DC Crater: Fact or Fiction?
Is the foundation of downtown Washington DC in a crater, secondary or primary, that was formed from
ballistic fallout
or from broken off pieces of the primary object that created the Chesapeake Bay Impact Structure(35Mya)?
Downtown Washington DC
Circular Feature in DC Topography
"The first indication of a possible meteorite impact structure
is frequently a distinct circular (or nearly circular) feature
in the topography or bedrock geology."
(Traces of Catastrophe, Page 98 7.2.1. Geological Features, French B. M )
"This circular region commonly shows distinctive and often
anomalous bedrock geology in comparison to the surroundings."
(Traces of Catastrophe, Page 98 7.2.1. Geological Features, French B. M )
Compare Downtown DC topography with an "eroded" crater on Mars - Solis Planum
Downtown Washington DC (Below Left) similar topographical features on Mars crater "Solis Planum" (Below Right)
Downtown Washington DC (Below Left) looking
northeast over the Potomac River towards Capitol Hill
,
Have secondary craters from the Chesapeake Impact been identified in the Potomac River?
Yes, a "chain" of eighteen (18) craters were identified in the lower Potomac.(below)
Identified Secondary Craters in the Potomac River(The Chesapeake Bay Crater, Page 156, C.W. Poag et.al.)
Location of "known" Potomac River secondary craters of the Chesapeake Bay Impact(35MYA) referenced to the location of the "DC Crater."
Shown below are the approximate geographic locations of the "known" secondary craters
in the Potomac River and Chesapeake Bay.
Note that the DC crater is at the tip of the "cone" of the possible path of secondary ejecta
from the Chesapeake Bay Impact.
"DISTAL EJECTA
Although most of the material (about 90 vol%) ejected,
from the crater is deposited relatively close (less than 5 Rc) to the
crater (Melosh, 1989, p. 90), a significant amount (about 10 vol%) may travel to even greater distances (greater than 5 Rc) to form
deposits of distal ejecta."
(Traces of Catastrophe, Page 78, French B. M )
Is the hypothetical DC Crater within this range?
Yes. Chesapeake Crater Rc=42.5km (5*42.5) = 212.5km
Chesapeake Bay Crater distance to Washington DC:
202 km (125 mi)
"The maximum diameters of secondaries are roughly proportional to the diameter of their primary craters (e.g. lunar secondaries are ~ 4% as wide as their primaries)"
(The Chesapeake Bay Crater, Page 153, Secondary Craters, C.W. Poag et.al.)
"Apparent diameters of the secondary craters range from 0.4 km to 4.7 km, and average 1.9 km; only four have apparent diameters greater than 3 km."
(The Chesapeake Bay Crater, Page 155, Secondary Craters, C.W. Poag et.al.)
Is the diameter of the DC Crater within this range?
Yes. The estimated diameter of the DC Crater is 4.7km
The text quoted is used for expository purposes only. Unless noted otherwise
it was taken from chapter 7 "How to Find Impact Structures" of the paper "Traces of Catastrophe".
It is not meant to imply Dr.French's agreement with the DC Crater hypothesis.
The link to this is below (FYI it is a 130 page PDF 19.7 mb)
Is Owen Powers the only person who thinks ballistic ejacta and tsunami deposits
from the Chesapeake Bay Impact might be found in the DC area?
No, read another independent view below!
The links to Dr. Griscom's paper and website (below) are for expository purposes only.
They describe his independent views of the ejecta from the Chesapeake Bay Impact being located in the Atlantic Coastal Plain including the Washington DC area.
It is not meant to imply Dr.Griscom's agreement with the DC Crater hypothesis.
I became aware of Dr. Griscom and the existence of his website via "Google" on September 23, 2009
"...Anyway, you've convinced me that DC is built on a crater ...or two!"
("Personal correspondence", Email, Sept. 24, 2009, Dr. David L. Griscom)
The following quotes concerning the Atlantic Coastal deposits are from the 1820's
"1820 HAYDEN HORACE H Geological Essays or An Inquiry into sonic of the Geological
Phenomena to be found in various parts of America and elsewhere 8vo 412 pp Baltimore 1820
The writer contends that the unconsolidated deposits bordering the Atlantic Ocean are not alluvial
materials but have been brought to their present position by an ocean current which swept over
the eastern part of the country in a southwesterly direction. The rise of the ocean is believed to
have been caused by an increase of water due to the melting of the polar ice produced by a
shifting of the earth's axis"
(Maryland Geological Survey, Prince George's County, 1911)
1824 FINCH JOHN Geological Essay on the Tertiary Formations in America Read before Acad Nat
Sci Phila July 15 1823 Amer Jour Sci vol vii pp 31 43 Objection is made to the term alluvial
formation of Maclure and others on the ground that the deposits are for the most part not of alluvial
origin and also that as used it includes a number of distinct formations that can be correlated with
the newer secondary and tertiary formations of France England Spain Germany Italy Hungary
Poland Iceland Egypt and Hindoo stan. The writer makes some provisional correlations which are
now known to be wrong. He admits however that the data are insufficient for accurate correlation.
