Impact Crater in New Mexico – Part 2 Lincoln County Revisited

In Impact Crater in New Mexico – Part 2 Lincoln County at
http://six.pairlist.net/pipermail/meteorite-list/2011-January/072230.html

Rob, about the features in 34° 0' 51.00" N 105° 8' 41.46" W
( 34.0142° N, 105.1448° W ) commented,

“Looking at these features in Google Earth, they appear 
to be capped limestone structures rather than depressions. 
Has anyone on the discussion list actually been there?”

I consulted the USGS topographic map and the 10-m DEM 
for the Cowboy Mesa SW 7.5 minute quadrangle. They
both show that these features are depressions and that 
they are certainly not limestone capped hills. Depending 
on how a person’s brain interprets the shadows, images 
on two-dimensional aerial photographs can appear to be 
either depressions or hills. Because of this quirk of how 
the brain works, it is useful to consult either topographic 
maps, digital elevations models (DEMs), or stereo pairs 
of aerial images when making interpretations.

Similar depressions can be seen elsewhere in the
regions in aerial photos and topographic maps. 
Similar depressions occur in Sections 29 and 28 of 
T. 4S., R. 17E. at 33.936° N, 105.179° W. This is 
about 9 km south-westsouth of Guenther’s depressions. 
Even more depressions can be seen about 32 km to 
the west – west-southwest in Sections 1, 2, 12, 20, 
21, 22, 33, 34, and others of T. 4S., R. 14E. Examples
of other similar depression can be found at 33.988° N,
105.435° W. and 33.946° N, 105.479 W. They all have 
the typical morphology of sinkholes. The typical
morphology of sinkholes as seen in topographic maps 
is discussed by Miller and Westerback (1989).

By the way the correct location for Guenther’s depressions 
is S1/2 of the SE1/4, of Section 27 and the N1/2 of the 
NE 1/4 of Section 34 of T. 3S., R. 17E. I mistakenly wrote 
“NE 1/2” instead of NE1/4”.

These posts are in reference to “Impact Crater in New Mexico” at 
http://six.pairlist.net/pipermail/meteorite-list/2011-January/072191.html

and “Impact Crater in New Mexico – Part 2 Lincoln County”
http://six.pairlist.net/pipermail/meteorite-list/2011-January/072228.html

Reference Cited,

Miller, V. C., and M. E. Westerback, 1989, Interpretation
of Topographic Maps. Merrill Publishing Company, 
Columbus, Ohio. 416 pp. ISBN-13: 978-0675209199
http://www.worldcat.org/title/interpretation-of-topographic-maps/oclc/19290228&referer=brief_results
Yours,

Paul H.

Impact Crater in New Mexico – Part 2 Lincoln County

Abe wrote in “Impact Crater in New Mexico” at
http://six.pairlist.net/pipermail/meteorite-list/2011-January/072191.html

 

 ;

“How about these 34° 0'51.00" N 105° 8'41.46" W? 
I notice a huge scatter of craters. Is much known 
about these or what they are? There are a lot of
these ancient scars for several miles around. If 
they aren't impact craters it would be interesting 
to know what they are.”

The features that are located at and near 34° 0'51.00" 
N 105° 8'41.46" W lie within the S1/2 of the SE1/4, of
Section 27 and the N1/2 of the NE 1/2 of Section 34 of 
T. 3S., R. 17E. within Lincoln County, New Mexico.
According to Scholle, P. A. (2003), this area is underlain 
by the San Andres Formation, which is described as 
“Limestone and dolomite with minor shale.”

Judging from what can be seen in the images, the 
depressions in this area are natural features. Their
morphology exhibits all the characteristics of typical 
sinkholes developed in the local limestone and 
dolomite bedrock. Unfortunately, I cannot at this
time find anything specific about the geology of 
this part of Lincoln County, New Mexico. 

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

References;

Scholle, P. A., 2003, Geologic Map of New Mexico.
scale 1:500,000, New Mexico Bureau of Geology 
and Mineral Resources, Socorro, New Mexico.

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=188

 

Map at http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/downloads/188/Lincoln_v1p-00.pdf

 

Text at http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/downloads/188/Lincoln_Report.pdf

 

Yours,

Paul H.

Impact Crater in New Mexico – Part 1 Lea County

About an area in Lea County, New Mexico, Abe wrote: 

“I plan to go on another meteorite hunting trip to New Mexico
soon before the Tucson show. Would you guys think that this 
is an impact crater? 32°21'54.39" N 103°23'47.50" W. I 
remember reading about it on a site but it appears that there 
are just too many craters in the area to all be impact craters. 
If they aren’t impact craters what would be the possibility 
they are ancient ponds for wildlife? I would imagine that as 
West Texas and New Mexico dried up, any remaining wet 
ground would become extremely populated with wild life 
and over centuries these locations would become deep ponds.”

