Explorations and field-work of the Smithsonian Institution in .. . limestone. SilverCreek limestone and Ik-echwood limestone. In the latter occur nearlyall the rare species cited above, making it reasonably certain thatthe Beechwood limestone correlates with the Centerfield limestone. In southwestern Illinois, near Anna and Jonesboro. faulted blocksof Paleozoic rocks expose middle Devonian sediments. Here a sand-stone or limestone of Onondaga age is overlain In- the dark Misen-heimer shale. Over this is the Lingle limestone, which contains/ ?itulina in alnmdance. This species and the brachiopo
Explorations and field-work of the Smithsonian Institution in .. . limestone. SilverCreek limestone and Ik-echwood limestone. In the latter occur nearlyall the rare species cited above, making it reasonably certain thatthe Beechwood limestone correlates with the Centerfield limestone. In southwestern Illinois, near Anna and Jonesboro. faulted blocksof Paleozoic rocks expose middle Devonian sediments. Here a sand-stone or limestone of Onondaga age is overlain In- the dark Misen-heimer shale. Over this is the Lingle limestone, which contains/ ?itulina in alnmdance. This species and the brachiopod CcntroncUa(see fig. 8) are also present in Indiana. The Lingle limestone, ac-cording to these and other fossils, appears to be at least partiallyequivalent to the Beechwood. From southern Illinois the party traveled to Iowa to study the CedarXalley formation which extends in a narrow belt northwest acrossIowafrom Davenport through Mason City to southeastern Minne-sota. The formation is divisible three members, all profusely 9 10 SMITHSONIAN INSTITUTION. 7 T - tu C. ^ Ct5 ^ ^-» 1- „ .OC Ojr 01 .. ^ ^ • ^ O °ffi S^ ^ u ? «o U 0-1 to S ?^ <H ?Ts c o N • <U N ~ y (u lu • - t- ayr s*^ o ^ a, ^ : D ^i >i: < o SMITHSONIAN EXPLORATIONS, I935 II
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1912