The clay which is found beneath the 54 feet of diluvial gravel on Capitol Hill Washington and which
contains remains of trees is considered by him the equivalent of the London clay."
(Maryland Geological Survey, Prince George's County, 1911)
Is Downtown Washington DC located in a secondary crater formed from the ballistic debris or ejecta from the Chesapeake Bay Impact Crater (35MYA)
This is my hypothesis. Data is still being collected and analyzed.
More of the hypothesis
I work in the Math Science Learning Center at Montgomery College in Montgomery County Maryland, USA
providing "out of classroom" support to students taking those courses.
DC Crater is an out growth of my amateur interests in geology and impacts.
Since I have a limited background in geology and impacts
it is my hope that someone with better qualifications than I have will become
interested in investigating the hypothesis further.
Was Washington DC built in an Impact Crater?
This web site is an attempt to answer that question by presenting information that I collected supporting the hypothesis that secondary ballistic ejecta
from the Chesapeake Bolide excavated a 4.5km diameter crater that became the foundation of downtown Washington DC.
I hope it will generate discussions and scientific research concerning the effects of the Chesapeake Bay Impact on the lithography
of the Atlantic Coastal Plain in general, and the Washington DC Area in particular.
Unless noted comments and images by Owen Powers (BS Physics/Earth & Space Sciences StonyBrook NY 1979)
Requests for research material specimens:
Contact: Opowers@aol.com
Quoted material from outside sources is in "red text and italicized"
(followed by the reference)
Images with a blue border will be enlarged if you click on them.
If you click on a "Link" or image use the back arrow <- in your browser to return to this page
GEOLOGY AND MINERALOGY
"A few years ago a correspondent of a New York print, (generally understood to be an intelligent member of Congress)
took a glance at some of the prominent geological features of this District; and although there be some imagination in the sketch,
yet, there is enough science to justify its insertion.
It is obvious, says he to the most careless observer, that over the site of the Capitol of the United States, and the country far around,
the waves of the ocean once rolled, and that these fields, now quietly tilled by the planter, were thrown from beneath it by some tremendous convulsion....
...The proofs of the amazing changes are numerous and conclusive. It is announced by the strata of earth; by the rounded stones,
like those which grind and polish each other on the sea shore; and by the numerous secondary formations, which without analysis,
instructs us satisfactorily on the slightest inspection. In many of the stones found even on the hights around us, are distinct impressions of marine shells. ,,, "
(A New and Comprehensive Gazetteer of Virginia, and the District of Columbia, Page 473, Joseph Martin, 1835)
See a possible concentric tektite mold, it may be the strongest evidence collected to date of Washington DC Ejecta
"I assure you that even at 5 inches you are considerably larger than the largest possible button shape tektite at around 1 inch or just slightly over.
The idea of this being a tektite mold is ridiculous. Even if it were a tektite and were the right size, button tektites, like Darwins,
only form about 4,000 plus km from the crater after oblique impact. They cannot form anywhere near the crater - it is impossible
This is definitely not a tektite mold and I can say this with absolutely no doubt.
Regards, Aubrey WhyMark"
Ok, that sounds like it is not a tektite mold. It now seems likey that it is an object as decribed in the following passage:
The Patuxent sands are often indurated by hydrous oxide of iron and take on very irregular and fantastic shapes, including hollow cylinders,
intricately corrugated plates and spherical and ellipsoidal gourds having the local names of " sand bullets," " sand clams," etc.
These indurated phases are well developed at the Homestead sand pits near the old Patterson mansion in Baltimore City.
(Lower Cretaceous By Maryland Geological Survey, Page 59, Baltimore The Johns Hopkins Press, 1911)
Does anyone know more about these "fantastically shaped" objects? (OP)
(The District of Columbia Its Rocks and Their Geologic History, Geological Survey Bulletin 967, Page 20, Martha S. Carr)
What is the Chesapeake Bay Impact (Bolide) ?
Primary Crater Location
("The Chesapeake Bay Crater", Page 3, C.W. Poag et.al.)
"The Chesapeake Bay Crater"
C.W.Poag C.Koeberl W.U.Reimold ISBN3-540-40441-4
Is the foundation of downtown Washington DC in a crater, secondary or primary, that was formed from ballistic fallout
or from broken off pieces of the primary object that created the Chesapeake Bay Impact Structure(35Mya)?
This is my hypothesis. Data is still being collected and analyzed.
More of the hypothesis
Has a city ever been identified as being built in a crater?
Yes, below is the Nördlinger Ries Crater in Germany.
It is a 26 kilometer (~16 mile) diameter crater with a town built within the walls of the crater.
It has been pointed out to me the need to clarify the caption of the image of Noerdlingen:
I had been under the wrong impression of the image: (OP)
"A detail: Please allow me to point out that the image of Noerdlingen, which you show on
http://www.dccrater.com
does not show the crater, as the caption and the circular structure of the city might suggest.
Noerdlingen is built as a fortified city within a circular town wall. The crater is, at 22km diameter,
so huge it is hard to take pictures of (and also heavily eroded).
I am sure you are aware of this, it is just that I find the description on your page misleading."
