Referee

Reviewer Comments

Date: Wed, 2 Jul 2008 07:13:22 -0400
To: Christian Koeberl <christian.koeberl@univie.ac.at>
From: Gerald Johnson <ghjmaj@widomaker.com>
Subject: Re: review request- Penrose conference proceedings - status?

Dear Christian:

In plain sight: The Chesapeake Bay crater ejecta blanket by David L. Griscom

This paper should be rejected for the following reasons:
1. The author's findings disregard extensive field studies on stratigraphic units that were deposited
long after the impact and are considered part of his "loam".

2. His loam is comprised of multiple units deposited under normal marine and fluvial-estuarine
processes with obvious sedimentary structures such as cross bedding, laminae and others.

3. The configuration (multiple paleochannels with pollen sequences) and geographic distribution of the
"loam" is inconsistent with an impact origin.

4. One wonders about his interpretation of the iron oxides, commonly called plinthites by soil scientists
in the Eastern U.S. They are a weathering product and vary in degree of development.

Given the nature of the paper, there is no need for comment on the figures.

You can use my name if you desire.

The paper should be rejected on scientific basis.

Gerald H. Johnson
Emeritus Professor,
College of William and Mary,
Williamsburg, Virginia, USA

The author replies:

RE 1: I’ve relied on Schlee (1957), who though confined to Southern Maryland surely performed the
most comprehensive field study of the upland deposits anywhere. Moreover, his references may also
constitute the best review of the prior century’s studies of the upland deposits by his predecessors.
Therefore, I have not “disregard[ed]” the things Prof. Johnson asserts I have.
RE 2 and 3: Here are some quotes from Schlee (1957) that make him sound pretty queasy about
“sedimentary structures” and “paleochannels” that do not fit the fluvial model (emphasis added):

(p. 1373): "In as much as pronounced physiographic (scarps) and sedimentologic breaks are

absent in the upland deposits,

the author feels justified in treating them as a single

stratigraphic

unit

(p. 1377): "Two kinds of cross-bedding predominate in the gravel: planar, in which the lower

bounding surfaces are essentially planes of erosion, and festoon or trough cross-bedding in

which the lower planes are curved surfaces of erosion.

The latter are rare and poorly

developed

(p. 1378): "

Cut and fill features and outlines of channels are rare

(p. 1398): "A consideration of modern rivers (Happ, 1940; Fisk, 1944) shows that the normal

flood plane or valley flat is a complex association of tributary alluvial fans, channel fill (sand,

silt and gravel), colluvial deposits (clay to boulders), and splay deposits (sand, silt, and gravel).

Equivalents of these deposits in all their ramifying interrelations were not recognized in the

upland gravels

RE 3: The two things I have demonstrated most emphatically are that the geographic distribution of
the upland deposits is (1) inconsistent with fluvial origin and (2) consistent with an impact origin.
RE 4: Prof. Johnson “wonders about [my] interpretation of the iron oxides” only because he didn’t
bother to read my 20-page article, Griscom et al. (2003), wherein I comprehensively deal with the
mineralogy, petrology, and materials science of the unusually hard ferric oxyhydroxides that are
ubiquitous to the upland deposits.
RE “no need to comment on the figures”: I spent at least 50 hours preparing them to be as
accurate and reader-friendly as I possibly could. The clasts that I illustrate are unique, never before
reported, and hence of intrinsic interest even if the reader should disagree with my interpretations of
them. Finally, my Fig. 9A was taken directly from a paper authored by Prof. Johnson.

So what exactly IS the “scientific basis” for his rejecting my paper?

Prof. Gerald H. Johnson:

David Powars:

Dear David Griscom,
I have reviewed your manuscript entitled:
“In plain sight: The Chesapeake Bay crater ejecta blanket”

I must say that I was disappointed and feel you have made little progress in validating your hypothesis
(s) with data, especially since your challenging strong scientific data that clearly show the uplands
deposits are fluvial Miocene to Pliocene deposits that are separated by scarps and have channelized
lower surfaces. Its is thrown together more as unconnected bullets with little organization ties and
mostly is personal opinion saga and therefore I do not think this is worthy of scientific publication!!
I have been rough and on the sarcastic side because you have chosen to write this in a very non-
scientific manner, how many sentences begin with “If” and build on more “Ifs” (dream world) as well
as your out of date selective use of references that in the case of lithology and depositional
interpretations you don’t understand and mis-interpret what was published.
Your lack of effort to get further identification of your Hollin Hills pseudo-diamicton is not going to
convince anyone and the pseudo-meteorite I suggested to you in 2001 ( like others) is a typical
weathered gneissic granite, your melt is typical lysigang banding, and the fractured quartz rich
deposits and the last two are typical for upland deposits from New Jersey to Alabama not just in
Maryland and Virginia. I have already informed and sent you some of the key more recent publications
that have mapped, dated, and interpreted these deposits and you choose to ignore them! You need to
stay more abreast of the recent publications including abstracts on the size and depth of the crater
from observations, geophysical data, and computer modeling, as your attempt at envisioning the
transient cavity doesn’t even come close to what has been published and what we are finding!
If you can prove that a clast or grain from the upland has impact shock features then I still think your
one story is that it had to be reworked from some preserved ejecta outlier.
Good Luck,
David Powars
dspowars@usgs.gov

The author replies:

RE “...strong scientific data that clearly show the uplands deposits are fluvial Miocene to Pliocene
deposits that are separated by scarps and have channelized lower surfaces”:

See what Schlee (1957) has to say about these things in my reply to Prof. Johnson above.

