Impact Origin of Silverpit Structure Disputed

Paul bristolia at yahoo.com
Fri Mar 30 09:48:46 EDT 2007

The controversy over the origin of the Silverpit
Structure continues.

UK impact crater debate heats up by Jonathan Fildes
BBC News, March 30, 2007

http://news.bbc.co.uk/2/hi/science/nature/6503543.stm

Geology of Silverpit Structure Area

http://news.bbc.co.uk/2/hi/science/nature/6503543.stm#map

Alternative Theory for Origin of Silverpit Structure

http://news.bbc.co.uk/2/shared/spl/hi/pop_ups/07/sci_nat_enl_1175254561/html/1.stm

Best Regards,

Paul
Baton Rouge, LA

New Meteorite Crater Found in California

Paul bristolia at yahoo.com
Fri Mar 30 09:04:18 EDT 2007

1. Giant Meteorite Hit Ancient California, Crater Study Suggests
by John Roach, National Geographic News, March 27, 2007

http://news.nationalgeographic.com/news/2007/03/070327-california-crater.html

"The proposed impact may have created the giant 3.4-mile-wide
(5.5-kilometer-wide) craterlike formation that the team found
buried 4,900 to 5,250 feet (1,490 to 1,600 meters) below sea
level west of Stockton, California."

they think it is between 37 to 49 million years old.

++++

2. Oil exploration in California Reveals Giant Impact Crater
CCN Magazine, CA - Mar 22, 2007

http://www.ccnmag.com/news.php?id=4947

++++

3. Crater' spied under California, BBC News, UK, March 16, 2007

http://news.bbc.co.uk/2/hi/science/nature/6458841.stm

Bets Regards,

Paul
Baton Rouge, LA

Need Recommendations for Petrographic Thin Section Maker

Paul bristolia at yahoo.com
Thu Mar 29 14:45:50 EDT 2007

Dear list members,

I need a number of petrographic thin sections made
for a project. Unfortunately, the petrographic thin
section lab, which I used has gone out of business.

Can anyone recommend, off list if desired, one or
more petrographic thin section lab(s), who make
quality standard petrographic thin sections?

Yours,

Paul
Baton Rouge, LA

New Paper in Chicxulub - K-T Boundary Controversy Published

Paul bristolia at yahoo.com
Tue Mar 13 08:36:08 EDT 2007

Dr. Gerta Keller and coauthors have published another paper
about their hypothesis that the Chicxulub impact predates
K–T boundary. This time, they reinterpret the K-T Boundary
found exposed along and near the Brazos River in Texas.

The paper is:

Keller, G., T. Adatte, Z. Berner, M. Harting, G. Baum, M.
Prauss, A. Tantawy and D. Stueben, 2007, Chicxulub impact
predates K–T boundary: New evidence from Brazos, Texas.
Earth and Planetary Science Letters. vol. 255, no. 3-4 , 30
pp. 339-356. doi:10.1016/j.epsl.2006.12.026

The link to the abstract can be found at:

http://www.sciencedirect.com/science/journal/0012821X

Best Regards,

Paul H.

Impact Origin of Carolina Bays Argued For at 2007AGU Meeting

Paul bristolia at yahoo.com
Sun Mar 11 11:04:01 EDT 2007

Sterling K. Webb wrote on Sun March 11, 2007

>Hi, List,

>

>Thanks, Paul, for those links.

You and the list might be interested to know that
there is a competing session Carolina Bays. A more
mainstream point of view on their formation will be
given at the Geological Society of America Southeastern
Section-56th Annual Meeting (29-30 March 2007) in a
session titled "S6. Geology and Ecology of Carolina
Bays" at:

http://gsa.confex.com/gsa/2007SE/finalprogram/session_18800.htm

The paper in this session include 1. "The Sedimentology
and Ages of Carolina Bays Sand Rims" by Dr. Ivestor at:

http://gsa.confex.com/gsa/2007SE/finalprogram/abstract_119179.htm

This abstract states in part:

"Water-lain pebbles intercalated with eolian sands indicate
that these are typical shoreline deposits resulting from
fluctuations in water level."

