Asphalt, Astrobleme, Batholith, Bathtub Effect, and Bog

Asphalt

Highly complex bituminous materials containing saturated and unsaturated aliphatic and aromatic compounds with up to 150 carbon atoms formed by the evaporation of volatile hydrocarbons. Asphalt ranges from dark brown to grayish-black and can be partially or nearly solid, semi-solid, or viscous. This cementitious material composed almost entirely of high molecular weight hydrocarbons and is found in oil-bearing strata and traps. However, its composition can vary depending on the source of the crude oil with which it is associated and can include varying amounts of sulfur, oxygen, and nitrogen as well as trace amounts of iron, nickel, and vanadium. Asphalt also occurs naturally in deposits known as asphalt lakes, which were most likely formed by the evaporation of larger quantities of petroleum at or near the surface. Asphalt occurs also as a natural mixture with sandstone or limestone strata and is known as asphaltic rock.

Real World Examples: The oil belt bordering the Orinoco River in eastern Venezuela is one of the principal regions in the world that yield the heavy material from which large amounts of asphalt can be manufactured. Citgo, which is owned by the Venezuelan company, Petróleos de Venezuela, has two East Coast asphalt plants, one in Paulsboro, New Jersey, and the other Savannah, Georgia, that rely totally on heavy Venezuelan crude. Citgo happens to be the dominant asphalt supplier in the eastern United States. The far greater majority of the asphalt used today is derived from petroleum distillation and is the heavy residue left after all the other lighter fractions (naphtha, gasoline, kerosene, etc.) have been removed. Very little commercial product is derived from other natural sources. When ignited, asphalt will burn with a smoky flame but leaves very little or no ash. Because of its intensely dark color, asphalt is used in the manufacture of paints, stains, and varnishes; however, its greatest worldwide use is as a road building material mixed with crushed rock or stone. That worldwide use relies on its remarkable waterproofing and binding properties. The hard surfaces of roads, for example, depend on the ability of asphalt to cement together aggregates of stone and sand. Author’s Note: Most asphalts are also efficient absorbers of light, which is why they are black. In the U.S. the word asphalt refers to the product that is known to the rest of the world as bitumen.

Historical Background: The first recorded use of asphalt as a road building material was in Babylon around 625 BCE, in the reign of King Nabopolassar. A cuneiform inscription on an ancient brick records that Processional Way, which led from the King’s palace to the north wall of the city, was paved with asphalt and fired brick. Not long after that, King Nebuchadnezzar II (604 BCE-562 BCE) constructed the Hanging Gardens for his homesick wife, who came from the forested mountains of what is now northern Iran. The name, Hanging Gardens, happens to be a poor translation of the Greek word for overhanging, as in the case of a vegetated terrace. The Greek historian and geographer, Strabo, who described the Hanging Gardens of Babylon in 1^st Century CE said: “It consists of vaulted terraces raised one above another, and resting upon cube-shaped pillars. These are hollow and filled with earth to allow trees of the largest size to be planted. The pillars, the vaults, and terraces are constructed of baked brick and asphalt.”

Another historical example of asphalt in Babylon was the famous Ishtar Gate, one of the eight gates of the inner city of Babylon, which was also built by the redoubtable and ever busy Nebuchadnezzar II (famous in the Bible for destroying Jerusalem, bringing the kingdom of Judah to an end, and dragging the Jews into exile). The double, fortified gate, constructed in about 575 BCE, was one of the most impressive monuments rediscovered in the ancient Near East. It was decorated with tiers of glazed brick bas reliefs of dragons and young bulls symbolizing the gods Marduk and Adad. The gate itself consisted of a double gate and on its south side was a vast antechamber. Through the gate ran the above-mentioned Processional Way. In part, the Dedicatory Inscription[1] on the Gate read: “Nebuchadnezzar, King of Babylon, the faithful prince and highest of princely princes,” blah-blah-blah, “the untiring governor, constantly concerned with the well-being of Babylon and Borsippa,” continued ceremonial bragging, “the wise, the humble, the caretaker of Esagila and Ezida, the firstborn son of Nabopolassar, the King of Babylon” . . .  yada yada yada . . . “pulled down the old gates and laid their foundations at the water table with asphalt and bricks and had them made of bricks with blue stone on which wonderful bulls and dragons were depicted. I covered their roofs by laying majestic cedars length-wise over them. I hung doors of cedar adorned with bronze at all the gate openings. I placed wild bulls and ferocious dragons in the gateways and thus adorned them with luxurious splendor so that people might gaze on them in wonder.” Fun Stuff: My bet is good old Nebu II watched all that hard work from the shade while getting friendly with one of his hundreds of curvy concubines and quaffing one of the early brewskis known to have been in style at that time while bitching, pissing, and moaning about the slowness of the workers.

