. Bulletin - New York State Museum. Science. REPORT OF THE STATE PALEONTOLOGIST 1902 1031 tion is largely a repetition of that of 1838. He recognizes three formations overlying the Hudson river beds, viz (1) the Water- lime group, including the Tentaculite limestone (Manlius), (2) the Catskill shaly limestone (New Scotland), and (3) the upper, Scutella, or Sparry limestone (Becraft). The Coeymans and Kingston were not differentiated from the limestones respec- tively underlying each, and the higher strata were not recog- nized. He determined the essential basin-shaped structure of the mountain
. Bulletin - New York State Museum. Science. REPORT OF THE STATE PALEONTOLOGIST 1902 1031 tion is largely a repetition of that of 1838. He recognizes three formations overlying the Hudson river beds, viz (1) the Water- lime group, including the Tentaculite limestone (Manlius), (2) the Catskill shaly limestone (New Scotland), and (3) the upper, Scutella, or Sparry limestone (Becraft). The Coeymans and Kingston were not differentiated from the limestones respec- tively underlying each, and the higher strata were not recog- nized. He determined the essential basin-shaped structure of the mountain, and the unconformity between the lowest bed of the series, and the underlying tilted and eroded Hudson river strata. This unconformity is depicted in his section 6, which furthermore illustrates with section 4, what he believed to be a series of tilted fault blocks. This structure was undoubtedly suggested by the numerous cuestalets which characterize the outcrops of the New Scotland, and to some extent the other beds also. The steep infaces or fronts of these erosion ridges and the surface slopes of their tops, which follow the dip, have all the aspect of the corresponding faces of slightly tilted fault blocks [fig. 1, a, b]. Mather also gives a section of the south- east end of Becraft mountain, which shows the overturned strata on the Fig. 1 Diagram illustrating the detailed structure of parts of Becraft mountain: a, as in- terpreted by Mather; b, as actually existing. In 1846 Emmons1 gave a section of the southeastern end of Becraft mountain, showing a conformable relation between the Hudson river and overlying waterlime. He also speaks of a mass of Oalciferous sandstone supported by the Taconic slate. This refers probably to the hill of Burden conglomerate opposite the center of the eastern face of the mountain. In 1858 Rogers2 mentions the unconformity at Becraft, which he states he discovered in 1837. He says: The lower Helderberg or Pre-meridian rocks are seen
Size: 4950px × 505px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