Dr. Juerg Alean
Rheinstrasse 6, CH-8193 EGLISAU, Switzerland
Could DC be another town built in a crater?
Yes, this could be a 4.5 kilometer (~3 mile) diameter crater with a town built within the walls of the crater.
The image below shows the green hills in the distance that form a "half moon" rim around northwest DC.
Ejecta from the Chesapeake impact would have come from the southeast of DC.
This would have caused the rim to be higher in the northwest.
The southeast section of the rim might not have been as prominent.
The bedrock around C & D street between 22 & 23 street (Darton) shows a scarp feature that could be interpreted as part of the rim.
The waters of the Potomac and Anacostia Rivers would have eroded most of the southeast section of the rim.
The last remnant of the rim in that area was probably "Braddocks Rock".
The "Rock" was a bedrock out cropping at the confluence of Tiber Creek (now Constitution Avenue)
and the Potomac River that was quarried for building material.
The deep gorge under 25th Street (described below) could have been caused by tsunami washback hitting the outside crater wall.
Eventually leading to the erosion of the lower crater rim that was redeposited to create what is now Capitol Hill.
"West of 20th Street the line passes into unusually coarse-grained river terrace materials
and across a deep gorge in bedrock at 25th Street filled primarily with torrential river terrace deposits."
( FINAL REPORT SUBSURFACE INVESTIGATION VOLUME 2 PENTAGON ROUTE MUESER, RUTLEDGE, WENTWORTH & JOHNSTON pg 3-4 section 3-7 DECEMBER 1967)
See the "Rock Creek to Farragut Square via Eye Street" cross section: Rock Creek to Farragut Square via Eye Street
Secondary Ballistic Ejecta (The Chesapeake Bay Crater, Page 378, C.W. Poag et.al.)
What are "chain craters"?
Chain craters are formed when the impacting object breaks into pieces and when those pieces impact
a line of craters are formed. They can also be formed when debris from the original impact
spreads out around the site of that impact. Just as a rock dropped in a mud puddle
will splash droplets of mud around that puddle.
Below are "Hypothetical" Chain Craters in the Potomac River south of Washington DC.
The second one down (2.4km) over SE DC is possible sediment from the lower rim of the DC Crater.
Could the Potomac River have been created by a chain of craters,
as a result of ballistic ejecta impact, that carved a flow back channel
for the subsequent tsunami wash back, into the Chesapeake Impact Crater?
Yes, below is an image of a chain of craters on Callisto, Jupiter's second largest moon.
It is not difficult to imagine water flowing in the channel of this string of craters.
The image below is about 13 kilometers (8 miles) across.
NASA JPL Callisto Chain Craters
Below are a chain of craters on Ganymede, another moon of Jupiter.
The picture covers an area about 120 miles wide.
NASA JPL Ganymede Chain Craters
DC Crater
What is known about the strata beneath the Middle Altantic Coastal Plain?
W.J. McGee - Three Formations of the Middle Atlantic Slope
"Four years ago the writer undertook to ascertain the origin and relations of certain conspicuous deposits in the District of Columbia,
under the auspices of the U.S. Geological Survey. It was soon found that while certain formations of the region-especially those containing fossils,
-had received more or less study, while the various formations had been classified by means of the fossils contained in a few of them,
and while the entire region had even been repeatedly mapped geologically, nothing was accurately known of the exact relations of the different fossiliferous
and unfossiliferous deposits forming the portion of the Coastal Plain within and contiguous to the District of Columbia; it was soon found,
moreover, that the formations in question are not only generally unfossiliferous in the district, but that the deposits themselves are destitute
of constant and definite petrographic and structural characters whereby the stratigraphy might be ascertained;
and thus it was early found difficult, if not impossible, either to correlate the different local exposures and deposits among themselves, or to establish their
relations to the formations already classified elsewhere by commonly employed methods."
(The American Journal of Science, Page 124, ART XI Three Formations of the Middle Atlantic Slope; W.J.McGee, January to June 1888)
On the formation of the Middle Atlantic Slope Terraces - Ocean Waves
"... But the forces concerned in the formation of the Middle Atlantic slope terraces acted horizontally over great distances and with uniform energy
for a considerable period, filling depressions, softening contours, and obliterating relief, yet so gently that the essential uniformity in the surface prevails for miles.
Only the undulatory and horizontally acting force of waves appears competent to produce so great expanses of uniform surface and constant structure as are exhibited
in this region...
(The American Journal of Science, Page 388, ART. XI Three Formations of the Middle Atlantic Slope; W.J.McGee, January to June 1888)
On the "Columbia Deposits" in the Washington Amphitheater - Prior to considering the geological processes of an impacting extra terrestrial object
The Genesis of the Deposits. An essential element in any philosophic classification of the rocks of the earth is genesis,
and geologic science has now reached a stage in which processes and products, agencies and results, are commonly correlated,
and in which at least the broader classifications are genetic.
There are recognized five principal categories of agencies by which the various superficial deposits of the earth are produced,
viz: chemic, igneous, glacial, aerial and aqueous.
