Download 4.5 billion years ago

4.5 BILLION YEARS AGO
A- MARS-SIZED PLANET HIT EARTH, SENDING
DEBRIS INTO ORBIT AROUND EARTH. A FRACTION
OF THAT DEBRIS FORMED THE MOON AND THE
REST RETURNED TO EARTH.
1 BILLION YEARS AGO
AS ANCIENT EUROPE (“BALTICA”) AND BRAZIL
(“AMAZONIA”) COLLIDED WITH PROTO-NORTH
AMERICA, SEDIMENTARY AND IGNEOUS ROCKS
WERE DEFORMED AND METAMORPHOSED TO
PRODUCE THE ROCKS OF THE GRENVILLE
MOUNTAINS. THESE ARE THE OLDEST ROCKS
FOUND IN CONNECTICUT.
460 MILLION YEARS AGO
THE TACONIC MOUNTAINS, PART OF THE
APPALACHIAN MOUNTAIN CHAIN, FORMED WHEN
VOLCANIC ISLANDS AND OCEAN SEDIMENTS
COLLIDED WITH NORTH AMERICA.
380 MILLION YEARS AGO
THE ROCKS OF THE APPALACHIAN MOUNTAINS
CONTINUED TO FORM AS A CONTINENTAL MASS
EARTH SCIENTISTS CALL “AVALONIA” COLLIDED
WITH EASTERN NORTH AMERICA.
350-250 MILLION YEARS AGO
THE SUPERCONTINENT PANGEA (MEANING “ALL
LANDS”) WAS FORMED WHEN ALL THE CONTINENTS
CAME TOGETHER. DURING THIS TIME, THE
APPALACHIAN MOUNTAINS CONTINUED TO FORM.
THE MOUNTAINS WERE AS HIGH AS THE HIMALAYAS
ARE TODAY, REACHING ELEVATIONS OF 20,00030,000 FEET ABOVE SEA LEVEL.
230-210 MILLION YEARS AGO
THE BREAKUP OF PANGEA STARTED AS THE
SUPERCONTINENT BEGAN TO RIFT APART,
ULTIMATELY CREATING THE ATLANTIC OCEAN
BASIN.
200 MILLION YEARS AGO
AS PANGEA CONTINUED TO BREAK UP, SOME
SMALLER RIFTS PERPENDICULAR TO THE MAIN RIFT
DID NOT OPEN COMPLETELY, PRODUCING FAILED
RIFT VALLEYS LIKE CONNECTICUT’S CENTRAL
VALLEY (NEWARK TERRANE). THE FAMOUS
BROWNSTONES OF CONNECTICUT ARE MADE FROM
SEDIMENTS THAT WERE DEPOSITED IN THE RIFT
VALLEY. THE FLOOD BASALT LAVAS THAT ERUPTED
ALONG THE RIFTS ARE NOW PRESERVED AS
TRAPROCK RIDGES. ONE LAVA FLOW WAS ABOUT
200 METERS (OVER 600 FEET) THICK! DINOSAURS
ROAMED THE CONNECTICUT VALLEY AND LEFT
FOOTPRINTS ALONG THE MUDDY MARGINS OF RIFT
VALLEY LAKES. ONE TYPE OF LARGE FOOTPRINT IS
NAMED EUBRONTES AND IS THE CONNECTICUT
STATE FOSSIL.
65 MILLION YEARS AGO
A 10-KILOMETER DIAMETER ASTEROID STRUCK
EARTH NEAR THE YUCATAN PENINSULA
(CHICXULUB CRATER) IN THE GULF OF MEXICO.
MANY EARTH SCIENTISTS THINK THAT THE
RESULTING CATACLYSMS CAUSED A MASS
EXTINCTION THAT WIPED OUT MANY SPECIES,
INCLUDING DINOSAURS LIKE TYRANNOSAURUS
REX.
25,000 YEARS AGO
A GLACIER DURING THE WISCONSINAN GLACIAL
PERIOD COVERED CONNECTICUT. THE ICE MAY
HAVE BEEN SEVERAL KILOMETERS (OVER A MILE)
THICK IN PLACES.
20,000 TO 12,000 YEARS AGO
THE GLACIERS MELTED, UNCOVERING
CONNECTICUT. THE TERMINAL MORAINES THAT
WERE LEFT BEHIND FORMED; LONG ISLAND, BLOCK
ISLAND, MARTHA’S VINEYARD AND NANTUCKET
ISLAND.