Image from the Biodiversity Heritage Library.
Contributed by Yale Peabody Museum of Natural History.
| www.biodiversitylibrary.org
Transcription
The low hills south of Leonard Mt. are folded and faulted rocks of the lithology of
the "Dugout Mt." series. They are orange-brown sandstone, dark silicified
limestone (clastic limestone) and "marls" (very fossiliferous silty clayey zones).
Collection 8/24/57/2 is from one of the fossiliferous "marls". (2 bags). The
fusulines look like Upper Wolfcamp or Hess ones. This could be terrva block or a
fault block. See aerial photos SW corner of Hess property.
[Fusulina sp; Desmoines Age].
I frankly don't know what formation the silicified dark limestone represents; it is
like those beds Conoly Brooks showed me at the SW corner of his W pasture. I
believe the rocks are badly faulted and folded and are part of the large thrust
sheet picture.
PG. 71
The lower conglomeratic contains rocks of the lithologies which are underlying
the areas south of Leonard Mt. The upper conglomeratic is a calcarudite and
seems to represent erosion of past lower conglomeratic limestones. Here the
history seems to be: 1) Thrusting and folding lifting area above sea; 2) erosion
and deposition of chert and quartzite (et al) conglomeratic; 3) Milder folding and
uplift. This seems to be after a period of quiet times, deposition of limestone and
orange sandstones (see Coll. 8/24/57/1). 4) Deposition of Calcarudite. 5)
Gradual subsidence as indicated by Hess-Leonard beds upward.
PG. 72
8/26/57
Hess Canyon Horst.
Level compass: up a stream gully - Sect.39a.
1) Igneous intrusive; [Syenite] Rhyolitic? (8/26/57/1)
1 2) Metamorphosed shales and limestones, varying dips as a result of
intrusion of #1 below 10'.
2 3) Limestone, slightly metamorphosed but with fusulines, very fetid even if it
is metamorphosed; 1'; 8/26/57/2; has mud blebs, crinoid stems, productid
brachs.
3 4) Covered, 8', mostly shale probably 9/1/58/5.
4 5) Shale, blue-gray, wood fragments, slightly metamorphosed; 8'; 8/26/57/3.
[did not breakdown, thrown out].
5 6) Shale, brown, fairly silty; with 3"-6" calcarenite zones. 3'. 8/26/57/4 -
calcarenite zone at base.
The beds here are in a little syncline and they come up higher in the stream gully.
PG. 73
Sect.39b, east 50 yards, across a fault in which 75' of section is removed (fault
isn't there). This removed interval is covered on West side of fault.
[ 7) Covered, 75' probably like #6.]