Now on comparing the upper member of the fluvial phase of the Columbia formation with the known products of each of these categories of agencies,
it becomes evident that the deposits were not produced by either of the first two classes of agencies, since they have no distinctive features in common
with chemic and igneous deposits; that they are not glacial, since they are too regularly and continuously stratified,
since the two members are distinct in structure and composition and yet intergraduate, and since the pebbles and bowlders are neither striated nor polished;
that they are not aerial since the materials are coarser and more continuously bedded than those transported by winds;
and hence that the deposits are aqueous in origin.
By legitimately extending the same process of reasoning it might equally be shown that they are not fluviatile, torrential, lacustral, nor marine,
and indeed that they can only be a sub-estuarine delta of the river on which they occur.
(The American Journal of Science, Page 371, ART. XI Three Formations of the Middle Atlantic Slope; W.J.McGee, January to June 1888)
What is known about the strata beneath the District of Columbia?
What's new? What's old under DC?
"Fossil Plants.- In the Pleistocene epoch, when the lower terraces were being formed, perhaps 100,000 years ago, giant bald cypress (Taxodium distchum) was growing here.
In 1922 an old swamp deposit containing huge upright stumps and knees of such trees was uncovered at the depth of 20 to 30 feet below the surface
in the excavation at the site of the Mayflower Hotel, at Connecticut Avenue and DeSales Street.
Stumps from this Pleistocene swamp as much as 8 feet in diameter were noted by members of the Geological Survey,
and considerably larger ones were reported by others."
(The District of Columbia Its Rocks and Their Geologic History, Geological Survey Bulletin 967, Page 42, Martha S. Carr)
Could this piled up charcoal drift wood found in the Potomac Formation be from the forest fires that ensued the Chesapeake Bay Impact?
Read about what was found under DC in the American Journal of Science 1916
"One of the writers has recently seized an opportunity to secure abundant material of lignite and charcoal
from the Patuxent horizon of the Potomac formation at two localities in the District of Columbia.
A deep and extensive excavation for the new Central High School of Washington at 11th [Street NW]and Florida Avenue
exposed several plant beds, and a deposit of blue clay which contained a great deal of lignite in the form of prostrate branches.
The lignite at this locality had the appearance of an accumulation of drift wood; there were no leaf impressions directly associated with it.
On account of the very irregular bedding of the Potomac strata it is quite useless to attempt to generalize a section even for so small
an area as the Central High School locality. The excavation was made on a somewhat steep slope and was terraced so that the entire section
could not be seen from any one point."
(American Journal of Science 1916 Vol. XLI Sinnott and Bartlett - Coniferous Woods page 278)
"In addition to lignite, the clay at the Central High School site also provided a fine collection of charcoal fragments,
which had obviously been transported by wind or water from a forest fire.
These fragments were unquestionably carbonized before they were buried,
for they were associated with typical lignite derived from the same kind of wood.
It must, therefore, be understood that the charcoal referred to in the following pages
is the charcoal in the usual acceptation of the word, and not the material sometimes called 'carbonized wood' or 'mineral charcoal.' "
(American Journal of Science 1916 Vol. XLI Sinnott and Bartlett - Coniferous Woods page 279)
I am studying drawings of cross sections of the earth beneath DC created during the 1960's for the construction the DC Metro
to better understand the sequence of sediment deposition that created the underlying surface of the District of Columbia.
It is difficult to discern a logical pattern in the strata sequence, take a look at what's below!
Download Downtown Metro Geologic Study Cross Sections "Colorized & graphic boulders added where indicated(OP)"
Work in progress. ( Check back for updated information.)
All three cross section images in one file for comparison
Florida Avenue to Farragut Square via Connecticut Avenue
Rock Creek to Farragut Square via Eye Street
Lafayette Park to 3rd Street NW via G Street
H Street to Mall via 12th Street NW (Benning Road Metro)
11th Street SW to lst Street SE via D Street SW & D Street SE (Benning Road Metro)
(1969, Preliminary subsurface investigation for Washington Metropolitan Area Rapid Transit Adopted Regional System 1968, revised 1969; U.S. Depratment of Commerce.
[Available from National Technical Information Service, Springfield VA 22161 as NTIS Report PB-186-066]
Anomalous DC Bedrock Geology
"This circular region commonly shows distinctive and often
anomalous bedrock geology in comparison to the surroundings."
(Traces of Catastrophe, Page 98 7.2.1. Geological Features, French B. M )
There were dozens of springs in DC because of the fractured bedrock.
Download an interesting account of Washington DC Geology by the former DC Geologist, Jim O'Connor.
Springs are listed on pages 5 & 6.
Intense and localized deformation
(fracturing, faulting, and brecciation) in the DC Area
"The region may also be the site of intense and localized
deformation(fracturing, faulting, and brecciation)..."
(Traces of Catastrophe, Page 98 7.2.1. Geological Features, French B. M)
"STRUCTURE The structure of the crystalline rocks of the District of Columbia is very complex..."
(The District of Columbia Its Rocks and Their Geologic History, Geological Survey Bulletin 967, Page 19, Martha S. Carr)
The above image is from USGS(1950) Professional Paper 217.
