Exploring Grindstone
This forest chews lava, and exhales the whispers of glaciers...
Sipping from rock once fuming and flowing
Drawing from deep water pebble-pimpled silt,
Splitting muck-mired cobbles of glacial mowings
Benefacting cycles of rise and wilt...
This forest
chews
lava,
and
exha
les
the
whispers
of
gla
ciers...
-D. Floyd
On Sunday the 12th,
a mother, a father, and a son explored the forest at Grindstone Campground on the north side of Mount Rogers. We were there to 'see what we could see'. Our walk took us around the short Grindstone loop trail, the 'Whispering Waters nature trail'. As has been experienced in the past, the beauty is blinding and the diversity overwhelming. One passes through at least two distinct forest types and transitions from glacial lake deposits to lava flow remains.
The forest along the upper portion of the trail is truly unique, as it is dominated by linden, ash, and cucumber magnolia. The great number of seeps along the trail provide for excellent exploration and the make-up of the forest shifts around every corner!
Here's a small bit of what we saw:
Geology:
Rock type #1, near the beginning of the trail, is :
Konnarock Formation
;
Maroon diamictite, rhythmite, and arkose.
These are rocks that were deposited in habitats that included deep icy lakes and glacial activity. They are the silicified (fancy word for 'turned into rock') remains of muds, silts, pebbles and cobbles carried by glaciers. Interestingly, the stones seen in the silicified mud were dropped into that muck and consist of materials from formations nearby...ryholites, greenstones, and granites. This makes sense because the glaciers would have been eroding these materials from the land during that time...and, it was a landscape devoid of plants and animals!...mountains and valleys of pure rock, silt, and sand!
Rock type #2, as one heads up the trail the rocks change to:
Mount Rogers Formation;
Phenocryst-poor rhyolite.
These rocks are a dark purple, and are the results of lava flows! Mount Rogers, White Top, and Pond Mtn. (NC) form the core of what was a massive and explosive volcanic complex. These once towering volcanoes have seen a lot of erosion, and have even found themselves buried beneath miles of sediment at different points in the geologic past. But today, we are afforded a view of these ancient volcanoes. It is worth noting here that this rock known as "Rhyolite" is high in silica, and breaks kind of like glass (chonchoidal fracture). This made it a choice material for use in making spears, knives, and other tools during prehistoric times. Somewhere on these mountains hides ancient quarries used by Native Americans!
Primary source:
Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia.
Trees and shrubs:
chestnut oak,
Quercus prinus
northern red oak
,
Quercus rubra
red maple,
Acer rubrum
sugar maple,
Acer saccharum
striped m
aple,
Acer pensylvanicum
black cherry,
Prunus serotina
yellow birch,
Betula alleghaniensis
black birch,
Betula lenta
American beech,
Fagus grandifolia
Fraser magnolia,
Magnolia fraseri
cucumber magnolia
,
Magnolia acuminata
witchhazel
,
Hamamelis virginiana
viburnum
sp.
yellow buckeye,
Aesculus flava
green ash,
Fraxinus pennsylvanica
white ash
,
Fraxinus americana
American linden,
Tilia americana
rhododendron
sp.
yellow poplar
,
Liriodendron tulipifera
eastern hemlock,
Tsuga canadensis
...and, maybe
Carolina Hemlock
,
Tsuga caroliniana
(need to revisit the site to verify)
Scientific name reference:
Two unidentified species of the Lycopodiaceae family.
Smaller plants:
ramps,
Allium tricoccum
white baneberry,
Actaea pachypoda
Solomon's seal,
Polygonatum sp.
false Solomon's seal,
Smilacina racemosa
Pipsissewa
,
Chimaphila maculata
Dutchmans pipe,
Aristolochia macrophylla
ground cedar,
Lycopodium sp.
clubmoss
,
Huperzia sp.
partridge Berry,
Mitchella repens
white snakeroot
,
Ageratina altissima
black cohosh,
Actaea racemosa (syn. Cimicifuga r.)
blue cohosh,
Caulophyllum thalictroides
yellow mandarin,
Disporum lanuginosum
jack in the pulpit
,
Arisaema triphyllum
Curtis's goldenrod
,
Solidago curtisii
**
Two aster species remain unidentified, see images below.
**Two Lycopodiaceae species remain unidentified. see image above.
My identification sources:
Newcomb's Wildflower Guide, by Lawrence Newcomb
On the way home
we could not resist stopping to take in a phenomenal meadow. Willows, hawthorns, alders, cinnamon ferns, golden rods, ironweeds, ladies' tresses and butterflies galore. This little boggy area is very close to Grindstone Campground and can be thoroughly enjoyed from the road. I suspect there are many locations in the Grayson highlands area that are similar to this one, as it is maintained as pasture.
