Argillite

[CMD]

Most collectors are somewhat familiar with argillite. It was used as a lithic in many parts of the country. Here in southern New England, it is the second most common lithic after quartz. Slaty, sometimes more of a siltstone, most would agree it is quite a poor choice for use in flaked stone tools. It usually works poorly, and the results are often crude. Throw in water weathering on a shore, and you get the picture. But, sometimes argillite can be nicely flaked, as seen in the first point on the left. The little triangle 3rd from left may be an early triangle. 2nd from left is a Vosberg, and last from left an Orient Fishtail. First was not a personal find, it was found in Dighton, Ma. The others are beach finds and all would be above average for this rough material.





Feel free to share argillite from elsewhere!

[tomclark]

Wow those are great examples of that material!  Love that "Dalton" (OOPS, read VOSBERG) or whatever they call similar up there boom!

[CMD]

tomclark wrote:

Wow those are great examples of that material!  Love that "Dalton" (OOPS, read VOSBERG) or whatever they call similar up there boom!

  Hey, never know, it was found near, very near, a site that yielded both a Hardaway and a Hardaway-Dalton.  Thanks, Tom.

[pkfrey]

Those all look like varieties of rhyolite in different color phases. Argillite is typically coal black when fresh, and weathers to a dull blackish/gray color, and is comonly pitted.  Here in Pa., it's a common lithic source used extensively during the Archaic period,and is a secondary material used during the Transitional period when rhyolite wasn't available, but never used during Paleo times. Fresh argillite in raw form will actually " ring " when tapped with an extremely hard object, like a quartzite hammerstone. Attached are two photos of characteristic argillite points. A 4 1/2 in. Perkiomen, and a 7 in. knife.

[CMD]

God, if I've had a nickel for every time I've had to explain that the material from south of New England, such as New Jersey, and what archaeologists recognize as argillite in New England are simply different  varieties of argillite, I'd surely be wealthy by now.  I've provided the evidence to prove this elsewhere, but could not find it searching 2 forums.  When I find it, I'll post a link.  For now, despite what the material  may resemble, I can say there is no professional archaeologist working in the field of prehistory in southern New England who would call this material anything other then argillite. It patinates grey, greenish-grey, and bluish-grey. It is jet black on a fresh interior. Like it or not, it's argillite and  every experienced collector from this region easily recognizes it as argillite. If we, both professionals and collectors are wrong, then someone can make a name for themselves re-writing the understanding of lithics in New England.  If it's a mistake, it's been in place for at least 6 decades to my knowledge.
There's more here, on page 2 of this thread. Turns out I got an education myself on the subject, on another forum, and not that long ago, so although I've always known our form of argillite when I see it, it took some digging a couple months ago to demonstrate we're talking about 2 types of argillite. sorry if I'm sounding testy, just thought, "oh no, not again" when I realized I would have to dig all this up again.

http://www.arrowheadology.com/forums/todays-finds-situ/32269-rhode-island-beach-walk-2.html

About half way down the thread at the above link, there's some useful info on argillite from Rhode Island and Ma., and the much grainier argillite from New Jersey, examples of which have been found by a friend on Martha's Vineyard.  Also a link for further info. I just posted the relevant passage describing our New England sources of argillite from that link further down this thread. I hope this info will help convey the point that our argillite is more platy, more slate in nature, with a fine grain, unlike argillite from NJ and Pa.

[CliffJ]

I thought the same thing. The first, third and fourth look like rhyolite. The second looks like a slate from the slate-y flake scars. Both of Paul's argillite points look like argillite I've seen, but we also have some NC/VA argillite that is red. Argillite is pretty grainy stuff, pitted and does not flake well. Rhyolite is usually pretty fine-grained and can be used to make nice points like those Charlie found.
I will say though, that the terms "rhyolite" and "argillite" are pretty broad categories mostly only used by collectors to lump types of rock.
I will also say that MOST if not all archaeologists would not know the proper geological term for any rock.

[CMD]

And in New England, argillite is VERY fine-grained. Someone will need to correct every professional archaeologist and geologist working in New England. That won't be my job. LOL. Refer to the links and quotes I provided in my previous post. I appreciate the knowledge of all you folks who are not seeing argillite here, but you are mistaken, and you really need to take it up with the regional authorities in New England. My word's only really going to go so far. That's what it's called here, and all the points I showed here are made from argillite. The link at my previous post ID's some of the quarry locations. What I'm saying is every collector and pro from New England that I've known from the 1950's onward calls the stuff argillite.
Let me put it this way. Since I know the material I've shown is called argillite in southern New England, I just don't want a collector from southern New England stumbling upon this thread, and have he/she think what they've always thought and was told was argillite, was in fact, not argillite.  It is, it's just not all that similar to argillite from further south.  Sorry if I sound irked, no need for that, it is about education I always like to believe, just didn't feel like going through justifying the description of this material again.  My bad, and at any rate, proof that the material has been mis-named for decades would constitute an achievement that deserves realization, if it's the case. So maybe it's a PhD waiting to happen. Until then, I'll stick with the description conventional to southern New England.

