

Sewell formation816

Lookout formation817

Fayette sandstone818

Campbell Ledge, Northern Anthracite field819

Relative horizons of the basal beds of the thin sections as compared to the thick eastern sections820

Upper limit of the Pottsville formation823

Flora of the base of the Lower Coal Measures in the Southern Anthracite field823

Flora in the roof shales of the Twin (Buck Mountain) coal824

The paleontologic upper limit of the formation829

Lower limit of the Pottsville formation831

The Pottsville formation in the Dauphin Basin832

Age of the coals in Lorberry Gap833

Section at Lorberry Gap833

The fault in Sharp Mountain835

Section at Fishing Creek Gap838

Western limit of the fault839

Position of the formation along Sharp Mountain841

Section at Black Spring Gap842

Section at Gold Mine Gap842

Section at Rausch Gap, Lebanon County844

Yellow Springs Gap845

Rattling Run Gap849

Big Flats850

Short Mountain shaftings west of Big Flats851

The Lykens coals in Stony Mountain854

General conditions relating to the occurrence of the Lykens coals in the Dauphin Basin855

Thickness of the formation in the Southern Anthracite field857

Variation in the constituent terranes in the formation862

Notes on or descriptions of some of the more characteristic species of fossil plants of the Pottsville formation in the Southern Anthracite field865

List of fossil plants from the Pottsville formation in the Southern Anthra- cite field866

Notes and descriptions868

Age of the Pottsville formation911

Summary of conclusions913