Every blogger knows the challenge. What shall I blog about next? What photos should I use? By the time the end of the year rolls around, there are always a few posts that never quite made it. And so, with this final post of the year, here they are from here and there.
A paper-thin veneer of new ice supports a bevy of gulls.
Chestnut Hill Reservoir, Newton, Massachusetts
Evidence for changing sea levels exists around the world including the Bahamas.
Low tide has exposed "shore rocks" along the island's north coast which are in reality
150,000 year old fossilized star, starlet and brain coral. This former patch reef was once covered by water considerably deeper during the last interglacial period. During the ensuing glacial period, the sea floor became exposed on land and covered by a limestone-derived soil. The crusty soil is eroding and can be seen on the coral, that is if you can take your eyes off the Caribbean's incredibly blue-green water.
Cable Beach, New Providence Island, Bahamas
This is a positive (upper member) cast of a portion of a trackway of a bipedal theropod in shallow-water, arkosic sandstones of the Lower Jurassic Portland Formation. This brownstone, the building stone that shaped America during the late 1800's, was deposited in an aborted rift basin called the Hartford Basin in response to the opening of the Atlantic Ocean. The foot-long footprint is likely that of a Dilophosaurus or Coelophysis, early carnivors of the Mesozoic. Not too far from here in South Hadley, Massachusetts, in 1802 a farm boy named Pliny Moody discovered the first trackway in North America. That was in the Deerfield Basin, a failed rift basin almost identical stratigraphically to the Hartford. The local preacher, seeing the print's three-toed anatomy, called it Noah's Raven, a prophetic analysis considering the evolutionary relationship between reptiles and birds.
Meehan Quarry, Hartford Basin of the Connecticut Valley, Portland, Connecticut
This hexagonal tholeiitic basalt, with its characteristic geometry of extremely regular polygonal joints, formed as a consequence of its cooling history. These erratics fractured from a colonade of the Lower Jurassic Holyoke Basalt Flow, the middle of three flood basalts that were generated in 1,200 miles of Mesozoic rift basins along the eastern margin of North America (and across the Atlantic as well) during early rifting of the Atlantic Ocean. This trap rock, as it's called colloquially, has its name derived from the Swedish word for stairs ("trappa") referring to the step-like pattern the extrusive igneous rock assumes once cooled and contracted. Interestingly, the generation of massive volumes of this flood basalt is cited as a possible cause of the Permo-Triassic extinction event.
Tilcon Trap Rock Quarry, North Branford, Connecticut
Preserved in the famous Bertie Waterlimes of Central New York, these are exoskeletal molts of Eurypterus remipes, also known as a "sea scorpion," a necessity of growth for all body- and limb-jointed arthropods. Classified as a chelicerate (along with spiders and horseshoe crabs) based on the morphology of its anterior appendages, it was a marine creature actually related to a similarly marine scorpion. Both plied the hypersaline seas that formed cratonward within the foreland basin of the Taconic Orogeny during the Late Silurian. Eurypterids went extinct at the end of the Paleozoic during the end Permian extinction along with up to 96% of marine species. Scorpions survived the Great Dying and now enjoy a terrestrial existence.
Bertie Waterlimes, Lang’s Quarry, Passage Gulf, Ilion, NY
I have been jogging around this reservoir for thirty-five years. It was constructed in 1870 to supply the fresh water demands of growing Boston and its environs but is now a haven of tranquility in the heart of the city. I’m continually astounded by the diversity of the wildlife that one finds here: geese, ducks, swans, gulls, hawks, falcons, turkeys, heron, egrets, fox, coyote, raccoons, muskrats, mice, snakes, frogs, fish, and the usual collection of squirrels, rabbits, dogs and humanoids. And it's decorated with fantastic ledges of the Roxbury Conglomerate!
Chestnut Hill Reservoir, Chestnut Hill, Massachusetts
...and even turtles.
