Dark days of the Triassic: Extraterrestrial Impact or Volcanic Eruption?

An online article in the new issue of Nature discusses 
whether either an extraterrestrial impact or volcanic
eruption caused mass extinctions at the end of the 
Triasssic about 200 million years ago. The article is:


Smith, Roff, 2011, Dark days of the Triassic: Lost world. 
Nature. vol. 479, pp. 287-289. DOI: doi:10.1038/479287a 
http://www.nature.com/news/dark-days-of-the-triassic-lost-world-1.9375  


"Did a giant impact 200 million years ago trigger a 
mass extinction and pave the way for the dinosaurs?"


Free pdf version of the article at:
http://www.nature.com/polopoly_fs/1.9375!/import/pdf/479287a.pdf


Yours,


Paul H.

Online PDF File of Henbury Impact Craters Publication and Map

One of the USGS publications lacking an online PDF  file at 
the USGS Publication warehouse at http://pubs.er.usgs.gov/ is

Milto, D. J., 1968, Structural geology of the Henbury meteorite 
craters, Northern Territory, Australia. Professional Paper 
no. 599-C, United States Geological Survey, Reston, Virginia.

However, a PDF file of this publication and its accompanying 
map can be found at:

http://www.scribd.com/doc/73594449
http://www.scribd.com/doc/73594449/Henbury-Meteorite-Craters-Australia-USGS

http://www.scribd.com/doc/73593979
http://www.scribd.com/doc/73593979/Henbury-Meteorite-Craters-Australia-Map

Yours,

Paul H.

Online PDF files of USGS Publications, i.e. Jeptha Knob, Sierra Madera, Etc.

Dear Friends,

Free PDF and other files of United States Geological Survey 
can found online and downloaded from the “USGS Publications 
Warehouse” at: 

http://pubs.er.usgs.gov/

Examples of the USGS publications with PDF files that can be 
downloaded from this site are:

Cressman, E. R., 1981, Surface geology of the Jeptha Knob 
cryptoexplosion structure, Shelby County, Kentucky.
Professional Paper no. 1151-B. United States Geological
Survey, Reston, Virginia. 16 pp.

PDF file at http://pubs.usgs.gov/pp/1151b/report.pdf
Plate 1 at http://pubs.usgs.gov/pp/1151b/plate-1.pdf
http://ngmdb.usgs.gov/Prodesc/proddesc_4735.htm

Wilshire, H. G., T. W. Offield, K. A. Howard, and D. Cummings,
1972, Geology of the Sierra Madera cryptoexplosion structure, 
Pecos County, Texas. Professional Paper no. 599-H. United 
States Geological Survey, Reston, Virginia. 41 pp.

PDF file at http://pubs.usgs.gov/pp/0599h/report.pdf
Plate 1 at http://pubs.usgs.gov/pp/0599h/plate-1.pdf
Plate 2 at http://pubs.usgs.gov/pp/0599h/plate-2.pdf
Plate 3 at http://pubs.usgs.gov/pp/0599h/plate-3.pdf
Plate 4 at http://pubs.usgs.gov/pp/0599h/plate-4.pdf

Geologic maps can be found in the National Geologic
Map Database at:

http://ngmdb.usgs.gov/ngmdb/ngmdb_home.html
http://ngmdb.usgs.gov/ngmdb/ngm_catalog.ora.html
http://ngmdb.usgs.gov/ngmdb/ngm_quicksearch.html

Yours,

Paul H.

Manmade Objects Found in Weird Places While Meteorite Hunting

Dear Friends,

As part of a short article, possibly paper, I am 
collecting accounts of out-of-place metal and other 
manmade objects that have been found in the middle 
of nowhere while meteorite hunting. I am looking
for examples of manmade objects that have been found 
in the mountains and on the dry lakes of the
southwestern United States, outback of Australia, 
or similar areas far from roads and inhabited areas. 
The article / paper needs accounts, which can be 
cited as personal communications, of manmade objects 
that have been found in places far from where they 
normally would be expected to be found. They are 
to be used as examples of how manmade objects get 
scattered all over the landscape often in the most
unexpected places in a geoarchaeology article / paper.

If possible, I would prefer separate emails, in addition
to what you post to this list. Digital pictures of such
objects that I might use in publications would be 
extremely useful.

