Digital Varves

The New England Varve Chronology Today

Since the time of Antevs (1922, 1928) there have been several additions and small revisions to the New England Varve Chronology (NEVC). An important part of updates has been the matching of new varve sections to Antevs’ original NEVC, which adds to the documented reproducibility of the varve sequences. Only sections added to the NEVC up to 2008 are shown on the profiles below. For the most updated compilation of varves in the northeastern U.S. go to North American Varve Chronology. The approximate geographic locations and relative ages of different varve series in Antevs’ NEVC are shown on the map below. The green bars (NE 2701-6352) in the Connecticut, Merrimack, Hudson, and Ashuelot valleys represent the older part of the NEVC, also called the lower Connecticut varves. The purple bars (NE 6601-7750) in the Connecticut and Winooski valleys represent the younger part of the NEVC, also called the upper Connecticut varves. The varve series are separated by the Claremont Gap of arbitrary length (NE 6353-6600) as interpreted by Antevs (1922). The map also serves as a key to detailed time-distance plots of all of the known varve sections that were either part of Antevs’ original compilation or have been matched to the NEVC in the Connecticut and Merrimack valleys. The plots show the time spans of individual varve sections plotted along the axis of the various valleys in the direction of ice recession. By placing your cursor in the red boxes you can view the detailed plots for each valley section including separate areas in: Connecticut, Massachusetts, southern Vt./N.H., central Vt./N.H., and northern Vt./N.H. in the Connecticut Valley. Also shown are sections in the Hudson Valley near Catskill and Newburgh, NY, the Merrimack Valley, and the Winooski Valley. The Ashuelot valley near Keene, NH has not been plotted because it is represented by only one section.

Use the map to locate the varve stratigraphy for a particular area by clicking in areas outlined in red. You may click on a tab heading to open the corresponding varve record as well. This page is best viewed at 1024x768 pixels and above.

VT/NH Northern Varve Sections Lake Winooski Varve Sections VT/NH Central Varve Sections Merrimack Valley Varve Sections VT/NH Southern Varve Sections Massachusetts CRV Varve Sections Connecticut CRV Varve Sections Hudson Valley - Newburgh Varve Sections Hudson Valley - Catskill Varve Sections
Connecticut CRV Varve Sections
Massachusetts CRV Varve Sections
Southern VT/NH CRV Varve Sections
Central VT/NH CRV Varve Sections
Northern VT/NH CRV Varve Sections
Merrimack Valley Varve Sections
Lake Winooksi Varve Sections
Hudson Valley - Newburgh Varve Sections
Hudson Valley - Catskill Varve Sections

Map and Section Key

Error in the Original Hudson Valley Record

The UMass core in the Connecticut Valley has revealed an error in the Hudson Valley record of the NEVC. Exceptionally thick couplets interpreted by De Geer to be varves in the Hudson Valley (NE 5669-5678) are missing from duplicate cores at the UMass core site. The Hudson Valley couplets are thought to be inter-annual flood events (Rittenour, 1999) produced by the drainage of a lake in the Mohawk Valley into the Hudson Valley. These flood units are no longer considered annual layers but instead beds formed by repeated Mohawk Valley water release and floods during the course of a single summer.

Plot of the UMass core (red; Rittenour, 1999) with its correlation to the Hudson Valley record of De Geer (blue) as reported in Antevs (1922). Varves NE 5669-5678 do not appear in the UMass cores with no apparent erosion. On the plot, varves NE 5600-5667 and 5724-5800 match very well while varves immediately after the flood events in the Hudson Valley record (NE 5679-5723) are noticeably thicker than varves prior to the flood and do not match any other regional record. Increased thickness and deposition that is not controlled by a regional glacial meltwater signal may be related to deposition immediately after the large flood events.

References