Here are a few of my favourite quotes by the late great American astronomer, Carl Sagan (1934-1996).


"Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home"
Carl Sagan, Pale Blue Dot


"The method of science is tried and true. It is not perfect, it's just the best we have. And to abandon it with its skeptical protocols is the pathway to a dark age"
-- Carl Sagan

"For years I've been stressing with regard to UFOs that extraordinary claims require extraordinary evidence"
-- Carl Sagan, quoted from Billions and Billions, chapter 5 ("Four Cosmic Questions"), page 49

"If some good evidence for life after death were announced, I'd be eager to examine it; but it would have to be real scientific data, not mere anecdote.... Better the hard truth, I say, than the comforting fantasy"-- Carl Sagan, The Demon-Haunted World, page 204

Minerals from Peru - new additions to my Mineral Collection!

Bournonite after Tetrahedrite with Quartz (~7 cm) from a new find at Mundo Nuevo mine













A large manganoan calcite crystal with pyrite on tetrahedrite. From the famous Casapalca mine












Orange orpiment with barite, Quirivilca mine


















A large Manganoan Calcite ~13 cm with calcite and sphalerite from Racrachanca mine.

















Purple Coquimbite (~6 cm) from Peru















Sphalerite with calcite (~8 cm) from Ticlio mine















These are a number of new mineral specimens added to my growing collection of minerals from the country of Peru. The new bournonite pseudomorph after tetrahedrite from Mondo Nuevo specimens are particulary intruiging and are just one of many fascinating pseudormorphs from Peru. The Sphalerite with calcite specimen from Ticlio mine has to be one of my favourites. There is a "shelf" of fine calcite in the center of the specimen that has several spheres of sphalerite on the shelf. The sphalerite have a dark blue iridescence which makes the entire specimen especially attractive!


Allan

African Rainstorm in the Waterberg

Late last year I visited the Waterberg area of South Africa. I was standing on a ridge overlooking a thunderstorm moving over a distant plain. The pictures above show the progression of the storm over about a half hour. The area is pristine and typical of the Waterberg area with thorn trees and low lying hills. I imagined that this scene would have been been witnessed by Australopithecus africanus or Homo Erectus as they looked over a similar landscape millions of years ago.

The hills in the distance are 1.6 billion year old sedimentary rocks called the Waterberg Supergroup rocks which are a sequence of conglomerates, sandstones and shales. Read more on the Waterberg rocks at http://www.onlineminerals.com/geo.htm

Allan

February 16

Scientists Rally against Creationists

The young Charles Darwin

Scientists rally against creationist 'superstition'


To mark a double anniversary celebrating Charles Darwin, the father of evolution, his supporters are taking the fight to their opponents The rise of creationism in Britain to the point where four out of 10 Britons believe it to be the literal truth – as well as the idea being taught in state-approved schools – has spread alarm throughout the scientific community. But this week sees the start of a concerted fightback, as an 18-month celebration of evolution and its greatest proponent, Charles Darwin, gets under way, marking the 150th anniversary of the unveiling of his theory and the 200th anniversary of his birth. People all over Europe will take part in a mass experiment to discover evolutionary changes to a species of snail; a major series of programmes is to be shown by the BBC; several books are to be published; and the Open University plans a new course on the subject. Entries for a competition to design "Darwin's Canopy" – a piece of art to cover a ceiling in the Natural History Museum – will be unveiled this week, and the museum will hold a major exhibition on Darwin beginning in November. Dr Bob Bloomfield, head of special projects at the museum and a key figure in the "Darwin200" project, said he was concerned by the prevalence of creationist ideas.

"The statistics in this country are quite frightening. If you add up the percentages that either believe in creationism or intelligent design, it is approaching 40 per cent," he said. "I don't think society can be complacent when ideas which are unsound are perpetrated. We are trying not to compromise people's faith views, other than where they are absolutely inconsistent with science." He said the teaching of creationism in schools was "very problematic". Professor Jonathan Silvertown of the Open University, who is writing a book entitled 99% Ape: How Evolution Adds Up, said the OU would be running a course called Darwin and Evolution. "The idea is to give people a feel for the modern evidence," he said. He and the geneticist Professor Steve Jones, of University College London, are involved in a mass science project to study changes in banded snails, by recruiting tens of thousands of people across Europe. Professor Jones said religious students – even those studying medicine – were becoming increasingly vocal in their opposition to evolution, saying he was "telling lies and insulting people's religion" by teaching the subject. "They want permission not to come to those lectures and sit those exam questions," he said. "I have been teaching genetics and evolutionary biology for 30 years and for the first 20 I think the issue arose once. That's changed."

Reposted from : http://www.independent.co.uk/news/science/scientists-rally-against-creationist-superstition-837832.html

Pale Blue Dot

No one could put it more heartfelt and passionate than Carl Sagan could. Listen to Sagan's narration from his book the Pale Blue Dot.

http://www.youtube.com/watch?v=p86BPM1GV8M

Ancient carbonate deposit and stromatolites

In 2008 a group of us visited Pering mine near Kuruman. Besides the very interesting minerals we collected the geology was fascinating.

The Pering deposit is a carbonate (limestone/dolomite) hosted zinc-lead mineralized breccias within the Campbell Rand member of the Ghaap Group, Transvaal Super Group (classified as the oldest Mississippi Valley Type (MVT) economic deposit in the world. It has been dated at approximately 2,550my old (Paleo-proterozoic in age), while all the other MVT deposits in the world are younger, ranging from middle Proterozoic (1,200my) to Jurassic (175 my) in age. For this reason Pering is unique and deserves more attention from a mineral collector’s point of view.

One could get a glimpse into the fascinating development of this unusual deposit as we drove down the ramp road into the large pit. The upper layers of dolomite still have well preserved stromatolite domes some as large as 5 metres across, with intercalated thin shale layers within the thick units of dolomite. These lower dolomites are characterised by smaller domed deformed stromatolitic lenses in the lower section of the exposures in the opencast pit. Stromatolites were simple algae-like plants requiring a warm shallow marine sea to thrive. These fossils represent the oldest living organisms on the planet, peaking about 1250 million years ago. These cyanobacteria are thought to be responsible for increasing the amount of oxygen in the primeval earth’s atmosphere through their photosynthetic action of taking in carbon dioxide and dispelling oxygen as waste (Allwood, et al, 2006).

Evidence of several fluctuations in sea-level resulted in the formation of limestone and dolomite deposits in deeper waters, with thin shale layers forming during shallow lagoonal/esturine conditions. Fossil ripple marks along bedding planes in the thin shale layers were evident at many of the collecting sites, indicating shallow gentle tidal flow when these sediments were deposited in the inter-tidal zone. These abrupt changes in sedimentary units were clearly visible on the mining benches as we explored the cliff-like rock walls of the open pit for pockets where we might be lucky to find mineral specimens.

Magnificent Desolation

Buzz Aldrin uttered "Magnificent Desolation" on seeing the surface of the Moon for the first time. There are many parts of our planet that resonate with me and I can describe as "Magnificent Desolation". I have added a few pictures here on some of the places that I have seen that would earn the title of "Magnificent Desolation".
Pictures from the top down: Peruvian Andes, Peruvian Andes with limestone cliffs, Rosh Pinah region in southern Namibia. More pictures to come.