I would be especially interested in accounts and pictures 
of spark plugs and other automobile parts that have been 
in either weird, unexpected, of out of the way places well
away from either roads or inhabited areas.

In return for such accounts, I am willing to do what
I can answer questions about geology that a person 
might have and find information or publications for 
which you are looking.

Best wishes,

Paul

Paul V. Heinrich
Louisiana Geological Survey
3079 Energy, Coast, and
      Environment Building
Louisiana State University
Baton Rouge, LA 70803

Statistically Speaking

Statistically Speaking


In "Statistically Speaking" at
http://six.pairlist.net/pipermail/meteorite-list/2011-November/081289.html
Ruben asked:

6. Q. How much in weight does the earth gain per year 
by all the meteorites that enter our atmosphere? Including 
all, from tiny grain of sand meteorites to large bunker-
busters.

Below is what I could find with a limited search.

1. Bland (2001) states:

"This, together with the number and mass distribution 
of paired meteorites in each region allows an estimate of 
the number of meteorite falls over a given mass per year: 
between 36 and 116 falls over 10 g per 1,000,000 km2/yr. 
In addition, the total mass flux to the Earth 's surface over 
the 10 g -1 kg interval is constrained to between 2900 and 
7300 kg/yr."

and

"These and other estimates of flux for cosmic dust yield 
a reasonably consistent estimate of 30-40 Gg per year."

Halliday (2001) states:

"About 4500 events per year appear to deposit at least 
a kilogram of meteorites somewhere on Earth, including 
those that land in oceans."

3. Hughes (1991) states:

"Unfortunately the only conclusion that can be drawn 
from this review is that the meteorite flux to the Earth's 
surface is still a quantity that is imperfectly known. The
parents of meteorites have masses in the range between 
1,000 and 1,000,000,000 g. The annual flux to the top of 
the atmosphere in this range is 12,400,000,000 g and 
this is made up of 870,000 individual bodies."

There is:

Meteorite Flux - Part 1 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01031.html

Meteorite Flux - Part 2 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01032.html

Meteorite Flux - Part 3 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01033.html

Meteorite Flux - Part 4 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01034.html

Meteorite Flux - Part 5 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01036.html

Meteorite Flux - Part 6 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01035.html

Part 6 has the type of statistic that newspaper and TV 
reporters seemingly love to throw into an piece.

"So each 18-hole golf course has about a 1 in 100,000 
chance of being hit by a meteorite every year."

References Cited:

Bland, P. A., 2001, Quantification of Meteorite Infall Rates 
from Accumulations in Deserts, and Meteorite Accumulations 
on Mars. in B, Peucker-Ehrenbrink and B. Schmitz, eds., 
pp. 267-304. Accretion of extraterrestrial matter throughout 
Earth's history. Kluwer Academic/Plenum Publishers, New 
York, New York.,

Halliday, I., 2001, The Present-day Flux of Meteorites to the 
Earth in B, Peucker-Ehrenbrink and B. Schmitz, eds., 
pp. 305-318. Accretion of extraterrestrial matter throughout 
Earth's history. Kluwer Academic/Plenum Publishers, New 
York, New York.,

Hughes, D. W., 1991, Meteroite flux. Space Science Reviews.
vol. 61, pp. 275-299,

Yours,


Paul H.

Holocene Extinctions and a different lake

In “[meteorite-list] Holocene Extinctions and a different 
lake”, Ed wrote:

“I'm glad to hear that all the debate about the dating of 
the Lake Misssoula flooding has now been cleared up. 
Does the same thing hold for Lake Bonneville, and 
other Ice Age plains lakes?”

I have PDF versions of about 70 publications about
geology and paleoliminology, and chronology of Lake 
Bonneville. There are numerous other minor publications
about Lake Bonneville. In addition, I have about a couple 
of dozen papers and other publications about other Ice 
Age pluvial lakes that existed in the Southwestern United
States, including pluvial Lake Estancia in New Mexico.

In none of these papers, is there any evidence of either 
any terminal Pleistocene impacts, including about 
“10,750 BCE,” or any Holocene impacts. The significant
change from Ice Age pluvial lake levels in Lake Bonneville
and other pluvial lakes towards modern playa lakes started 
about 12,600 14C yr BP (15,000 cal yr B.P.). This is long 
before any of your proposed impacts. This is simply the 
time that the colder, wetter climates of the Last Glacial 
Maximum transitioned to the warmer, drier conditions 
of the late Pleistocene and early Holocene. This change 
is coincident with comparable drops (regression) in 
lake-level in Lake Lahontan, Lake Estancia, and other
southwestern pluvial lakes and with the onset of the
Bolling-Allerod warming event. 

