Meteorites and impacts / Meteoriten und Impakte

SPACE AND TIME - FEEL AMAZEMENT
RAUM UND ZEIT - STAUNEN KÖNNEN

"Who can no longer feel amazement, is as good as dead, a snuffed-out candle." These words of Albert Einstein are worth to reflect also in our fields of activity, be it the paleontology (near "endless" time) or the astronomy ("endless" space). This amazement is the cause of the research and the research is the cause of scientific knowledge. Everyone should preserve this emotion so that science does not ossify but develop verhemently.

The picture shows a "Hubble" photo. It is the Carina Nebula in a distance of 8000 light-years. One light-year is equivalent to 9,46 trillions of kilometers. - The little slice of a nickel-iron-meteorite shows the typical "Widmanstätten" structure of such material coming from the space, in this case from the meteorite belt between Mars and Jupiter. It reached us in Sweden 1906. (Collection and photo: Troppenz)

In the facebook group "Fossils Rocks Minerals Paleontology Geology Biology Astronomy & The Universe" Maria Angelica Muniz Frosi commented: "Thought and imagination. The dazzle of the indescribable that surrounds us is the first cause of the questions that science tries to explain !!! No scientist should miss this first look at the allure of existence!"

 

 

EINER DER ÄLTESTEN STEINE
IM SONNENSYSTEM: ALLENDE

ONE OF THE OLDEST STONES
IN OUR SOLAR SYSTEM: ALLENDE

I know: meteorite collectors smile tired. But for me and surely also for others this little stone (5,4 g) I got today of "The Meteorite Market"/USA is an estonishing-one. It outmatches Isua, Acasta, Nuvvuagittuq and even the zircons of Jack Hills - this stone is older than the Earth and has the name Allende. The meteorite had several tons, came down 1969 over Mexico, exploded and there was a rain of parts over an area of ca 10x50 kilometers.

Allende contains chondrules and others that are estimated to be 4.567 billion years old, the oldest known matter. This material is 30 million years older than the Earth. Thus, the Allende meteorite has revealed information about conditions prevailing during the early formation of the Solar System. Carbonaceous chondrites, including Allende, are the most primitive meteorites, and contain the most primitive known matter. They have undergone the least mixing and remelting since the early stages of Solar System formation. Because of this, their age is frequently taken as the "age of the Solar System."

The meteorite was formed from nebular dust and gas during the early formation of the Solar System. It is a "stony" meteorite, as opposed to an "iron," or "stony iron," the other two general classes of meteorite. Most Allende stones are covered, in part or in whole, by a black, shiny crust created as the stone descended at great speed through the atmosphere as it was falling towards the earth from space. This causes the exterior of the stone to become very hot, melting it, and forming a glassy "fusion crust."

My friend Ray Easterday wrote I should mention the ~ five billion year old presolar nanodiamonds (I.e., stardust) found within the Allende.

Ich weiß: Meteoritensammler lächeln müde. Aber für mich und gewiss auch für andere ist dieser kleine Stein (5,4 g), den ich heute vom "Meteorite Market"/USA erhielt, etwas Erstaunliches. Es schlägt Isua, Acasta, Nuvvugittuq und sogar die Zirkone von Jack Hills - dieser Stein ist älter als die Erde und trägt den Namen Allende. Der Meteorit wog mehrere Tonnen, kam 1969 über Mexiko nieder, explodierte, und es gab einen Regen von Teilen über einem Gebiet von rund 10x50 Kilometern.

Der Allende Meteorit besteht aus vielen rundlichen Calcium-Aluminium-reichen Einschluessen (Chondren) von ca 0.1 bis 2 mm Durchmesser in einer kohlig-metallischen Matrix. Die Materie des Meteoriten hat sich offenbar direkt aus der Gaswolke des enstehenden Sonnensystems geformt und ist damit etwa 30 Millionen Jahre älter als die Erde, die sich aus derselben Wolke vor etwa 4,54 Millionen Jahren formte.

