UMass Sesquicentennial

Influence of rock fabric on fracture attribute distribution and implications for groundwater flow in the Nashoba Terrane, eastern Massachusetts

TitleInfluence of rock fabric on fracture attribute distribution and implications for groundwater flow in the Nashoba Terrane, eastern Massachusetts
Publication TypeJournal Article
Year of Publication2008
AuthorsManda, AK, Mabee, SB, Wise, DU
JournalJournal of Structural Geology
Volume30
Issue44
Pagination464 - 477
Date Published2008/04/01/
PublisherElsevier : Oxford, International
ISBN Number01918141
Keywords#StaffPubs, foliation, fractures, ground water, Hydrogeology 21, joints, massachusetts, movement, Nashoba terrane, preferred orientation, statistical distribution, structural analysis, Structural geology, style, terranes, United States
Abstract

Attributes (i.e. trace-length, spacing, termination and orientation) of joints and foliation-parallel fractures (FPFs) are used to assess the influence of lithology and fabric on fracture type and distribution in metamorphic and igneous rocks of the Nashoba terrane, Massachusetts. Orientations of NE-SW and NW-SE trending joints are consistent throughout the region, whereas FPFs are sub-parallel to the axis of the terrane. Joint spacing generally decreases to the northeast across the terrane reflecting lithologic changes from metamorphic to igneous rock types. Although trace-length and spacing frequency distributions of both joints and FPFs are best described by lognormal functions, FPFs possess narrower fracture spacing than joints. Median fracture trace-lengths of all FPFs are comparable to those of all steep joints, but the median fracture spacing is half that of all steep joints. Trace-lengths of FPFs vary as a function of the degree of development of foliation. Fracture attributes and groundwater flow models suggest that FPFs may significantly increase fracture connectivity and potential for groundwater recharge. FPFs may account for as much as 30% of flow in fracture networks suggesting that in addition to joints, FPFs play a significant role in groundwater hydraulics that may include imparting flow anisotropy on the groundwater system.

URLhttp://www.sciencedirect.com/science/article/pii/S0191814107002362
Short TitleJournal of Structural Geology
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