Our Bedrock – The “Foundation” of Entangled Acres

Entangled Acres used to be under the sea!

It’s easy to forget to wonder about what’s right under our feet. With so many plants to discover and learn about, fungi, and wildlife captivating my attention, it took me at least a year to start wondering about the local geology. My curiosity started when I found some seashell fossils on the property, and went down a rabbit hole trying to find out more…

According to this gorgeous map from the


Notable Excerpts from other publications – please click for link to original source.

Oriskany Fonnation. The Oriskany Formation (Vanuxem, 1839) is the basal transgressive sandstone of
Sloss’ (1963) Kaskaskia Supersequence York. It overlies the Wallbridge Unconformity (Sloss, 1963), one
of six major unconformities in the Phanerozoic of North America. The unit consists dominantly of mature
quartz arenite that was deposited under relatively widespread, shallow-marine conditions across much of
eastern North America (Boucot and Johnson, 1967). These shoreface to nearshore sandstones are
characterized by abundant large, robust brachiopods (“Big-Shell Community” of Boucot and Johnson,
1967). The Oriskany Formation in New York ranges from 0 to < 3 m along the New York outcrop belt
(Hodgson, 1970; up to-30m-thick in subsurface of Tioga Co., N.Y.; Rickard, 1989), and is up to 100mthick to the south in parts ofPennsylvania, Maryland, and West Virginia.
The Oriskany Sandstone sharply and unconformably overlies older Lower Devonian or Upper
Silurian rocks along its outcrop belt in New York. The formation is thin in eastern New York and thin to
absent in central New York, and is generally absent in the western part of the state. Locally, quartz sands of
the Oriskany Formation fills fissures and karstic cavities in underlying carbonates (Brett and Ver Straeten,
1994). In eastern New York, the unit laterally grades into the Glenerie Limestone and Connelly
Conglomerate (see below). The Oriskany Formation and equivalent strata are assigned to the Icriodus
huddlei conodont zone and the Costispirifer arenosus subzone of the Rensselaeria brachiopod range zone
(Lower Devonian; Klapper, 1981; Dutro, 1981 ). Previous work on the Oriskany Formation includes
Hodgson (1970), Eaton (1921), and Oliver and Hecht (1994)


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