New Paper on Permian-Triassic Extinction

Saturday, March 27, 2010 3:06 AM

Dear Friends,

There is a new paper about the Permian-Triassic extinction in
Chemical Geology. It is:

Brookfield, M. E., J. G. Shellnutt, L .Qi, R. Hannigan, G. M. Bhat ,
and P. B. Wignall, 2010, Platinum element group variations at
the Permo–Triassic boundary in Kashmir and British Columbia
and their significance. Chemical Geology. vol. 272, pp. 12-19.

the abstract is at:

"http://dx.doi.org/10.1016/j.chemgeo.2010.01.008

The paper concludes that the sources of the platinum element group
anomalies found at and near the Permian-Triassic boundary

are “either contemporaneous seawater or older basaltic volcanics
associated with the sections and the PGE were precipitated by
a possible combination of development of anoxia in the oceans
and post-depositional redistribution.”

A related paper is:

Brookfield, M. E., R. J. Twitchett and C. Goodings, 2003,
Palaeoenvironments of the Permian–Triassic transition sections
in Kashmir, India. Palaeogeography, Palaeoclimatology,
Palaeoecology. vol. 198, no. 3-4, pp. 353-371.

http://dx.doi.org/10.1016/S0031-0182

(03)00476-0

Yours,

Paul H.

Summary Paper About Scandinavian Impact Structures Wednesday, March 17, 2010

Summary Paper About Scandinavian Impact Structures

Wednesday, March 17, 2010 9:46 PM

Dear Friends,

There is an interesting summary paper about
Scandinavian impact structures that downloaded as
a PDF file. It even has a mps of recognized impact
structures in Scandinavia and discusses the fossil
meteorites found in the Thorsberg Quarry,
southern Sweden, and K-T boundary at Stevns
Klint, Denmark.

It is:

Dypvik, H., J. Plado, C. Heinberg, E. Hakansson, L. J.
Pesonen, B. Schmitz, and S. Raiskila, 2008, Impact
structures and events – a Nordic perspective.
Episodes. vol. 31, no. 1, pp. 107 -114.

The PDF files can be downloaded directly form:

http://www.episodes.org/backissues/33igc/15%20Impact%20%20structures-r.pdf

The link to the PDF file can be in “Episodes Special
Issue Title: “Nordic Geoscience and 33rd IGC 2008”” at:

http://www.episodes.org/backissues/33igc/33igc.htm

Yours,

Paul H.

K/T Boundary Clay at Stevns Klint Wednesday, March 17, 2010

K/T Boundary Clay at Stevns Klint

Wednesday, March 17, 2010 12:25 AM

In http://six.pairlist.net/pipermail/meteorite-list/2010-March/062190.html

,
(“K/T Boundary Clay”), Ed Majden wrote:

“There is some dispute with this material, as some
think it may be of volcanic origin, rather than
a meteorite impact, K/T boundary layer material”

The volcanic origin is an old hypothesis that has been
largely abandoned. The Fish Clay at Klint now is largely
regarded to consist of terrigenous sediments that
accumulated in the absence of biogenic carbonate during
the aftermath of the terminal Cretaceous impact. There
is an extraterrestrial component that has been mixed with
detrital terrestrial sediments by bioturbation and
reworking and redeposition of pre-existing sediments.

For example, Premovi (2009) concluded:

1. “IIIA smectite is probably mainly detrital and
redeposited from adjacent coastal and/or marine
areas.”

2. “The goethite-/FeS2-rich microspherules of layer
IIIA were initially enriched in Fe-oxides which were
replaced by goethite or FeS2 during early diagenesis

and 3. “Most of the microspherules and glasses of
layer IIIA are also probably detrital and simultaneously
redeposited with the smectite.”

The Fish Clay contains goethite-rich microspherules.
Currently, are argued as being authigenic in origin and
unrelated to any Cretaceous-Paleogene ejecta. Premovi
(2009) regards these microspherules to have been
created by pseudomorphic replacement of FeS2 rich
biogenic spherules.

Locality: Stevns Klint, Description of a Danish GeoSite
http://geosites.dk/lokaliteter/sjaelland/stevns_klint.html

Some papers about this are:

Bauluz, B., D. R. Peacor, and W. C. Elliott, Coexisting
Altered Glass and Fe-Ni Oxides at the Cretaceous-
Tertiary Boundary, Stevns Klint (Denmark): Direct
Evidence of Meteorite Impact,” Earth Planet. Science
Letters. vol. 182, pp. 127–136.