USGS(1950) Professional Paper 217 takes a few minutes to download but the exquisite mapping artistry make it worth the wait.
After choosing the link below e.g. "From USGS web site: Configuration..."
You will be given a choice of how to view USGS(1950) Professional Paper 217
The two choices below are the best way to view the paper and images.
View Report as .DJVU *Requires plug-in*
View Plate as .DJVU *Requires plug-in*
"The span of time during which the author accumulated the data for this
paper approximates half a century, paralleling his unusually long term of
service on the Geological Survey. Mr. Darton came to Washington in 1886
to start his geological career on the Survey."
(Preface by Alice S. Allen, CONFIGURATION OF THE BEDROCK SURFACE OF THE DISTRICT OF COLUMBIA
AND VICINITY, Geological Survey Professional Paper 217, N. H. Darton)
"Although the southeasterly slope of the bedrock is in general
very regular at a rate of 100-150 feet to the mile, there are
local variations in direction and amount. Where data are
closely spaced they reveal low mounds and ridges and shallow
valleys which had been developed as surface features on the
old pre-Cretaceous rocks upon which the beds of the Potomac
group were deposited. Possibly also some faulting or even flex-
ing has taken place, which would cause irregularities in the
bedrock floor.These local irregularities are described in as
much detail as data permit and are illustrated by a number of
maps and sections."
(CONFIGURATION OF THE BEDROCK SURFACE OF THE DISTRICT OF COLUMBIA
AND VICINITY, Geological Survey Professional Paper 217, Page 1, N. H. Darton)
Rock Creek Shear Zone
Tangential to Circular Topography
"The major structural feature in the Washington West quadrangle
is the Rock Creek shear zone (Fleming and others, 1992). It is a
major belt of severe ductile deformation accompanied by two
systems of oblique-slip faults. It is well-exposed in Rock Creek
Park,where its northerly trend cuts obliquely across the strike of
the crystalline rocks (fig. 3). It extends an unknown distance into
the Kensington quadrangle to the north. To the south,it passes
beneath unconsolidated sediments near the mouth of Rock Creek..."
"4. The steep, relatively straight aeromagnetic gradient that
characterizes the shear zone along its entire length (USGS, unpub. data)
is distorted in the area of the thrust faults"
(USGS Geological Quadrangle Map Washington West Quadrangle,
D.C.,MD,VA GQ-1748, Flemming et.al. (1994))
Note: The Rock Creek Shear Zone passes through the deep "gouge" in bedrock under Eye St & 25th St NW
Faults in Washington DC -
The Calvert Street to Lafayette Park Reverse Fault
"... we can expect to find numerous additional secondary craters
scattered around the perimeter of the Chesapeake Bay primary crater
at locations of dip reversal."
(The Chesapeake Bay Crater, Page 170, Secondary Craters, C.W. Poag et.al.)
This is N.H. Darton's 1901 photo of the Calvert St Fault
Read about the Lafayette Park 50 ft Bedrock drop below
"At the beginning of Potomac deposition, some old
fault scarps may have remained, causing local breaks
in the bedrock, which now appears to slope regularly
eastward. Erosion also produced many- local ridges
and valleys. The uplifts and submergences of the Coastal
Plain, in later Cretaceous, Tertiary, and Pleistocene
times must have been attended by flexing and faulting,
which would affect the position of the bedrock surface,
but few such features are revealed. A few faults in
bedrock and overlying strata have been observed in the
western part of Washington, but the displacement is
small and apparently the faults are rather short.
Along one fault exposed in a trench on Eighteenth
Street near California Street, where arkose of the
Potomac group rested on gneiss, there was a drop of
40 feet or more on the east side. (See fig. 6.)
A fault, probably local, in the terrace deposit on
Adams Mill Road (see pI. 6, A) has a throw of about 8
feet. Another small fault was formerly exposed in the
north side of the alley just north of Calvert Street. (See
pl. 6, B.) These exposed faults suggest that others may be
present under the covered areas."
(CONFIGURATION OF THE BEDROCK SURFACE OF THE DISTRICT OF COLUMBIA
AND VICINITY, Geological Survey Professional Paper 217, Page 8, N. H. Darton)
(CONFIGURATION OF THE BEDROCK SURFACE OF THE DISTRICT OF COLUMBIA
AND VICINITY, Geological Survey Professional Paper 217, figure 6, Page 7, N. H. Darton)
Was the Calvert St to Lafayette Park Fault (OP) caused by the transfer of the linear momentum
from the impacting object to the earth?
There are many indications that that could be the case.
The Calvert St to Lafayette Park Fault (OP) is drawn on the
USGS Geological Quadrangle Map Washington West Quadrangle.
See the dashed black and red line on the map and the explanation of the map symbols below.
The light red lines on the map indicate irregular bedrock contour lines.
The heavy red line, (OP added), indicates the Calvert St to Lafayette Park Fault (OP) line.
It has a ~50ft throw under Lafayette Park and is lined up in the direction of the Chesapeake Impact
The fault is deepest at Lafayette Park (south) and the "down side" of the fault is on the eastern side.
