Bulletin of the Geological Society of America (1923) (14778744751)

Identifier: bulletinofgeolo341923geol (find matches)
Title: Bulletin of the Geological Society of America
Year: 1890 (1890s)
Authors: Geological Society of America
Subjects: Geology
Publisher: (New York : The Society)
Contributing Library: Smithsonian Institution Libraries
Digitizing Sponsor: Biodiversity Heritage Library



Text Appearing Before Image:
e. Specimen number 2 has been ground to show the chan-nel originally filled by the root. From the sand beds at RideauJunction, Ontario. Figures 5-10.—Pseudoconcretions composed of soft blue clay filling irregular-shaped vertical tubes in the sand beds, Rideau Junction, Ontario. Figures 11 and 12.—Side and cross-section of a root-shaped concretion con-sisting of indurated clay, brick clay pits southwest of BillingsBridge one-half mile. Figures 13 and 14.—Soft or very slightly indurated concretions with a rootnucleus. Figure 13 is a ground specimen showing the concentricorange-brown colored zones which surround the axis. Upperclay beds southwest of Billings Bridge, Ottawa, one-half miie. Plate 12.—Concretions Figures 1 and 2.—Concretions (rhizoconcretions) formed in a bed of uncon-solidated shells by calcium carbonate cementation of shells ad-jacent to roots. Note the root nucleus in figure 1. Pleistocenebeds, Saint Augustine, Florida. BULL. GEOL. SOC. AM. VOL. 31, 1922, PL. 5
Text Appearing After Image:
CONCRETIONS BULL. GEOL. SOC. AM. VOL. 34, 1922, PL. 6