HYPOTHESES OF STREAM DEVELOPMENT IN THE FOLDED APPALACHIANS OF PENNSYLVANIA

Abstract

Research Article| January 01, 1945 HYPOTHESES OF STREAM DEVELOPMENT IN THE FOLDED APPALACHIANS OF PENNSYLVANIA ARTHUR N STRAHLER ARTHUR N STRAHLER COLUMBIA UNIVERSITY, NEW YOKK, N. Y. Search for other works by this author on: GSW Google Scholar Author and Article Information ARTHUR N STRAHLER COLUMBIA UNIVERSITY, NEW YOKK, N. Y. Publisher: Geological Society of America Received: 13 Mar 1944 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1945, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1945) 56 (1): 45–88. https://doi.org/10.1130/0016-7606(1945)56[45:HOSDIT]2.0.CO;2 Article history Received: 13 Mar 1944 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ARTHUR N STRAHLER; HYPOTHESES OF STREAM DEVELOPMENT IN THE FOLDED APPALACHIANS OF PENNSYLVANIA. GSA Bulletin 1945;; 56 (1): 45–88. doi: https://doi.org/10.1130/0016-7606(1945)56[45:HOSDIT]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract New evidence is brought forward in a critical discussion of four hypotheses of origin of southeast-flowing streams in the Pennsylvania folded Appalachians. Development of subsequent streams along transverse faults is concluded to be an unsatisfactory explanation because a study of major water gaps revealed no evidence of faulting and because the few recognized important transverse faults are not the sites of water gaps.The hypothesis of southeast-flowing Permian consequent streams, modified throughout a long erosion history, is not supported by a study of the positions of present streams with respect to geologic structures. Field evidence fails to sustain certain postulated processes of local superposition. The reversal of a considerable amount of Pennsylvania drainage is not explained.The hypothesis of progressive piracy and local superposition employs a process of water-gap formation which is not accepted because the numerous wind gaps in the Pennsylvania folded belt show that abandonment of gaps, rather than their production, is the normal process now active. The hypothesis does not account for abundant wind gaps, for repeated alignment of wind and water gaps, or for dual water gaps maintained close together in the same ridge.Additional evidence supporting the hypothesis of regional superposition is the seeming absence of faults in major water gaps and the failure of streams to utilize the few known fault lines breaking major ridges. Accumulated data invalidate various objections which have been urged against the hypothesis. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.