Clarifying note: The Tusk, not Dr. Burchard, suggested the name Crater Burchard for this feature. And yes, I know. Craters are named for nearby geographic features, not people.
The always smug but relatively well informed Paul Heinrich had a post on the Meteorite-list serve today disputing the cosmic origin of circular features identified by Hermann Burchard in the South China Sea and posted last month on the Cosmic Tusk. Paul is one of those guys that doesn’t sleep well if someone is still up having some fun. But nonetheless he is a fine scientist and always willing to dig deep in the literature and his own extensive knowledge base to dispute claims he finds thinly supported.
I’ll leave it to the crowd to sort through Heinrich’s criticisms, but they seem solid. However, I have to take issue with his claim that common folks using Google Earth to poke around for craters is simply “dubious” and cannot contribute to the search for craters. The world is a big place and crowd sourcing is a valid approach for citizens to scientists. A few meteor wrongs, or Google crater that are truly center-pivot irrigation, do not stress the system so badly that it deters professional research.
I have a feeling that if Heinrich falsely believed he had stumbled upon a previously un-noted math proof, Dr. Burchard would graciously walk him back. In fact I know he would.
Message: 10
Date: Thu, 5 Dec 2013 10:14:50 -0500
From: “Paul H.” <[email protected]>
Subject: [meteorite-list] An Evaluation of the Proposed Spratly
Islands Impact Structure
To: “[email protected]”
Message-ID: <20131205101450.SVDSW.383296.imail@eastrmwml214>
Content-Type: text/plain; charset=utf-8
In November 3, 2013, on the Cosmic Tusk, Hermann G W
Burchard proposed that the region underlying the Spratly Islands
is the center of a multi-ring circular to oval impact structure,
informally called Crater Burchard, that has a diameter of
about 275 km (175 miles). Given that crater are not normally
named after people, but after geographic locations, this proposed
impact structure will be referred to as the ?Spratly Islands
Impact Structure? for purposes of discussion after the Spratly
Islands in the South China Sea. The center of this proposed
275 km (175 miles) in diameter impact structure is an atoll
called Union Reefs, or Union Bank at Latitude 9.788666? and
Longitude 114.351768?. Burchard speculates that the Union
Reefs atoll might lie on top of the top of the central uplift of
such an impact crater. he further speculates that this proposed
crater might be the long searched for Australasian tektite impact
crater Burchard (2013). The existence of this impact structure
is based entirely upon hypothetical circular features found by
the visual examination of bathymetry as portrayed by Google
Earth.
The Spratly Islands is part of a larger area called the “Dangerous
Ground.” The Dangerous Ground is a part of southeast South
China Sea that is characterized numerous low islands, reefs,
submerged banks, shoals, and atolls that often rise abruptly from
the depths of the South China Sea. Because this area is poorly
and inconsistently charted, it was, and in part still is, a dangerous
place for navigation. Tropical depression, typhoons, unpredictable
squalls, modern day pirates, and armed naval vessels involved in
various international jurisdictional disputes are additional hazards
found within this region (Anonymous 2011).
Burchard (2013) is right about there being significant information
(?news?) about the geology of the Spratly Islands and adjacent
Dangerous Ground having been collected because of the oil and
gas potential of the area. Contrary to what he assumed, specifics
about the geology of region were quite easy to locate and were
collected in only a few hours of effort. In addition to geological
research associated with oil and gas studies, detailed geological
data for this part of the South China Sea was gathered during
Ocean Drilling Program (ODP) Leg 184 (Shipboard Scientific
Party 2000a). Thus, the published data available for the Spratly
Islands and adjacent Dangerous Ground includes seismic lines
that cut across the proposed impact structure and an ODP drillhole,
ODP Site 1143 of Leg 184, that lies just within the alleged rim
of the proposed Spratly Islands Impact Structure. The drillhole
at ODP Site 1143 was continuously cored to from the sea floor
at a depth of 2772 m below sea level to a depth of 512.4 m
(1,680 feet) below the sea bottom (Shipboard Scientific Party,
2000b).
