Sectioned igneous slab with metallic-iron inclusions
Suggested YD impact comet-crust meteorite


    Comet Encke and the Taurid meteor stream has been suggested as a possible debris stream of a much larger Kuiper belt object (KBO) that fragmented in the inner solar system in the last 20,000 to 30,000 years. The ‘Younger Dryas impact hypothesis suggests that several large chunks of the fragmented comet may have struck the Laurentide ice sheet, 12,900 years ago.
    What follows is an argument for the formation and composition of that KBO, particularly focusing on its suggested rocky-iron crust, with a composition close to that of industrial iron-furnace slag.
    Alternative planet and star formation mechanisms suggests that the hot classical KBO population formed from a siderophile-depleted reservoir with a 3-oxygen-isotope signature that lay on the ‘terrestrial fractionation line’. The alternative star formation mechanism is suggested to have formed a binary-Sun, whose binary components spiraled in to merge at 4,567 Ma in a luminous red nova (LRN). The LRN apparently enveloped the solar system out to the classical Kuiper belt. Immersion in solar plasma of the LRN drove off volatiles from the surface of KBOs and melted the remaining refractory material into rocky-iron, siderophile-depleted crust. While the KBOs experienced considerable volatile loss, the igneous surface would will have concomitantly condensed refractory material from the solar plasma, presumably enriching a thin crust in platinum-group elements, which should be detectable in YD impact comet-crust meteorites.
    Large chunks of rocky-iron comet crust appear to have been strewn across Eastern Pennsylvania and beyond. Larger deposits of rocky-iron comet crust were historically mined and melted (not smelted) for their metallic iron content. The iron from industrially melted comet crust was presumably used for undemanding applications where embrittling contaminants were not an issue, such as window sash weights. During the industrial revolution, the discovery of comet crust with native iron in mines and quarries was presumably dismissed as poorly-processed colonial iron furnace slag, due to the chemical and physical similarity; however, centimeter-scale blobs of molten metallic iron can not be suspended in molten rocky slag on our high-gravity planet.

High-density rock specimen with cratered surface from City Island, Harrisburg, PA
Suggested YD impact comet-crust meteorite


    No crater has been positively identified for the several posited YD impacts on the Laurentide ice sheet in the Great Lakes region, 12,900 BP. The absence of a crater means the absence of primary bolide debris, although there’s no shortage of extraterrestrial indicators below widely-distributed black mat deposits and in the Greenland ice sheet. The leading proponents of the YD impact theory suggest a comet origin, possibly with Comet Encke and the Taurid meteor stream as the debris stream of a much larger Kuiper belt object (comet) which presumably fragmented quite recently, presumably within the last 20,000 to 30,000 years.

    A new class of meteorite resembling iron furnace slag is suggested here. which fell 12,900 years across North America and beyond. ‘YD comet crust’ meteorites were not distributed in a classical strewn field from a solitary object which disintegrated in Earth’s atmosphere, but instead rained down, perhaps worldwide, from the Taurid meteor stream, with additional fragmentation in Earth’s atmosphere. YD comet crust falls appears to have a local density peak in Southeastern Pennsylvania, where it was apparently exploited by the iron industry for its metallic iron content, and, where it is often mixed with industrial iron furnace slag in the vicinity of 19th century iron furnaces.

YD comet crust meteorites exhibit a number of unusual features that occur with variable frequency;
– Variable-sized chunks of gray igneous matrix with millimeter- to centimeter-scale metallic iron inclusions, some strongly highly vesicular, some lacking vesicles
– Variable-sized chunks of massive magnetite
– Masses of metallic iron up to 100 kg, some composed of massive iron and some composed of iron nodules sintered together
– Some chunks of gray igneous matrix exhibit one undulating surface, with ~10–15 cm undulation radius
– Some chunks of gray igneous matrix exhibit fusion crust, and some fusion crust exhibits apparent flow lines
– All types of YD comet crust exhibit a strong propensity to be variably covered with a white, gritty cement-like coating.

