Monday, November 23, 2009
Saturday, October 17, 2009
Tuesday, August 18, 2009
Sunday, July 5, 2009
Friday, July 3, 2009
Monday, June 22, 2009
Tuesday, June 2, 2009
Monday, June 1, 2009
BEAUTY IN STRANGE PLACES
There is beauty in strange places. An ordinary life can leave traces of us that gather into something oddly appealing. Something more than the sum of its parts.Those of you who live near the sea understand the compulsion to collect shells. They add a little something to our homes and gardens. Most end up in dishes in the bathroom. This could just reflect the color scheme and shouldn't be taken too personally by the relegated object. As well as beautiful debris, shells also played an embalming role as they collect in shell middens from coastal communities. These piles of discarded shells, now garbage, holdsinterest for those who study archaeology, a term used since garbology didn't sound as scientific. Having food “packaging” accumulate in vast heaps around towns and villages is hardly a modern phenomenon.
Many First Nations sites were inhabited continually for centuries. The discarded shells and scraps of bone from their food formed enormous mounds called middens. Left over time, these unwanted dinner scraps can transform through a quiet process of preservation. Time and pressure leach the calcium carbonate, CaCO3, from the surrounding marine shells and help “embalm” bone and antler artifacts that would otherwise decay. Calcium carbonate is a chemical compound that shares the typical properties of other carbonates.
CaCO3 is common in rocks and shells and is a useful antacid for those of you with touchy stomachs. In prepping fossil specimens embedded in limestone, it is useful to know that it reacts with stronger acids, releasing carbon dioxide: CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
It also releases carbon dioxide on heating (to greather than 840 °C in the case of CaCO3), to form calcium oxide or quicklime, with reaction enthalpy 178 kJ / mole: CaCO3 → CaO + CO2
Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate: CaCO3 + CO2 + H2O → Ca(HCO3)2
Bone already contains calcium carbonate, as well as calcium phosphate, Ca2, but it is also made of protein, cells and living tissue. Decaying bone acts as a sort of natural sponge that wicks in the calcium carbonate displaced from the shells. As protein decays inside the bone, it is replaced by the incoming calcium carbonate, making makes the bone harder and more durable.
The shells also make the surrounding soil more alkaline, helping to preserve the bone and turning the dinner scraps into scientific specimens for future generations.
Monday, February 16, 2009
MCABEE & THE PALAEOCENE-EOCENE THERMAL MAXIMUM
In 2004, a scientific crew braced the cold and the odds to extract a sediment core from 400m below the seabed of the Arctic Ocean. The core showed that Fifty-five million years ago, deep in the Eocene, the North Pole was ice-free and enjoying tropical temperatures. It also told us that the temperature of the ocean was 20C, instead of the coolish –1.5C we see today… a truth that is hard to imagine with all the hype around global warming.The bottom end of that core helped explain the fossils found at Eocene sites around British Columbia, species commonly seen in more tropical environments today.
The warmer temperatures seen at McAbee and around the globe were recorded in the core sample and reveal evidence for a global event known at the Palaeocene-Eocene Thermal Maximum. Back in the Eocene, a gigantic emission of greenhouse gases was released into the atmosphere and the global temperature warmed by about 5C.
While the bookends of the geologic time scale slide back and forth a wee bit, the current experts in the geologic community set the limits to be 33.9 +_ 0.1 to 55.8 +_ 0.2 million years ago. The fossil record tells us that this part of British Columbia and much of the Earth was significantly warmer around that time, so warm in fact that we find temperate and tropical plant fossils in areas that now sport plants that prefer much colder climes, or as is the case in the Arctic, snow and ice.
The Okanagan Highlands is an area centred in the Interior of British Columbia, but the term is used in a slightly misleading fashion to describe an arc of Eocene lakebed sites that extend from Smithers in the north, down to the fossil site of Republic Washington. The grouping includes the fossil sites of Driftwood Canyon, Quilchena, Allenby, Tranquille, McAbee, Princeton and Republic. These fossil sites range in time from Early to Middle Eocene, and the fossil they contain give us a snapshot of what was happening in this part of the world because of the varied plant fossils they contain..
While the area around the Interior of British Columbia was affected. McAbee was not as warm as some of the other Middle Eocene sites, a fact inferred by what we see and what is conspicuously missing.
In looking at the plant species, it has been suggested that the area of McAbee had a more temperate climate, slightly cooler and wetter than other Eocene sites to the south at Princeton, British Columbia and Republic and Chuckanut, Washington. Missing are the tropical Sabal (palm), seen at Princeton and the impressive Ensete (banana) and Zamiaceae (cycad) found at Republic and Chuckanut, Washington.
While we are the likely culprits of much of the warming of the Arctic today, natural processes operating in the not too distant past have also resulted in significant temperature fluxuations on a world-wide scale.
Wednesday, February 11, 2009
OLYMPIC PENINSULA FOSSIL FIELD TRIP
One of the most beautiful drives in the Pacific Northwest is the coastline along the Olympic Peninsula from Port Angeles to Neah Bay. This stretch of coastline is also home to the Clallam Formation, a thick, mainly marine sequence of sandstones and siltstones that line the northwestern margin of the Olympic Peninsula, western Washington. The sequence offers plentiful fossils for those keen to make the trek.
The beautifully preserved clams, scallops and gastropoods. The fossils found at Clallam are mostly shallow-water from the late Eocene to Miocene. Time, tide and weather permitting, a site well worth visiting is the south flank of a syncline at Slip Point, near Clallam BayGetting there…
Directions: From Vancouver it is a 5-6 hour drive to the Olympic Peninsula. Head South on Oak or Knight to connect up with Hwy 99 to the US border and continue South on Hwy 5, past Bellingham, take Hwy 20 to Anacortes.Head South on Hwy 20 until you get to the Keystone Jetty. Take the ferry from Keystone to Port Townsend. From Port Townsend take Hwy 20 until it connects with Hwy 101. Turn right onto Hwy 101 and head West.
You will pass through Port Angeles. This is an excellent place for you to top up your food stores and fill up with gas. Just after Port Angeles, look for a sign for Hwy 112 (towards Joyce, Neah Bay & Seiqu). Turn right and head West. It is about another 30 kms from Port Angeles to Whiskey Creek.From the turn-off it is about 10 miles to Joyce. This little town has restaurants and gas stations. From Joyce it is another 3 miles to our campsite at Whiskey Creek where Joe or Ronee can help direct you to your cabin or campsite.
EARTH: THE BLUE PLANET
The Earth formed over 4,500 million years ago. Bacteria were likely the first life forms, didn't appear until about 3,5000 million years ago. Since that time, a great variety of life has evolved. Most of the plant and animal life that has arisen has subsequently gone extinct and our only ties to them are through the fossil record.
Tuesday, February 3, 2009
Monday, January 5, 2009
Subscribe to:
Posts (Atom)