The relationship of joints and stream drainage in flat-lying rocks of south-central New York and northern Pennsylvania

Zeitschrift fur Geomorphologie
By:

Metrics

6
Crossref references
Web analytics dashboard Metrics definitions

Links

Abstract

Examination of the relationship of joints to stream development shows that the oft-cited development of streams parallel to joint directions does not, in general, apply in south-central New York and adjacent northern Pennsylvania. Streams whose courses are oblique to the joint directions (joint-oblique valleys) tend to erode easily owing to increased corrasion and subsequent undercutting at the upstream intersection of joints. The removal of joint-bounded blocks in joint-oblique valleys forms cascades that advance headward by apical erosion. Streams whose courses are parallel and perpendicular (joint-parallel valleys) to the nearly orthogonal joint sets erode by waterfall and plunge-pool formation; bedrock is undercut on the downstream side, and unstable blocks subsequently collapse into the plunge pool. Most valleys in the Finger Lakes region are joint-oblique, although some well-developed valleys are joint-parallel. These joint-parallel valleys are usually due to (1) a single deep, pervasive joint whose presence acts as a barrier to lateral expansion of the stream, or (2) erosion along joint zones whose intense fracturing produces weak erosional resistance in the rocks.

Suggested Citation

Pohn, H., 1983, The relationship of joints and stream drainage in flat-lying rocks of south-central New York and northern Pennsylvania: Zeitschrift fur Geomorphologie, v. 27, no. 3, p. 375-384, https://doi.org/10.1127/zfg/27/1983/375.

Study Area

Publication type Article
Publication Subtype Journal Article
Title The relationship of joints and stream drainage in flat-lying rocks of south-central New York and northern Pennsylvania
Series title Zeitschrift fur Geomorphologie
DOI 10.1127/zfg/27/1983/375
Volume 27
Issue 3
Year Published 1983
Language English
Publisher Schweizebart Science Publishers
Description 10 p.
First page 375
Last page 384
Country United States
State New York, Pennsylvania
Additional publication details