Because of their potential oil and gas potential and the multiple
and contentious international claims and jurisdictional disputes
concerning the Spratly Islands and adjacent Dangerous Ground
region, they have been the subject of intensive and repetitive
geological studies from a wide variety of governmental and
nongovernmental agencies and private corporations of various
nationalities. Although much of the data, including seismic lines
and drillhole data, remain proprietary, scientifically significant
and revealing data, including regional multi-channel seismic
data, and their interpretations, have been published in sufficient
number to provide a clear picture of their geology as discussed
in Blanche and Blanche (1997), Hutchison (2004, 2010),
Hutchison and Vijayan (2010), Hinz and Schlueter (1985),
Metcalfe (2010), Wei-Weil and Jia-Biao (2011), Zhen et
al (2011) and various other publications.
The above research found that at the surface the Spratly Islands
consist of reefs, banks, and shoals that are composed of
biogenic carbonate that have accumulated on the higher crests
of major sea-floor seafloor ridges. These ridges consist of a
series of uplifted fault-blocks, called horsts, which are part of
a series of parallel and en echelon, half-grabens and rotated
fault-blocks. The axes of the ridge crests (horsts) and their
associated grabens form well-defined linear trends that lie
parallel to magnetic anomalies of the contiguous oceanic crust
of the adjacent South China Sea. These fault-blocks consist of
Triassic, Jurassic, and Cretaceous strata that include calcalkalic
extrusive rocks, intermediate to acid intrusive rocks, sandstones,
siltstones, dark-green claystones, and metamorphic rocks
that include biotite-muscovite-feldspar-quartz migmatites or
gamet-micaschists (Blanche and Blanche 1997, Hutchison 2004,
2010, Hutchison and Vijayan 2010, Hinz and Schlueter 1985,
Wei-Weil and Jia-Biao 2011).
These horsts and grabens are the result of two distinct periods
of tectonic stretching of continental crust along underlying
deeply-rooted detachment faults. The early period of tectonism
occurred during the Late Cretaceous and Early Oligocene and
resulted in the formation of horsts, half-grabens, and rotated
fault-blocks. This tectonism was associated with the rifting
and stretching of continental crust that corresponded with the
initial sea-floor spreading within the South China Sea. Further
stretching and block faulting of continental crust occurred
within the Spratly Islands and adjacent Dangerous Ground area
during the Late Oligocene-Early Miocene and eventually halted
afterwards. After tectonic activity had ceased, the crest of the
horsts that lay in shallow water were colonized and biogenic
carbonates accumulated on them to form reefs, shoals and
cays known as the Spratly Islands (Wei-Weil and Jia-Biao
2011, Zhen et al. 2011)
The history of faulting and related tectonism within the Spratly
Islands and adjacent Dangerous Ground region can be confidently
reconstructed on the basis of regional unconformities that can be
clearly seen and identified in regional and local seismic sections.
Because they have been dated using biostratigraphy in drillholes
that intersect them, they form timelines that can be traced using
seismic across the entire Dangerous Ground region, including
the Spratly Islands. The most important of these unconformities
is known as either the ?Mid-Miocene,? “Breakup,” or ?T60″
unconformity (Hutchison 2004, Hutchison and Vijayan 2010,
Wei-Wei and Jia-Biao 2011, Zhen et al. 2011). This unconformity
is an angular unconformity that separates syn-rift strata, which
accumulated during the faulting that formed these regional half-
grabens and rotated blocks, from post-rift strata, which
accumulated after the regional tectonism had ceased during the
Early Miocene. The T60 unconformity clearly demonstrates that
faulting within Spratly Islands and Dangerous Ground had
ended by Early Miocene (Hutchison and Vijayan 2010, Wei-Wei
and Jia-Biao 2011, Zhen et al. 2011). Thus, there is complete
absence of either any significant faulting or any other tectonism
that can be associated with a 0.78 Ma extraterrestrial impact. The
relatively undisturbed and intact nature of post- Early Miocene
sediments within the Spratly Islands and Dangerous Ground region
completely refutes any hypothesis about they being the site of a
relatively large 0.78 Ma extraterrestrial impact being associated
with the Spratly Islands and Dangerous Ground region.
