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Diamonds and the Eocene climate of the Bell River Basin

Diamonds mined from the kimberlite pipes of the Lac de Gras diamond field in Northwest Territories, Canada, are among the world’s youngest known diamonds, dating from 75 million to 45 million years ago. In some cases, when the magmas that carried these diamonds to Earth’s surface encountered water-saturated rock at shallow depths, violent steam explosions called phreatomagmatic eruptions resulted. Such explosions can form volcanic craters known as maars, which often fill with water and accumulate lake sediment, along with soil and vegetation that collapse into them from their margins. In the case of the Panda kimberlite pipe at the Ekati Mine in the Lac de Gras area, maar sediments accumulated far below the surrounding terrain, such that they were later buried under glacial deposits rather than being eroded away by ice sheets during the past million years. Wood and other organic materials were entombed and preserved in their natural state, thereby preserving shreds of the Paleo-Bell River Basin.

25 Jul 2018

Saglek Basin sediments suggest a Grand Canyon connection

Pollen makes an ideal fossil. Pollen grains — each only a few tens of microns in diameter — are produced in astronomical quantities by plants and record information about the ecosystem from which they came, thus providing a way to reconstruct past environments. Additionally, pollen is composed of a highly stable organic substance, sporopollenin, which resists decay as well as the high heat and pressure associated with deep burial, lithification and tectonism. It is so resistant, in fact, that it can be eroded from rock and recycled into younger sediments, a process recognized in the 1980s by V. Eileen Williams of the University of British Columbia in her studies of Paleo-Bell River sediments deposited in the Labrador Sea.

25 Jul 2018

Getting There And Getting Around Vancouver

Most visitors to Vancouver and the surrounding area arrive via Vancouver International Airport (YVR) or by road, approaching the city from the east along the Trans-Canada Highway or from a U.S. border post to the south. Although flights into YVR are often good value, especially as a stopover for trans-Pacific flights, it’s often cheaper for U.S. travelers to fly into Seattle, as we did, and then drive across the border. 

16 Jul 2018

"Greening" stormwater in Philadelphia

When environmental geologist David Wilcots joined Sci-Tek Consultants in 2014, he became involved with the Philadelphia Water Department’s Green Stormwater Infrastructure project. Sci-Tek’s goal was to redesign certain areas of the city’s urban landscape so that “less stormwater goes into the sewage system” and more goes into the ground, explains Wilcots. 

29 May 2018

Oceanic crust in all its glory

Our loop drive through the high Hajar Mountains boasted excellent exposures of every oceanic crustal layer. One good exposure of the sequence of mantle rocks is found in the hills surrounding Oman’s capital city Muscat. They consist of a variety of peridotite called harzburgite, which is the pyroxene-depleted residue left behind after basaltic magma is extracted. That extracted magma forms the oceanic crust, whose characteristic rock sequence is, from bottom to top: 1) dark, layered gabbro overlain by massive gabbro (the intrusive equivalent of basalt that comprises solidified magma chambers); 2) sheeted basaltic dikes (the conduits that transported lava from the magma chambers up to the ocean floor); and 3) bulbous pillow lavas, which form when basalt erupts directly into seawater.

06 May 2018

Gyres spin up, currents get muddled

In addition to polynya formation and warming-induced surface freshening, other factors may also impact open-ocean convection in the Southern Ocean. The warming atmosphere is shifting global climatic zones and their associated wind fields poleward in both hemispheres. In the Weddell Sea Gyre, one of two clockwise-spinning circulation patterns in the Southern Ocean, this shift has resulted in a dramatic increase in wind stress curl (the strength of the wind’s influence on ocean water flow) over the past two years.

20 Mar 2018

Getting There & Getting Around Corsica

The two largest of Corsica’s four airports, Ajaccio (AJA) and Bastia (BIA), are located on the island’s southwestern and northeastern coasts, respectively. There are no direct flights from the U.S. to Corsica, so it’s usually cheapest and most convenient to fly into Paris and then catch a 1.5-hour flight to the island. Air France and Air Corsica operate connecting flights year-round from most major French cities. During the bustling summer months, other carriers, including the budget airlines EasyJet and Ryanair, offer direct service from numerous European cities. If you prefer to arrive by ferry, several lines, including Corsica Ferries and Moby Lines, offer year-round transport from Marseille, Nice and Toulon, as well as summer routes from several Italian ports.

 
09 Mar 2018

How do earthquakes impact landslides?

Sensitive instruments installed on and near the slow-moving landslide in Maca, Peru, have allowed scientists to observe the response of the landslide to earthquakes: information that can help researchers predict hazards from other slow-moving landslides in the region and perhaps around the world. But scientists are wondering whether the findings could also shed light on the triggering of fast-moving landslides by earthquakes.

27 Feb 2018

Getting there and getting around Las Vegas

McCarran International Airport is the main gateway for exploring Las Vegas and the surrounding area. Except for sights along the Strip, it’s necessary to rent a car to see the attractions described here. If you fly in, you can rent a vehicle at the airport or take a shuttle or taxi into the city and rent a car as needed. Although all of these sites are open year-round, the best times of year to visit are in the spring and fall. In winter, it’s not possible to hike high in the Spring Mountains due to snow, and in summer the valley heat can be stifling. There are currently no visitor facilities or infrastructure at Tule Springs National Monument, but you can catch a glimpse of the fossil beds near one of two National Park Service signs, one located at the intersection of Moccasin Road and Durango Drive, and the other where North Decatur Boulevard meets Horse Drive.

14 Feb 2018

Getting there and getting around Scotland's Southwestern Islands

Ferry service to Arran and Islay is the primary way to access the islands from the Scottish mainland. Caledonian MacBrayne (“CalMac”) offers a “hopscotch” ticket package that goes from Ardrossan (close to Glasgow) to Brodick (Arran), across the Kintyre Peninsula, to Port Ellen (Islay), and then back to Kintyre, all on your own schedule, for £150, including ferrying your rental car. (We brought a rental car with us from the mainland, in the interest of being able to access outcrops where and when we wanted, but each island offers a municipal bus service as well.) Reserve a space for your car on the ferry during peak tourist times. Also, be prepared to be stuck on an island for a bit (usually not more than a few hours) if the weather turns.

 
06 Nov 2017

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