Welcome to Lake Pontchartrain.....the area designated by the
co-ordinates is handicapped accessible and will give you a nice
view of the lake at a location the locals call the “ old
beach “ ( the new beach was the now closed Pontchartrain
Beach Amusement Park ) .To the west you can see the worlds longest
bridge, the Lake Pontchartrain Causeway ( a round trip will take
you over 50 miles ). The concrete retaining wall with its unique
steps made it easy to get in and out of the lake when swimming or
fishing.
Lake Pontchartrain is not a true lake but an estuary connected to
the Gulf of Mexicovia the Rigolets strait (known locally as "the
Rigolets") and Chef Menteur Pass into Lake Borgne , another large
lagoon, and therefore experiences small tidal changes. It receives
fresh water from the, Tangipahoa ,Tchefuncte ,Tickfaw , Amite and
Bogue Falaya Rivers, and from Bayou Lacombe and Bayou
Chinchuba.
Salinity varies from negligible at the northern cusp west of
Mandeville up to nearly half the salinity of seawater at its
eastern bulge near Interstate 10.Lake Maurepas , a true fresh water
lake, connects with Lake Pontchartrain on the west via Pass
Manchac. The Industrial Canal connects the Mississippi River with
the lake at New Orleans. Bonnet Carre’ Spillway diverts water
from the Mississippi into the lake during times of river
flooding.
Currently almost 1.5 million people (one-third of the entire
population of Louisiana) live in the 14 parishes of the Lake
Pontchartrain Basin.
The Lake Pontchartrain Basin is a 12,170-km2 watershed in
southeastern Louisiana, stretching from the State of Mississippi on
the north and east to the Mississippi River on the west and south,
and to Breton Sound at the Gulf of Mexico. The Pontchartrain Basin
is about 200 km along strike and 75 km along dip, with modern lakes
(Maurepas, Pontchartrain, and Borgne) covering the southern portion
of the basin. Lake Pontchartrain and its adjacent lakes form one of
the largest estuaries in the United States.
The following details geological information about how the lake was
created as well as its place in New Orleans history.
Geology of Lake Ponchartrain
The geologic history of the Lake Pontchartrain Basin begins
about 20,000 years ago in the Pleistocene Epoch during the late
Wisconsin glaciation, when continental and alpine glaciers covered
a majority of the North American continent .
At that time, sea level was at a lowstand with an elevation
approximately 91 m (300 ft) lower than present. Coastal plain
rivers were incising their valleys with their channels discharging
at the outer edge of the continental shelf. As the late Wisconsin
glaciers began to melt 18,000 years ago, sea level began to rise
and the Holocene Transgression ensued. As sea level rose, the
incised river valleys flooded and the shoreline shoreface eroded
into and beveled these Pleistocene uplands. Sea level rose rapidly
and continued to rise until the Holocene Transgression ended about
3,000-4,000 years ago.
When the rise in sea level ended and the highstand was achieved, a
barrier island system developed and extended from what is today
Hancock County, Mississippi east across a shallow embayment to the
present location of New Orleans.. Geologists refer to this barrier
island system as the Pine Island barrier trend. The first stage in
formation of the Lake Pontchartrain Basin was the achievement of
the highstand 3,000-4,000 years ago, followed by the development of
the Pine Island barrier shoreline trend which resulted in the
formation of Lakes Maurepas and Pontchartrain .
The next stage in the formation of the Lake Pontchartrain Basin was
when the St. Bernard delta complex of the Mississippi River Deltaic
Plain built out of the alluvial valley onto the continental shelf
about 3,000-4,000 years ago. The northern boundary of the St.
Bernard delta complex coincided with the south shore of the
modern-day Lake Pontchartrain. The St. Bernard delta complex buried
the Pine Island barrier island trend under a sequence of deltaic
sediments. About 2,000 years ago, the Mississippi River abandoned
the St. Bernard delta complex and diverted out of the Basin to the
new location of the Lafourche delta complex. This stage in the
development of the Basin saw the natural transgression of the St.
Bernard delta complex, as coastal land loss began to occur and the
Chandeleur Islands started to form approximately 2,000 years
ago.
The Mississippi River moved back into the Basin about 1,000 years
ago by diverting from the Lafourche delta complex to the Modern
delta complex in the southern region of the Basin, completing the
development of this magnificent estuarine ecosystem.
Native Americans were the first residents along the lake
Native American tribes (Bayougoula, Mougoulacha, Chitimacha, Oumas,
Tangipahoa, Colapissa, and Quinipissalive) lived in the area we now
know as the Lake Pontchartrain Basin. Today evidence of their
villages exist in the form of piles of discarded clam shells or
'middens'. Okwa-ta, which means 'Wide Water,' is the name the
Choctaws used for the lake.
1699 - Iberville names Lake Pontchartrain
French explorer Pierre LeMoyne Sieur d'Iberville (March 26 - 30)
enters the waterway, which his men name the d'Iberville River
(later to be renamed Bayou Manchac). With rough portages and log
jams to encountered, the small group eventually reaches a lake
which d'Iberville names 'Lake Maurapas' and then on to a large lake
which d'Iberville names 'Lake Pontchartrain' after the current
French Minister of Marine, Louis Pontchartrain. Source: Pierre
LeMoyne Sieur d'Iberville--Discoverer of the Mississippi Gulf
Coast
1700s Old Basin Canal
The 'Old' Basin Canal built in the late 18th century by Governor
Carondelet to link the city to the Lake. Originally called the
Carondelet Canal. Mules pulled barges filled with people to the
Lake.
1812 - New Orleans joins the United States
New Orleans becomes part of the United States after the Louisiana
Purchase. Several important ports flourish on Lake Pontchartrain's
shores. Sailboats carry cargo and people between the Gulf of Mexico
and the Lake Pontchartrain Basin ports. Commerce grows on the south
and north shores of Lake Pontchartrain. Exported products include:
lumber, charcoal, bricks, shells, cotton, and oysters. Imported
products include: raw materials and food unavailable locally. The
wealthy spend their leisure time on the lake shore at several
exclusive resorts, eating at the famous restaurants, gambling and
enjoying the lake breezes. The first resort to open is at Spanish
Fort at the mouth of Bayou St. John.
1831 New Basin Canal
Builders of the New Basin Canal, which connected the downtown
American sector of New Orleans with Lake Pontchartrain, preferred
to hire Irishmen because the work was dangerous, and they did not
want their valuable slaves injured or killed. Laboring in water up
to their hips, canal diggers were very susceptible to yellow fever,
malaria, and cholera. Estimates of the number of Irishmen buried
along the New Basin Canal ranged from 3,000 to 30,000.
To get credit for this Earthcache you must complete the following
requirements.
PLEASE SEND AN EMAIL TO BAMBOOZLE AND ANSWER THE FOLLOWING:
1. If Lake Pontchartrain is not a lake what is it ?
2. What did the Mississippi River do about 1000 yrs ago to complete
the “ lakes “ development ?
3. Who gave the “ lake “ its name ?
4. Name one tribe of indians who were among the “lakes”
first residents ?
5. Is the “ lake “ affected by rising and falling tides
?
6. Standing at the co-ordinates you are close to the “ lakes
“ widest point.....how wide do you think it is ?
7. Lastly, when you log your visit please post a photo of something
you find interesting with the “ lake “ in the
background. Even you if you like, but that is not a
requirement.
Do not post your answers to these questions when you log your
visit. Any log entry with the answers, even if they are encrypted,
will be deleted.
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