(USGS Geological Quadrangle Map Washington West Quadrangle,
D.C.,MD,VA GQ-1748, Flemming et.al. (1994))
\
Looking North perpendicular to Connecticut Ave southeast of Rock Creek
For location of B-B section see map plan above, upper left hand corner
(USGS Geological Quadrangle Map Washington West Quadrangle,
D.C.,MD,VA GQ-1748, Flemming et.al. (1994))
Compare the faults in DC (above) to those found in the Lower Potomac River (below)
(Poag 1997a, 1998 1999a;Fig 5.2)
Seismic reflections of the Lower Potomac secondary craters P-17 and P18
Lower Potomac river secondary craters near Colonial Beach VA
(The Chesapeake Bay Crater, Page 168, C.W. Poag et.al.)
Could the water main break be related to the Calvert Street fault?
As far as the pipe break, perhaps like a "cantilever beam",
the pipe overhanging the "hanging wall" of the reverse fault built up
moments, stresses, and shear forces over the years.
The large amount of rain in this area might have caused
the "load" to exceed the bearing capability of the pipe and snapped it.
Because of the different soils on either side of the fault there would be a different weight bearing capabilities.
Small effects at first but over the years significant enough to become noticeable and cause damage.
Or,the reason for the break had nothing to due with those stresses and it was caused by something
that I am not aware of (internal pressure) since I have not investigated it further.
IDENTIFICATION OF NEW IMPACT STRUCTURES
Distal Impact Ejecta
Where I looked for evidence of Distal Impact Ejecta in the DC area.
1) In the stream beds of Rock Creek and it's tributaries.
Why did I look there?
I became curious after finding a number of "Sponge Rocks" that were volcanic in appearance in Rock Creek.
I have found them as far west as the Potomac River near Chain Bridge and as far east as Piscataway, MD.
Rock Creek Area Collection Locations
Has any impact material been found in the DC area?
The material that I have collected in the DC area is illustrated below.
Whether it is impact related and where it came from are open questions.
As expected there are a variety of opinions concerning the collected material.
They range from it looks like construction debris to it looks like impact related material.
Impact related material or construction debris? It could be both!
"...The economic products of impact structures include such diverse
items as local building stone, diamonds, and uranium..."
"...Within and around other impact craters, the other kinds of breccias
produced by the impact have provided building stone [Ries Crater (Germany);
Rochechouart (France)] and industrial limestone [Kentland (Indiana)]..."
(Traces of Catastrophe, Page 1, 1.1.THE NEW GEOLOGY: METEORITE IMPACTS ON THE EARTH, French B. M )
Origin Opinions
(personal correspondence)
Rocks Referenced in Origin Opinions Above
(personal correspondence)
Could they have originated from the Chesapeake Crater?
Perhaps, because the surrounding hills were capped in some places by Potomac Group Formation older than 40 million years.
In other places by the Calvert Formation about 18 millions years old.
Fallout from the Chesapeake Crater is about 35 million years old.
The stream beds covered Bedrock older than 400 million years.
The Chesapeake Crater fallout must be have eroded out in places into the mix of rocks in the area creeks.
Rock Creek Tributary Creek Banks
Rock Creek Tributary Creek Banks
Volcanic Type Rock: "Sponge Brick", Washington, DC
"Sponge Brick Thin Section PDF"
Dozens of this type rock collected
in local stream beds:"Sponge Rocks"
"...or it may contain unusual (or even normal-looking)
volcanic or intrusive igneous rocks."
(Traces of Catastrophe, Page 98 7.2.1. Geological Features, French B. M )
"Sponge Rock Thin Section PDF"
Sponge Rock Collected in red Cretaceous Clay (Below)
District of Columbia
Fizzles with Hydrochloric Acid
Sulfur odor when split (Hi Res image below right)
Sponge Rock with glass inclusion collected in Rock Creek near Norman Stone Creek, NW DC(Below)
"Download Sponge Rock Glass PDF"
Fact: Carbonaceous Chondrite material (Gehlenite)
found in DC Area Volcanic type rock: Sponge Rock with Glass Inclusion
Apparently "Gehlenite" is found in man made slag and carbonaceous chrondrites. The author of the report leaves no doubt that he thinks the "sponge rock" is man made slag.
I wonder about the outer crust and the different cooling rates of the "sponge rock" material.
What is produced when a huge metorite crashes into the ocean floor and splashes molten sand and metal from an area the size of Rhode Island around the DC area?
"Gehlenite is found in carbonaceous chondrites from which it condensed as a refractory mineral in the hotter stages (FU Ori) of the presolar nebula..."
(http://en.wikipedia.org/wiki/Gehlenite)
GlassQuartz fused collected in Bladensburg, MD (Below)
"Download GlassQuartz fused PDF"
IronQuartz fused collected in Bladensburg, MD (Below)
"Download IronQuartz fused PDF"
Concentric Rock Collected in Bladensburg, MD (Below)
"Download Concentric Rock PDF"
In Darwin's description (below) in reference to the volcanic bomb (tektite left) he remarks:
"It seems to have been embedded in some red tufaceous matter;"
(Geological Observations on the Volcanic Islands, Chapter III, Ascension Island, C. Darwin Smith, Elder & Co., London, 1844.)