Christensen, L., S. Fregerslev, A. Simonsen, and
J. Thiede, 1973, Sedimentology and depositional
environment of Lower Danian fish clay from Stevns
Klint, Denmark. Bulletin of the geological Society
of Denmark. vol. 22, pp. 193-212.
http://2dgf.dk/xpdf/bull22-03-193-212.pdf

Drits, V. A., H. Lindgreen, B. A. Sahaov, H. J.
Jakonson, and B. B. Zviagina, 2004, The detailed
structure and origin of clay minerals at the
Cretaceous/Tertiary boundary, Stevns Klint (Denmark).
Clay Minerals. vol. 39, no. 4, pp. 367-390;
DOI: 10.1180/0009855043940141
http://claymin.geoscienceworld.org/cgi/content/abstract/39/4/367

http://cat.inist.fr/?aModele=afficheN&cpsidt=16450276

Ekdale, A. A., and R. G. Bromley, 1984, Sedimentology
and ichnology of the Cretaceous-Tertiary boundary in
Denmark; implications for the causes of the terminal
Cretaceous extinction. Journal of Sedimentary Research.
vol. 54, no. 3, p. 681-703
http://jsedres.sepmonline.org/cgi/content/abstract/54/3/681

Note: The above paper is a strong supporter of volcanic origin.

Hart, M. B., S. E. Feist, G. D. Price and M. J. Leng,
2004, Reappraisal of the K/T boundary succession at
Stevns Klint, Denmark. Journal of the Geological
Society. vol. 161, no. 5, pp. 885-892;
http://jgs.lyellcollection.org/cgi/content/abstract/161/5/885

Kastner, M., F. Asaro, H. V. Michel, W. Alvarez,
and L. W. Alvarez, 1984, The Precursor of the
Cretaceous-Tertiary Boundary Clays at Stevns Klint,
Denmark, and DSDP Hole 465A. Science. vol. 226.
no. 4671, pp. 137-143 DOI: 10.1126/science.226.4671.137
http://www.sciencemag.org/cgi/content/abstract/226/4671/137

“Formation from impact rather than from volcanic
glass is supported by its major element chemistry.”

Ortega-Huertas, M., F. Martinez-Ruiz, I. Palomo-Delgado,
and H. Camley, 2002, Review of the mineralogy of the
Cretaceous-Tertiary boundary clay: evidence supporting
a major extraterrestrial catastrophic event. Clay
Minerals. vol. 37, no. 3, pp. 395-411;
DOI: 10.1180/0009855023730054
http://claymin.geoscienceworld.org/cgi/content/abstract/37/3/395

Premovi, P. I., 2004, Cretaceous-Tertiary boundary
deposits in Denmark: A diachroneity. Journal Serbian
Chemical Society. vol. 71, no.7, pp. 793-806.
http://www.doiserbia.nb.rs/img/doi/0352-5139/2004/0352-51390407555P.pdf

Premovic, P. I., 2009, The conspicuous red “impact”
layer of the Fish Clay at Højerup (Stevns Klint,
Denmark). Geochemistry International. vol. 47, no. 5,
pp. 513-521.
http://www.springerlink.com/content/2tq1551k02800715/

“Smectite of the red layer of the KPB section at
Højerup is probably detrital and redeposited from
adjacent coastal or marine areas. This clay mineral
is likely mixed with a small amount of smectite
derived from impact glasses. Most of the
microspherules and nano-size glasses of the red
layer at Hojerup are probably detrital and
simultaneously redeposited with smectite.”

Premovi, P. I., B. Z. Todorovi, and M. S. Pavlovi,
2007, Cretaceous Paleogene boundary Fish Clay at
Hojerup (Stevns Klint, Denmark): trace metals in
kerogen. Bulletin de la Societe Geologique de France.
vol. 178, no. 5, p. 411-421; DOI: 10.2113/gssgfbull.178.5.411
http://bsgf.geoscienceworld.org/cgi/content/abstract/178/5/411

http://www.doiserbia.nb.rs/img/doi/0352-5139/2008/0352-51390804453P.pdf

Premovic, P. I., B. Z. Todorovic, and M. S.
Pavlovic, 2008, Cretaceous-Paleogene boundary (KPB)
Fish Clay at Hojerup (Stevns Klint, Denmark): Ni, Co,
and Zn of the black marl Geologica Acta, vol. 6,
no. 4, pp. 369-382. DOI: 10.1344/105.000000264
http://www.geologica-acta.com/pdf/vol0604a07.pdf

Premovi, P. I., M. M. Krsmanovic, B. Z. Todorovi,
M. S. Palovi, N. D. Nikolic, and D. M. Djordjevi,
2006, Geochemistry of the Cretaceous-Tertiary
boundary (Fish Clay) at Stevns Klint (Denmark): Ir,
Ni and Zn in kerogen. Journal Serbian Chemical
Society. vol. 71, no.7, pp. 793-806.
http://www.doiserbia.nb.rs/img/doi/0352-5139/2006/0352-51390607793P.pdf

Surlyk, F., T. Damholt, and M. Bjerager, 2006, Stevns Klint,
Denmark: Uppermost Maastrichtian Chalk, Cretaceous–
Tertiary Boundary, and Lower Danian Bryozoan Mound
Complex. Bulletin of the Geological Society of Denmark.
vol. 4, pp. 1–48.
http://2dgf.dk/xpdf/bull54.pdf

Yours,
Paul H.

