Index for Category – Rocks, Fossils and Lichen

Click on a Title to View Concretions Nevada Mine Samples Desert Trails Rockface      Sub-Category -  Fossils & Pseudofossils (7 posts)      Sub-Category -  Lichen (6 posts)      Sub-Category -  Stone Images (5 posts)

Concretions

I recently picked up this specimen on a hike to the Weiser Ridge area in Nevada on 03/29/2012. Though its shape vaguely reminded me a little of the state of Idaho, it was the concretions that really caught my eye. A concretion is a hard, compact mass of sedimentary rock formed by the precipitation of mineral cement within the spaces between the sediment grains. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin con meaning 'together' and crescere meaning 'to grow'. Concretions form within layers of sedimentary strata that have already been deposited. They usually form early in the burial history of the sediment, before the rest of the sediment is hardened into rock. This concretionary cement often makes the concretion harder and more resistant to weathering than the host stratum. Thus, as in the image above, over hundreds and sometimes thousands of years, the effects of wind and rain erode the softer materials found in the base rock, leaving these harder minerals as ‘bumps’ on the surface.  The image below was taken on 11/10/2011 while hiking the Muddy Mountains Wilderness Area. This area has many sandstone rocks filled with red concretions that were created as the result of iron oxide or 'rust' growing within the rock. It is unclear why they begin to form, however, once the process starts, the iron continues to concentrate there. Iron spots, being harder than the sandstone, form a 'bump' as the softer exposed sandstone wears away.

Birds Head

I found this specimen lying in a wash that I was hiking at Weiser Ridge, Nevada on 03/29/2012. Immediately the bright orange portion of the stone reminded me of a  birds head with a long beak. I know, it’s just my imagination going wild again.

Title – “Stone Fright”

On a drive thru the Valley of Fire State Park on 03/22/2012, I spotted this grouping of weather worn hole on a rock outcropping just outside the Visitor Center. Almost everywhere you look you in this park you find rock that is punctuated with holes. These holes are called “Wind Holes”. Over thousands of years the sandstone, weakened by weathering, often develops small pits which are then enlarged by the action of wind and water. As the moisture dissolves away the minerals that cement the sand grains together, winds whirl the loosened sand within the pit, literally sand-blasting the holes. Though it’s not Halloween yet, I thought the image above looked like a carved Halloween pumpkin. Connie was the one who came up with the name, “Stone Fright”.

Crustose Lichens, Mt. Charleston Loop

On 04/07/2011, I found these brilliantly colored lichen covered rocks in a wash area on a hike along Robber’s Roost Trail off NV State Road 158, also known as Deer Creek Road. Some of the least known forms of life, lichens are among the most fascinating living organisms on this planet. Their very structure is unique: a symbioses of two organisms -- a fungus and algae -- so complete that they behave and look like an entirely new being. A lichen can literally eat stones, survive severe cold, and remain dormant for long periods without harm. Those that cover a substrate like a crust are called Crustose lichens. Lichens need sunlight, but because of their small size and slow growth, they thrive in places where higher plants have difficulty growing. They often settle in places lacking soil, constituting the sole vegetation in some extreme environments such as those found at high mountain elevations and at high latitudes.

Crustose Lichens, Nipton Road, NV

This picture was taken on 02/24/2011 along Nipton Road between Searchlight Nevada and Nipton California, while on a hike with the rock hounds from the Henderson Senior Center. For more info on lichens visit … http://www.perspective.com/nature/fungi/lichens.html#crustose.

Crustose Lichens, Grapevine Canyon, Laughlin, NV

This picture was taken on 02/23/2010 while on a hike Connie and I made to Grapevine Canyon, located just north of Laughlin, Nevada.  As I have said before, I love to find pictures like this which seem remind me of other images. Call me crazy again, or maybe it's just the artist in me, but the main shape of the focused area reminds me of a left side view of a bust, face and head (looking towards you) and shoulders. I think it is easier to see if you stare at the picture and then squint your eyes.

Nevada Mine Samples

This table-top rock collage was created from a collection of rock pieces I gathered on a hike through Columbia Pass, just north of the Table Mountain range with the rock hounds from the Heritage Park Senior Facility on 01/27/2011. They were collected from three different mine sites along Sandy Valley Road a few miles east of Sandy Valley. Each collage has a felt-like base made of Eco-fi, a hig quality polyester fiber made from 100% post-consumer recycled plastic bottles. See also ... Rock Still Life #004

Crustose Lichens, Eldorado Canyon, NV

These pictures were taken on a hike to Eldorado Canyon, just southeast of Nelson, NV, on 02/17/2011. Lichens are among the most fascinating organisms on this planet. Their very structure is unique: a symbioses of two organisms -- a fungus and algae -- so complete that they behave and look like an entirely new being. I have always been fascinated by these living organisms and the variety of colors that they often present. The yellow ones pictured here are probably what is know as Common Yolk Lichens (Acarospora spp.). Red ones are Caloplaca spp.; and green ones are called Lecanora spp.

Background Info:  Lichens rank among the least well known forms of life. Common names, when available, typically apply to the entire genus rather than to individual species. Lichens are generally divided into three basic forms: crustose, or crust-like; foliose or leaf-like; and fruticoseor stalked. Crustose lichens, such as those shown here, are flaky or crust-like. They can be found covering rocks, soil, bark, etc. -- often forming brilliantly colored streaks. Lichens can be divided into three basic forms: crustose, or crust-like; foliose or leaf-like; and fruticoseor stalked. A lichen can literally eat stones, survive severe cold, and remain dormant for long periods without harm. Classification of lichens is undergoing change as well. In fact, Mycologists now suggest eliminating the Lichens as a Phylum and, instead, reclassifying each invidual lichen according to its fungal component -- mostly Sac Fungi (Ascomycota). Never-the-less, lichens look so different from other fungi that they deserve separate treatment here.

Crustose Lichens, Redstone, NV

This picture was taken on 01/20/2011 while on a hike to the Redstone Loop Trail with the Henderson Heritage Park Senior Facility rock hounds. The Redstone Loop Trail is located at mile marker 27 along the North Shore Drive on the western side of Lake Mead, NV. Situated within an area called Redstone, the trail, at an elevation of 2,238 to 2,323 feet, is a short half-mile walk that surrounds several red sandstone outcroppings which are reminiscent of the Valley of Fire or Red Rock Canyon. I just love to find pictures like this which seem remind me of other images. Call me crazy, but when I first noticed these lichens, their shape immediately reminded me of an ‘old world’ map with all of the continents laid out flat.

Rockface

This picture was taken on 05/02/2009 at Bellagio’s Conservatory and Botanical Garden.

Desert Trails

This picture was taken in late March of 2008 on a hike into Red Rock Canyon with my cousin Johnny. It is merely a close-up of a relatively small rock I found lying on the surface of the ground. I found the striations to be fascinating and to this day still wonder what caused their intricate creation. Here (on the right) is the original picture from which the crop was made.