The ancient Greeks were very familiar with asphalt and its properties. The word itself comes from the Greek asphaltos, meaning secure. The Romans modified the word to asphaltus and widened its use as a sealant for their baths, reservoirs, and aqueducts. Many centuries later, Europeans exploring the New World discovered natural deposits of asphalt in the New World. In 1595, Sir Walter Raleigh described a lake of asphalt on the Island of Trinidad, off the coast of Venezuela. Not one to ignore the material’s obvious utility, the industrious Brit used it to re-caulk his leaky ships and then took off for more adventures. That particular Asphalt Lake is still situated in the southwest peninsula of Trinidad. For centuries after its discovery by Raleigh it fascinated explorers, scientists, and thousands of ordinary, curious people. Research in the late 20^th Century by geo-scientists from Simon Bolivar University in Caracas, Venezuela, demonstrated that the Lake’s shape was not a three-dimensional bowl as had previously been thought but had an irregular shape, with a possible plug at the center. Their seismic research and modeling also indicated the existence of two large faults that are connected to the Los Bajos fault system to the south. Those two faults intersect at the asphalt outcrop and the asphalt seeps to the surface along the fault lines. About ten million tons of asphalt have been mined from the Lake since 1867. The refined product continues to be used on the island in the manufacturing and road surfacing industries.

Astrobleme

Circular erosional crater attributed to the impact of a bolide (meteorite or comet); meteor fragments, strange conical fracture patterns, and coesite (a super dense, high-pressure form of quartz) found in the rocks at astrobleme sites indicate an impact origin. Real World Examples: The most famous example may be the Sudbury Astrobleme in Ontario, Canada, an area with mines that supply about half the world’s nickel. Other well-known examples include Barringer Crater in Arizona (commonly known as Meteor Crater), Brent Crater in Ontario, and the Vredefort Ring in Orange Free State, South Africa. Author’s Note: No matter at what oblique angle the bolides intersect the Earth, the craters are always circular. Really. Check out the web site; it’s a treasure trove of fascinating information on the Vredefort Ring in South Africa: http://www.hartrao.ac.za/other/vredefort/vredefort.html. Fun Stuff: The word astrobleme is derived from Greek astron, star, plus blema, wound. Star wound, quite a romantic description for usually prosaic geo-scientists but all students of geoscience should know the term was coined by that most unusual and gifted geoscientist, Robert Dietz. Daffynition: Zit of enormous proportions universally feared by teenagers that erupts two or three days before prom night and totally resists all desperate attempts to pop it or disguise it with multiple layers of make-up. Author’s Rant: Been there, done that, don’t ever want to do it again since being a teenager sucks.

Batholith

Large irregular mass of coarse-grained, intrusive igneous rock exposed over an area of at least 60 square miles formed by the intrusion of numerous plutons in the same region or by wide-spread alteration of country rock through intense metamorphism Today most geoscientists believe that the innate buoyancy of batholiths is responsible for their formation and placement near the Earth’s surface. Because the magma in batholiths is less dense than that of the surrounding country rock, it gradually rises, essentially similar to the formation of salt domes in coastal Louisiana, which also deform plastically under heat and pressure.

Author’s Note: However, students should note the significant scientific disagreement as to the true nature of batholiths, especially with respect to the granite formation controversy. For several different theories and hot, juicy details concerning the formation of granitic batholiths, look up granitic magma in the overall definition of magma, origins of. Today, unlike when I was a young pup studying geology back in the day (1960s), most geoscientists no longer believe that batholiths are gigundous, bottomless masses. That said, there still is a good deal of controversy about batholiths and all that equally interesting intrusive stuff. The term is derived from combining the Greek, bathos, deep, and lithos, rock.

Fun Stuff: The next time you shake up a transparent bottle containing red wine vinegar and oil, watch what happens after the shaking stops and the fluid is allowed to sit for a few minutes. The oil migrates to the top and the heavier wine vinegar settles to the bottom. Now there’s an analogy to which most of us can relate without any trouble. Or watch the lumps in a lava lamp bubble up. But does that have anything to do with the formation of batholiths? Good question. The real answer: certainly not. But all analogies are only good if they kick-start your brain and get you thinking about whatever topic is puzzling you.