"At individual bays where concentric rims occur, dating has
established that rims are progressively younger toward the center
of the bay, reflecting a regressive sequence and confirming that
the bays are not single-event features but evolve as a result of
processes active episodically over a long period of time. Active
shorelines and associated eolian deposition occurred during
marine isotope stage (MIS) 2 to late MIS 3 (~12 to 50 ka), MIS 4
to very late MIS 5 (60-80 ka), and late MIS 6 (120 to 140 ka)
based on a cumulative total of 45 OSL dates. These age ranges
also correspond with the ages of other eolian landforms in the
Coastal Plain, including sand sheets and dunefields, and suggest
a climatic threshold was crossed during the transition toward
glacial stadials, initiating both bay and dune activity."

Another abstract is "Geomorphic History of the Carolina Bays"
by Ray Kaczorowski at:

http://gsa.confex.com/gsa/2007SE/finalprogram/abstract_118906.htm

Needless to say, this activity will be quite fun to watch as
all of these ideas are sorted out.

Best Regards,

Paul H.

Meteorite Article From Gem and Mineral Society Newsletter

Paul bristolia at yahoo.com
Sat Mar 10 17:50:38 EST 2007

An example of what is being written about meteorites
in the newsletters of gem and mineral societies can
be found online. It is:

Rike III, Z. W., 2006, Meteoroids, Meteors and
Meteorites - Part 1. Pineywoods Rooter, Novmeber 2006,
Pine Country Gem & Mineral Society.

This article is repinted on pages 27 – 31 of vol. 38,
no.2 (February 2007) of the Backbend's Gazette, which
published by the Houston Gem and Mineral Society
( http://www.hgms.org/ ). The article and issue
can downloaded from the February 2007 link on the back
issue web page at:

http://www.hgms.org/Backbender'sGazetteIssues.html

and directly from:

http://www.hgms.org/BBG/Feb07.pdf

One way of reaching new people, would be to write popular
articles for your local Gem and Mineral Society about
various topics related to meteorites, impactites, tektites,
and so forth. These newsletters would be a good places
to educate the public about meteorites and meteorwrongs.

Best Regards,

Paul H.

Impact Origin of Carolina Bays Argued For at 2007 AGU Meeting

Paul bristolia at yahoo.com
Sat Mar 10 15:00:15 EST 2007

Dear Friends,

Apparently, there is going to be some interesting papers
at the 2007 Joint Assembly of the American Geophysical
Union as there will be a session presenting evidence for
an impact having occurred during Younger-Dyras times
at the "end of the last Ice Age. Below are links to
representative abstracts:

1. Evidence for an Extraterrestrial Impact Event 12,900 years
ago that Contributed to Megafaunal Extinctions and the Younger
Dryas Cooling

http://submissions5.agu.org/aguconvener/ConvenerView.asp?ref=1388

2. Formation of the Carolina Bays: ET Impact vs. Wind-and-Water
http://submissions5.agu.org/aguconvener/ConvenerView.asp?ref=1334

3. Extraterrestrial Markers Found at Clovis Sites Across North
America

http://submissions5.agu.org/aguconvener/ConvenerView.asp?ref=1393

4. Is There Evidence for Impact-Triggered Fires at the End
Pleistocene?

http://submissions5.agu.org/aguconvener/ConvenerView.asp?ref=513

The session itself is " PP05: New Insights into Younger Dryas
Climatic Instability, Mass Extinction, the Clovis People, and
Extraterrestrial Impacts

http://www.agu.org/meetings/ja07/?content=search&show=detail&sessid=159

It looks like Firestone and his supporters are refining their
arguments and dropping the implausible ones, i.e. the so-called
meteor crater in Lake Michigan, and concentrating on what they
regard the basic evidence for their ideas.

Best Regards,

Paul H.

