CENTAURS AND ICY PLANETARY BODY IMPACTS ON OCEAN VOLUMES AND CHEMISTRY

THROUGH TIME

Pat WILDEPangloss Foundation1735 Highland Pl. #28

Berkeley, California 94709pat.wilde.td.57@aya.yale.edu

Mary S. QUINBY-HUNTLawrence Berkeley Laboratory

Berkeley, California 94720mshunt@sbcglobal.net

The number of icy bodies reported in the solar system has increased dramatically in the past few years suggesting their potential importance in Earth history via impacts. Wilde (1987) proposed that icy bodies may be a significant source of the oceans during the later stages of accretion. Wilde and Quinby-Hunt (1997) discussed the chemical consequences of impacts of ice-volatile bolides of various compositions. The 'rain' of icy bodies hitting the Earth throughout time suggests implications for the following Earth processes.

Jupiter (orbit)

Mars (orbit)

Earth

Mercury (orbit)

Venus (orbit)

Plot of the Inner Solar SystemThe plot shows the current location of the major planets (Mercury through

Jupiter) and the minor planets that are in the inner region of the solar system. Source: http://cfa-www.harvard.edu/iau/lists/InnerPlot.html

Light Blue: The orbits of the major planets

Large Colored Dots: the current location of the major planets

Green Circles: The locations of the minor planets, including numbered and multiple-apparition/long-arc unnumbered objects

Red Circles Objects with perihelia within 1.3 AU are shown by red circles.

Objects observed at more than one opposition are indicated by filled circles, objects seen at only one opposition are indicated by outline circles.

Deep Blue Circles: The two "clouds" of objects 60° ahead and behind Jupiter (and at or near Jupiter's distance from the sun) are the Jupiter Trojans

Filled Light-Blue Squares - Numbered periodic comets Unfilled Light-Blue Squares - Other comets

PlutoNeptune

Jupiter (orbit)

Saturn (orbit)

Uranus (orbit)

Plot of the Outer Solar SystemThe plot below shows the current locations and orbits of the Jovian planets (Jupiter through

Neptune) and the current locations of various distant minor bodiesSource: http://cfa-www.harvard.edu/iau/lists/OuterPlot.html

Light Blue: The orbits of the planets Dark Blue Symbol: the current location of each object

The current location of the minor bodies of the outer solar system are shown in different colors to denote different classes of object.

Cyan triangles: Unusual high-e objects Orange triangles: Centaur objects White circles: Plutinos (objects in 2:3 resonance with Neptune)Large white symbol: Pluto

Magenta circles: scattered-disk objects Red circles: "classical" or "main-belt" objects

Objects observed at only one opposition are denoted by open symbols, objects with multiple-opposition orbits are denoted by filled symbols.

Filled light-blue squares Numbered periodic comets. Unfilled light-blue squares: Other comets.

Jupiter Europa 3136 3.57 0.25 4.07E+09 2.97

Ganymede 5258 1.94 0.46 3.53E+10 25.8

Callisto 4796 1.86 0.48 2.79E+10 20.4Saturn Mimas 389 1.17 0.77 2.37E+07 0.017

Enceladus 500 1.24 0.73 4.75E+07 0.04

Tethys 1049 1.26 0.71 4.32E+08 0.3

Dione 1120 1.44 0.63 4.60E+08 0.3

Rhea 1529 1.33 0.68 1.27E+09 0.9

Titan 5150 1.88 0.48 3.42E+10 0.2

Iapetus 1438 1.21 0.74 1.16E+09 0.8Uranus Miranda 470 1.35 0.67 3.62E+07 0.03

Ariel 1158 1.66 0.54 4.41E+08 0.3

Umbriel 1168 1.51 0.60 4.97E+08 0.4

Titania 1578 1.68 0.54 1.10E+09 0.8

Oberon 1519 1.58 0.57 1.05E+09 0.8Neptune Triton 2700 2.07 0.43 4.48E+09 3.3

Icy Satellites

Planet Satellite Diameter (km) Density

Ice Ratio

Ice Vol? (km3)

# of Earth Oceans

PLATE TECTONICS AND THE EVOLUTION OF GRANITIC CRUST

Earliest sediments thus found are greenstones, basically basaltic sediments suggesting lack of a granite source. Without a granite-oceanic basaltic crustal difference, early surface terrains would be limited to a relatively low relief consisting of abyssal plains, seamounts, and the ridge-rise system.