45 kg metallic-iron ‘ring-of-flames’ from Conshohocken, PA
Suggested YD impact comet-crust meteorite

Alternative solar system model:

Symmetrical flip-flop fragmentation:
    An alternative star formation mechanism, designated, ‘symmetrical’ ‘flip-flop fragmentation’, is suggested to have ‘condensed’ twin-binary disk instability objects around a large brown dwarf core, where the disk instability objects were much-more massive than the diminutive core. Orbital interplay progressively transferred kinetic energy and angular momentum from the twin-binary protostars to the diminutive brown dwarf by the mechanism of equipartition. Equipartition ‘evaporated’ the diminutive brown dwarf into a circumbinary orbit around the much-more-massive protostars, causing the protostars to sink into close-binary orbits around their common barycenter.

Trifurcation and its primary debris disk:
    Equipartition transfers orbital kinetic energy and angular momentum from more massive objects to less massive objects in close orbital encounters, and it also transfers rotational energy and angular momentum, causing diminutive objects to ‘spin up’, increasing their rotation rate. Equipartition caused the brown dwarf to spin up and distort into a bar-mode instability. Additional pumping of rotational energy caused the bar-mode instability to ‘trifurcate’, fragmenting the brown dwarf into three components (hence ‘trifurcation’), composed of a twin-binary pair of super-Jupiters in orbit around a diminutive residual core. First-generation trifurcation promotes second-generation trifurcation and etc., ultimately creating 4 trifurcation generations of twin-binary objects;
– 1st gen. ― binary-Companion
– 2nd gen. ― Jupiter-Saturn
– 3rd gen. ― Uranus-Neptune
– 4th gen. ― Venus-Earth
    Trifurcation is presumably an inefficient process, causing a sizable percentage of the trifurcating core to evaporate or boil off, escaping from gravitational clutches of the fragmenting core. Presuming the trifurcating core was internally differentiated into an iron-nickel (siderophile) inner core, the evaporated material would be siderophile depleted. Thus, four generations of trifurcation created a siderophile-depleted trifurcation debris disk from the homogenous brown dwarf reservoir, which lay on the 3-oxygen-isotope brown-dwarf fractionation line, known on Earth as the ‘terrestrial fractionation line’ (TFL).
    The trifurcation debris disk condensed siderophile-depleted Kuiper belt objects (KBOs), presumably by streaming instability, against Neptune’s outer 2:3 mean motion resonance.

Binary-Sun spiral-in merger luminous red nova (LRN), 4,567 Ma:
    Secular perturbation between former binary-Sun and former binary-Companion caused binary-Sun to spiral in and merge in at 4,567 Ma in a luminous red nova (LRN), which briefly created a fireball that apparently engulfed the classical Kuiper belt, vaporizing volatiles from the surface of KBOs and melting refractories into a rocky-iron crust.
    The red giant phase of (theorized stellar-merger) luminous red nova LRN M85OT2006-1 would have reached far into the Kuiper belt, with a fireball estimated at R = 2.0 +.6-.4 x 10^4 R☉, and a peak luminosity of about 5 x 10^6 L☉. (Rau et. al. 2007) “Previously published line indices suggest that M85 has a mean stellar age of 1.6+/-0.3 Gyr. If this mean age is representative of the progenitor of M85 OT 2006-1, then we can further constrain its mass to be less than 2 M☉.” (Ofek et al. 2007) If the size of the less than 2 M☉ LRN M85OT2006-1 fireball was in the range of 74–121 AU (R = 2.0 +.6-.4 x 10^4 R☉), then it’s readily conceivable that our greater than 1 M☉ LRN fireball, at 4,567 Ma, should easily have scorched a preexisting Kuiper belt reservoir centered around 43 AU.
    The LRN quickly retreated, leaving a low-angular-momentum ‘LRN debris disk’ in the inner solar system, which ‘condensed’ rocky-iron asteroids, presumably by streaming instability against the Sun’s greatly expanded magnetic corotation radius, and later condensed chondrites by streaming instability against Jupiter’s strongest inner resonances, but the low angular momentum content of the LRN debris disk precluded forming a debris disk at the distance of the Kuiper belt.