Cassini Captures Colossal Crater on Tethys Tuesday, March 16, 2010

Cassini Captures Colossal Crater on Tethys

Tuesday, March 16, 2010 8:47 PM

Cassini Captures — Colossal Crater Contrast
SatNews Publishers - ‎Mar 15, 2010‎

http://www.satnews.com/cgi-bin/story.cgi?number=525315055

Yours,

Paul H.

Ancient Clams Reveal How Earth Rebounded From Mass Extinction Tuesday, March 16, 2010

Ancient Clams Reveal How Earth Rebounded From Mass Extinction

Tuesday, March 16, 2010 8:41 PM

Ancient clams discovered by College of Wooster geologist reveal
how Earth rebounded from mass extinction by John Mangels,
The Plain Dealer, February 27, 2010

http://www.cleveland.com/science/index.ssf/2010/02/ancient_clams_discovered_by_co.html

Yours,

Paul H.

Why isn`t documenting meteorites stressed enough? Monday, March 15, 2010

Why isnt documenting meteorites stressed enough?

Monday, March 15, 2010 10:37 AM

cdtucson@cox.net wrote:

>Interesting points here.
>Falls a bit outside of the field of meteoritics but, still a
>fair use for old strewnfield co-ords.
>I wonder Paul. Has this data ever been used in such a way?

I do not know of meteorite strew fields being used this way
specifically. However, the strewn fields for impact ejecta
have been used widely in geology as part of a field of
geologic research called "Impact stratigraphy,"which
a subdivision of "event stratigraphy".

Go see:

Keller, G., 2008, Impact stratigraphy: Old principle, new
reality. In The Sedimentary Record of Meteorite Impacts,
Special Papers no. 437, Geological Society of America.

http://specialpapers.gsapubs.org/content/437/147.abstract

and Montanari, A., 2000, Impact Stratigraphy. Lecture
notes in earth sciences no. 93. Springer, New York.

http://openlibrary.org/b/OL18113398M/Impact_stratigraphy

One extreme example is the way that the Cretaceous- Tertiary
ejecta layer has been used a global time-stratigrapher marker.
Also, the tektites, mainly the microtektites, of the Australasian
tektite strewn field has been used as time-stratigraphic marker
bed in correlating deep sea cores, Chinese loess deposits, and
for use in geomorphic studies. One archaeological site in
China is dated by Australasian tektites. Similarly, iridium
anomalies and microtektites have been used to correlate
Eocene deposits in Europe. Most recently, impact ejecta
from the Sudbury impact has been to correlate Precambrain
strata in the Lake Superior region and the ejecta from other
Precambrian ejecta have been used to correlate Precambrian
strata across Australia and Africa.

Examples of using the ejecta strewn field of Precambrian
impacts to correlate and date Precambrian strata can found in:

Gostin, V. A., P. W. Haines, R. J. F. Jenkins, W. Compston,
and I. S. Williams, 1986, Impact ejecta horizon within late
Precambrian shales, Adelaide Geosyncline, South Australia.
Science. vol. 233, pp. 198-200.

http://www.sciencemag.org/cgi/content/abstract/233/4760/198

Yours,

Paul

Meteorites may have kick-started life on Earth Sunday, March 14, 2010

Meteorites may have kick-started life on Earth

Sunday, March 14, 2010 2:50 AM

1. Meteorites may have kick-started life on Earth, The Telegraph,
March 11, 2010,

http://www.telegraph.co.uk/science/space/7418915/Meteorites-may-have-kick-started-life-on-Earth.html

"Meteorites that bombarded Earth four billion years ago could
have kick-started life rather than wiping it out, a study shows."

2. Meteorites may have nurtured early life on Earth, TG Daily

http://www.tgdaily.com/general-sciences-features/48805-meteorites-may-have-nurtured-early-life

The paper is:

Parnell, J., A. Boyce, S. Thackrey, D. Muirhead, P. Lindgren,
C. Mason, C. Taylor, J. Still, S. Bowden, G. R. Osinski, and
P. Lee, 2010, Sulfur isotope signatures for rapid colonization
of an impact crater by thermophilic microbes. Geology.
vol. 38, no. 3, pp. 271-274. doi: 10.1130/G30615.1

http://geology.geoscienceworld.org/cgi/content/abstract/38/3/271

Yours,

Paul H.

New Paper about Cretaceous-Paleogene Extinctions Sunday, March 14, 2010

New Paper about Cretaceous-Paleogene Extinctions

Sunday, March 14, 2010 10:56 AM

Dear Friends,

There is a new paper that proposes an interesting and novel
idea about the selectivity of the Cretaceous-Paleogene Extinctions.

