A. Where does it come from?
Ian said:
A. Where does it come from?
Same place as other sand – erosion.
Fraser Island has lots of white sand. Most of it originates from the rivers of northern NSW, and is borne north on ocean currents.
The whiteness comes from the age of the sand, and the gradual leaching away and grinding away of any organic matter contained in the sand. It’s old sand, very much worn and washed.
B. How much of it is fish shit?
Unfortunately your questions are a bit too general.
White sands are most likely monomineralic quartz (SiO2) or cryptocrystalline (SiO2) or calcite (CaCO3), although other monomineralic sands are possible.
Unlikely to have much fish fecal matter.
Do you have a specific location?
Michael V said:
Do you have a specific location?
How about Hawaii?
http://www.flickr.com/photos/chancefate/1220428221/in/photostream/
Hawaii often has green sands. These are monominerallic olivine.
Hawaii has black sands – sand sized basalt particles.
The white sands there are carbonate sands – monomineralic calcite – derived from fringing coral reefs.
There is very little quartz or cryptocrystalline silica on the Hawaiian Islands.
Ian said:
Yeah, partly true.
http://www.flickr.com/photos/chancefate/1220428221/in/photostream/
Much of the carbonate sand is tumbled coral fragments. Those are mainly derived from wave action. Even the weak wave action behind the fringing reef is sufficient.
Most fish don’t eat the mineralised portion of coral. Most fish don’t eat coral at all because of the nematocysts. (Imagine getting a mouthful of bluebottles.) Some do eat coral and an even smaller proportion of fish eat the mineralised portion of coral, to get the most amount of the coral animal they can.
Note that calcite is a relatively soft mineral. Much softer than quartz or olivine.
>olivine.
Lots of that on the moon and asteroids.
Michael V said:
Ian said:Yeah, partly true.
http://www.flickr.com/photos/chancefate/1220428221/in/photostream/
Much of the carbonate sand is tumbled coral fragments. Those are mainly derived from wave action. Even the weak wave action behind the fringing reef is sufficient.
Most fish don’t eat the mineralised portion of coral. Most fish don’t eat coral at all because of the nematocysts. (Imagine getting a mouthful of bluebottles.) Some do eat coral and an even smaller proportion of fish eat the mineralised portion of coral, to get the most amount of the coral animal they can.
Mmm, thanks Michael.
So sites like this..
http://www.sportdiver.com/keywords/marine-life/species-7-parrotfish-facts
..are laying it on a bit thick by saying, “6. Sunbathers beware! Much of the crystal white sand forming tropical beaches is former parrotfish poop: After digesting coral rock, it’s excreted as sand.”?
Ian said:
Yeah, a bit thick, really. “Sunbathers beware” has an unnecessarily alarming tone.
Michael V said:
Ian said:Yeah, partly true.
http://www.flickr.com/photos/chancefate/1220428221/in/photostream/
Much of the carbonate sand is tumbled coral fragments. Those are mainly derived from wave action. Even the weak wave action behind the fringing reef is sufficient.
Most fish don’t eat the mineralised portion of coral. Most fish don’t eat coral at all because of the nematocysts. (Imagine getting a mouthful of bluebottles.) Some do eat coral and an even smaller proportion of fish eat the mineralised portion of coral, to get the most amount of the coral animal they can.
Mmm, thanks Michael.
So sites like this..
http://www.sportdiver.com/keywords/marine-life/species-7-parrotfish-facts
..are laying it on a bit thick by saying, “6. Sunbathers beware! Much of the crystal white sand forming tropical beaches is former parrotfish poop: After digesting coral rock, it’s excreted as sand.”?
Parrotfish are one of the species that ingest the mineralised portion of the coral. But it’s hardly shit. It passes through the fish’s gut as mineralised particles. And the parrotfish is not the most plentiful fish on the reef, so I guess wave action is still the biggest cause of sand-sized particles. And I doubt the fish has any human pathogens.
It’s like saying “don’t walk on that soil – it is made of worm poop”.
It’s like saying “don’t walk on that soil – it is made of worm poop”.
