| Pages:
1
2
3
4
5 |
wilderone
Ultra Nomad
Posts: 3880
Registered: 2-9-2004
Member Is Offline
|
|
"there is no bulk obsidian around that I know of."
Isla Miramar (off Huerfanito) has a huge solid obsidian deposit on its west coast, right on the beach. Also, this island is a pelican breeding and
dying locale.
|
|
|
bent-rim
Nomad
Posts: 294
Registered: 7-31-2007
Location: Marin County
Member Is Offline
Mood: Living la vida mota
|
|
Next time I fall off my dirt bike bike, I'll look around a little bit.
|
|
|
Osprey
Ultra Nomad
Posts: 3694
Registered: 5-23-2004
Location: Baja Ca. Sur
Member Is Offline
|
|
Fujita's excavations on Espiritu Santo were extensive and almost all of the oldest strata tools were broken shells -- hence the jury being out. We are
all still waiting and it has been many years since her find. Another problem she may have is that it is very difficult to pinpoint sea levels 40,000
years BP. The specialists who do that sort of thing now use coral and coral islands and the dating process from that sounds wonderfully simple and
accurate but science moves carefully, slowly. Drives me nuts. The La Paz office of INAH has literally hundreds of sites yet to explore with the
world's best and smallest army of professionals. The peninsula holds surface treasures to outnumber those found in Egypt and Peru but Mexico does not
have the resources for investigation right now. The place is a museum with the doors still closed.
|
|
|
shari
Select Nomad
Posts: 13049
Registered: 3-10-2006
Location: bahia asuncion, baja sur
Member Is Offline
Mood: there is no reality except the one contained within us "Herman Hesse"
|
|
There is a really neat valley near here where you can walk through coral reefs...the coral was around a meter high and have obviously fallen over but
the pieces are all there on the ground nearly intact...pretty neat being in a coral bed from who knows how many thousands of years ago...sure wish
someone could come and teach us about this area.
|
|
|
David K
Honored Nomad
Posts: 65285
Registered: 8-30-2002
Location: San Diego County
Member Is Offline
Mood: Have Baja Fever
|
|
Yes, amazing that ocean levels were once (or several times) much higher, ...long before man ... it is a 'normal' thing, and will happen again no
matter what we do!. 
|
|
|
Mexitron
Ultra Nomad
Posts: 3397
Registered: 9-21-2003
Location: Fort Worth, Texas
Member Is Offline
Mood: Happy!
|
|
One problem with finding proof of coastal sites older than 20,000 yrs is that they would likely be under water now, as sea level was at least 100 feet
lower before that (maybe 300 feet at times in the depths of the last ice age).
|
|
|
Tomas Tierra
Super Nomad
Posts: 1281
Registered: 3-23-2005
Location: oxnard, ca
Member Is Offline
Mood: Tengo Flojera
|
|
| Quote: | Originally posted by wilderone
ooooh Tomas - very nice. where did those come from? |
All are from BCS, between San Jaunico and La Laguna....We only found a few of those shown...The rest were traded for in El Datil, "Pengua" wanted
every dang spare part I had for his Toyota .
I was on the way home so he got em all..I got Pedernales..He had so many, If we had not found a few in the lagoon, I would have thought he was getting
real good at making them..Ha had a bag with maybe 75 pieces in it..
TT
|
|
|
Osprey
Ultra Nomad
Posts: 3694
Registered: 5-23-2004
Location: Baja Ca. Sur
Member Is Offline
|
|
Shari, that's an entriguing thought; wanting people to come tell us about where we live in Baja. I think we would all want that. Someday maybe we can
invite college science students to do their field work while telling all about what they know, what information they are trying to expand upon, what
they hope to find and prove. In the meantime there are some very knowledgable people on the board and I'll bet if we asked the right questions we
could get some excellent answers right here, right now. Took me all morning but here's a rare picture of sea levels that would help all of us answer
questions about artifacts and sites in Baja California: http://en.wikipedia.org/wiki/Sea_level_rise
|
|
|
David K
Honored Nomad
Posts: 65285
Registered: 8-30-2002
Location: San Diego County
Member Is Offline
Mood: Have Baja Fever
|
|
Thanks for the link Osprey... In the past 100 years they say the ocean has risen 8 whole inches! 