It is:

Kikuchi, R., and M. Vanneste, 2010, A theoretical
exercise in the modeling of ground-level ozone resulting
from the K–T asteroid impact: Its possible link with the
extinction selectivity of terrestrial vertebrates.
Palaeogeography, Palaeoclimatology, Palaeoecology.
vol. 288, no. 1-4, pp.14–23.

http://dx.doi.org/10.1016/j.palaeo.2010.01.027

A somewhat unrelated and downloadable PDF file about
about "meteorites, impacts, and mass extinction" is:

Meteorites, Impacts, and Mass Extinction
by Prof. Stephen A. Nelson, Tulane University

http://www.tulane.edu/~sanelson/geol204/impacts.pdf

http://www.tulane.edu/~sanelson/geol204/index.html

Yours,

Paul H.

Why isn't documenting meteorites stressed enough?

Paul Heinrich
Sun Mar 14 21:37:52 EDT 2010

cdtucson wrote:

>Interesting points here.
>Falls a bit outside of the field of meteoritics but, still a
>fair use for old strewnfield co-ords.
>I wonder Paul. Has this data ever been used in such a way?

I do not know of meteorite strew fields being used this way
specifically. However, the strewn fields for impact ejecta
have been used widely in geology as part of a field of
geologic research called "Impact stratigraphy,"which
a subdivision of "event stratigraphy".

Go see:

Keller, G., 2008, Impact stratigraphy: Old principle, new
reality. In The Sedimentary Record of Meteorite Impacts,
Special Papers no. 437, Geological Society of America.

http://specialpapers.gsapubs.org/content/437/147.abstract

and Montanari, A., 2000, Impact Stratigraphy. Lecture
notes in earth sciences no. 93. Springer, New York.

http://openlibrary.org/b/OL18113398M/Impact_stratigraphy

One extreme example is the way that the Cretaceous- Tertiary
ejecta layer has been used a global time-stratigrapher marker.
Also, the tektites, mainly the microtektites, of the Australasian
tektite strewn field has been used as time-stratigraphic marker
bed in correlating deep sea cores, Chinese loess deposits, and
for use in geomorphic studies. One archaeological site in
China is dated by Australasian tektites. Similarly, iridium
anomalies and microtektites have been used to correlate
Eocene deposits in Europe. Most recently, impact ejecta
from the Sudbury impact has been to correlate Precambrain
strata in the Lake Superior region and the ejecta from other
Precambrian ejecta have been used to correlate Precambrian
strata across Australia and Africa.

Examples of using the ejecta strewn field of Precambrian
impacts to correlate and date Precambrian strata can found in:

Gostin, V. A., P. W. Haines, R. J. F. Jenkins, W. Compston,
and I. S. Williams, 1986, Impact ejecta horizon within late
Precambrian shales, Adelaide Geosyncline, South Australia.
Science. vol. 233, pp. 198-200.

http://www.sciencemag.org/cgi/content/abstract/233/4760/198

Yours,

Paul

Canadian lasers key to NASA asteroid landing project

Paul Heinrich
Sun Mar 14 01:08:37 EST 2010

---

Canadian lasers key to NASA asteroid landing project
http://www.montrealgazette.com/technology/Canadian+lasers+NASA+asteroid+landing+project/2677412/story.html

"Three high-precision, Canadian-built lasers are at the centre
of a NASA-led proposal to land an unmanned probe on a
distant asteroid that's expected to yield crucial clues about
the origins of the Earth."

Yours,

Paul H.

Why isn't documenting meteorites stressed enough?

Paul Heinrich
Sat Mar 13 21:33:45 EST 2010

Eric wrote:

"Meteorite fragments found on dry lake beds or
anywhere on "old ground", do in fact move. In
my opinion coordinate data is still valuable, but
not as valuable as say data from a fresh meteorite
fall."

As a geomorphologist, I would disagree. Such data
from either "old ground" or "prehistoric falls" might
be just as valuable as data from fresh falls. The
distribution data from prehistoric falls, if collected
and preserved might be useful in evaluating the type
and rate of the geomorphic processes that modify and
the age of the landforms on which they are found.
This is because a meteorite strewn field in many ways
is a chronostratigarphic equivalent of a volcanic ash
beds in terms of providing a "deposit" that is of the same
age / point in time everywhere that pieces of it are found.
The way that individual meteorites belonging to a single
strewn field are moved about could be used to infer how
the surface of a landform has been modified and at what
rate since the meteorite fall creating it occurred. If the
strewn field data was collected and was accessible, I
would suspect that geomorphologists would use that
data in a wide variety of novel ways that neither I or
nobody else on this list could at this time predict or image.

Of course, once the "taphonomic" processes determining
how meteorites are moved around after a fall and whether
or not they are preserved are understood, I suspect that a
person can "back engineer" the process to predict where
to look for "fossil meteorites" from past falls even if they
have been buried. I still think that there a number of
Chinese falls, where even though they occurred centuries
ago, a person has a significant chance of still being able
to find meteorites from them if their "taphonomy" could
be figured out and predictions made as to where exactly
to look.