————————————————————————-
It’s like saying “don’t walk on that sand – it is made of invertebrates backbone…
Fixed.
Funny but fixed.
It’s like saying “don’t walk on that soil – it is made of worm poop”.
————————————————————————-
It’s like saying “don’t walk on that sand – it is made of invertebrates backbone…
Fixed.
Funny but fixed.
Michael V said:
It’s like saying “don’t walk on that soil – it is made of worm poop”.
Except that worm poop is done under the soil. It isn’t deposited on top.
Mr Ironic said:
invertebrates backbone…
what have you done there?
neomyrtus_ said:
Mr Ironic said:invertebrates backbone…what have you done there?
Rewritten the dictionary?
Mr Ironic said:
invertebrates backbone…
——————————————-
what have you done there?
————————————————-
The impossible.
Happy with that?
I’d be happier for you to consider what particular anatomical character defines an invertebrate.
I’d be happier for you to consider what particular anatomical character defines an invertebrate.
——————————————————————-
OK
Some may say that they lack a backbone…
Others that the backbone is outside instead, internally… infused.
Anyhoo – there’s a bit of work done on parrotfish as grazers who can do a bit of erosion and certainly drive the dynamics of some coral reefs – especially when they take out algae which competes with coral polyps. Very important critters because of their functional role. They like a few fish, eat ‘worked sediments’.
Some folks have estimated sediment production by grazers like parrotfish and sea urchins (the pits or depressions that you see in some limestone reefs are from sea urchins – as found in limestone along Perth beaches.
http://archives.datapages.com/data/specpubs/carbona1/data/a045/a045/0001/0250/0281.htm
neomyrtus_ said:
Calcrete probably dates from a time prior to parrotfish?
Anyhoo – there’s a bit of work done on parrotfish as grazers who can do a bit of erosion and certainly drive the dynamics of some coral reefs – especially when they take out algae which competes with coral polyps. Very important critters because of their functional role. They like a few fish, eat ‘worked sediments’.Some folks have estimated sediment production by grazers like parrotfish and sea urchins (the pits or depressions that you see in some limestone reefs are from sea urchins – as found in limestone along Perth beaches.
http://archives.datapages.com/data/specpubs/carbona1/data/a045/a045/0001/0250/0281.htm
Michael V said:
Hawaii often has green sands. These are monominerallic olivine.Hawaii has black sands – sand sized basalt particles.
The white sands there are carbonate sands – monomineralic calcite – derived from fringing coral reefs.
There is very little quartz or cryptocrystalline silica on the Hawaiian Islands.
Stealth said:
Michael V said:
Hawaii often has green sands. These are monominerallic olivine.Hawaii has black sands – sand sized basalt particles.
The white sands there are carbonate sands – monomineralic calcite – derived from fringing coral reefs.
There is very little quartz or cryptocrystalline silica on the Hawaiian Islands.
New Zealand black sand beaches are mined for the iron content.
Yep, NZ Steel used to be the only mill in the world that made steel using ironsand as the primary ingredient, it wasn’t a great success story.
Why is the west coast of NZ black sand, and the east coast white? Tasman sea vs Pacific, less coral in the rough Tasman sea?
http://www.youtube.com/watch?v=—E3kamCZmg
Logies 2010: Underborough (Neighbours skit)
start watching at 1:42
puts summer bay to shame
Anywho said:
Stealth said:
Michael V said:
Hawaii often has green sands. These are monominerallic olivine.Hawaii has black sands – sand sized basalt particles.
The white sands there are carbonate sands – monomineralic calcite – derived from fringing coral reefs.
There is very little quartz or cryptocrystalline silica on the Hawaiian Islands.
New Zealand black sand beaches are mined for the iron content.
Yep, NZ Steel used to be the only mill in the world that made steel using ironsand as the primary ingredient, it wasn’t a great success story.
Why is the west coast of NZ black sand, and the east coast white? Tasman sea vs Pacific, less coral in the rough Tasman sea?
The black sand is from volcanic activity so it seems a bit odd both coasts aren’t black.