RE “Its is (sic) thrown together more as unconnected bullets with little organization ties and mostly is
personal opinion saga and therefore I do not think this is worthy of scientific publication!!”:

“saga” is

ale

several

terlinking

and

strongly reasoned arguments

, each

based on

known

physics of impact cratering and/or

well documented

geological, petrological,

mineralogical, or

materials-science

acts

. Otherwise,

what

hould

an author’s

writing style

with the

worthiness of

a technically correct

manuscript for scientific publication

RE “I have been rough and on the sarcastic side because you have chosen to write this in a very non-
scientific manner”:

Mr. Powars would be better off standing back and taking

stock of

his

own

very non-scientific

manner of

refereeing

RE “Your lack of effort to get further identification of your Hollin Hills pseudo-diamicton...”:

Hello-o!

MY l

ack of effort

, you say

I’ve put

hundreds of hours over a period of years

characterizing the

Hollin Hills

diamicton. That’s hundreds of hours more than the entire USGS!

can’t find the

term “pseudo-

diamicton” in my Glossary of Geology. However, from my

inspection

of the Hollin

Hills deposit

(and also Kevin Pope’s) I believe

it's

correctly

identified as a debris flow.

Mr.

Powars

were

tru

ly interested in

finding

some reason

to dispute

my interpretation of it

, he

might well have

made

the effort to visit it himself

It's not far from USGS headquarters.

RE “...the pseudo-meteorite ... is a typical weathered gneissic granite”:

Once again Mr. Powars is pontificating on something he has never

even set eyes on

e is

proving

himself guilty of what he's accusing me of

RE “...your melt is typical lysigang (sic)...”:

Mr. Powars evidently didn’t bother to read Griscom et al. (2003), where I explained in

ainstaking

detail

why the penetration

of the ferric oxyhydroxides of the upland deposits into

some

quartzite

clasts are

NOT liesegang (simply put, because true liesegang obeys the diffusion

equation and the

upland

quartzite

clasts I

've

saw

in half did

not).

N.B.

I’ve

personally

refereed between 500

and 700 manuscripts, and

each time the

validity of an author’s conclusion

depended

critically

one of

hat person's

references, I

've

withheld

judgement

until I read that reference myself

RE “I have already informed and sent you some of the key more recent publications that have mapped,
dated, and interpreted these deposits and you choose to ignore them!”:

My Figure 5 uses a figure taken directly from one of the

ublication

s Mr. Powars kindly sent

me.

was a big help.

ow then can he

complain that

I chose to ignore his stuf

RE “You need to stay more abreast of the recent publications including abstracts on the size and depth of
the crater from observations, geophysical data, and computer modeling, as your attempt at envisioning the
transient cavity doesn’t even come close to what has been published and what we are finding!”:

First, I am in fact

well read on these materials. Second, my manuscript does not explicitly

treat

the

“transient cavity.” I explained very clearly that my calculation was of

the ejecta blanket

and

that I

artificially introduced a right-cylindrical cavity of volume equal to the calculated amount

ejected

material as a

visual

reference

(

hich fortuitously is a vague match to

the

final

crater

)

Why is

Mr.

Powars

omplaining

about

this ancillary and essentially irrelevant feature of my Fig 4,

while

giving

me no credit for my correct calculation of the radial depth

profile

of the ejecta

blanket?

Personally,

m proud of this

original

calculation, and no one can deny its importance to my

hypothesis.

RE “If you can prove that a clast or grain from the upland has impact shock features then I still think
your one story is that it had to be reworked from some preserved ejecta outlier.”:

First, I

've

argue

that the upland gravels are

interference-zone eject

that

have been subjected to

high pressure

gradients

but relatively

low maximum pressures

– see Melosh (1989). Thus,

shocked

quartz in the form usually required to prove

impact origin

is not expected.

Second, I’ve

shown

that the ferric oxyhydroxides

that

commenly weld together the

upland

gravels c

ontain

"floating"

angular quartz grains

, indicating the

to be

a form of

melt

matrix

breccia

The iron-oxide matrix

cannot

possibly have

result

from

precipitation from aqueous solutions

because

the

mbedded

quartz

clasts are not

self-supporting

All known

melt-

matrix breccias

are

either lavas or impact

breccias

, and

there

are no

known

lavas

that are 95% iron oxide,

thus

leading

Griscom

et al.

(2003)

conclude

that the upland ferric

oxyhydroxides

ust be

impact derived

Third, since these

materials are ubiquitous to the upland

deposits,

the

re's no reason to suppose they've

been

reworked

RE Mr. Powars’ abusive comments hand written all over my manuscript (the multiply-underlined finale
that I’ve pasted in above being only the tip of the iceberg):

Even

the cases of the very worst papers

among

the 500

700

that

I’ve reviewed, I’ve treated

the

submitting

authors with respect. I regard

refereeing

as just being a fellow scientist offering

best advice as to how

those

authors might make their papers into higher-value publications –

or at

least

acceptable

publications

hen

truly gross errors

are

pparent

I’ve rejected very few

papers

outright. By contrast, David Powars seems to view his refereeing role as that of “decider”

– and

umiliato

r of those he decides against – rather than

dutiful

facilitator of the scientific process.