Looking at some of the phrase diagrams that
archaeologists have made showing the relationship
between different physical characteristics of soils
and sediments and the long term survival of iron
artifacts, it is quite clear that iron objects, including
meteorites, under specific circumstances can survive
even in wet soils and sediments that they become
buried in for significantly long periods of time.
They might be bit too rusty for many collector's
tastes. Still, they still have scientific value even in
less than pristine condition.

Just Some Thoughts,

Paul H.

New Paper about Cretaceous-Paleogene Extinctions

Paul Heinrich
Sat Mar 13 20:56:17 EST 2010

Dear Friends,

There is a new paper that proposes an interesting and novel
idea about the selectivity of the Cretaceous-Paleogene Extinctions.

It is:

Kikuchi, R., and M. Vanneste, 2010, A theoretical
exercise in the modeling of ground-level ozone resulting
from the K–T asteroid impact: Its possible link with the
extinction selectivity of terrestrial vertebrates.
Palaeogeography, Palaeoclimatology, Palaeoecology.
vol. 288, no. 1-4, pp.14–23.

http://dx.doi.org/10.1016/j.palaeo.2010.01.027

A somewhat unrelated and downloadable PDF file about
about "meteorites, impacts, and mass extinction" is:

Meteorites, Impacts, and Mass Extinction
by Prof. Stephen A. Nelson, Tulane University

http://www.tulane.edu/~sanelson/geol204/impacts.pdf
http://www.tulane.edu/~sanelson/geol204/index.html

Yours,

Paul H.

Shocked quartz and other mineral inclusions in Australasian microtektites Tuesday, March 9, 2010

Shocked quartz and other mineral inclusions in Australasian microtektites

Tuesday, March 9, 2010 10:39 PM

Folco, L. N. Perchiazzi, M. D'Orazio, M. L. Frezzotti, B. P.
Glass, and P. Rochette, 2010, Shocked quartz and other mineral
inclusions in Australasian microtektites. Geology, v. 38,
no. 3, p. 211-214.

http://geology.geoscienceworld.org/cgi/content/abstract/38/3/211

Shocked quartz and other mineral inclusions in Australasian
microtektites. March 2010 Geology and GSA Today Highlights

http://www.physorg.com/wire-news/29077449/march-2010-geology-and-gsa-today-highlights.html

“In a study by Folco et al., the application of high-resolution
analytical techniques including syncrothron X-ray diffraction,
field emission scanning electron microscopy, and microraman
spectroscopy led to the discovery of microscopic mineral
inclusions in Australasian microtektites recovered from deep-sea
sediment cores within 2000 km of Indochina. Inclusions consist
of frequent shocked quartz plus a Zr-phase and trace of Fe-oxide
crystallites. The shocked quartz and the Zr-phase are interpreted
as relicts of the target rock. The occurrence of partially melted
quartz relicts and fluidal structures (schlieren) confirms that
microtektites are quenched molten droplets and not condensates
from a hot plume of vaporized crustal rocks. Furthermore, the
internal homogeneity of Australasian microtektites in terms of
abundance of relict mineral inclusions, vesicles, and schlieren
increases with distance from Indochina. This finding strengthens
the current hypothesis that the source crater of the largest and
youngest tektite-strewn field on Earth is located in the Indochina
region, as internal heterogeneity characterizes normal impact
glass found in or near the source crater. This finding also indicates
that the Australasian microtektites with the longest trajectories
experienced the highest temperature-time regimes. Lastly, the
definition of microtektites should include the possible occurrence
of microscopic relict inclusions as an indication of proximity to
the source crater.”

Related papers are:

Glass , B. P., and C. Koeberl, 2006, Australasian microtektites and
associated impact ejecta in the South China Sea and the Middle
Pleistocene supereruption of Toba. Meteoritics & Planetary Science
vol. 41, no. 2, pp. 305–326.

PDF file at:
http://www.univie.ac.at/geochemistry/koeberl/publikation_list/279-Australasian-microtektites-and-Toba-MAPS2006.pdf

Prasad, M. S., V. P. Mahale and V. N. Kodagali, 2007, New sites of
Australasian microtektites in the central Indian Ocean: Implications for
the location and size of source crater. Journal of Geophysical Research,
(E: Planets), vol.112, E06007, doi:10.1029/2006JE002857.

PDF file at:
http://drs.nio.org/drs/bitstream/2264/635/4/J_Geophys_Res_112_E_E06007.pdf

Extraterrestrial matter in the oceans, lecture by Dr. M. S. Prasad. PDF file at:
http://drs.nio.org/drs/bitstream/2264/738/2/Refresher_Course_Mar_Geol_Geophys_2007_Lecture_Notes_84.pdf

Yours,

Paul H.

