[meteorite-list] (no subject)

[Paul H.]

In “[meteorite-list] 6 crater fields in central New Mexico: 
Dennis Cox: Rich Murray 2011.07.09 at
http://six.pairlist.net/pipermail/meteorite-list/2011-July/078188.html
Rich Murray wrote:

“6 crater fields in central New Mexico: Dennis Cox: Rich Murray 2011.07.09 

http://craterhunter.wordpress.com/ 

A Catastrophe of Comets 
More New Mexico Craters 
Rich Murray: I slightly adjusted the view locations. 
They sure look like impact craters... “

No they do not look like meteorite craters. First, these featrues
lack the morphology, which would suggest that they might be 
meteorite craters. The majority lack the circular or elliptical outline 
that might characterize an impact crater. The majority of them 
are far to irregular to be candidates for  impact craters. In addition,  
sinkholes can also have nice circular outlines as can be seen in 
the Bottomless Lakes of Bottomless Lakes State Park about 14 
miles southeast of Roswell, New Mexico. 

The Bottomless Lakes are discussed at:

Bottomless Lakes State Park, New Mexico
http://www.emnrd.state.nm.us/PRD/bottomless.htm

Kottlowski, F. E., 1979, Bottomless Lakes: New Mexico
Geology, vol. 1, pp. 57-58.

McLemore, V. T., 1999, Bottomless Lakes: New Mexico
Geology, vol. 21, no. 2, p. 51-55.
http://geoinfo.nmt.edu/tour/state/bottomless_lakes/home.html

Rawling, G., and D. J. McCraw, 2010, Geologic map of
the Bottomless Lakes quadrangle, Chaves County,
New Mexico. Open-file geologic map. no. 126. scale
1:24,000, New Mexico Bureau of Geology and Mineral
Resources. Socorro, New Mexico.
http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/details.cfml?Volume=126

Second, if a person looks at the regional topographic maps, 
these features lack any sign of the rim that an impact crater 
would typically have. Finally, geologists have looked
at these features and found them to be classic examples 
of carbonate karst, which are developed in the alternating 
layers of limestone and dolomite of the San Andres 
Formation, which underlies this area.

What one of these sinkholes looks like near the ground
surface can be seen the web page for Fort Stanton Cave,
Lincoln County, New Mexico, at
http://www.fscsp.org/photos/entrance_aerial_view_1200.jpg
http://www.fscsp.org/

The cave is located at lat. 33.50673°, long. -105.4936248°
about 28 miles south of the above area of karst.

I have talked about these features before in:

[meteorite-list] Impact Crater in New Mexico – Part 2
Lincoln County Revisited, January 6, 2009, 
http://six.pairlist.net/pipermail/meteorite-list/2011-January/072231.html

A couple of web pages:

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

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

There might be an impact crater or few lost among all of these
sinkholes. However, distinguishing them from the sinkholes
and demonstrating that they are impact craters will take a lot 
a field work. It is certainly something that will be impossible
to do simply from aerial imagery.

Rich Murray wrote:
“Ground samples may reveal evidence of blast and surface 
melting and coating.”

A person can look if they want. I suspect that it such a search
will find a complete absence of any credible evidence “blast 
and surface melting and coating.” 

If a person wants to look for features to investigate as 
possible impact craters, they can check out a reported 
possible impact crater by Skotnicki (2009) within the 
Lincoln 7.5 quadrangle, Lincoln County, New Mexico. 

The reference is:

Skotnicki , S. J., 2009, Preliminary Geologic Map
of the Lincoln Quadrangle, Lincoln County, New
Mexico. scale: 1:24,000. Open‐file Digital Geologic
Map OF‐GM 188. New Mexico Bureau of Geology
and Mineral Resources, Socorro, New Mexico.
http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/details.cfml?Volume=18
8
http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/downloads/188/Lincoln_Report.pdf
http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/downloads/188/Lincoln_v1p-00.pdf

Rich Murray wrote:
“69 views are in: 
https://www.dropbox.com/gallery/2268163/1/CraterField?h=c40610 

A Cox 
34.281890 -105.139342 1.755 km area el 
just S of County Road 3Ka, which comes from 
10M SW of 285 
and then W and N to 54, 60, 285 just W of Vaughn -- 
22 M S of Vaughn 
75 M NNW of Roswell 
many craters .01 to 0.1 km size”

No craters. Just craterwrongs in the form of sinkholes.
 
Rich Murray wrote:
“B Cox 
34.254942 -105.117973 
10 M SW of 285 
many craters”

No craters. Just more sinkholes.

Rich Murray wrote:
“C Cox 
34.203891 -105.058533 1.674 km area el 
9 M SW of 285 
.05 km wide 4 m deep”

Even more sinkholes.

Rich Murray wrote:
“D Cox 
34.191197 -105.027841 1.644 km area el 
8 M SW of 285 
.07 km size 13 m deep”
Just another sinkhole.

Rich Murray wrote:
“E Cox 
34.207906 -105.02134 1.606 km area el 
7 M SW of 285 
.04 km wide 3 m deep”

Just another sinkhole.

34.207906 -105.02134
“F Cox 
34.210453 -105.03963 1.645 km area el 
8 M SW of 285 
.05 km wide 4 m deep”

More sinkholes. :-) 

Best wishes,

Paul H.