[Butch Wilson]

Seems we got deeply into this discussion over Ryolite, argillite, siltstone, slate, mudstone in this discussion on AH.com once before. Had my head spinning !

http://forums.arrowheads.com/forum/general-discussion-gc5/learn-about-lithic-material-types-gc24/25822-carolina-rhyolite

[kayakaddict]

This argillite piece is amazingly well preserved, and it has pressure flaking like I've never seen on argillie.  It was in a little mud hole.

usually argillite is worn, and here in S. Jersey looks likes this, though I think these below are from a variety of sources. 

[Hoss]

Argillite is a sedimentary rock. The Argillite that hails from the Cambridge formation in Massachusetts. tend to have a grennish hue. The Argillite that comes from the Lockatong formation in New Jersey is Dark colored red browns greys.
I have hunted Southern New England all my life but the difference here is I never ventured far the east from where I lived my Hunts were always south, west and north. I never ventured past Branford really. Wel I did make a day trip to some fields in Norwich and found a couple broken quartzite triangles. My point is Argillite comes from several locations in eth formations that it is present there is more than just Argillite in the formations. Shale  Slate Argillite Graywacke all can be found in the smae places all sedimentary and in layers.

[CMD]

This is the material the points I've shown are made of, in a brief description.. I notice sometimes a cover page loads rather then the article, but if you try clicking it a 2nd time, the article loads.....

http://baywood.metapress.com/app/home/contribution.asp?referrer=parent&backto=issue,2,5;journal,92,126;linkingpublicationresults,1:300328,1

The Dr. Murray mentioned is a geologist at URI, not an archaeologist and the descriptive definition of Narragansett Basin argillite is based on geology, not archaeology. In this case, the archaeologists, and the collectors in southern New England , correctly recognize the material as argillite. Even if I agreed that most, if not all, archaeologists would fail to know the correct geological term for any rock, which I do not, in fact I find that notion to be an absurd generality, that would not preclude the possibility, that they might actually recognize and know the correct name of the material in this instance. Which they, and I, do
  http://t.capecodonline.com/apps/pbcs...late=tabletart
ArgilliteArgillites are fine grained sedimentary rocks (like mudstone and slate) that have beenmetamorphosed to varying degrees. As a result, these stones are harder than their originalsedimentary rock and thus suitable for limited stone knapping to produce tools. Unfortunately,argillites still maintain a degree of sedimentary platyness and have a tendency to flake in layers,making them somewhat difficult to work. Types of argillite include Black (originating in theDelaware River Valley of New Jersey and Pennsylvania), Maroon (originating from the Chicopeeshales in western Massachusetts), Blue-Grey, Tan, Grey (all originating from either theCambridge slates in the Boston basin or Barrington, Rhode Island), Green Platy (originating inBarrington, Rhode Island and also occurring in glacial drift deposits in the Taunton River Basin),Banded (originating in the Cambridge slates in the Boston basin) and Coarse grained green(Originating in Hull, Massachusetts). Argillites are common in glacial drift deposits in manylocals in eastern Massachusetts and occurr predominatly in the Late Archaic, although they werealso used to a lesser degree in other time periods.
The above paragraph discussing argillites from different regions is taken from this report:

http://www.scribd.com/doc/70367470/A...orical-Society

  The green platy  argillite, very fine grained and not looking at all like NJ coarse grained argillite, predominates where I hunt.
Only the section on argillite are relevant but the report does not need to be downloaded. Just touch the screen on the right and you can scroll the entire thing, but I excerpted the passage above as relevant.

[CMD]

Here are more examples of New England argillite.  Before he passed away last August,  New England typology expert Jeff Boudreau of the Massachusetts Archaeological Society identified the dark blue-green point in the upper left corner as the 15th known example of a Hardaway Side Notch from New England.  He also told me it was the 4th known Hardaway made of argillite that he was aware of, (I've seen the other 3)so at 9000-10000 years old, this indicates argillite was sourced here in fairly early times, the early most Archaic. A crude bifurcate at bottom right also demonstrates very early usage of Narragansett Basin argillite and its' relatives in the Boston Basin. In our experience, it is easily the 2nd most common lithic found, and we tend to be disappointed when we find it, as it is simply not, with exceptions, a very attractive or well flaked rock.
ii

[CMD]

And, just a few more very average argillite points from RI.

[CMD]

Seems like the folks of the broad point tradition, makers of Susquehanna and Atlantic points(Atlantic in New England corresponds to Snook Kill and Savannah River Stemmed), used argillite often, in addition to exotics and regional volcanics. Here are examples of what's referred to as the Broad Point Tradition in New England, intrusive in relation to the narrow point tradition. Both bluish-green and green patination is seen here.

[Hoss]

Charlie they have some but igly material in your neck o the woods but they sure did know how to make a nice point out of some real crappy material.
That Vosburg looking point in the first picture is some rough material but that point overall is a beauty.