|
|
|
shari
Select Nomad
Posts: 13049
Registered: 3-10-2006
Location: bahia asuncion, baja sur
Member Is Offline
Mood: there is no reality except the one contained within us "Herman Hesse"
|
|
my question was where did the people who made pedernales here get the raw obsidian....where is the closest obsidian? I googled it and came up with
this answer which makes alot of sense...san ignacio lagoon area is close and I imagine this is where they got it.
http://www.swxrflab.net/VDAZUFRE.HTM
now I'm gonna try to find out what those little barbed pedernales are for.
|
|
|
wilderone
Ultra Nomad
Posts: 3880
Registered: 2-9-2004
Member Is Offline
|
|
very interesting, Shari - thanks.
Actually, there is a LOT of information online from scientific studies done in Baja over the years. These are pretty technical and make for difficult
reading, and, personally, I have to research meaning of some of the words to understand the articles. I was just reading about the many seismic rifts
that criss-cross the Baja peninsula. And, in spite of general theory about sea levels rising, because of the ongoing volcanic plates, rifts, shifts,
faults, etc., in Baja the LAND is rising. This exposes ancient marine shelfs - some from the miocene era - some 5 to 23 million years ago. Really -
tons of info online. A couple years ago, I read an article on the fossil shells near Bahia Asuncion. There's an article on the Loreto Basin -
describing how the alluvial fan/delta area behind Loreto Bay was once part of the gulf, but off and on, until the land lifted up.
|
|
|
wilderone
Ultra Nomad
Posts: 3880
Registered: 2-9-2004
Member Is Offline
|
|
like, for instance -
Five main petrologic and geochemical groups can be identified among the Middle to Late Miocene lavas from the western part of southern Baja
California: (1) calc-alkaline and K-rich andesites emplaced between 15.5 and 11.7 Ma; (2) adakites and (3) associated niobium-rich basalts erupted
between 11.7 and 8.5 Ma in the Santa Clara volcanic field, Vizcaino Peninsula; (4) 10.6-9.2 Ma tholeiitic basalts and basaltic andesites that form
large tabular plateaus near San Ignacio; and (5) magnesian and basaltic andesites of adakitic affinity whose emplacement started at 11.7 Ma south of
San Ignacio and between 9.7 and 8.8 Ma near La Purisima. These lavas, although spatially and temporally related, display very different geochemical
signatures. Their trace elements and isotopic characteristics suggest that three different magma sources were involved in their genesis. Partial melts
of subducting altered oceanic crust produced the adakites when erupted directly at the surface. These magmas were eventually trapped in the mantle
wedge where they reacted with ultramafic lithologies. Such slab-melt-metasomatized mantle could then melt to produce niobium-rich basalts or magnesian
andesites, depending on the pressure that controlled the stability of garnet into the mantle wedge.
[from wikipedaea]: The Miocene is a geological epoch of the Neogene Period and extends from about 23.03 to 5.33 million years before the present
(23.03 to 5.33 Ma). The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words μείων (meiōn,
“less”) and καινός (kainos, “new”) and means "less recent" because it has 18% fewer modern sea invertebrates than the
Pliocene. The Miocene follows the Oligocene Epoch and is followed by the Pliocene Epoch. The Miocene is the first epoch of the Neogene Period.
The earth went from the Oligocene Epoch through the Miocene and into the Pliocene as it cooled into a series of Ice Ages. The Miocene boundaries are
not marked by a single distinct global event but consist rather of regional boundaries between the warmer Oligocene and the cooler Pliocene.
|
|
|
shari
Select Nomad
Posts: 13049
Registered: 3-10-2006
Location: bahia asuncion, baja sur
Member Is Offline
Mood: there is no reality except the one contained within us "Herman Hesse"
|
|
please pass on any links anyone might have to info on this topic for our area...love to read about the fossil shells around here. There are some
monster petrified pismo clams around and arroyos full of smaller ones.
still no luck identifying what the obsidian flints were used to hunt.
|
|
|
Osprey
Ultra Nomad
Posts: 3694
Registered: 5-23-2004
Location: Baja Ca. Sur
Member Is Offline
|
|
Shari, here's the link to your possible arrowhead makers, the Guaycura: http://www.innerexplorations.com/catsimple/exped4.htm
|
|
|
wilderone
Ultra Nomad
Posts: 3880
Registered: 2-9-2004
Member Is Offline
|
|
Microfacies Study of Dissolution and Precipitation in Littoral Deposits on the Western Coast of Baja California Sur (Mexico), by Socorro
Celis-Gutierrez and Victor M. Malpica-Cruz © 1987 Coastal Education & Research Foundation, Inc..
