scholarly journals Upper Silurian and Lower Devonian stratigraphy of northeastern Pennsylvania, New Jersey, and southeasternmost New York

10.3133/b1243 ◽  
1967 ◽  
2017 ◽  
Vol 53 ◽  
pp. 269-284
Author(s):  
Martin A. Becker ◽  
Rebecca B. Chamberlain ◽  
Harry M. Maisch ◽  
Alex Bartholomew ◽  
John A. Chamberlain

Glacial erratics belonging to the Rickard Hill facies (RHF) of the Saugerties Member of the Schoharie Formation (upper Emsian: Lower Devonian) occur scattered throughout the Piedmont of northern New Jersey and Lower Hudson Valley of New York. These RHF glacial erratics contain an assemblage of trilobites belonging to: Anchiopella anchiops, Burtonops cristatus, Calymene platys, Terataspis grandis, cf. Trypaulites sp. and cf. Coniproetus sp. This RHF glacial erratic trilobite assemblage consists predominately of disarticulated cephala and pygidia that were originally preserved as part of a localized, third-order eustatic sea level lag deposit in the Helderberg Mountains region of central New York State and subsequently transported in glacially plucked blocks by the Hudson-Champlain Lobe of the Laurentide Ice Sheet southward into New Jersey. Physical and chemical weathering during glacial erosion, transportation and deposition of the RHF glacial erratics has revealed some anatomical features of these trilobites in high detail along with other invertebrates. This unique sequence of weathering reveals additional characteristics that bear upon issues of bathymetric controls on upper Schoharie Formation lithology, trilobite faunal abundance and taphonomy during the upper Emsian (Lower Devonian) of eastern New York State.  


Palaios ◽  
2019 ◽  
Vol 34 (9) ◽  
pp. 405-423
Author(s):  
ANYA V. HESS ◽  
JEFFREY M. TROP

ABSTRACT Silurian–Devonian boundary interval strata deposited during the expansion of land plants record a major perturbation of the carbon cycle, the global Klonk Event, one of the largest carbon isotope excursions during the Phanerozoic. In the Appalachian Basin, these marine strata record the regional buildup to the Acadian Orogeny. This study reports new sedimentologic, paleontologic, ichnologic, and carbon isotope data from an exceptional quarry exposure in central Pennsylvania, USA, a historically understudied area between better-documented outcrops >500 km away to the southwest (West Virginia, Virginia, Maryland) and northeast (New York). Facies spanning the continuous 113-m thick outcrop are dominantly carbonate and fine-grained siliciclastic strata interpreted as being deposited in supratidal through subtidal environments, including oxygen-limited environments below storm wave base. They record parts of three transgressive-regressive cycles, in the (1) upper Silurian Tonoloway Formation, (2) upper Silurian–Lower Devonian Keyser Formation through lower Mandata Member of the Old Port Formation, and (3) Lower Devonian Mandata through Ridgeley Members of the Old Port Formation. Micrite matrix δ13Ccarb analyses exhibit a large, positive δ13Ccarb excursion (>5‰ amplitude). Outcrops of this interval in the Appalachian Basin occur in two belts, between which correlation has been historically challenging. The regional correlation presented herein is based on carbon-isotope trends and is more consistent with published conodont biostratigraphy and volcanic ash ages, an improvement over published correlations based on lithostratigraphy. Transgressive-regressive trends at the central Pennsylvania study site are not consistent with regional trends, indicating that local controls (tectonics, sediment supply) rather than global (eustasy) dominated depositional patterns in the Silurian–Devonian boundary interval in the Appalachian Basin.


2019 ◽  
Vol 94 (1) ◽  
pp. 11-27
Author(s):  
Carl W. Stock ◽  
Judith A. Burry-Stock

AbstractThree species of Habrostroma dominate stromatoporoid faunas in the Lower Devonian (Lochkovian) of five areas in North America: New York, Virginia, Maine, Bathurst Island, and Ellesmere Island. In addition, they occur in what could be the upper Silurian (uppermost Pridoli) of Virginia, and possibly New York. Measurements of nine morphologies from 127 specimens of Habrostroma were subjected to an average linkage cluster analysis. Using average linkage between groups, three distinct clusters were revealed. Group assignments made from the cluster analysis were saved, and entered into a canonical discriminant analysis with the nine morphological variables. An overall Wilks’ lambda was calculated, and is statistically significant at alpha <0.001. The hit rate for classifying group 1 is 98%, that for group 2 is 100%, and that for group 3 is 97.9%; the total hit rate is 100%. The morphological variables contributing most to group membership are: (1) percent cystlike microlaminae, (2) microlaminae per mm, (3) gallery height, (4) laminae per mm, and (5) laminar thickness. The statistics confirm that there are three species: H. centrotum, H. microporum, and H. consimile.Habrostroma centrotum occurs in all five areas. This is unusual because Virginia, New York, and Maine are part of the Eastern Americas Realm, and the arctic islands are part of the Old World Realm. Separation of the realms is based on a high percentage of unique genera in each. A breach in the inter-realm barrier is proposed to have existed across the Canadian Shield during the Lochkovian. The nature of the breach is determined to be a shallow-water filter, allowing the passage of a limited number of taxa.


2000 ◽  
Author(s):  
William C. Schwab ◽  
J.F. Denny ◽  
Bradford Butman ◽  
W.W. Danforth ◽  
D.S. Foster ◽  
...  

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