Many United States Geological Survey Publications Now Online

Paul bristolia at yahoo.com
Fri Mar 9 10:12:19 EST 2007

Gary wrote:

“DJVU files... does this stand for Deja Vu files? I
have some of them that pop up once in a while :)”

Yes. I would much prefer if the USGS had used PDF
files instead. I have no idea why they choose the
Deja Vu format over the PDF format.

The plugins for Deja Vu files can be found at

http://www.lizardtech.com/download/dl_download.php?detail=doc_djvu_plugin&platform=win

or

http://www.lizardtech.com/download/dl_download.php?detail=doc_djvu_plugin&platform=macx

For some reason my Mac PowerPC G5 does not
print Deja Vu files. Although it acts like it is
printing the files, nothing ever comes out of the
Tektronix Phaser 7300 printer.

Yours,

Paul

Many United States Geological Survey Publications Now Online

Paul bristolia at yahoo.com
Thu Mar 8 22:32:48 EST 2007

Many Unites States Geological Survey Publications are
now online as DJVU files. Advanced Search for these
publications is at:

http://pubs.er.usgs.gov/usgspubs/index.jsp

For example, meteorite related USGS publications, which
can be viewed and downloaded are:

1. Cosmochemistry; Part 1, Meteorites, Professional Paper
440-B-1, by B. Mason at:

http://pubs.er.usgs.gov/usgspubs/pp/pp440B1

and 2. The disintegration of the Wolf Creek meteorite
and the formation of pecoraite, the nickel analog of
clinochrysotile, Professional Paper 384-C, by Faust,
George T.; Fahey, J. J.; Mason, B. H.; and Dwornik, E. J.

http://pubs.er.usgs.gov/usgspubs/pp/pp384C

Yours,

Paul H.

"Meteorites in Indiana" web page

Paul bristolia at yahoo.com
Thu Mar 1 08:24:49 EST 2007

Dear Friends,

There is a "Meteorites in Indiana" web page at

http://igs.indiana.edu/geology/extraTerrestrial/meteorites/index.cfm

They have a list of meteorites found in Indiana.

Best Regards,

Paul
Baton Rouge, LA

New Papers on Triassic - Jurassic Extinctions and Boundary

Paul bristolia at yahoo.com
Tue Jan 23 13:11:52 EST 2007

The latest issue, vol. 244, no. 1-4 (February 9,
2007), of Palaeogeography, Palaeoclimatology,
Palaeoecology is devoted to “Triassic-Jurassic
Boundary events: problems, progress, possibilities”.
It contains a number of papers, which discuss the
various theories about what created the Triassic
- Jurassic extinctions. The table of contents can be
found at:

http://www.sciencedirect.com/science/journal/00310182

They include:

Hesselbo, S. P., McRoberts, C. A., and Palfy, J., 2007,
Triassic–Jurassic boundary events: Problems, progress,
possibilities. Palaeogeography, Palaeoclimatology,
Palaeoecology. vol. 244, no. 1-4 , pp. 1-10.

In the above paper, they stated:

"The debate about extraterrestrial versus volcanic drivers
for environmental change has not yet been concluded, and
it is noteworthy that all of the candidate indicators of
extraterrestrial impact - reports of PGE's and soft sediment
deformation - occur shortly prior to CAMP volcanic activity.
Pure coincidence aside, this observation keeps alive the idea
that there is an 'impact signal'-LIP connection, even if the
mechanisms remain highly controversial; for example,
impact decompression melting, as recently articulated by
Elkins-Tanton and Hager (2005), or lithospheric gas
explosion (Phipps Morgan et al., 2005)."

Another paper is:

Michalíka, J., Lintnerovab, O., Gadzickic, A., and Sotakd,
J., 2007, Record of environmental changes in the Triassic-
Jurassic boundary interval in the Zliechov Basin, Western
Carpathians. Palaeogeography, Palaeoclimatology,
Palaeoecology. vol. 244, no. 1-4 pp. 71-88.