Binary-Companion spiral-in merger, ~ 650 Ma:
    Almost 4 billion years later, the super-Jupiter-mass components of binary-Companion spiraled in to merge at about 650 Ma in an asymmetrical merger explosion that gave the newly-merged Companion escape velocity from the Sun, and the resulting ‘binary-Companion-merger debris disk’, condensed the young (650 Ma), cold, classical KBO population against Neptune’s outer 2:3 resonance. And this binary-Companion-merger tertiary debris disk also coated the old (> 4,567 Ma) hot, classical KBO population with a veneer of binary-Companion merger dust and ice that was not siderophile depleted. This late veneer is suggested to be the origin of most of the iridium and platinum found in black mats across North America and elsewhere, as well as the origin of the whitish cement-like coating on many suggested ‘YD impact comet-crust meteorites’. Presumably the bulk of the unconsolidated binary-Companion-merger dust and ice sloughed off in the atmosphere, becoming widely distributed, whereas the consolidated igneous comet crust impacted in greater local concentrations.

Hybrid composition of comet-crust meteorites:
    Suggested siderophile-depleted KBOs lying on the TFL were exposed to solar plasma at 4,567 Ma from the binary-spiral-in-merger of former binary-Sun, volatilely depleting the surface, and creating an rocky-iron igneous comet crust. The comet crust is slightly contaminated by condensed solar refractories that are not siderophile depleted, presumably with a thicker solar refractory veneer concentrated on the undulating wrinkled surface of the former KBO.
    Unlike the high-temperature plasma of the binary-Sun merger, the binary-Companion merger presumably occurred near the inner Oort cloud, at a sufficient distance to preclude melting or further volatilization of KBOs, where the cumulative accretion of dust and ice presumably occurred at < 100 K. Under these conditions, the binary-Companion-merger dust and ice accretion rained down on the igneous comet crust and remained frozen until perturbed into the inner solar system, whereupon solar radiation vaporized the icy accretion into a cometary tail. The binary-Companion-merger accretionary material in the Taurid meteor stream that entered the Earth’s atmosphere generally vaporized or in some cases may have melted onto the surface of igneous comet crust, becoming part of the fusion crust, and some of the accretionary material that survived Earth impact intact and became fused onto the surface of igneous comet crust, becoming the whitish, gritty cement-like coating, typical of YD comet-crust meteorites.


INAA/mass spec analysis of suggested YD impact comet-crust meteorites

YD comet crust characterization:

Rocky matrix with millimeter- to centimeter-scale metallic iron inclusions:
    Igneous comet crust meteorites are highly variable with respect to size, density, metallic iron concentration, void prevalence, void size, and surface texture. The metallic-iron component of comet crust is highly variable as well, ranging from millimeter- to centimeter-scale metallic-iron inclusions within igneous matrix to metallic iron that hardened in an unconfined setting, to masses of nodular iron apparently sintered together into various size and shape masses, to molten iron molded into fractal shapes. Metallic iron masses range in size from sub-millimeter-sized spherule inclusions to metallic-iron masses ranging to 100 kg, or more.
    The shape of the iron inclusions and masses is particularly notable, with many bizarre 3 dimensional shapes having no flat top surface, as would be expected from metallic iron which was cooled from a molten state on our high-gravity planet. Analyzing the scale at which KBO microgravity flattens molten globules from cohesive spherical symmetry within the confining igneous matrix may allow the calculation of the microgravity. Metallic iron falls into two categories, massive or nodular. Curiously, nodular metallic iron appears not to be associated with igneous matrix, but generally exhibits the white, gritty cement-like coating.
    The most inexplicable phenomenon for an industrial slag interpretation on our high-gravity planet is the presence of centimeter-scale metallic-iron blebs suspended within the igneous matrix, where the metallic-iron density is nearly 3 times that of the surrounding matrix. By comparison, glassy iron furnace slag from historic Joanna furnace, PA contains zillions of microscopic iron spherules that are clearly evident in thin flakes, backlit under 40X magnification.

Nodular metallic iron
Suggested YD impact comet-crust meteorite

Sectioned igneous slab with metallic-iron inclusions
Suggested YD impact comet-crust meteorite

Broken boulder with magnet attached to metallic-iron inclusion
Suggested YD impact comet-crust meteorite

Nodular metallic-iron mass with whitish cement-like coating
Suggested YD impact comet-crust meteorite

Metallic-iron specimens from Doe Run, PA
Suggested YD impact comet-crust meteorites

Magnified (40x) chip of glassy industrial slag from historic Joanna furnace, PA showing metallic-iron spherules

Whitish, gritty, cement-like coating:
    A whitish, gritty, cement-like coating is suggested to be one of the most reliable indicators of YD comet crust; however, its absence is not evidence against membership. The cement-like coating apparently has a high calcium-carbonate composition, causing it to fizz on exposure to vinegar.