There is a very slight rise in lake levels to the Lake Gilbert 
highstand in response to climate changes associated with
the Younger Dryas. There is nothing obvious in the lake
sediments to indicate any direct association with any sort 
of extraterrestrial impact. Whatever caused the Younger 
Dryas climatic changes is what indirectly caused the high 
lake levels of Lake Gilbert.

In terms of basic reading, a person can start with:

Allen, B. D., 2005, Ice Age Lakes in New Mexico. in S. G. 
Lucas, G. S. Morgan, and K. E. Zeigler, eds., pp. 107-114, 
New Mexico’s Ice Ages. Bulletin no. 28, New Mexico 
Museum of Natural History and Science.
http://geoinfo.nmt.edu/staff/allen/documents/iceagelakesnm.PDF

Balch, D. P., A. S. Cohen, D. W. Schnurrenberger, B. J. Haskell, 
B. L. V. Garces, J. W. Beck, H. Cheng, and R. L. Edwards, 2005,
Ecosystem and paleohydrological response to Quaternary 
climate change in the Bonneville Basin, Utah. Palaeogeography, 
Palaeoclimatology, Palaeoecology. vol. 221, no. 1-2, pp. 99-122.
http://www.sciencedirect.com/science/article/pii/S0031018205000829

Benson, L. V., D. R. Currey, R .I. Dorn, K. R. Lajoie, C. G. Oviatt, 
S. W. Robinson, G. I. Smith, and S. Stine, 1990, Chronology of 
expansion and contraction of four great Basin lake systems 
during the past 35,000 years. Palaeogeography, Palaeoclimatology, 
Palaeoecology. vol. 78, no. 3-4, pp. 241-286.
http://www.sciencedirect.com/science/article/pii/003101829090217U

Benson, L. V., S. P. Lund, J. P. Smoot, D. E. Rhode, R. J. Spencer, 
K. L. Verosub, L. A. Louderback, C. A. Johnson, R. O. Rye, and
R. M. Negrini, 2011, The rise and fall of Lake Bonneville 
between 45 and 10.5 ka. Quaternary International. vol. 235, 
no. 1-2, pp. 57-69.
http://www.sciencedirect.com/science/article/pii/S1040618210004829

Louderback, L. A., and D. E. Rhode, 2009, 15,000 Years of 
vegetation change in the Bonneville basin: the Blue Lake 
pollen record. Quaternary Science Reviews. vol. 28, no. 3-4, 
pp. 308-326.    
http://www.sciencedirect.com/science/article/pii/S0277379108002680

Godsey, H. S., C. G. Oviatt, D. M. Miller, and M. A. Chan, 2011,
Stratigraphy and chronology of offshore to nearshore deposits 
associated with the Provo shoreline, Pleistocene Lake Bonneville, 
Utah. Palaeogeography, Palaeoclimatology, Palaeoecology. 
vol. 310, no. 3-4,pp. 442-450.

Oviatt, C. G., D. M. Miller, J. P. McGeehin, C. Zachary, and S. 
Mahan, 2005, The Younger Dryas phase of Great Salt Lake , 
Utah. Palaeogeography, Palaeoclimatology, Palaeoecology.
vol. 219, no. 3-4, pp. 263-284.
http://www.sciencedirect.com/science/article/pii/S0031018211004317

Patrickson, D. S., A. R. Brunelle, and K. A. Moser, 2010, Late 
Pleistocene to early Holocene lake level and paleoclimate 
insights from Stansbury Island, Bonneville basin, Utah.
Quaternary Research. vol. 73, no. 2, pp. 237-246.
http://www.sciencedirect.com/science/article/pii/S0033589409001653

Spencer, R. J., M. J. Baedecker, H. P. Eugster, R. M. Forester, 
M. B. Goldhaber, B. F. Jones, K. Kelts, J. Mckenzie, D. B. 
Madsen and S. L. Rettig, 1984, Great Salt Lake, and precursors, 
Utah: The last 30,000 years. Contributions to Mineralogy 
and Petrology. vol. 86, no. 4, pp. 321-334.
http://www.springerlink.com/content/j7744044505082r0/