These are playa lakes. They are neither impact craters nor 
related any type of impact processes. Some of these playa 
lakes have been  in existence throughout the Pleistocene. 
However, there is one known exception to how playa lakes 
typically form, it is the playa lake that occupied the Odessa 
impact crater.

About playa Lakes, Holliday et al. (1996) states

“These lithostratigraphic and chronostratigraphic
relationships show that some basins have a prolonged 
history as depressions, persisting in more or less the 
same location as the High Plains surface aggraded by 
eolian addition (Blackwater Draw Formation) throughout
the Pleistocene. Sizes of the basins varied through time as 
they were encroached upon by the Blackwater Draw 
Formation, enlarged by fluvial, lake margin, and eolian 
erosion, were filled and reexposed, or were buried. 
Some basins are newly formed on the High Plains 
surface and have no apparent predecessors.”

About the origin of playa basins, Gustavson et al. (1995a) wrote

“The initial formation of playa basins involved many 
processes but most likely started with collection of runoff 
in small, irregular topographic depressions on the High 
Plains. Initial depressions may have resulted from surface
drainage, dissolution of the Caprock calcrete, subsidence 
caused by salt dissolution, differential compaction, animal 
wallows, or blowouts where vegetation was missing. 
Ponded runoff killed vegetation or inhibited plant growth 
and allowed deflation to remove some of the surface 
sediment when the pond dried out. As the initial small 
basin expanded, fluvial erosion and lacustrine sedimentation 
became more important. centripetal drainage enlarged the 
basin by eroding the basin margin and carrying sediment 
to the basin floor. Periodic flooding continued to keep the 
center of the playa basin relatively clear of vegetation. 
Wind deflated dry sediment from the playa center. 
Deflation may have been accelerated after large herds of 
bison pulverized dried surface soils and carried small 
amounts of sediment out of the basin on their hooves. 
Sediments deflated from these basins were carried 
downwind.”

Some Publications About Playa Lakes

Gustavson, T. C., V. T. Holliday, and S, D. Hovorka, 1995a 
Development of Playa Basins, Southern High Plains, Texas 
and New Mexico. In Proceedings of the Playa Basin 
Symposium, edited by L.V. Urban and A.W. Wyatt, pp. 5-14. 
Texas Tech University, Water Resources Center, Lubbock.

Gustavson, T. C., V. T. Holliday, and S. D. Hovorka, 1995b 
Origin and Development of Playa Basins, Sources of 
Recharge to the Ogallala Aquifer, Southern High Plains, 
Texas and New Mexico. The University of Texas at Austin, 
Bureau of Economic Geology Report of Investigation 229.

Holliday, V. T., T. C. Gustavson, and S. D. Hovorka, 1996, 
Stratigraphy and Geochronology of Playa Fills on the 
Southern High Plains. Geological Society of America 
Bulletin. vol. 108, no. 8, pp. 953-965.
Abstract at http://gsabulletin.gsapubs.org/content/108/8/953.short

 

PDF file at http://www.argonaut.arizona.edu/articles/holliday_etal1996.pdf

 

and http://www.argonaut.arizona.edu/holliday.htm

 

Hovorka, S.D., 1997, Quaternary evolution of ephemeral playa 
lakes on the Southern High Plains of Texas, USA: cyclic 
variation in lake level recorded in sediments. Journal of 
Paleolimnology. vol. 17, pp. 131–146.
http://www.springerlink.com/content/u20316917821568q/

 

Osterkamp, W. R. and W. W. Wood, 1987, Playa-lake basins 
on the Southern High Plains of Texas and New Mexico: 
Part I. Hydrologic, geomorphic, and geologic evidence for 
their development. Geological Society of America Bulletin.
vol. 99, no.2, pp. 215-223.
http://bulletin.geoscienceworld.org/cgi/content/abstract/99/2/215

 

Wood, W. W., and W. R. Osterkamp, 1987, Playa-lake basins 
on the Southern High Plains of Texas and New Mexico: Part II. 
A hydrologic model and mass-balance arguments for their 
development. Geological Society of America Bulletin.
vol. 99, no.2, pp. 224-230.
http://bulletin.geoscienceworld.org/cgi/content/abstract/99/2/224

 

Playa lakes are an extremely important to local wildlife as
the primary wetlands in this part of the southern High Plains
as discussed in:

Haukosa,  D. A., and L. M. Smith, 1994, The importance of 
playa wetlands to biodiversity of the Southern High Plains.
Landscape and Urban Planning. vol. 28, pp. 83-98.
http://dx.doi.org/10.1016/0169-2046

 

(94)90046-9

Smith, L. M., 2003, Playas of the Great Plains. University of 
Texas Press, Austin, Texas. 275 pp. ISBN: 978-0-292-70177-9
http://www.utexas.edu/utpress/books/smipla.html

 

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1781&context=greatplainsresearch

 

Yours,

Paul H.