This paper states:

“The negative delta 13C excursion is correlated with a
positive delta 18O peak and the beds containing the
excursion are overlain by a thin layer with unusual
lithological and mineral composition. This layer is
composed of small calcitized microspheres showing
complex alteration during diagenesis. The origin of this
layer, traceable over tens of kilometres, is problematic
(impact ejecta, volcanic glass, or altered aragonitic
particles).”

Yours,

Paul H.

Alleged Meteorites and Craters Found Near Egyptian Pyramids

Paul bristolia at yahoo.com
Sun Jan 21 21:07:21 EST 2007

Does anyone know what the below research is about?

Meteorites from under the pyramids, "mp, tr.ajfb krx",
AGH University of Science and Technology

http://en.naukawpolsce.pl/naukaen/index.jsp?place=Lead02&news_cat_id=269&news_id=4944&layout=2&forum_id=1118&page=text

In part the article stated:

"According to "Dziennik Polski", the scientists were
intrigued by some unusual structures, which resembled
craters formed after meteorites hit the ground. They
noticed them when analysing satellite pictures of areas
north of the great pyramids in Giza."

“We found very solid metallic fragments in this area.
These are probably meteorite fragments” – says Prof.
Maciej Pawlikowski from the Mineralogy, Petrography
and Geochemistry department at AGH University, who
was the supervisor and main organiser of the
geological expedition. “We hope that further tests on
the patina covering the rocks, which formed during
the meteorites’ fall, will help us to establish the
exact time of the event” – the scientists said."

According to the article;, they found the alleged
craters and meteorite fragments as part of expedition
to study "geoglyphics'. They are described as
"gigantic pictures on the ground" which are located
east of Cairo and consist of "two several-kilometre-
long curved lines, which almost meet in one point"
and "look like a huge drawing of a scarab".

Does anyone have the latitude and longitude for
either the alleged "craters" or alleged "geoglyphic"?

Best Regards,

Paul H.

the ULTRA scam!

Paul bristolia at yahoo.com
Sat Jan 6 14:59:55 EST 2007

Greg wrote:

“I received the same email yesterday but had deleted
it after reading the first couple words. After Michael
posted his scam email, I went back and re-read it.
They were the same.’

You might want to look at the “2005 Ig Noble Award
for Literature” at:

http://interactive.usc.edu/members/sfisher/archives/2005/10/2005_ig_noble_a_1.html

and “The 2005 Ig Nobel Prize Winners” at:

http://www.improb.com/ig/ig-pastwinners.html#ig2005

The 2005 ignoble for literature was awarded to
"The Internet entrepreneurs of Nigeria, for creating
and then using e-mail to distribute a bold series of
short stories, thus introducing millions of readers
to a cast of rich characters”
”

Also, there is the “Nigerian Fraud Email Gallery” at:

http://www.potifos.com/fraud/

Yours

100, 000 to 200, 000 BP Western Desert of Egypt Impact

Paul bristolia at yahoo.com
Mon Dec 18 09:58:49 EST 2006

Dear Friends,

A paper about a proposed Pleistocene impact in the
western Desert of Egypt is in press in the Earth and
Planetary Science Letters.

It is:

Osinski, G. R., H. P. Schwarcz, J. R. Smith, M. R.
Kleindienst, A. F.C. Haldemann and C. S. Churcher.
in Press, Evidence for a 200-100 ka meteorite impact
in the Western Desert of Egypt. Earth and Planetary
Science Letters. available online December 2006

http://www.sciencedirect.com/science/journal/0012821X

This paper argues that unusual silicate glasses found
near the Dakhleh Oasis, Western Desert, Egypt is the
result of either a "cratering event or a large aerial burst",
which occurred about 100,000 to 200,000 year ago
according to Ar/Ar dating and geoarcaheological
evidence.