Equally revealing are the cores recovered from drilling at ODP
Site 1143. The examination of these cores by Shipboard Scientific
Party (2000b) found only one recognizable lithologic unit, which
is subdivided into two subunits, Subunits, IA and IB, within the
512 m-long (1,780 foot-long) core. The upper 160 m (525 feet)
of the sedimentary sequence, Subunit 1A, consists of typically
massive, olive-gray, light grayish green, hemipelagic, calcareous
clay with abundant nannofossils and foraminifera. Distinct green
clay layers are present. Foraminifer ooze turbidites were also occur
within this subunit. The turbidites are normally graded. They
often exhibit a scoured basal contact. The part of the sedimentary
sequence that is below 160 m (525 feet), Subunit 1B, consists
of are clayey nannofossil mixed sediment, nannofossil clay, and
nannofossil ooze with clay. This subunit has a higher carbonate
content; more turbidites; and fewer green clay layers then
Subunit 1A. In addition, it contains infrequent dark gray volcanic
ash layers and volcanic breccias. Subunit 1B also exhibits trace
fossils, such as Zoophycos and Chondrites, and sedimentary
structures associated with slumps and turbidites (Shipboard
Scientific Party 2000b).
These sediments can be readily dated from the abundant
microfossils, including nannofossils and foraminifera. These
fossils demonstrate that the Pleistocene/ Pliocene boundary is
located between 93.5 and 94.3 m (307 and 309 feet) below the
sea bottom and the Pliocene/Miocene boundary is located
between 213.0 and 200.6 m (699 and 658 feet) below the sea
bottom. In addition, a clear paleomagentic declination change
of nearly 180? at 43.2 m (142 feet) below sea bottom and in the
middle of Core 184-1143C-5H was interpreted to represent the
Brunhes/Matuyama reversal at about 0.78 Ma. The sedimentary
sequence cored at ODP Site 1143 clearly shows that hemipelagic
sedimentation of fine-grained terrigenous material and calcareous
nannofossils occurred essentially uninterrupted from the late
Miocene to present at this site (Shipboard Scientific Party
2000b).
Being located just within the rim of the proposed Spratly Islands
Impact Structure, this core, as does published seismic sections,
demonstrates the lack of any significant Pleistocene-age
extraterrestrial impact structure being associated with the Spratly
Islands. The ODP Site1143 cores, seismic data, and other
published research effectively refute the existence of the
proposed Spratly Islands Impact Structure and relegates it to a
long of imaginary extraterrestrial impact structures that have
been proposed solely on the basis of remote sensing data. It
shows how dubious a methodology using Google Earth alone
to identify extraterrestrial impact craters.
Note: For other examples of the dubious use of Google
Earth to identify extraterrestrial impact structures, go read
1. The Manuel Benavides Craterwrong and Cratermania
http://www.mail-archive.com/[email protected]/msg92117.html
2. Preliminary Evaluation of a Proposed ?Younger Dryas
Impact? Crater
https://www.mail-archive.com/[email protected]/msg102013.html
References,
Anonymous, 2011, Sailing Directions (Enroute): South China
Sea and the Gulf of Thailand, Publication 161, 13th edition,
National Geospatial-Intelligence Agency, Bethesda, Maryland.
Blanche, J. B. and J. D. Blanche, 1997, An Overview of the
Hydrocarbon Potential of the Spratly Islands Archipelago
and its Implications for Regional Development. in A. J.
Fraser, S. J. Matthews, and R. W. Murphy, eds., pp. 293-310,
Petroleum Geology of South East Asia. Special Publication
no. 126, The Geological Society, Bath, England 436 pp.
Burchard, H. G. W., 2013, Crater Burchard? The Cosmic
Tusk. November 3, 2013 https://cosmictusk.com/crater-burchard/
Hinz K., and H. U. Schlueter, 1985, Geology of the Dangerous
Grounds, South China Sea, and the continental margin off
southwest Palawan: results of SONNE Cruises SO-23 and
SO-27. Energy. vol. 10, no. 3-4, pp. 297-315.
Hutchison, C. S., 2004, Marginal basin evolution; the southern
South China Sea. Marine and Petroleum Geology. vol. 21,
no. 9, pp. 1129?1148
Hutchison, C. S., 2010, The North-West Borneo Trough Marine
Geology. vol. 271, pp. 32?43
Hutchison, C. S., and V. R. Vijayan, 2010, What are the
Spratly Islands? Journal of Asian Earth Science. vol. 39,
no. 5, pp. 371?385.