Mein Freund Ray Easterday schrieb, ich sollte die ca. 5 Milliarden Jahre alten präsolaren Nanodiamanten erwähnen ("Sternenstaub"), die im Allende-Meteoriten gefunden worden sind.

 

Dünnschliff

Scheibe / Samml. Troppenz

 

 

ENTSTEHUNG DES SONNENSYSTEMS: SCHEIBE
VON "ALLENDE" MIT SICHTBAREN INHALTEN

GENESIS OF THE SOLAR SYSTEM: A SLICE
OF "ALLENDE" TO SHOW THE INGREDIENTS

I ordered a new piece of the Allende meteorite - which was generated during the genesis of the solar system nearly five billion years ago. When I posted a thin-section of the meteorite, Pranay Kumar asked me in the facebook group „Fossils Rocks Minerals Paleontology Geology Biology Astronomy & The Universe“, whether I could say something about "the exact composition" of this picture. But there was no explanation at the source. Now I show here my new Allende slice, another thin-section and a slize with a description of the ingredients. - Pictures: www.meteorites-for-sale.com and www.marmet-meteorites.com.

Ich habe ein neues Stück des Allende-Meteoriten bestellt - der sich während der Entstehung des Sonnensystems gebildet hat, fast fünf Milliarden Jahre vor unserer Zeit. Pranay Kumar fragte mich in der Facebook-Gruppe „Fossils Rocks Minerals Paleontology Geology Biology Astronomy &The Universe“, ob ich etwas über "die genaue Komposition" dieses Bildes sagen könne. Aber die Quelle sagte nichts darüber aus. Nun zeige ich also hier meine neue "Errungenschaft", einen anderen Dünnschliff und eine Allende-Scheibe mit der Beschreibung des Inhalts. - Bilder: www.meteorites-for-sale.com und www.marmet-meteorites.com.

Description:
 
The Allende meteorite fell just a few months before the Apollo 11 astronauts landed on the Moon, providing a unique opportunity for scientists to test many of the analytical techniques that they had developed to study the lunar samples.

Allende is a rare type of meteorite, a carbonaceous chondrite, so called because it is rich in carbon. Allende contains CAIs, calcium-aluminum inclusions, predominantly white to light gray in color, irregularly shaped, and rich in refractory (high-temperature) minerals and they are thought to have formed at the very beginning of the solar system about 4567 million years ago. In addition, Allende has many well defined, more or less spheroidal chondrules. Both, the chondrules and the CAIs formed during rapid heating events at the dawn of the solar system. Numerous analyses indicate that CAIs formed about two million years earlier than chondrules. Relict pieces of CAIs have even been found inside chondrules, and so must have formed earlier. However, rather strange is the fact, that two Japanese scientists of the Tokyo Institute of Technology found a chondrule inside a CAI, which strongly indicates that some chondrules must have formed before CAIs...

(a) shows amoeboid olivine aggregates, (b) an orthopyroxene rich chondrule, (c) might be a CM inclusion, (d) a melilite-fassaite-anorthite chondrule.

 


 

EIN STRAHLENKEGEL ERZÄHLT UNS VOM
SUDBURY-IMPAKT VOR 1,85 MILLIARDEN JAHREN

A SHATTER CONE TELLS US OF THE
SUDBURY IMPACT 1.85 BILLIONS AGO

Today I got a parcel of my friend Rich Helms with a remarkable stone in it: a shatter cone of the Sudbury Impact, 1.85 billions years old! I wrote about the evolutions and catastrophes in the Proterozoic in my book "The New Precambrian". So I mentioned the Vredefort Impact (South Africa) 2 billion years ago, which could have finished the Franceville Biota (Gabun, 2.1 billions), and the Sudbury Impact (Canada) 1.85 billlion years ago, which stood at the beginning of a new evolution I called the Montana Biota. Now I am happy to have a little part of this unbelievable important event in my hands...