Some web pages:

1. Dakhleh Oasis, Egypt
http://epsc.wustl.edu/~kieniewicz/dakhleh_oasis.htm

2. Excavations at Mut el-Kharab, Dakhleh Oasis
http://arts.monash.edu.au/archaeology/excavations/dakhleh/index.html
http://arts.monash.edu.au/archaeology/excavations/dakhleh/mut-el-kharab/index.html

3. Haldemann, A. F. C., M. R. Kleindienst, C. S.
Churcher, J. R. Smith, H. Schwarcz, K. Markham, and
G. Osinski, 2005, Mapping Impact Modified Sediments:
Subtle Remote-Sensing Signatures of the Dakhleh
Oasis Catastrophic Event, Western Desert, Egypt.
American Astronomical Society, DPS meeting #37, #17.03;
Bulletin of the American Astronomical Society, Vol. 37, p.648

http://adsabs.harvard.edu/abs/2005DPS....37.1703H

Yours,

Paul H.

New Papers About Permian Mass Extinctions

Paul bristolia at yahoo.com
Tue Nov 28 13:25:21 EST 2006

Dear Friends,

Two recent papers, which are coauthored by Dr. Greg J.
Retallack and discuss the Permian mass extinction, have
been recently published.

They are:

Retallack, G.J. and Krull, E.S. 2006. Carbon isotopic evidence
for terminal-Permian methane outbursts and their role in
extinctions of animals, plants, coral reefs and peat swamps.
In Greb, S. and DiMichele, W.A., Editors, Wetlands through
time. Special Paper of the Geological Society of America.
vol 399, p 249-268.

The 3 MB version of the above paper can be downloaded from:

http://www.uoregon.edu/~gregr/Papers/Ragnarok2.pdf

This paper provides a very detailed discussion of what he and
his coauthors argued caused the Permian mass extinction.

Also, there is:

Retallack, G.J., Greaver, T., Jahren, A.H., Smith, R.M.H.,
Sheldon, N.D., and Metzger, C.A., 2006, Middle-Late
Permian mass extinction on land. Geological Society of
America Bulletin. vol. 118, p. 1398–1411.

The 1.5 MB version of the above paper can be downloaded from:

http://www.uoregon.edu/~gregr/Papers/Mid-Late%20Permian%20extinction.pdf

The above Geological Society of America Bulletin paper is
interesting because, they recognize two distinct and separate
geologically abrupt mass extinctions on land. One of these
occurs at the end of the Middle Permian (Guadalupian) at
260.4 Ma and a later one occurring with the Permian Period
at 251 Ma. Both of these correspond to previously recognized
marine mass extinctions. He is quite skeptical of the Permian
mass extinctions as having been related to any asteroid or
comet impact.

Other papers coauthored by Greg J. Retallack, which are
related to the Permian extinction can be found at:

http://www.uoregon.edu/~gregr/publications.html

They include:

Retallack, G.J., Jahren, A.H., Sheldon, N.D., Chakrabarti, R.,
Metzger, C.A., and Smith, R.M.H., 2005. Permian-Triassic
boundary in Antarctica. Antarctic Science 17, 241-258.

The PDF file for this paper can be found at:

http://www.uoregon.edu/~gregr/Papers/PTAntarctica.pdf

Yours,

Paul

Stalking the Wily Shattercone

Paul bristolia at yahoo.com
Fri Oct 13 14:05:35 EDT 2006

While browsing the Internet, I came across a paper, which provides
a very nice summary of the different criteria, which can be use to
authenticate a impact structure.

The paper is:

French, B. M., 2005, Stalking the Wily Shattercone: A Critical Guide for
Impact-Crater Hunters. Impacts in the Field. vol. 2 (Winter), pp. 3-10.

The Winter 2005 issue of "Impacts in the Field", which contains this
article can be downloaded from

http://web.eps.utk.edu/ifsg_files/newsletter/Winter_2005.pdf

links to other issues of "Impacts in the Field" can be found at:

http://web.eps.utk.edu/ifsg.htm

Best Regards,

Paul H.