Note the typical cement-like coating characteristic of suggested YD impact comet-crust meteorites

Massive high-density magnetite/hematite:
    Some iron is the metallic state, some in silicates, while some is in the oxide state, presumably mostly magnetite, judging from its ferromagnetic properties.
    Most specimens of magnetite associated with igneous comet crust exhibit cement-like coating, but there’s a class of iron-oxide specimens with particularly smooth surfaces showing strong flow lines that are invariably free of cement-like coating, pointing to an industrial process.

Magnetite with whitish, gritty, cement-like coating

Undulating syncline-anticline comet crust, with ~10–15 cm undulation radius:
    Many comet-crust specimens from Pottstown, PA are roughly triangular, with one rounded side, resembling a thick slice of pie. The rounded surface was presumably the upper surface of the KBO exposed to the solar plasma, with the syncline-anticline undulations caused by folding of the igneous crust due to subsidence as underlying ices sublimed into outer space. As the diameter of the comet decreased due to vaporization and densification under the withering exposure to LRN plasma, the igneous KBO crust wrinkled like a grape drying to form a raisin. The ~10–15 cm undulation radius was presumably the local folding scale in the fully to partially molten state, but as the crust cooled and stiffened, it also became more brittle, with additional subsidence forcing reverse faulting, causing tectonic plates to ride up over adjacent plates.

Large metallic-iron mass with igneous rocky matrix. The undulating top surface is suggested to be part of the wrinkled surface of the former Kuiper belt object.
Suggested YD impact comet-crust meteorite

Pie-slice-shaped specimen, with the rounded side as a fragment of the undulating wrinkled surface of the former Kuiper belt object
Suggested YD impact comet-crust meteorite

Pie-slice-shaped specimen, with the rounded side as a fragment of the undulating wrinkled surface of the former Kuiper belt object
Suggested YD impact comet-crust meteorite

Absent to strongly vesicular:
    Comet-crust meteorites are most often visually dismissed by experts for the prevalence of vesicles, although many specimens have no vesicles. Some specimens are so completely saturated with vesicles as to resemble scoria, perhaps with strongly-vesicular material forming in thin, weak sections of the formerly molten KBO crust percolated by pressurized outgassing from within. And the relative absence of vesicles may have formed in regions of thicker stronger crust.
    Comet-crust meteorites make frequent appearances in meteorwrong writeups and meteorwrong image galleries due to their high density, high iron content, and vague similarity to several meteorite classes. The Washington University in St. Louis, Department of Earth and Planetary Sciences, photo gallery of MeteorWrongs appears to include a number of comet-crust specimens with the following entry numbers; 11, 16, 93, 109, 183, 223, 294, 298, 325.

Large vesicles in specimen from Harrisburg, PA
Suggested YD impact comet-crust meteorite

Fusion crust, some with flow lines:
    Suggested fusion crust on comet-crust specimens varies in coloration from brown to jet black, where the black coloration is probably pristine, whereas the brown coloration is probably due to oxidation. On small hand-sample-sized specimens, fusion crust is frequently evident on all sides, whereas on larger (> 10 cm) specimens, fracturing upon impact generally creates fractured surfaces on one or more sides.
    While fusion crust is easy to spot on rocky comet crust, iron exposed to atmospheric ablation forms regmaglypts rather than fusion crust; however, no unambiguous regmaglypts are evident on metallic-iron specimens discovered to date. Ablation may also cause regmaglypts/melting on the surface of comet-crust magnetite.
    Additionally, a couple of the fusion crust specimens appear to exhibit flow lines.

Igneous specimens exhibiting apparent fusion crust
Suggested YD impact comet-crust meteorites

Suggested fusion crust on specimens from Phoenixville, PA
Suggested YD impact comet-crust meteorites

Suggested fusion crust on specimen from Phoenixville, PA
Suggested YD impact comet-crust meteorite

Suggested fusion crust with flow lines and embedded spherules in YD impact comet-crust meteorite

Specimen with suggested fusion crust with flow lines
Suggested YD impact comet-crust meteorite


    Despite the large volume of suggested comet crust distributed throughout Southeastern Pennsylvania, no impact craters are evident, and the surviving specimens appear to be remarkably intact, suggesting a low velocity encounter, where perhaps the Taurid meteor stream overtook Earth from behind in its orbit around the Sun causing their heliocentric orbital velocities to subtract.