Jungle-Covered Impact Crater in Columbia (Vichada crater) Tuesday, March 9, 2010

Jungle-Covered Impact Crater in Columbia (Vichada crater)

Tuesday, March 9, 2010 10:42 PM

Jungle-Covered Impact Crater by R. Martin, February 27, 2010

http://scienceblogs.com/aardvarchaeology/2010/02/jungle-covered_impact_crater.php

Planetary Society Researcher Max Rocca Discovers Largest
Impact Crater in South America: A Target Earth update by Amir
Alexander, The Planetary Society

http://www.planetary.org/programs/projects/targetearth/20100213.html

Yours,

Paul H.

Using Grain-Size to Interpret Cretaceous-Paleogene Extinction Event Tuesday, March 9, 2010

Using Grain-Size to Interpret Cretaceous-Paleogene Extinction Event

Tuesday, March 9, 2010 10:47 PM

Bralower, T., L. Eccles, J. Kutz, T. Yancey, J. Schueth, M. Arthur,
and D. Bice, 2010, Grain size of Cretaceous-Paleogene boundary
sediments from Chicxulub to the open ocean: Implications for
interpretation of the mass extinction event. Geology, v. 38,
no. 3, p. 199-202; DOI: 10.1130/G30513.1

http://geology.geoscienceworld.org/cgi/content/abstract/38/3/199

Grain size of Cretaceous-Paleogene boundary sediments from
Chicxulub to the open ocean: Implications for interpretation
of the mass extinction event March 2010 Geology and GSA
Today Highlights.

http://www.physorg.com/wire-news/29077449/march-2010-geology-and-gsa-today-highlights.html

“The causes of the mass extinction of 75% of marine and 50%
of terrestrial species (including the dinosaurs) at the
Cretaceous-Tertiary boundary, 65 million years ago, has been
the subject of raging debate. The majority of scientists support
the theory that the impact of an asteroid on the Yucatan
Peninsula (Mexico) was the trigger of the extinctions. The most
potent evidence for this theory is a layer of rock containing
telltale signs of impact, including melt droplets and shocked
mineral grains that can be traced from the Yucatan around the
world. Basing their research on fossils in rocks around the
Gulf of Mexico, a group of scientists have recently proposed
that the Yucatan impact preceded the mass extinction by 300
thousand years, and that the extinction was caused by a
massive volcanic event in India. The current study by Bralower
et al., however, leads to a different conclusion through the
analysis of sediment particle size in Cretaceous-Tertiary
boundary samples to determine the origin of fossil shells. The
data demonstrate that fossils in Cretaceous-Tertiary boundary
rocks around the Gulf of Mexico region are eroded from
underlying layers by a tsunami at the impact event. Thus
they rule out the correlation of the mass extinction event with
Indian volcanism and conclusively support the connection with
the Yucatan impact.”

Yours,

Paul H.

Clue to Antarctica Space Blast Thursday, March 4, 2010

Clue to Antarctica Space Blast

Thursday, March 4, 2010 12:57 PM

Greg wrote:

“Interesting

http://news.bbc.co.uk/2/hi/science/nature/8547534.stm

Clues to Antarctica space blast By Paul Rincon
Science reporter, BBC News, The Woodlands, Texas”

The paper is:

Engrand, C. B. Narcisi, J. r. Petit, E. Dobrica, and J. Duprat,
2010, Isotopes of EPICA — Dome C Extraterrestrial Dust Layers:
Constraints on the Nature of the Impactors. 41st Lunar and
Planetary Science Conference, held March 1-5, 2010 in The
Woodlands, Texas. LPI Contribution No. 1533, p.1981

http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1981.pdf

http://adsabs.harvard.edu/abs/2010LPI....41.1981E

Related papers are:

1. Misawa, K., M. Kohno, T. Tomiyama, T. Noguchi, T.
Nakamura, K. Nagao, T.Mikouchi, and K. Nishiizumi, 2010,
Two extraterrestrial dust horizons found in the Dome Fuji
ice core, East Antarctica. Earth and Planetary Science Letters.
vol. 289, no. 1-2, pp. 287-297.

http://dx.doi.org/10.1016/j.epsl.2009.11.016

http://www.ssl.berkeley.edu/cosmochem/publications.html

The PDF for the above paper can be downloaded from
the link for this paper at:

http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235801%232010%23997109998%231578540%23FLA%23&_cdi=5801&_pubType=J&view=c&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0377f75ed4c6eabaca0119b87f30f76c

2. Narcisi, B., J. Robert Petit, and B. Delmonte, nd, Extended
East Antarctic ice-core tephrostratigraphy Quaternary Science
Reviews, Article in Press, Corrected Proof

http://dx.doi.org/10.1016/j.quascirev.2009.07.009

3. Narcisi, B., J. R. Petit, and C. Engrand, 2007, First discovery
of meteoritic events in deep Antarctic (EPICA-Dome C) ice cores.
de la Recherche Scientifique & Université Paris Sud, Orsay, France)
Geophysical Research Letters. vol. 34, no. 15, CiteID L1550

http://adsabs.harvard.edu/abs/2007GeoRL..3415502N

http://www.agu.org/pubs/crossref/2007/2007GL030801.shtml

A summary paper about the ice cores:

Wolff, E. W., C. Barbante. S. Becagli, and many, many others,
2010, Changes in environment over the last 800,000 years from
chemical analysis. Quaternary Science Reviews. vol. 29,
pp. 285–295.

http://www.climate.unibe.ch/~stocker/papers/wolff10qsr.pdf

http://www.climate.unibe.ch/~stocker/publications10.html

Yours,

Paul H.

