The Black Lake Shear Zone: A Possible Terrane Boundary in the Adirondack Lowlands

• William Peck, associate professor of geology
• Bruce Selleck, Harold Orville Whitnall Professor of geology
• Martin Wong, assistant professor of geology

Supported by the Keck Geology Consortium

Friends of the Grenville, 2011

Black Lake Shear Zone: NW Adirondack Lowlands
September 9-11, 2011

The 2011 Friends of the Grenville Field Trip focused on the geology of the NW Adirondack Lowlands and the proposed boundary between the Lowlands and the Frontenac terrane: the Black Lake Shear Zone. For more information please see the guidebook and references at the bottom of the page.

For more information please visit: http://www.friendsofthegrenville.org/

Download a PDF of photos of the Rockport Granite contact relations discussed on the field trip.

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Over the last several years William Peck, Bruce Selleck, Martin Wong, and a number of students have been looking at the geology of the Adirondack Lowlands near Alexandria Bay, NY. The Black Lake shear zone in this area has been proposed as a potentially important tectonic boundary based on geologic and isotopic evidence. For this research, we have made a new structural, geochronologic and petrologic studies to constrain the location, kinematics and timing of deformation in the region, and the regional setting of this structure. U-Pb SHRIMP geochronology show that significant deformation occurred from ca. 1170-1100 Ma, likely dating the late stages of the Shawinigan orogeny and recording accretion of the Adirondacks to the margin of Laurentia during terrane assembly. William, Bruce, and Martin led a nine-student Keck project to investigate this region in 2008. View the abstracts from those projects.

Related Research

(*indicates student author)

Peck, WH, Selleck, BW, and Wong, MS, 2011, Geology of The Black Lake Shear Zone and Northwestern Adirondack Lowlands, Grenville Province, New York, Friends of the Grenville Annual Field Trip, September 10-11, 2011, Alexandria Bay, N.Y., 63 p. (download PDF)

Wong, MS, Peck, WH, Selleck, BW, *Catalano, JP, *Hochman, SD, and *Maurer, JT, 2011, The Black Lake Shear Zone: A boundary between terranes in the Adirondack Lowlands, Grenville Province: Precambrian Research, v. 188, p. 57-72.

Chiarenzelli, J, *Regan, S, Peck, WH, Selleck, BW, Cousens, B, Baird, G, Shrady, C, Shawinigan Magmatism in the Adirondack Lowlands as a Consequence of Closure of the Trans-Adirondack Back-Arc Basin: Geosphere, in press.

Peck, WH, Selleck, BW, Wong, MS, 2009, The Black Lake shear zone: A possible terrane boundary in the Adirondack Lowlands (Grenville Province, New York): Twenty-second Keck Research Symposium in Geology (Franklin and Marshal College), p. 1-6.

*Catalano, J., Hollocher, K., Wong, M., 2009 Anisotropy of Magnetic Susceptibility and Trace element geochemistry of the Hyde School Gneiss and Rockport Granite, Northwest Adirondack Lowlands, New York. GSA Abstracts with Programs Vol. 41, No. 3

*Russell, AK, *Will, CN, Peck, W, Perkins, D, Dunn, SR, 2009, Recent calcite-graphite, Ti-in-biotite, garnet-biotite, and two feldspar thermometry of the Adirondack Lowlands, NY, and southern Frontenac terrane, Ontario: Geological Society of America Abstracts with Programs, v. 41(7), p. 634.

*Regan, SP., Peck, WH, Selleck, BW, Cousens, BL, Chiarenzelli, JR, 2009, Significance of the Antwerp-Rossie granitoids, Adirondack Lowlands, northern New York: Geological Society of America Abstracts with Programs, v. 41(3), p. 109.