Anywho said:
Anywho said:
Stealth said:New Zealand black sand beaches are mined for the iron content.
Yep, NZ Steel used to be the only mill in the world that made steel using ironsand as the primary ingredient, it wasn’t a great success story.
Why is the west coast of NZ black sand, and the east coast white? Tasman sea vs Pacific, less coral in the rough Tasman sea?
The black sand is from volcanic activity so it seems a bit odd both coasts aren’t black.
Depends upon which beach one stands, as far as I can see. There’s a lot of coastline in NZ to view.
Aha..
What’s the story with the brilliant white sand beaches in Florida then?
They studied hard to get where they are today…
What’s the story with that image link?
furious said:
- What’s the story with the brilliant white sand beaches in Florida then?
They studied hard to get where they are today…
What’s the story with that image link?
dunno about the image link too complex.. but.. Much of the sand on Florida beaches is made up of quartz crystals.
neomyrtus_ said:
I’d be happier for you to consider what particular anatomical character defines an invertebrate.
It is the Fascia(physio-sheath) that is definitive. Technically it is the fascia that is more developed in invertebrates, it’s extra development incorporating spinal formations into the structure that minimise or eliminate proprioceptive lag or to provide comprehensive physical support.
roughbarked said:
furious said:
- What’s the story with the brilliant white sand beaches in Florida then?
They studied hard to get where they are today…
What’s the story with that image link?
dunno about the image link, too complex.. but.. Much of the sand on Florida beaches is made up of quartz crystals.
Special things take time. In fact, it took more than 2 million years to make the fine, white sand you’ll find at the very special beaches in the St. Pete/Clearwater area.
With every soft, relaxing step you take, a million tiny particles crunch underfoot. But it wasn’t always like that. The glowing white powder you see started as mountains of impenetrable quartz hundreds of miles away, massive geologic formations ground into tiny specks over the millennia and deposited on the Gulf coast by raging rivers that no longer exist.
Unlike the darker, coarser sands you’ll find on Florida’s east coast and in the Keys – which are composed mostly of ground up bits of shell and coral – these beaches are velvet-smooth and cool to the bottom of a bare foot. Some say it looks like snow or sugar, but no matter what you think it looks like, it has an enchanting quality that beckons you to dig your toes in, to frolic and to stay awhile.
roughbarked said:
Some say it looks like snow or sugar, but no matter what you think it looks like, it has an enchanting quality that beckons you to dig your toes in, to frolic and to stay awhile.
If The Beach Boys genuinely appreciated beaches they would have mentioned this in lyrics. They should have called themselves “The California Slutabouts!!”
bwahhahahaha
did you forget the url of that quote?
JudgeMental said:
did you forget the url of that quote?
yep. http://www.visitstpeteclearwater.com/articles/how-white-sand-shells-are-made
and.. the Beach Boys and California are worlds apart from Florida.
roughbarked said:
JudgeMental said:
did you forget the url of that quote?
yep. http://www.visitstpeteclearwater.com/articles/how-white-sand-shells-are-made
and.. the Beach Boys and California are worlds apart from Florida.
my point is that were they truly connuissers of the beach environment they would have sung the praises of the Florida beaches. As it turns out, they were simply another bunch of skirt sniffing californian bums that have ensured that I have to check my childs toy recordings to ensure there are no inappropriate sentiments included. “Two girls for every guy” might be farout for the times the words were written but including those lyrics in a modern childs toy is pretty difficult to explain.
“Two girls for every guy”
I always took that to mean the gender demographic where females outnumbered males by approx 2:1.
Tamb said:
“Two girls for every guy”I always took that to mean the gender demographic where females outnumbered males by approx 2:1.
What the Sex Pistols did for punk, The Beach Boys did for the free love hippy movement. It is a convenient statistical pun.
Riff-in-Thyme said:
Tamb said:“Two girls for every guy”I always took that to mean the gender demographic where females outnumbered males by approx 2:1.