Metcalfe, I., 2011, Tectonic framework and Phanerozoic
evolution of Sundaland. Gondwana Research. vol. 19, pp. 3?21
Wei-Wei1, D., and L, Jia-Biao, 2011, Seismic Stratigraphy,
Tectonic Structure and Extension Factors Across the Dangerous
Grounds: Evidence from Two Regional Multi-Channel Seismic
Profiles. Chinese Journal of Geophysics. vol. 54, no. 6,
pp. 921?941.
Shipboard Scientific Party, 2000a, Volume 184 Initial Reports.
(South China Sea) Proceedings of the Ocean Drilling Program,
Initial Reports. vol. 184, Ocean Drilling Program, Texas A&M
University, College Station, Texas.
Shipboard Scientific Party, 2000b, 4. Site 11431. Proceedings
of the Ocean Drilling Program, Initial Reports. vol. 184, Ocean
Drilling Program, Texas A&M, University, College Station,
Texas.
Zhen, S., Z. Zhong-Xian, L. Jia-Biao, Z. Di, and W. Zhang-
Wen, 2013, Tectonic Analysis of the Breakup and Collision
Unconformities in the Nansha Block. Chinese Journal of
Geophysics. vol. 54, no. 6, pp. 1069-1083.
Yours,
Paul H.
My crater wrong (Darwin’s Valentine) has been extremely useful to me in helping to identify a preferred pro-glacial lake discharge nexus and in the Younger Dryas Lake Agassiz Moorhead phase discharge controversy, which is still ongoing.
The dutch paper on the alleged Younger Dryas impact has shown up in the scholar searches and Andrew Madden’s nanodiamond result is in PNAS peer review (such that it is), so the fun continues!
Regarding Mr. Heinrich assessment he Benavides Structure,
I doubt that very many folks reading this blog will shell out the 60 bucks or so to drag it out from behind GSA’s pay wall; much less take the time to go down there and spend some time on the ground wandering in the desert to see it for themselves. (My own trip down there nearly cost me my left arm) But in fact the “highly detailed”, and “recent” work he’s talking about is based around two very crude, hand drawn maps done by a couple of graduate students back in the early eighties. Then 2010 F. W. McDowell simply kludged the two of them together into a single sad excuse for a geologic map that when laid over a very high resolution satellite image of the same area shows almost no correlation at all to the actual terrain features it is supposed to represent. In fact, in spite of the fact that he did his compilation in 2010 there is a complete disregard for any satellite data at all; much less satellite image data that’s not supportive of his own assumptions.
The map, and McDowell’s commentary can be acquired at:
McDowell, F. W., 2010, Geologic Map of Manuel Benavides area, Chihuahua, Mexico. Map and Chart no. 99. Geological Society of America, Boulder, Colorado.
So basically what McDowell proposes there (note that he states it as unquestionable fact) is the existence of a giant 17 mile wide, perfectly circular, hinged trapdoor that’s covering an as yet undefined super volcano sized magma chamber that’s prone to lateral blasts capable of explosively emplacing hundreds of cubic miles of lava, and thousands of cubic miles of ash, and debris in an eruptive event.
But he gives no explanation of the crazy mantle physics required for a perfectly circular, hinged trapdoor vent. Nor does he give any consideration to the physics required for the kind of explosive event he’s proposing. There is also no mention in that paper whatsoever of the mountain sized piles of mega breccias that ring the southwestern edge of the ring structure.
In this case “highly detailed” is a hand drawn geologic map done by a couple of kids back in the ‘80s that wouldn’t get a passing grade in a 5th grade, science class of today. And “recent” means that in 2010 it was explained by 20 pages of geophysical baffle-speak that just doesn’t stand up to close scrutiny.
Above posting on Tusk by Paul Heinrich, LSU and Louisiana Geologic Survey, — not as I first thought the slightly more famous Hartmut Heinrich of Heinrich events, — is a welcome contribution on a geological event of great importance for the human tribe.
However there are several serious flaws in how he argues and presents his negation of the Spratlies crater as an impact structure and hence its relevance for the Australasian tektite (AA) impact, that I feel obliged to bring to his attention, thinking that he might read these comments.
I may refer him to my Tusk comment posted November 13, 2013 at 4:54 pm, in addition to the earlier Tusk posting, where George Howard graciously posted my email to Ed Grondine & to a Cc list including George, who gave it the title, “Crater Burchard?” His remarks suggest that he has not carefully read, or not considered fully, these my explanations.