Re: Egypt's Craters Pose Geological Riddle

Paul bristolia at yahoo.com
Mon Oct 9 14:10:02 EDT 2006

In “Egypt's Craters Pose Geological Riddle”, Ron
Baalke wrote:


> http://dsc.discovery.com/news/2006/10/06/crater_pla.html?category=travel&guid=20061006103030



> Egypt's Craters Pose Geological Riddle, Larry O'Hanlon

> Discovery News October 6, 2006


There are a number of links, which provided more detail
about this ongoing controversy. They are:

1. Remarks to the origin of the craters around Gilf
Kebir and Djebel Uweinat (Egypt)and the supposed
impact craters of Libya by Norbert Brugge, Germany,
2004, at

http://hometown.aol.de/SLVehicles4/Clayton%20Craters/Clayton-Craters.htm

2. di Martino, and others, 2006, Non-Impact Origin of
the Crater Field in the Gilf Kebir Region (SW Egypt).
European Space Agency First International Conference on
Impact Cratering in the Solar System ESTEC, Noordwijk,
The Netherlands, 08 - 12 May, 2006. The abstract can
be found at:

http://www.rssd.esa.int/SYS/docs/ll_transfers/296053_dimartino.pdf

and 3. The actual presentation of the above paper can
be found at

Non-impact origin of the crater field in the Gilf
Kebir region (SW Egypt) by M. Di Martino, L. Orti,
L. Matassoni, M. Morelli, R. Serra, and A. Buzzigoli.

The 3.3 MB PDF can be found file at:

http://www.rssd.esa.int/SYS/docs/ll_transfers/296053_Di2DMartino_pres.pdf

and in “40th ESLAB First International Conference on Impact
Cratering in the Solar System Agenda, Monday 8 May 2006 at:

http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=39029

On page 25 of the above PDF file, Di Martino and coauthors
dispute the impact origin of what has been called the “Kebira
crater” in Libya - Egypt.

Yours,

Paul H.

Kilmichael Structure, Mississippi, Revisited

Paul bristolia at yahoo.com
Tue Sep 26 21:23:49 EDT 2006

Tomorrow afternoon, David T. King of the Department of Geology,
Auburn University, Auburn, AL will talk recent research conducted
on the Kilmichael Structure, Mississippi, at this weeks Gulf Coast
Assicaition of Geological Societies 2006 Annual Meeting in
Lafayette, louisiana. The paper accompanying this talk is;

King, D. T., Jr., and L. W. Petruny, 2006, Cosmic impact in the coastal
plain of Mississippi? The Kilmichael structure. Gulf Coast Association
of Geological Societies Transactions, vol. 56, pp. 341-351.

Its abstract states:

"The Kilmichael structure, a probable impact crater in Montgomery
County, Mississippi, is a circular, structurally disturbed feature
possessing a diameter of approximately 5.6 mi. A refraction seismic
survey reveals subsurface characteristics of an impact structure,
including a central uplift, annular graben, and concentric inward-
dipping faults. A gravity profile like that of some confirmed impact
craters is present. In a key core hole at the structure’s center,
770 ft of section, consisting mainly of breccias and large intact
blocks, was penetrated and sampled. In this paper, we have
reinterpreted the sequence of drilled strata as follows (in reverse
stratigraphic order): (1) soil and colluvium; (2) post-impact
laminated marine sediments; (3) conglomeratic aqueouswashback
or resurge deposits of mixed provenance; (4) interbedded impact
breccias and target rock blocks, i.e., surgeback deposits; (5) large,
deformed and rotated blocks of the Upper Cretaceous Ripley
Formation; and (6) interbedded impact breccias and target rock
blocks, mainly Upper Cretaceous chalks. The stratigraphic age
of this structure is probably late early to early late Paleocene,
based on the fossil age of material from the youngest
recognizable intact block drilled in the key core hole. The
Kilmichael area was in a marginal marine to shallow marine setting
at the time of deformation and the drilled stratigraphy is consistent
with aqueous or “wet-target” impact."