What the Sex Pistols did for punk, The Beach Boys did for the free love hippy movement. It is a convenient statistical pun.
roughbarked said:
Anywho said:
Anywho said:Yep, NZ Steel used to be the only mill in the world that made steel using ironsand as the primary ingredient, it wasn’t a great success story.
Why is the west coast of NZ black sand, and the east coast white? Tasman sea vs Pacific, less coral in the rough Tasman sea?
The black sand is from volcanic activity so it seems a bit odd both coasts aren’t black.
Depends upon which beach one stands, as far as I can see. There’s a lot of coastline in NZ to view.
Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
That was the whole point, wasn’t it?
Tamb said:
Riff-in-Thyme said:
Tamb said:“Two girls for every guy”I always took that to mean the gender demographic where females outnumbered males by approx 2:1.
What the Sex Pistols did for punk, The Beach Boys did for the free love hippy movement. It is a convenient statistical pun.
Shame the SP didn’t have melody to go with their “music”
Heavy music minimises the backbeat. The melody becomes a riff. Depends what you are trying to communicate. The Pistols genuinely have more melodic reference than they are given credit for and Steve Jones’s compilations are less atonal than many of his contemporaries. There is also the point that citing The Sex Pistols for musical technicality is irrelevant. They never professed to be competing with Led Zep on any level. They were simply out to prove a point.
furious said:
- Shame the SP didn’t have melody to go with their “music”
That was the whole point, wasn’t it?
A bit of that, anti-music, anti establishment. But still, I like the music, The Great Rock ‘n’ Roll Swindle is a great album.
furious said:
- Shame the SP didn’t have melody to go with their “music”
That was the whole point, wasn’t it?
Yes, on reflection it was.
Anywho said:
roughbarked said:
Anywho said:The black sand is from volcanic activity so it seems a bit odd both coasts aren’t black.
Depends upon which beach one stands, as far as I can see. There’s a lot of coastline in NZ to view.
Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
Well NZ is on the edges of the tectonic plates.
roughbarked said:
Anywho said:
roughbarked said:Depends upon which beach one stands, as far as I can see. There’s a lot of coastline in NZ to view.
Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
Well NZ is on the edges of the tectonic plates.
I guess the most obvious answer might be that there’s an underwater volcanoe somewhere off the west coast of NZ which feeds those beaches.
http://www.nps.gov/whsa/naturescience/index.htm
This is just over the mountains from me. Some interesting stuff.
Anywho said:
roughbarked said:
Anywho said:Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
Well NZ is on the edges of the tectonic plates.
I guess the most obvious answer might be that there’s an underwater volcanoe somewhere off the west coast of NZ which feeds those beaches.
Need not necessarily be an active volcano.
kii said:
http://www.nps.gov/whsa/naturescience/index.htmThis is just over the mountains from me. Some interesting stuff.
Anywho said:
roughbarked said:
Anywho said:Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
Well NZ is on the edges of the tectonic plates.
I guess the most obvious answer might be that there’s an underwater volcanoe somewhere off the west coast of NZ which feeds those beaches.
no, this is neither an answer, nor and obvious answer.
The mineralogy of the sand found on a particular beach is typically a function of the surrounding depositional and erosional processes.
Glacial erosional processes play a large role on the West Coast of the South Island.
jjjust moi said:
kii said:
http://www.nps.gov/whsa/naturescience/index.htmThis is just over the mountains from me. Some interesting stuff.
It is. Do they “mine” the Gypsum at all?
They do in WA and sold to local farmers. In the SE where rainfall is low, there are a couple of large salt or playa lakes, in one the dune mounds are very powdery where you sink to your ankles as you walk over them. The other produces not only the powdery form, but also the white sand type as shown in the link.
In both cases, after winter rainfall evaporates from the lake by spring/summer, it leaves behind the gypsum crystals, which are then blown around the lake to form dunes/mounds. Although vegetation is sparse on these gypsum deposits, they can be highly localised and restricted only to them.
jjjust moi said:
kii said:
http://www.nps.gov/whsa/naturescience/index.htmThis is just over the mountains from me. Some interesting stuff.
It is. Do they “mine” the Gypsum at all?