Considering the rock composed of fused glass and sand (below right,3 views), was collected in the same location, Bladensburg, MD, as the "concentric" mold rock,
it is very likely that the "concentric" rock is a partial mold of a concentric obsidian tektite that was embedded in red tufaceous matter.
Based on the arc size of the rings in this rock, (above image second from left) I made a crude clay model (below left, bottom and side view),
of what the shape of the eroded tektite, that left the impression, might have looked like.
"Download GlassQuartz fused PDF"
Read (below) Charles Darwin's descriptions of concentric rock formation.
M. Bory St. Vincent[4] has described some balls of lava from the Isle of Bourbon, which have a closely similar structure;
his explanation, however (if I understand it rightly), is very different from that which I have given; for he supposes that they have rolled,
like snow-balls, down the sides of the crater. M. Beudant,[5] also, has described some singular little balls of obsidian,
never more than six or eight inches in diameter, which he found strewed on the surface of the ground: their form is always oval;
sometimes they are much swollen in the middle, and even spindle-shaped:
their surface is regularly marked with concentric ridges and furrows, all of which on the same ball are at right angles to one axis:
their interior is compact and glassy. M. Beudant supposes that masses of lava, when soft, were shot into the air, with a rotatory movement
round the same axis, and that the form and superficial ridges of the bombs were thus produced.
Sir Thomas Mitchell has given me what at first appears to be the half of a much flattened oval ball of obsidian;
it has a singular artificial-like appearance, which is well represented (of the natural size) in the accompanying woodcut.
It was found in its present state, on a great sandy plain between the rivers Darling and Murray, in Australia,
and at the distance of several hundred miles from any known volcanic region. It seems to have been embedded in some red tufaceous matter;
and may have been transported either by the aborigines or by natural means. The external saucer consists of compact obsidian, of a bottle-green colour,
and is filled with finely-cellular black lava, much less transparent and glassy than the obsidian.
The external surface is marked with four or five not quite perfect ridges, which are represented rather too distinctly in the woodcut.
Here then we have the external structure described by M. Beudant, and the internal cellular condition of the bombs from Ascension.
The lip of the saucer is slightly concave, exactly like the margin of a soup-plate, and its inner edge overlaps a little the central cellular lava.
This structure is so symmetrical round the entire circumference, that one is forced to suppose that the bomb burst during its rotatory course,
before being quite solidified, and that the lip and edges were thus slightly modified and turned inwards.
It may be remarked that the superficial ridges are in planes, at right angles to an axis, transverse to the longer axis of the flattened oval:
to explain this circumstance, we may suppose that when the bomb burst, the axis of rotation changed.
(Geological Observations on the Volcanic Islands, Chapter III, Ascension Island, C. Darwin Smith, Elder & Co., London, 1844.)
Read more of Charles Darwin's descriptions of various types of volcanic rocks.
Basaltic Lavas Comments (Charles Darwin)
"Darwin's Sponge Rock Description"
Basaltic lavas—Numerous craters truncated on the same side—Singular structure of volcanic bombs—
Aëriform explosions—Ejected granitic fragments—Trachytic rocks—Singular veins—Jasper, its manner of formation—
Concretions in pumiceous tuff—Calcareous deposits and frondescent incrustations on the coast—
Remarkable laminated beds, alternating with, and passing into obsidian—Origin of obsidian—Lamination of volcanic rocks.
Why are dropped beer cans like vesicular rocks? Read the paper below to find the answer!
"Impact vesiculation a new trigger for
volcanic bubble growth and degassing"
Volcanic Type Rock: "Cracked" Quartz Rock, Washington, DC (below)
Volcanic Type Rock: "Angular 'Gravel' Clast" (Breccia), Washington, DC (below)
"Angular Gravel Clast(Breccia)"
Black lines indicate section cuts (see below).
Possbile Glass inclusions
Volcanic Type Rock: "Angular 'Gravel' Clast" (Breccia Sections), Washington, DC (below)
Sections stained dark from "cutting oil". Machinist reported rock very hard and was difficult to cut through.
Volcanic Type Rock: "Angular Clast" (Breccia), Washington, DC (below)
"Angular Clast(Breccia) Thin Section PDF"
Volcanic Type Rock: "Melted Glass Rock", Washington, DC (below)
Volcanic Type Rock: "Slag Rock", Washington, DC (below)
Thin Section Planar Deformation Features
Glass Microsperules (below)
(The Chesapeake Bay Crater, Page 229, C.W. Poag et.al.)
USGS Thin Section Comments
(personal correspondence)
Sheared Quartz rock (District of Columbia)
Could the DC terrace topography be remnants of oscillating damped tsunamis?
Below is the DC Topography showing hypothetical DC Crater location & Calvert Street-Lafayette Park Fault(OP)
If extended southeast, the fault line would intersect the primary Chesapeake Impact Crater.
The sequence below also shows the DC topography with water levels starting at 115ft above sea level and lowering to 0ft (current level)
Note the topograghy of the 50 ft terrace and the adjacent tsunami wave front.