Clue to Antarctica Space Blast

Paul Heinrich
Wed Mar 3 22:57:21 EST 2010

Greg wrote:

“Interesting

http://news.bbc.co.uk/2/hi/science/nature/8547534.stm

Clues to Antarctica space blast By Paul Rincon
Science reporter, BBC News, The Woodlands, Texas”

The paper is:

Engrand, C. B. Narcisi, J. r. Petit, E. Dobrica, and J. Duprat,
2010, Isotopes of EPICA — Dome C Extraterrestrial Dust Layers:
Constraints on the Nature of the Impactors. 41st Lunar and
Planetary Science Conference, held March 1-5, 2010 in The
Woodlands, Texas. LPI Contribution No. 1533, p.1981

http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1981.pdf
http://adsabs.harvard.edu/abs/2010LPI....41.1981E

Related papers are:

1. Misawa, K., M. Kohno, T. Tomiyama, T. Noguchi, T.
Nakamura, K. Nagao, T. Mikouchi, and K. Nishiizumi, 2010,
Two extraterrestrial dust horizons found in the Dome Fuji
ice core, East Antarctica. Earth and Planetary Science Letters.
vol. 289, no. 1-2, pp. 287-297.

http://dx.doi.org/10.1016/j.epsl.2009.11.016
http://www.ssl.berkeley.edu/cosmochem/publications.html

The PDF for the above paper can be downloaded from
the link for this paper at:

http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235801%232010%23997109998%231578540%23FLA%23&_cdi=5801&_pubType=J&view=c&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0377f75ed4c6eabaca0119b87f30f76c

2. Narcisi, B., J. Robert Petit, and B. Delmonte, nd, Extended
East Antarctic ice-core tephrostratigraphy Quaternary Science
Reviews, Article in Press, Corrected Proof

http://dx.doi.org/10.1016/j.quascirev.2009.07.009

3. Narcisi, B., J. R. Petit, and C. Engrand, 2007, First discovery
of meteoritic events in deep Antarctic (EPICA-Dome C) ice cores.
de la Recherche Scientifique & Université Paris Sud, Orsay, France)
Geophysical Research Letters. vol. 34, no. 15, CiteID L1550

http://adsabs.harvard.edu/abs/2007GeoRL..3415502N
http://www.agu.org/pubs/crossref/2007/2007GL030801.shtml

A summary paper about the icecores:

Wolff, E. W., C. Barbante. S. Becagli, and many, many others,
2010, Changes in environment over the last 800,000 years from
chemical analysis. Quaternary Science Reviews. vol. 29,
pp. 285–295.

http://www.climate.unibe.ch/~stocker/papers/wolff10qsr.pdf
http://www.climate.unibe.ch/~stocker/publications10.html

Yours,

Paul H.

Impacts do not initiate volcanic eruptions

Tuesday, March 2, 2010 7:06 AM

Dear Friends,

I found a PDF reprint file of the below paper:

Ivanov, B. A., and H. J. Melosh, 2003, Impacts do not initiate
volcanic eruptions: Eruptions close to the crater. Geology.
vol. 31, no. 10, pp. 869-872; DOI: 10.1130/G19669.1

http://www.lpl.arizona.edu/~jmelosh/ImpactVolcanism.pdf

the comment and reply are also free as PDf files:

Glikson, A. Y., 2004, Impacts do not initiate volcanic eruptions:
Eruptions close to the crater: Comment and Reply: Comment.
Geology. vol. 32, no. 1 p. e48.

http://geology.gsapubs.org/content/32/1/e48.1.full.pdf+html

http://geology.gsapubs.org/content/32/1/e48.1.full

http://geology.gsapubs.org/content/32/1.toc

Ivanov, B. A., and H. J. Melosh, 2004, Impacts do not initiate
volcanic eruptions: Eruptions close to the crater: Comment
and Reply: REPLY. Geology. vol. 32, no. 1,
pp. e48-e49, doi:10.1130/0091-7613-32.1.e49

http://geology.gsapubs.org/content/32/1/e48.2.full

http://geology.gsapubs.org/content/32/1/e48.2.full.pdf+html

http://geology.gsapubs.org/content/32/1.toc

Yours,

Paul H.