Not that I am aware of. It’s a national monument – so it’s protected.
Anywho said:
roughbarked said:
Anywho said:Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
Well NZ is on the edges of the tectonic plates.
I guess the most obvious answer might be that there’s an underwater volcanoe somewhere off the west coast of NZ which feeds those beaches.
I doubt that is the case.
diddly-squat said:
Anywho said:
roughbarked said:Well NZ is on the edges of the tectonic plates.
I guess the most obvious answer might be that there’s an underwater volcanoe somewhere off the west coast of NZ which feeds those beaches.
no, this is neither an answer, nor and obvious answer.
The mineralogy of the sand found on a particular beach is typically a function of the surrounding depositional and erosional processes.
Glacial erosional processes play a large role on the West Coast of the South Island.
I haven’t been to any South Island beaches, but if you take Auckland as an example of a highly volcanic area Piha on the west coast has black sand, but 50km away the east coast beaches have white sand.
The black sand is from volcanoes, but if it was land based volcanoes then why wouldn’t both coasts have black sand as a result of the areas volcanic past?
However, if the black sand is a result of an offshore volcano then it would be expected to effect one coast but not the other.
Anywho said:
diddly-squat said:
Anywho said:I guess the most obvious answer might be that there’s an underwater volcanoe somewhere off the west coast of NZ which feeds those beaches.
no, this is neither an answer, nor and obvious answer.
The mineralogy of the sand found on a particular beach is typically a function of the surrounding depositional and erosional processes.
Glacial erosional processes play a large role on the West Coast of the South Island.
I haven’t been to any South Island beaches, but if you take Auckland as an example of a highly volcanic area Piha on the west coast has black sand, but 50km away the east coast beaches have white sand.
The black sand is from volcanoes, but if it was land based volcanoes then why wouldn’t both coasts have black sand as a result of the areas volcanic past?
However, if the black sand is a result of an offshore volcano then it would be expected to effect one coast but not the other.
For it to be sand, it would need more likely to have been from activity long ago rather than current.
roughbarked said:
Anywho said:
diddly-squat said:no, this is neither an answer, nor and obvious answer.
The mineralogy of the sand found on a particular beach is typically a function of the surrounding depositional and erosional processes.
Glacial erosional processes play a large role on the West Coast of the South Island.
I haven’t been to any South Island beaches, but if you take Auckland as an example of a highly volcanic area Piha on the west coast has black sand, but 50km away the east coast beaches have white sand.
The black sand is from volcanoes, but if it was land based volcanoes then why wouldn’t both coasts have black sand as a result of the areas volcanic past?
However, if the black sand is a result of an offshore volcano then it would be expected to effect one coast but not the other.
For it to be sand, it would need more likely to have been from activity long ago rather than current.
I never suggested otherwise.
Here is a picture of some white sand from Margaret River in WA. Sorry I haven’t got the scaling in the image, but it shows some quartz and some type of shells. MV may be able to comment further.
Speaking of WA, I remember walking on a beach which was roughly 50% garnet. pinkish sands.
So roughly how much of the white sand on the beaches (of Florida for example) has been processed in the gut of Parrot (and other) fish?
Ian said:
So roughly how much of the white sand on the beaches (of Florida for example) has been processed in the gut of Parrot (and other) fish?
NFI. You can work it out if you like. You’ll need parameters like:
a: volume of sand excreted per individual for each reef species within a set time period.
b: the population size of each species on adjacent reef
c: the total volume of sand processed by the sum of all fish within set time period
d:the volume of sand deposited from nearby reef to the beach in question for the set time period
e: the proportion of that deposited sand processed by all the fish (from c).
f: entire volume of sand on beach in question
g: proportion of f as e
You can find some or all of these estimates from the literature. You may even find a publication on marine sediment dynamics and biological functional groups in which this has been estimated. I already found one publication which estimated gut passage rates.