Conshohocken, PA:
    A large volume of comet crust has been used to level a triangle of land just off Light Street, Conshohocken, PA (40.0807, -75.3127), readily identifiable on Google satellite due to the herbicide properties of granulated material. A possible Conshohocken impact crater is the round Ivy Rock quarry, about a mile due north along Conshohocken Road on the east bank of the Schuylkill River (40.095, -75.315).
    Suggested comet-crust material in Conshohocken is liberally mixed with iron furnace slag; however, the slag appears to have been melted rather than smelted for its metallic iron content. Suggested melted comet-crust slag contains no macroscopic metallic iron, and often contains angular chunks of fire brick.

Mound of granular slag-like material from from Conshohocken, PA (40.0807, -75.3127)
Suggested YD impact comet-crust material

Loose metallic-iron nodules from Conshohocken, PA
Suggested YD impact comet-crust material

Ivy Rock Quarry, Conshohocken, PA

Phoenixville, PA:
    In Phoenixville, PA, a significant quantity of triangular pie-slice shaped comet-crust fragments
are mixed with a smaller quantity of industrial iron furnace slag from the nearby historic Phoenixville iron works. Here, the industrial slag appears to be of two types, dense slag from ad hoc melting of extraterrestrial material for its metallic iron content with its iron oxide intact, and conventional low-density smelted iron furnace slag, without iron oxide.
    The slag and comet-crust material has been tumbled into the French Creek ravine from the south bank, between N. Main St. and Ashland St. (40.135, -75.513), just east of Phoenixville Foundry; however, recent condo construction may cut off access to part of the material.

Harrisburg, PA:
    As elsewhere, comet crust has been used as clean fill in the Harrisburg Area. Comet crust has been used to build what looks like an abandoned road spur off Paxton Ave. between Paxton Ministries and Faulkner Honda (40.2545, -76.8505).
    Harrisburg also has a round quarry that might be a comet-crust impact crater, and it’s barely a stone’s throw from Faulkner Honda. The quarry is in the 2200 block of Paxton St. Harrisburg/Swatara Township, PA 17111 (40.256, -76.847).
    Comet crust been used as clean fill on the East Shore of the Susquehanna River to extend residential parking on the river side of Front St. in Enola, PA, and the material has been spotted as far west as Wesley Dr. in Mechanicsburg, PA.

Paxton St. quarry in Harrisburg, PA

    Finally, a strong rare earth magnet is the only necessary prospecting tool.

Rare-earth magnet attached to metallic-iron inclusion in specimen
Suggested YD impact comet-crust meteorite

Future work:

– An old age determination (> 4.5 Ga) would be the gold standard for a new class of siderophile-depleted meteorites which fails multiple other tests, such as a low iron-nickel ratio, little or no iridium, an igneous origin, and manifold internal voids.

– Several comet crust samples were analyzed by INAA for iridium, including one analysis on a metallic-iron inclusion, but no iridium was found down to 5 ppb. INAA does not detect platinum, however, which is a prevalent YD black mat marker, and platinum was found in Greenland ice cores from 12,900 BP. Analysis of the undulating surface of pie-slice-shaped rocks which were theoretically exposed to LRN plasma, would be a promising place to analyze for platinum and iridium, as well as analysis of the whitish, gritty, cement-like coating of suggested binary-Companion-merger origin.


Ofek, E. O.; Kulkarni, S. R.; Rau, A.; Cenko, S. B.; Peng, E. W.; Blakeslee, J. P.; Cote, P.; Ferrarese, L;. Jordan, A.; Mei, S.; Puzia, T.; Bradley, L. D.; Magee, D.; Bouwens, R., (2007), The Environment of M85 optical transient 2006-1: constraints on the progenitor age and mass, arXiv:0710.3192 [astro-ph]

Rau, A.; Kulkarni, S. R.; Ofek, E. O.; Yan, L., (2007), Spitzer Observations of the New Luminous Red Nova M85 OT2006-1, The Astrophysical Journal, Volume 659, Issue 2, pp. 1536-1540