DC Topography sea level raised 115 ft
DC Topography sea level raised 90 ft
DC Topography sea level raised 50 ft
The Tsunami wave front is depicted on the map (near left).
Compare the wave front line (black line) with the DC "50 Foot Terrace" line (far left).
DC Topography sea level raised 25 ft
DC Topography at current sea level 0 ft
The Chesapeake Impact MegaTsunamis reworked the coastal plain deposits.
Could the layers of "sandy" strata (see Metro Cross Sections) be the "varied depositional imprint" left by the tsunamis?
...Secondary water movement, such as that generated by back flow from shallow-water and coastal run-up,
together with offshore-directed surges and associated sediment gravity flows (e.g. turbidity currents),
will be capable of generating a wide range of bed forms.
Mega-tsunamis can thus leave a varied depositional imprint of their passage.
This is characterized by chaotic mixing of sediments from different coastal environments and of diverse grain sizes...
(Sedimentary Geology 161 (2003), Page 328, H. Dypvik, L.F. Jansa)
On the formation of the Middle Atlantic Slope Terraces - Ocean Waves
"... But the forces concerned in the formation of the Middle Atlantic slope terraces acted horizontally over great distances and with uniform energy
for a considerable period, filling depressions, softening contours, and obliterating relief, yet so gently that the essential uniformity in the surface prevails for miles.
Only the undulatory and horizontally acting force of waves appears competent to produce so great expanses of uniform surface and constant structure as are exhibited
in this region...
(The American Journal of Science, Page 388, ART. XI Three Formations of the Middle Atlantic Slope; W.J.McGee, January to June 1888)
On the "Columbia Deposits" in the Washington Amphitheater - Prior to considering the geological processes of an impacting extra terrestrial object
The Genesis of the Deposits. An essential element in any philosophic classification of the rocks of the earth is genesis,
and geologic science has now reached a stage in which processes and products, agencies and results, are commonly correlated,
and in which at least the broader classifications are genetic.
There are recognized five principal categories of agencies by which the various superficial deposits of the earth are produced,
viz: chemic, igneous, glacial, aerial and aqueous.
Now on comparing the upper member of the fluvial phase of the Columbia formation with the known products of each of these categories of agencies,
it becomes evident that the deposits were not produced by either of the first two classes of agencies, since they have no distinctive features in common
with chemic and igneous deposits; that they are not glacial, since they are too regularly and continuously stratified,
since the two members are distinct in structure and composition and yet intergraduate, and since the pebbles and bowlders are neither striated nor polished;
that they are not aerial since the materials are coarser and more continuously bedded than those transported by winds;
and hence that the deposits are aqueous in origin.
By legitimately extending the same process of reasoning it might equally be shown that they are not fluviatile, torrential, lacustral, nor marine,
and indeed that they can only be a sub-estuarine delta of the river on which they occur.
(The American Journal of Science, Page 371, ART. XI Three Formations of the Middle Atlantic Slope; W.J.McGee, January to June 1888)
"Terrace Deposits" on top of bedrock in the banks of a Rock Creek tributary, Normanstone Drive, NW DC.
These "Terrace Deposits" are a poorly sorted mix of rounded cobbles and pebbles.
"The internal structure and stratigraphy of the Patuxeut formation is at times very complex,
more so than that of any of the other Coastal Plain formations. Contemporaneous erosion planes,
very coarse and steeply inclined cross-bedding and alternations of extremely dissimilar and sharply
demarked beds and lenses in irregular attitudes, although not the rule, are not at all uncommon."
(Maryland Geological Survey: The Lower Cretaceous of Maryland,1911, Page 63 )
"Maryland Geological Survey: The Lower Cretaceous of Maryland,1911"
Below read excerpts about the origin of the terraces and...
Why the USGS says that the ages of the upland gravels are inferential and speculative in the map area.
USGS Birds Eye View Downtown Washington DC (1950)
(The District of Columbia Its Rocks and Their Geologic History, Geological Survey Bulletin 967, Plate 1, Martha S. Carr (1950))
Washington DC image with slanted parallel lines.
In the direction of the blue line I drew starting under the letter "e" in the word "lines".
Are they just image artifacts or are they real topographical features?
The boulders shown below are from piedmont rock and are being exposed near Piscataway Creek, MD and the Potomac River.
Could they have been deposited there from the Chesapeake Impact's tsunamis?
Are they similar to those found under DC?
"What Next? Current Problems and Future Investigations
During the brief history of meteorite impact geology, all
past predictions about the importance of impacts and the
range of their effects have turned out to be inaccurate and
unimaginative underestimates. Although a lot has been
learned in the last couple of decades, there is no reason to
expect that today’s estimates will turn out to be any more
accurate. We must now do what geologists have always done
when suddenly faced with ideas that are new, exciting, poorly
explored, and only dimly understood. We must take the new
ideas out into the field and look at the rocks again"
(Traces of Catastrophe, Page 105, 8.7, Impacts and the Early Earth, French B. M)
,
These "Terrace Deposits" are a poorly sorted mix of rounded cobbles and pebbles.