Anywho said:
Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
The black sand beaches are are North Island thing, being derived from the Volcanic Plateau in the ‘naki by erosion. The West Coast is actually a region of the South Island, and you have white sandy beaches at places like Karamea and lubberly pebble-cobblestone beaches like at south of Okarito, and combinations thereof which receive outputs of greywacke tumbling down from the Southern Alps and being washed out by rivers. There’s limestone around, but AFAIK, you don’t get (much) sands derived from extinct or extant tropical coral reefs forming NZ beaches, because you don’t and didn’t have the reefs around/on the NZ . AFAIK, the Oligocene limestones of NZ ain’t of tropical reef origin – but formed by limey waters percolating through soil and rock.
as for the calcareous sands coming from reefs and marine critters – the word(s) RiT required was ‘calcareous exoskeleton’. e.g. a shell in the case of marine molluscs or in the case of corals, the calicle. It’s not a vertebral column (which is a synapomorphy among Subphylum Vertebrata and which is not found in the paraphyletic grouping of ‘invertebrates’).
neomyrtus_ said:
Anywho said:Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
The black sand beaches are are North Island thing, being derived from the Volcanic Plateau in the ‘naki by erosion. The West Coast is actually a region of the South Island, and you have white sandy beaches at places like Karamea and lubberly pebble-cobblestone beaches like at south of Okarito, and combinations thereof which receive outputs of greywacke tumbling down from the Southern Alps and being washed out by rivers. There’s limestone around, but AFAIK, you don’t get (much) sands derived from extinct or extant tropical coral reefs forming NZ beaches, because you don’t and didn’t have the reefs around/on the NZ . AFAIK, the Oligocene limestones of NZ ain’t of tropical reef origin – but formed by limey waters percolating through soil and rock.
as for the calcareous sands coming from reefs and marine critters – the word(s) RiT required was ‘calcareous exoskeleton’. e.g. a shell in the case of marine molluscs or in the case of corals, the calicle. It’s not a vertebral column (which is a synapomorphy among Subphylum Vertebrata and which is not found in the paraphyletic grouping of ‘invertebrates’).
Ahh, if ‘naki means mt taranaki then that makes sense why the west coast of the north island has black sand but noti the east coast.
LookIng at mt taranaki on a map it is on a part of the west coast that juts out into the sea, almost a peninsula which would naturally feed the west coast (of the north island).
Anywho said:
neomyrtus_ said:
Anywho said:Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
The black sand beaches are are North Island thing, being derived from the Volcanic Plateau in the ‘naki by erosion. The West Coast is actually a region of the South Island, and you have white sandy beaches at places like Karamea and lubberly pebble-cobblestone beaches like at south of Okarito, and combinations thereof which receive outputs of greywacke tumbling down from the Southern Alps and being washed out by rivers. There’s limestone around, but AFAIK, you don’t get (much) sands derived from extinct or extant tropical coral reefs forming NZ beaches, because you don’t and didn’t have the reefs around/on the NZ . AFAIK, the Oligocene limestones of NZ ain’t of tropical reef origin – but formed by limey waters percolating through soil and rock.
as for the calcareous sands coming from reefs and marine critters – the word(s) RiT required was ‘calcareous exoskeleton’. e.g. a shell in the case of marine molluscs or in the case of corals, the calicle. It’s not a vertebral column (which is a synapomorphy among Subphylum Vertebrata and which is not found in the paraphyletic grouping of ‘invertebrates’).
Ahh, if ‘naki means mt taranaki then that makes sense why the west coast of the north island has black sand but noti the east coast.
LookIng at mt taranaki on a map it is on a part of the west coast that juts out into the sea, almost a peninsula which would naturally feed the west coast (of the north island).
Thinking is the best way to travel.