Science page update / desert varnish on meteorites

Tuesday, March 2, 2010 7:23 AM

Greg wrote:

“I’m wondering if the formation of desert varnish
can vary depending on different biological and
environmental factors. Perhaps in one area a
similar thickness may take a shorter period of
time. 100,000 years is a long time, but I guess
not that long in geological time. This is interesting
in that some meteorites may have been sitting
on earth for a very long time.”

Below are some interesting pages about desert varnish:

Rock Varnish (desert varnish): An Internet Primer for
Rock Art Research by Ronald I. Dorn , Professor of
Geography Arizona State University

http://alliance.la.asu.edu/dorn/VarnishPages/VarnishPrimerIntro.html

Chapter 8 in Geochemical Sediments and Landscapes
http://alliance.la.asu.edu/dorn/VarnishPages/GeochemicalSediments/GeochemicalSediments.html

http://alliance.la.asu.edu/dorn/DornCh08.pdf

Note: the above URL to Chap. 8, has numerous links to
PDF file of papers about rock varnish.

Desert Varnish
http://alliance.la.asu.edu/dorn/DesertVarnishDornFormat.pdf

Varnish Micro-Lamination (VML) Dating

http://www.vmldating.com/

PDF files of various publication about rock varnish can
be downloaded from “Selected Publications on
Methodology and Application of VML Dating” at:

http://www.vmldating.com/selectedpapers.html

Yours,

Paul H.

Microfossils Shed Light on Cretaceous/Palaeogene Extinction Tuesday, March 2, 2010

Microfossils Shed Light on Cretaceous/Palaeogene Extinction

Tuesday, March 2, 2010 10:36 PM

Tiny Shelled Creatures Shed Light on Extinction and
Recovery 65 Million Years Ago, Science Daily, March 1, 2010

http://www.sciencedaily.com/releases/2010/03/100301102805.htm

“An asteroid strike may not only account for the demise
of ocean and land life 65 million years ago, but the
fireball's path and the resulting dust, darkness and
toxic metal contamination may explain the geographic
unevenness of extinctions and recovery, according to
Penn State geoscientists.”

Jiang, S. T. J. Bralower, M. E. Patzkowsky, L. R. Kump,
and J. D. Schueth, 2010, Geographic controls on
nannoplankton extinction across the Cretaceous/Palaeogene
boundary. Nature Geoscience, DOI: 10.1038/ngeo775

http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo775.html

Yours,

Paul H.

Recent Papers About Permian-Triassic Extinction Tuesday, March 2, 2010

Recent Papers About Permian-Triassic Extinction

Tuesday, March 2, 2010 10:37 PM

Flash Recovery Of Ammonoids After Most Massive Extinction
Of All Time. Science Daily, Sep. 14, 2009.

http://www.sciencedaily.com/releases/2009/09/090902122331.htm

The paper is:

Brayard ,A., G. Escarguel, H. Bucher, C. Monnet, T. Brühwiler,
N. Goudemand, T. Galfetti, and J. Guex, 2009, Good Genes
and Good Luck: Ammonoid Diversity and the End-Permian
Mass Extinction. Science, 2009, vol. 325, no. 5944,
pp. 1118 DOI: 10.1126/science.1174638

http://www.sciencemag.org/cgi/content/abstract/325/5944/1118

Another article is:

Mass Extinctions: 'Giant' Fossils Are Revolutionizing Current
Thinking. Science Daily, Feb. 11, 2010.

The paper is:

http://www.sciencedaily.com/releases/2010/02/100210171413.htm

Brayard A., A. Nutzel, D. A. Stephen, K. G. Bylund, J. Jenks,
and H. Bucher, 2010, Gastropod evidence against the Early
Triassic Lilliput effect. Geology. vol. 38, no. 2, pp. 147-150.
DOI: 10.1130/G30553.1

http://geology.gsapubs.org/content/38/2/147

Yours,

Paul H.

"What kind of Meteorite do I have?"

by Paul Heinrich
Mon Mar 1 00:36:40 EST 2010

Dear Friends,

Someone on this list might want to help out a person
on "Yahoo Answers", who is in need of an answer
and some reality about a rock that he has. The question
can be found in"What kind of Meteorite do I have?" at:

http://answers.yahoo.com/question/index;_ylt=AiYLiv68eezwjYD40iKJy_AjzKIX;_ylv=3?qid=20100226200734AA5yizm

The pictures of the alleged "meteorite" are at:

http://i1020.photobucket.com/albums/af327/mastermindjo/100_0202.jpg
http://i1020.photobucket.com/albums/af327/mastermindjo/100_0201.jpg
http://i1020.photobucket.com/albums/af327/mastermindjo/100_0200.jpg

Someone, who has a lot more experience with being
diplomatic in breaking the bad news than I have, likely
needs to answer his question.

Yours,

Paul H.
Baton Rouge, LA 70803