Maps of the pluvial lakes of the Southwest US can be found at:

1. Late Quaternary Paleohydrology of the Mojave Desert
http://esp.cr.usgs.gov/info/mojave/paleoenviron.html
http://esp.cr.usgs.gov/info/mojave/images/fig13.gif

2. Reheis, M,, 1999, Extent of Pleistocene Lakes in the 
Western Great Basin. Miscellaneous Field Studies Map 
MF-2323, U.S. Geological Survey, Denver, CO.
http://pubs.usgs.gov/mf/1999/mf-2323/mf2323.pdf
http://pubs.usgs.gov/mf/1999/mf-2323/

3. Matsubara, Y., and A. D. Howard, nd, Spatially-explicit 
modeling of modern and Pleistocene runoff and lake 
extent in the Great Basin region, western United States.
Department of Environmental Sciences, University of 
Virginia, Charlottesville, Virginia.
http://erode.evsc.virginia.edu/papers/matsubara_Pleistocene_GB.pdf

One of the stranger claims that has been made about Lake 
Bonneville and other pluvial lakes in the southwest is that 
the salt and other evaporite deposits that characterize the 
modern playa lakes associated with them are the result of 
the evaporation of sea water splashed into them from the 
Pacific Ocean by multiple-kilometer-high impact generated 
megatsunamis from a terminal Pleistocene /early Holocene 
impacts as argued by Tollmann and Tollmann (1994) and 
Knight and Lomas (2000). 

Now, as in either 1994 and 2000, there exists ample data, 
interpretations, and other information in published literature
to soundly refute their arguments. The change from fresh
water, pluvial lakes towards the modern saline playa lakes 
occurred long before their proposed impacts as documented 
in the above papers. The accumulation of evaporites in these 
lakes started thousands of years before the hypothetical 
impact. In addition, the geochemistry and sedimentology 
of the salt and other evaporites found in these lakes clearly 
demonstrates that they are the result of the evaporation of
water carrying dissolved minerals from rocks exposed 
within the drainage basin of these lakes as discussed by
Hart et al. (2004), Spencer et al.  (1985a, 1985b). Also, 
despite the continuous record of lake sedimentation 
recovered in cores from Lake Bonneville and other lakes,
there is a complete lack of either an event bed of deposits
that such an event would most certainly have left behind.  
The many problems with the arguments of Tollmann and 
Tollmann (1994), which Knight and Lomas (2000) simply
ignore, are discussed in detail by Deutsch et al. (1994).

References Cited,

Deutsch, A., C. Koeberl, J. D. Blum, B. M. French, B. P. Glass, 
R. Grieve, P. Horn, E. K. Jessberger, G. Kurat, W. U. Reimold,
J. Smit, D. Stöffler, and S. R. Taylor, 1994, The impact-flood 
connection: Does it exist? Terra Nova. vol. 6, pp. 644-650.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3121.1994.tb00532.x/abstract

Christopher Knight and Robert Lomas. 2000 Uriel's Machine: 
‘The Ancient Origins of Science. Element Books Ltd. 480 pp.

Kristan-Tollmann, E. and A. Tollmann, 1994, The youngest 
big impact on Earth deduced from geological and 
historical evidence. Terra Nova. vol. 6, no. 2, pp. 209-217.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3121.1994.tb00656.x/abstract

Hart, W. F., J. Quade, D. B. Madsen, D. S. Kaufman, and C. G. 
Oviatt, 2004, The 87Sr/86Sr ratios of lacustrine carbonates 
and lake-level history of the Bonneville paleolake system. 
Geological Society of America Bulletin. vol. 116, no. 9-10, 
pp. 1107-1119.

Spencer, R. J., H. P. Eugster, and B. F. Jones, 1985a, Geochemistry 
of great Salt Lake, Utah II: Pleistocene-Holocene evolution. 
Geochimica et Cosmochimica Acta.  vol. 49, no. 3, pp. 739-747
http://www.sciencedirect.com/science/article/pii/0016703785901681

Spencer, R. J., H. P. Eugster, B. F. Jones, and S. L. Rettig, 1985b,
Geochemistry of Great Salt Lake, Utah I: Hydrochemistry 
since 1850. Geochimica et Cosmochimica Acta. vol. 49, 
no. 3, pp. 727-737
http://www.sciencedirect.com/science/article/pii/001670378590167X

Best wishes,

Paul H.