Here is some more white sand, this time from my place. It is quite a fine sand and I believe that its origin is the granite bedrock that underlies here. You can see that it is mainly quartz, unlike the calcareous sand from Margaret River. There is a little bit of ferruginous stuff on the surface, but it is otherwise quite clean. This sand is normally embedded in a black organic matrix, but when moved around by water, the organic material is washed away, leaving the sand in quite clean, white deposits around the place. On tracks for example.
roughbarked said:
Anywho said:
neomyrtus_ said:The black sand beaches are are North Island thing, being derived from the Volcanic Plateau in the ‘naki by erosion. The West Coast is actually a region of the South Island, and you have white sandy beaches at places like Karamea and lubberly pebble-cobblestone beaches like at south of Okarito, and combinations thereof which receive outputs of greywacke tumbling down from the Southern Alps and being washed out by rivers. There’s limestone around, but AFAIK, you don’t get (much) sands derived from extinct or extant tropical coral reefs forming NZ beaches, because you don’t and didn’t have the reefs around/on the NZ . AFAIK, the Oligocene limestones of NZ ain’t of tropical reef origin – but formed by limey waters percolating through soil and rock.
as for the calcareous sands coming from reefs and marine critters – the word(s) RiT required was ‘calcareous exoskeleton’. e.g. a shell in the case of marine molluscs or in the case of corals, the calicle. It’s not a vertebral column (which is a synapomorphy among Subphylum Vertebrata and which is not found in the paraphyletic grouping of ‘invertebrates’).
Ahh, if ‘naki means mt taranaki then that makes sense why the west coast of the north island has black sand but noti the east coast.
LookIng at mt taranaki on a map it is on a part of the west coast that juts out into the sea, almost a peninsula which would naturally feed the west coast (of the north island).
Thinking is the best way to travel.
Stealth said:
roughbarked said:
Anywho said:Ahh, if ‘naki means mt taranaki then that makes sense why the west coast of the north island has black sand but noti the east coast.
LookIng at mt taranaki on a map it is on a part of the west coast that juts out into the sea, almost a peninsula which would naturally feed the west coast (of the north island).
Thinking is the best way to travel.
Ok, you can think about traveling to NZ, but I will physically move to the black sand beacbes of Karatahi for a few days across Christmas, and then head West to the white sand beaches of Pauanui for almost three weeks.
:) enjoy.
Stealth said:
roughbarked said:
Anywho said:Ahh, if ‘naki means mt taranaki then that makes sense why the west coast of the north island has black sand but noti the east coast.
LookIng at mt taranaki on a map it is on a part of the west coast that juts out into the sea, almost a peninsula which would naturally feed the west coast (of the north island).
Thinking is the best way to travel.
Ok, you can think about traveling to NZ, but I will physically move to the black sand beacbes of Karatahi for a few days across Christmas, and then head West to the white sand beaches of Pauanui for almost three weeks.
With that sense of direction I’m picking you’ll never make it lol
Anywho said:
neomyrtus_ said:
Anywho said:Perhaps, but I have been to plenty of NZ beaches and never seen black sand on the east coast nor white sand on the west coast, there seems, at least anecdotally, to be a distinct divide between the two coasts.
The black sand beaches are are North Island thing, being derived from the Volcanic Plateau in the ‘naki by erosion. The West Coast is actually a region of the South Island, and you have white sandy beaches at places like Karamea and lubberly pebble-cobblestone beaches like at south of Okarito, and combinations thereof which receive outputs of greywacke tumbling down from the Southern Alps and being washed out by rivers. There’s limestone around, but AFAIK, you don’t get (much) sands derived from extinct or extant tropical coral reefs forming NZ beaches, because you don’t and didn’t have the reefs around/on the NZ . AFAIK, the Oligocene limestones of NZ ain’t of tropical reef origin – but formed by limey waters percolating through soil and rock.
as for the calcareous sands coming from reefs and marine critters – the word(s) RiT required was ‘calcareous exoskeleton’. e.g. a shell in the case of marine molluscs or in the case of corals, the calicle. It’s not a vertebral column (which is a synapomorphy among Subphylum Vertebrata and which is not found in the paraphyletic grouping of ‘invertebrates’).
Ahh, if ‘naki means mt taranaki then that makes sense why the west coast of the north island has black sand but noti the east coast.
LookIng at mt taranaki on a map it is on a part of the west coast that juts out into the sea, almost a peninsula which would naturally feed the west coast (of the north island).
And a little bit of reading shows that shows that there is indeed a lot of off shore volcanoes on the taranaki region.