1.) Paul cites the Tusk posting as my contribution incorrectly as follows:
Burchard, H. G. W., 2013, Crater Burchard? The Cosmic Tusk. November 3, 201
Whereas as mentioned the title is George’s, not mine and cannot be used to suggest that I have attempted to name and take credit for the crater with my name, in my Nov 13 commenting specifically “what I would call the Spratlies Crater.”
2.) As I already had give to the feature the name of “Spratlies crater” he is not entitled to rename it, as he writes “this proposed impact structure will be referred to as the “Spratly Islands Impact Structure” for purposes of discussion.”
3.) He cites as relevant the article: Hutchison, C. S., and V. R. Vijayan, 2010,, What are the Spratly Islands, for which George had posted link. But as pointed out in my Nov 13 comment this paper is completely irrelevant for the impact crater itself, although important for interpreting the effects of the impact on the surrounding landscape:
The article entirely misses the crater and indeed is addressing areas S or SE of the crater. Only a few of the reefs mentioned straddle its S or SE margin.
4.) He completely ignores the land slide which is have prominently discussed in my initial posting.
5.) ODP leg 184, bore hole 1143 is located at 9.362 N, 113.285 E, a site that just barely touches the outermost discernible rim of the crater, not as he writes “just within the alleged rim of the proposed” Spratlies crater (he, of course, uses his own illegitimate name here.) One would not expect a drill hole there to contain any impactites. Especially considering this was an oceanic impact and the huge 275 km size is probably due in part to the water wave moving the seafloor along and making ground swells that way.
There is much more to be said as I have in several emails as to the identification from the impact exploding within a mass of collapsing continental shelf on the SW flank of the S China Sea and creating an embayment, which of course means that a large amount of the weakly consolidated continental slope sediments was blown into space as AA tektites. The predominantly southerly extent of the strewnfield is explained becasuse in this direction the overburden of soil converted into ejecta was largest.
Hello to all
I gave up trying to engage with this kind of “scientist”. In Brazil and around the world, they are more than 90%. They are junk! Even those who publish in the most prestigious indexed journals. Of course, not all is lost, they can also be recycled.
They keep throwing garbage under the rug, stay alert.
They have at their disposal scientific and financial resources. Only themselves could confuse or argue with a wheel of Agriculture for the impact crater. They always try to denigrate the uninitiated. Or, who knows, may be some sort of jealousy, because the information is on the internet since 2005 and they have not seen ……………
I do not have the means they have. However, I’ve applied scientific principles that I learned in high school and knowledge acquired later, of course. Images increasingly higher definition leaves no doubt for the first selections of cosmogenic possible candidates. I have traveled by car within 300 km, or even plane, for distances greater than 700 km to collect possible impactites. I did not always find them. But one or two in a dozen structures visited, possible impactites are found. Already more than 10 probable or possible structure I have confirmed in 5 different fields palaeolagoons. Focusing on this hypothesis, I began research in 2009.
I have not yet started to catalog the 11 kg of rock samples that I collected on my last expedition to the region of Petrolina, last November. Soon I will update my page.
Yes, the palaeolagoons are probably cosmogenic.
best regards
pierson
I sent Paul an image of a possible shallow impact crater within the known impactite field. At first he pointed out an irrigation complex within it.
It only takes Paul a short time to do geological research.
I am hoping he provides me with some pointers to the existing data on the Mississippi drainage ca 10,850 BCE.
Ed,
evidently the rifting making horsts and cuestas SW of the actual crater is from the continental shelf and slope collapsing due to the impact explosion. If you read some of his references, the Miocene date for the rifting event is mere guess work.
Only one atoll was cored, the date was Pleistocene. This is the only solid age for the Dangerous Ground.
Did you read my rebuttal above, the flaws in his note?
BTW, he is practically quoting you verbatim, not to name craters after people. Instead, when you wrote to him, you might have explained to him that George named the crater with my name, not me.
Anyone; Can anyone explain to me how a trapdoor cauldera works. Is it similar to a ball check valve or a swing check valve? I would think that the cauldera would need subterranian PSI to stay closed then it would open with PSi drop? Or does the door float on the magma and open with level loss possibly leaking magma until the levels return to “normal” and seals the cauldera again?