Abstract
The study area, located on the western coast of Baja California, in its south-central portion, discloses several outcrops of well-preserved marine
deposits at various elevations and thicknesses which are attributed to a series of Quaternary marine transgressions. The paleolittoral deposits form a
belt parallel to the present coastline, and in some places there are as many as nine of these belts with heights between 5 and 90 m.The microfacies
study provided an understanding of various diagenetic processes which have taken place in these deposits. The deposits consist mainly of well-
consolidated sandstones and beach conglomerates, with both macrofauna and microfauna. The microfauna has been reworked and broken. These diagenetic
processes took place in a mainly subaerial environment. The lithification began usually in a shallow marine environment and continued after the
emergence under the influence of fresh water and variations of the water table, which led to the dissolution of the organic carbonates, mainly fossil
shells. The oldest deposits show evidence of several dissolution phases and successive recrystallization of the cement, also the epigenesis of quartz
and feldspar grains as well as caliche production as a result of Quaternary climactic changes.
|
|
|
wilderone
Ultra Nomad
Posts: 3880
Registered: 2-9-2004
Member Is Offline
|
|
this one is more interesting:
http://boletinsgm.igeolcu.unam.mx/epoca03/1980-41-1%20y%202%...
|
|
|
shari
Select Nomad
Posts: 13049
Registered: 3-10-2006
Location: bahia asuncion, baja sur
Member Is Offline
Mood: there is no reality except the one contained within us "Herman Hesse"
|
|
whew...that WAS interesting and answers some of my questions of why fossilized megaladon teeth can be found on the top of the mountain...the article
described "uplifting events" around middle Miosene times...so these sharks teeth are twice as old as we thought...around 15 million years
old....cool...thanks for the links...been a real science day!
still dont know what little critters were hunted with those teeny obsidian flints.
[Edited on 5-22-2010 by shari]
|
|
|
mtgoat666
Select Nomad
Posts: 19934
Registered: 9-16-2006
Location: San Diego
Member Is Offline
Mood: Hot n spicy
|
|
| Quote: | Originally posted by shari
whew...that WAS interesting and answers some of my questions of why fossilized megaladon teeth can be found on the top of the mountain...the article
described "uplifting events" around middle Miosene times...so these sharks teeth are twice as old as we thought...around 15 million years
old....cool...thanks for the links...been a real science day!
still dont know what little critters were hunted with those teeny obsidian flints.
[Edited on 5-22-2010 by shari] |
the 'material' is obsidian, chert or flint (flint is really a variant of chert). no such thing as "obsidian flint."
the small points were often arrow points for bow/arrow setups (arrowheads shot with bow need be small and sharp, not heavy). the small arrowheads
could have been used for anything from rabbits to deer. a small arrowhead going fast can bring down a big animal.
arrows often tarvel better, faster and deeper into flesh when they have smaller tips, so don't be confused into thinking small arrowheads are for
small critters
|
|
|
shari
Select Nomad
Posts: 13049
Registered: 3-10-2006
Location: bahia asuncion, baja sur
Member Is Offline
Mood: there is no reality except the one contained within us "Herman Hesse"
|
|
in the dictionary, the translation for pedernal is flint...so I'm confused... these "arrowheads" are made of obsidian...is a flint an arrowhead? are
you sure these tiny ones about the lenth of my baby fingernail but narrower...would be on the tip of an arrow?? did they shoot mice?
It was an interesting article about the guaycuras and what they ate and made me wonder how they caught them or hunted them...and bats??? wonder how
they taste?
|
|
|
woody with a view
PITA Nomad
Posts: 15939
Registered: 11-8-2004
Location: Looking at the Coronado Islands
Member Is Offline
Mood: Everchangin'
|
|
| Quote: |
I give modern man another 50 years living as we are on the planet, before we go through a huge extinction (largely through our own stupidity) we are
after all just another animal on the planet!
|
PERFECT!
i should be just dead by then!
|
|
|
| Pages:
1
2
3
4
5 |
![[*]](images/xmbforum/default_icon.gif){kind=icon}