Incrementally the impact of icy objects would provide fluid for the then shallow ocean basins. During subduction at depth the pressure and temperature plus fluids could hydrate the basaltic crust producing granitic compositions. With time the production of granite could produce the continental blocks raising the present freeboard of the continents and the relief of the ocean basins. Chondritic compositions are too water poor to support Rubey's (1951) theory that volatile components such as water largely come from expression from the mantle.

Source: http://www.physicalgeography.net/fundamentals/10e.html

Anorthite + Clinopyroxene + Orthopyroxene + Water = Amphibole

2(CaAl2Si2O8) + 2(CaMgSi2O6) + 3(Mg2Si2O6) +2(H2O) = 2(Ca2Mg4Al2Si7O22(OH)2)

Hydration of basalt

Molecular Weight of Amphibole = 814Molecular Weight of Water = 18

Molar Ratio = 0.022

Continental Crust = 5 e+22 KgOceans = 1.3 e+21 Kg

For 15% Amphibole = 7.5 e+21 Kg

Water needed to produce amphibole: 0.0221 x 7.5 e+21 = 1.658 e+20 Kg

Input Water = 3.77 E10 Kg over 4.4 Billion Years

Amount Water/Yr needed to convert Basalt to Amphibole

0.0377 Km3/Yr

A bolide this big per year is enough to maintain the oceans and granitize the basalt

Amount H2O/MillionYr 37700 Km3/MillionYr

Amount H2O/100 Million Yr 3770000 Km3/100 MillionYr

SEISMIC STRATIGRAPHY AND TIME SCALE OF ICY IMPACTS

Third-order sea level rises of durations of a few million years can not be related to known glacio-eustatic climatic events. These sea level rises may be the result of impacts of icy Centaur-like bodies briefly adding to the ocean volume and eventually being absorbed in the granitizing process of subduction. The frequency of the third-order events could record the timing of icy impacts of significant size.

Centaurs

1

100

10,000

1,000,000

100,000,000

10,000,000,000

1 13 25 37 49 61 73 85 97 109121133145

Number in decreasing volume

Volu

me

in K

m^3

0.00001

0.001

0.1

10

1000

100000

Appa

rent

Sea

Lev

el

rise

in M

eter

s

3rd ORDER SEA LEVEL RISE

3rd ORDER SEA LEVEL RISE

Centaurs

1

10

100

1,000

10,000

100,000

1,000,000

10,000,000

100,000,000

1,000,000,000

1 15 29 43 57 71 85 99113127141

Vo

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1

10

100

1,000

10,000

100,000

1,000,000

10,000,000

100,000,000

1,000,000,000

10,000,000,000

Tim

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Effect of adding the mass of water in impacting objects

Estimated potential maximum sea level rise from the total melting of present-day glaciers

VARIATIONS IN OCEANIC COMPOSITION

Berner (2004) and others have discussed changes in the bulk composition of the oceans during Phanerozoic time. A potential contribution to such variations would be the introduction of icy planetary bodies with the variation a function of bolide composition. Such events may be seen in the delta spike of C and S isotope values against the background of terrestrial isotopic processes.

From: Carbon and Sulfur isotope anomalies across the Permian-Triassic boundary (PTB) in W. Slovenia

Matej Dolenec and Barbara Vokal

Carbon, organic carbon and sulfur isotope variability across the PTB in the Idrijca Calley (W. Slovenia)

Perm

ian

Tria

ssic

CHEMICAL CHANGE

Effect of adding the mass of C in impacting objects

CHEMICAL CHANGE

TESTS OF CONJECTURES

Upcoming missions to analyze the composition of comets and other icy bodies, thought to be remnants of original solar system building blocks, will be useful in discerning the contributions of icy extraterrestrial bodies to on-going Earth processes.

REFERENCES

Berner, R. A., 2004, A model for calcium, magnesium and sulfate in sea water over Phanerozoic Time: American Journal of Science, v. 304, p. 438-453.

Rubey, W. W., 1951, Geologic history of seawater: an attempt to state the problem: Geological Society of America Bulletin, v. 62, p. 1111-1147.

Wilde, P., 1987, Primordial origin of the oceanic Rubey Volatiles as a consequence of accretion of ice-sulfur planetesmals, (abst.): EOS, 68: no. 44, p. 1337.

Wilde, P. and M. S. Quinby-Hunt, 1997, Collisions with ice/volatile objects: Geological implications- A qualitative treatment: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 132, p. 47-63.