Yours,

Paul

Eltanin Impact Area - A Few References - was "Eltanin - Part 2 of 2 "

Paul bristolia at yahoo.com
Thu Sep 7 09:52:05 EDT 2006

In the post "Eltanin - Part 2 of 2", bernd.pauli wrote:

"Bostwick J.A. et al. (1995) Asteroid sample return
mission II: Eltanin recovered (abs. Meteoritics 30, 490)"

A few of a number of other papers about the Eltanin
Impact Area are:

Kyte1, F. T., 2001, Chapter 9, Data Report: A Search
for Deposits of the Late Pliocene Impact of the Eltanin
Asteroid in Rise Sediments from the Antarctic Peninsula,
Site 1069. In Barker, P. F., Camerlenghi, A., Acton,
G. D., and Ramsay, A. T. S., eds., Proceedings of the
Ocean Drilling Program, Scientific Results. vol. 178

http://www-odp.tamu.edu/publications/178_SR/VOLUME/CHAPTERS/SR178_09.PDF

Kyte1, F. T., R. Gersonde, and G. Kuhn, 2005, Detailed
Results on the Analyses of the Eltanin Impact, Recovered
in Sediments Cores from Polarstern expedition
ANT-XVIII/5A. Lunar and Planetary Science XXXVI (2005)

http://www.lpi.usra.edu/meetings/lpsc2005/pdf/2129.pdf

Gersonde, R., and F. T. Kyte, 2001, Exploration of the
Eltanin Impact Area (Bellingshausen Sea): Expedition ANT
XVIII5a 64th Annual Meteoritical Society Meeting.

http://www.lpi.usra.edu/meetings/metsoc2001/pdf/5421.pdf

Gersonde, R., F. T. Kyte, U. Bleil, B. Diekmann, J. A.
Flores, K. Gohlk, G. Grahl, R. Hagen, G. Kuhn, F. J. Sierro,
D. Volker, A. Abelmann, and J .A. Bostwick, 1997, Geological
record and reconstruction of the late Plioceneimpact of
the Eltanin asteroid in the Southern Ocean. Nature.
vol. 390, pp. 357-363.

Gersonde1, R., F. T. Kyte, T. Frederichs, U. Bleil, and
G. Kuhn, 2003, New Data on the Late Pliocene Eltanin
Impact into the Deep Southern Ocean. Large Meteorite
Impacts 2003.

http://www.lpi.usra.edu/meetings/largeimpacts2003/pdf/4094.pdf
http://www.lpi.usra.edu/meetings/largeimpacts2003/pdf/sess06.pdf

Shuvalov, V. V., 2003, Numerical Modeling of the Eltanin
Impact. Lunar and Planetary Science XXXIV.

+++++ Volume 49, Number 6 (2002) of Deep Sea Research
Part II: Topical Studies in Oceanography +++++

This issue contains the following papers

1. Calcareous plankton stratigraphy around the Pliocene
"Eltanin" asteroid impact area (SE Pacific): documentation
and application for geological and paleoceanographic
reconstruction by J. A. Flores, F. J. Sierro, and R.
Gersonde, pp. 1011-1027.

2. Composition of impact melt debris from the Eltanin
impact strewn field, Bellingshausen Sea by F. T. Kyte,
pp. 1029-1047.

3. Iridium concentrations and abundances of meteoritic
ejecta from the Eltanin impact in sediment cores from
Polarstern expedition ANT XII/4 by F. T. Kyte,
pp. 1049-1061.

4. Unmelted meteoritic debris collected from Eltanin
ejecta in Polarstern cores from expedition ANT XII/4 by
F. T. Kyte, pp. 1063-1071.

5. Impact tsunami-Eltanin by S. N. Ward and E. Asphaug,
pp. 1073-1079(7)

+++++ Bathymetric Maps of the Eltanin Impact Area +++++

AWI Bathymetry & Geodesy - Eltanin Impact Survey: Analyses
of High Resolution Bathymetric Data in the Eltanin Impact
Area by Merijn J. Jacops at:

http://www.awi-bremerhaven.de/GEO/Bathymetry/eltanin/eltanin.html

The maps of the Eltanin Impact Area consist of:

1. Eltanin Impact Area at 57°25'00'' overview map, 1:200.000
- 4.0 MB PDF file available at;

http://www.awi-bremerhaven.de/GEO/Bathymetry/eltanin/eltanin_overview.pdf

2. Bathymetric chart Eltanin Impact Area northwest, 1:100.000,
sheet 1 - 2.6 MB Pdf file available at;

http://www.awi-bremerhaven.de/GEO/Bathymetry/eltanin/eltanin_1a.pdf

3. Bathymetric chart Eltanin Impact Area northeast, 1:100.000,
sheet 2 - 3.1 MB Pdf file available at;

http://www.awi-bremerhaven.de/GEO/Bathymetry/eltanin/eltanin_2a.pdf

4. Bathymetric chart Eltanin Impact Area southwest, 1:100.000,
sheet 3 - 5.7 MB Pdf file available at;

http://www.awi-bremerhaven.de/GEO/Bathymetry/eltanin/eltanin_3a.pdf

5. Bathymetric chart Eltanin Impact Area southeast, 1:100.000,
sheet 4 - 4.7 MB Pdf file available at;

http://www.awi-bremerhaven.de/GEO/Bathymetry/eltanin/eltanin_4a.pdf

Yours,

Paul

Re: Geological History of terrestrial "Olivine Bomb"?

Paul bristolia at yahoo.com
Mon Sep 4 19:39:16 EDT 2006

Gerald Flaherty wrote:

"I picked up an Olivine Bomb from Norbert and
Helke Kammel of "Rocks On Fire" a couple of
years ago when I knew less than I know now of
meteorites. It's Location is listed as Mt.
Shadwell, Victoria, Australia. At the time the
very word "olivine" immediately brought pallasite
to mind. I think I'd just invested in my first
Imilac. This piece is tantalizing in every way,
from is thick jet black volcanic crust, to its
beautifully polished green interior. Is this
terrestrial mantle tossed up in a violent
volcanic blast? Are these common?"

Technically speaking, they are not volcanic bombs, which are
thrown out of volcanoes during eruptions. Rather, they are
exotic chunks of rocks, called xenoliths, carried upward by
magma as it ascended through the crust. The best preserved
xenoliths are those carried up rapidly from deep in the
mantle by the formation of diatremes.

Mount Shadwell is the highest of a cluster of basaltic scoria
cones. It is well known as a source of olivine and augite
ultramafic xenoliths and clinopryoxene and orthoclase
megacrysts contained in basalts and scoria. My understanding
that although such xenoliths can be found in many basaltic
lavas, the ones found at Mount Shadwell are uncommon for
their size and preservation. The xenoliths found at Mt.
Shadwell are inferred to have come from both the lower
crust and upper mantle.

Some web pages:

1. Mount Shadwell - Victorian Resources Online
http://www.nre.vic.gov.au/dpi/vro/coranregn.nsf/pages/eruption_points_shadwell

2. Coexisting Andesitic and Carbonate Melts in a
Lherzolite Xenolith from Mt. Shadwell, Victoria

http://www.es.mq.edu.au/geology/MNAGC98.html
http://www.es.mq.edu.au/geology/MNHP.html

3. Melting and Metasomatism in the Lithospheric Mantle Beneath
SE Australia: Trace Element Studies by Laser Microprobe by
Marc Norman and Suzanne O'Reilly

http://www.es.mq.edu.au/GEMOC/annrep97/abs96/Norm396.htm

4. Roach, I. C., 2004, Mineralogy, Textures and P-T
Relationships of a Suite of Xenoliths from the Monaro
Volcanic Province, New South Wales, Australia. Journal of
Petrology. vol. 45, no. 4, pp. 739-758.

http://petrology.oxfordjournals.org/cgi/content/abstract/45/4/739

5. Ellis. D. J., 1976, High pressure cognate inclusions
in the Newer Volcanics of Victoria. Contributions to
Mineralogy and Petrology. vol. 58, no. 2, pp. 149-180.

http://www.springerlink.com/content/r02x704tlm23w415/

6. Xenolith

http://en.wikipedia.org/wiki/Xenolith

Yours,

Paul H.