Real World Examples: The Sierra Nevada, Idaho, and Coast Range Batholiths are aligned along the west coast from south the north, respectively. Now, why do you think that is? You better be thinking about plate tectonics if you want to go very far in geoscience. In addition, one of North America’s best known batholiths is the Idaho Batholith of central Idaho and western Montana.

Bathtub Effect

Term and concept originated by John Sterman, an analyst of risk perception and management at the Sloan School at MIT. According to Sterman, injecting carbon dioxide and other gases into the atmosphere is analogous to pouring water into a bathtub whose drain is slightly open (absorption of gases by the ocean, etc.). Even if flow from the spigot is greatly reduced, the water level in the bathtub will not decrease because the outflow is so slow. Therefore, Sterman believes if you want to reduce the chances of passing dangerous climate alteration thresholds that may be irreversible then you have to reduce emissions to a point where accumulation stops and then cut emissions to reduce the amount of gases remaining in the “bathtub.” According to Sterman: “Stabilizing atmospheric concentrations requires emissions to fall to the net removal rate.” Which means simply stabilizing emissions is only the necessary first step toward stabilizing climate change and that changes to the climate caused by GHG emissions in the 20^th and 21^st Centuries may take up to 1,000 years to reverse. That precise point was made by Susan Solomon, et al, in a 2007 paper published in PNAS.[2]
Author’s Note: If you look at it another way, it’s a lot like a person who has a large credit card debt. Continuing to use the credit card increases the debt load but stopping new purchases does nothing to reduce the debt. You must first stop charging new debt and then pay more than the interest rate to stop debt accumulation. That and other analogies are not quite perfect since the reality of atmospheric emissions is quite complex. For example, even if we somehow totally stop injecting new GHGs into the atmosphere, the levels of those gases will continue to increase for up to 100 years and perhaps more because of the lag time it takes for those gases to work their way into the upper atmosphere.

Bog

Habitat that consists of waterlogged, spongy ground; standing body of water that typically is not fed by streams or underground fresh water springs. Bog water is usually cold, highly acidic, and low in oxygen. Various types of moss, especially Sphagnum moss, form a thick mat of floating plants at the edge of the bog and, over time, will expand to cover over the pond with a peat layer that may be firm enough to support bushes and even trees. Real World Examples: Although bogs are common in the American Northwest, western Canada, Ireland, Russia, and Scandinavia the ones you should be familiar with are the famous cranberry bogs of the American Northeast, especially in Massachusetts, New Jersey, Maine, and Nova Scotia.

Fun Stuff: Everyone who has read early American history knows that the colonies were England’s dumping ground for undesirables, a fairly loose classification that included religious dissidents, criminals (including a large number of bankrupt debtors), orphans, homeless and disposed people, political prisoners, and bond servants. Some of those miscreants were sent to New York and New Jersey and built smelting furnaces for bog iron (limonite) taken from the Peconic River and elsewhere. Many of the central and southern New England swamps and pinelands proved to be ideal sites for iron production. The peat soils provided the ore, nearby forests were used for charcoal, and oyster shells from the coast and native shell middens provided the calcium that was used as a flux. True to the spirit of American ingenuity, the production of iron soon wiggled out from under English control and the ever hated taxes. Local residents harvested the ‘iron plantations’ (otherwise known as peat bogs) and blacksmiths built their own smelters to provide for the needs of their communities. By the time of the Revolutionary War, smithies were producing a variety of war materiel for the colonies. Naturally, the Brits tried their damnedest to destroy every smelter and every blacksmithy they came across but in large part were unsuccessful.

By the early 1800s, the bog iron was gone. With the discovery of hard coal deposits and high-grade iron ore in Pennsylvania, the iron industry packed up and migrated west. Many landowners in the northeastern states were left with no income and an environment devastated by what were in essence open pit mines and by the loss of trees. One of the first plants to recolonize the damaged wetlands was Vaccinium macrocarpon Aiton, the lowly cranberry. The fruit had previously never been planted and harvested systematically. It wasn’t long before landholders in the New England states were transforming their relict bog iron plantations into profitable cranberry bogs. It was an early example of environmental restoration that was of economic value. Author’s Note: How many of those sitting down to a Thanksgiving meal realize that the cranberries on the table are a wonderful example of environmental restoration in action? Go figure.

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[1] Found online at: http://www.bible-history.com/babylonia/BabyloniaThe_Ishtar_Gate.htm

[2] Susan Solomon, et al. “Irreversible climate change due to carbon dioxide emissions.” PNAS; February 10, 2009, vol. 106, no. 6, pp.1704-1709.