The Sudbury Impact took place 1.852 billion years ago (+4/-3 million years), when a roughly 15-km-big asteroid struck today's Canadian province of Ontario and created a crater with a diameter of 200 to 250 km. - In order to visualize the huge consequences of two mentioned impacts, we can think of the impact at the K-Pg boundary between Cretaceous and Paleogene. This event contributed to one of the largest mass extinction events in the history of the Earth, with the dinosaurs among the extinct species. In the end, it paved the way for the new biosphere of the mammals. The Chicxulub crater: 66 million years ago, a 10- to 14-km-large asteroid hit the Gulf of Mexico with the five-billion-fold force of the atomic bomb on Hiroshima and a speed of just under 72,000 kilometres per hour. It created a crater with a depth of 10 km and a diameter of 200 km. As it were, this event is responsible for the transition from the Mesozoic era to the Cenozoic era. Thus, it forms a highly important geological and palaeontological cardinal point. The asteroid of the K-Pg boundary was considerably smaller than the two Precambrian specimens!

Heute erhielt ich ein Paket von meinem Freund Rich Helms mit einem bemerkenswerten Stein darin: ein Strahlenkegel vom Sudbury-Impakt, 1,85 Millliarden Jahre alt! Ich habe über die Evolutionen und Katastrophen im Proterozoikum in meinem Buch "The New Precambrian" (Deutsch: "Wohin die Spuren führen, Bd. 2) geschrieben. Dabei erwähnte ich den Vredefort- Impakt (Südafrika) vor 2 Milliarden Jahren, der vielleicht die Franceville-Fauna beendet hat (Gabun, 2,1 Milliarden), und den Sudbury-Impakt (Kanada) vor 1,85 Milliarden Jahren, der am Anfang einer neuen Entwicklung stand, die ich Montana-Fauna genannt habe. Jetzt bin ich sehr froh, einen kleinen Teil dieses unglaublich wichtigen Ereignisses in meinen Händen zu halten...

Der Sudbury-Groß-Impakt ereignete sich vor 1,852 (+4/-3 Mio.) Milliarden Jahren, als ein etwa 15 km großer Asteroid in der heutigen kanadischen Provinz Ontario einschlug und einen Krater mit einem Durchmesser von 200 bis 250 km verursachte. - Um sich vorzustellen, welche gewaltigen Folgen solche Impakte haben, kann man sich den Einschlag an der KT-Grenze zwischen Kreidezeit und Paläogen vor Augen halten, der mitverantwortlich für eines der größten Massen-Aussterben der Erdgeschichte war, darunter auch die Saurier, und den Weg freimachte für eine neue Biosphäre der Säugetiere. Der 10 bis 14 km große Asteroid, der sich vor 66 Millionen Jahren im Golf von Mexiko mit der fünfmilliardenfachen Kraft der Hiroshima-Atombombe und einer Geschwindigkeit von knapp 72.000 km/h in den Erdboden bohrte, riss den 10 km tiefen Chicxulub-Krater mit einem Durchmesser von 200 km in die Erde. Dieses Ereignis ist sozusagen verantwortlich für den Übergang zwischen dem Erdmittelalter und der Erdneuzeit, also ein ganz wichtiger geologisch-paläontologischer Kardinalpunkt. Der Asteroid an der KT-Grenze war erheblich kleiner als die beiden präkambrischen Exemplare!

 

 

IMPAKTE VOR 3 UND 2 MILLIARDEN JAHREN

IMPACTS 3 AND 2 BILLIONS OF YEARS AGO

 

As early as about 3 billion years ago, an asteroid impacted in the area of what today is Greenland. The original crater diameter is estimated at 500 to 600 kilometres.

The crater was discovered in 2012 by a research team led by Adam A. Garde at the Geological Survey of Denmark and Greenland (GEUS).  

Above computer graphics by Carsten E. Thuesen, GEUS.

The Vredefort crater in South Africa (to the right, photo: NASA) is roughly 2 billion years old and has a diameter that is hardly half as big.