Chestnut Hill Reservoir, Chestnut Hill, Massachusetts
It's the world's tallest freestanding stone structure, standing sentinel over our nation's capital since 1884. The Washington Monument is incredibly photogenic. It virtually begs to be photographed. The challenge is to capture it in a uniquely individual way. Architectural geology can be a lot of fun especially if you're familiar with the quarry of origination. The obelisk's exterior is marble from Maryland, Texas and Massachusetts, while its interior backing is composed of sandstone and crystalline rocks (glassy intrusive igneous rocks) from Maryland. The Massachusett quarry is named the Lee Lime in my home state. Its carbonate rocks were part of a coastal shelf along the then, southern seaboard of the supercontinent of Rodinia over a billion years ago. They were subsequently metamorphosed into marble by the collisional events of the Taconic and Acadian orogenies during the Paleozoic. Knowing the geology seems to give greater depth (no pun intended) to any subject.
National Mall, Washington, District of Columbia
My colleague and I, while traveling through northwestern New Mexico, spotted the stone edifice from a distance. Not intending to stop, we became overwhelmed by its mystical presence and stayed for a day. Unlike our conventional perception of volcanoes that exude lava and build up a conical, vertical structure, Ship Rock emplaced within the Earth's crust phreatomagmatically, gas-charging its magma when it hit the water table. Its maar-crater at the surface and over 3,000 feet of overburden have eroded away in the last 25 million years, give or take. That left the erosion-resistant diatreme as testimony to the fury, topping out at 1,583 feet. The wall-like linear structure off to the left is a radial dike, one of three major feeder-conduits that emanate from Ship Rock.
Ship Rock, San Juan County, New Mexico
Volcanoes to the west in the Thirtynine Mile volcanic field and the Sawatch Range periodically filled the air
with volcanic ash 35 million years ago. Carried by the wind, ash rained down on the region of ancient
Lake Florissant in Colorado, and along with mudflows, preserved a diverse Upper Eocene ecosystem of fish, insects, mammals and plant material. Silica derived from the ash, in a scenario remniscent of Pompeii, and its interaction
with planktonic blooms produced biofilms that retarded organic decomposition. Perhaps most remarkable
to be silicified are the VW-size tree stumps of Sequoia's, members of an ancient redwood forest
that blanketed the lake region. Notice the two, rusted ends of a saw embedded within the "Big Stump,"
a vestige of wanton and destructive fossil collecting in the late 1800's.
Florissant Fossil Beds National Monument, Florissant, Colorado
Minutes from Lake Placid in northern New York State, we're viewing the High Peaks Region
across a dry, pro-glacial lakebed drained by an active Holocene stream. Both formed
after the retreat of the Laurentide Continental Ice Sheet at the end of the Pleistocene.
The bedrock throughout the region, unless buried below glacial erratics, till and outwash,
is Middle Proterozoic Grenville metanorthosite, final vestiges of the supercontinent of Rodinia.
North Elba, Adirondack State Park and Reserve, New York State
For the second consecutive year, this brightly-colored, orange-yellow cluster of mushrooms arose from exactly the same location and at precisely the same time of year in my neighbor’s yard. They fruited on the stump of an aging Maple tree following a week of humid, soaking rains. Their scientific name is Omphalotus but are commonly known as the Jack O’Lantern mushroom. Under suitable conditions of day length, heat,
humidity and nutrition, spores in the soil germinate to produce hyphae. When hyphae of the opposite mating type meet (a romantic love affair made in the soil rather than in heaven), a fruitbody is produced, in this case a mushroom. Mushrooms possess the spore-shedding organs of a new generation. The mushroom and its spores is analogous to an apple and its seeds. The hidden mycelium beneath the soil is the "tree" (sort of). Mushrooms are fungi, nature’s morticians in the natural environment, beneficially biodegrading and nutrient-recycling. As we all know, not all of them are edible. These delectable-looking delicacies are deadly poisonous (as in difficulty breathing, drop in blood pressure, irregular heartbeat and respiratory failure). They also exhibit bioluminescence by glowing in the dark. I returned the following day to harvest a few and observe that peculiar property in a dark room, but my neighbor unfortunately excavated his crop before I could. Based on my calculations, next August there’ll be new specimens to collect. Lesson learned? Don't eat mushrooms that glow in the dark, and you never know what’s growing in your neighbor's yard.
Taken at sunrise, the autumnal colors are totally natural.
This pond is in the heart of town next to a parking lot at the back of a shopping center.
Chestnut Hill, Massachusetts