How long did the Sauk sequence last?

recognized of these are the Sauk Sequence (Late Precambrian to mid-Ordovician; about 650 to 460 million years ago), the Tippecanoe Sequence (mid-Ordovician to Early Devonian; about 460 to 400 million years ago), the Kaskaskia Sequence (Early Devonian to mid-Carboniferous; about 408 to 320 million years ago), and the …

When did the Sauk sequence start?

The Sauk sequence in Illinois consists of Cambrian and Lower Ordovician rocks deposited approximately 543 to 490 million years ago (mya).

When give the periods and the years did the Sauk sea cover much of the United States?

It dates from the late Proterozoic through the early Ordovician periods, though the marine transgression did not begin in earnest until the middle Cambrian. At its peak, most of North America was covered by the shallow Sauk Sea, save for parts of the Canadian Shield and the islands of the Transcontinental Arch.

When did the Tippecanoe sequence end?

The massive evaporite deposits of the Michigan Basin were created during this period. The Tippecanoe sequence ended with a regression in the early Devonian, to be followed later by the Kaskaskia sequence.

When was the Sauk transgression?

Sauk transgression(s)

The 530–520 Myr middle Sixtymile Formation is similar in age to the middle/upper Wood Canyon Formation (ref. ³⁶; their data repository) west of the continental hingeline (Fig. 2).

What caused the Sauk sequence?

– the continents have been flooded periodically throughout the Phanerozoic. Transgressions yield thick sequences (Sauk, Tippecanoe, etc.) of shallow marine sediments on the craton and probably result from periods of fast seafloor spreading.

What happened during the Sauk sequence?

The sauk sequence was terminated abruptly about 490 million years ago when sea level suddenly dropped (on geological timescales, taking a few million years), leading to widespread erosion and the formation of a worldwide unconformity surface on top of the sauk sequence.

What are Sloss sequences?

DEFINITION: The Sauk Sequence (Sloss and others, 1949) comprises those strata that overlie an interregional conformity cut on late Pre- cambrian and older rocks and underlie an Page 4 96 L. L. SLOSS—SEQUENCES IN CRATONIC INTERIOR OF NORTH AMERICA interregional unconformity at the base of the succeeding Tippecanoe …

Why the basal Sauk sandstone is so mature?

Basal Sauk units almost everywhere are mature sand- stones, probably derived from reworkings of the Pre- cambrian rocks of the Canadian Shield and the cratonic platfonn. Because of the long-tenn gradual submergence of the craton, basal Sauk sands range in age from late Pre- cambrian to Late Cambrian.

Where is the Sauk sequence?

The Sauk Sequence consists of all strata between the unconformity on the top of the Precambrian rocks and the sub-Tippecanoe unconformity at the base of the St. Peter Sandstone or Everton Formation.

What happened during the Taconic Orogeny?

In the Appalachians, the Taconic orogeny produced angular unconformities (interruptions in the deposition of sedimentary rock) in the Appalachian Basin and the Taconic Allochthon in New York, and it also caused igneous intrusions and regional metamorphism in the northern and southern Appalachians.

Which of these cratonic sequences began in the Cambrian?

There have been six cratonic sequences since the beginning of the Cambrian Period. For North America, from oldest to youngest, they are the Sauk, Tippecanoe, Kaskaskia, Absaroka, Zuñi, and the Tejas.

What rocks are typical of the Kaskaskia sequence?

The Kaskaskia sequence is dominated by carbonate rock but also contains siliciclastics—shale, siltstone, and sandstone. These rocks were deposited in the Illinois Basin over a pe- riod of about 60 million years.

How long did the Sauk sequence last quizlet?

How long did the Sauk sequence last? From the Neoproterozoic to the Early Ordovician.

How long did the Absaroka sequence last?

The first order cycle being the Absaroka, the second being the Carboniferous Period, and third order being rock formations or groups which are generally 8 to 10 million years long.

Which orogenic processes affected the Absaroka sequence?

Which orogenic processes affected the Absaroka sequence? The Appalachian orogeny to the east and the Ouachita orogeny to the south.

What is the difference between orogeny and epeirogeny?

orogenic forces are that forces which means block making . they make Block mountains. epeirogenic forces are that forces which are continent making they make continent.

What are orogenic and epeirogenic movements?

orogenic processes involving mountain building through severe folding and affecting long and narrow belts of the earth’s crust. epeirogenic processes involving uplift or warping of large parts of the earth’s crust. earthquakes involving local relatively minor movements.

How are Cyclothem formed?

Cyclothems are cyclic stratigraphic sequences that are unique to the Pennsylvanian and earliest Permian periods within the US Midcontinent, that formed as a result of marine transgressions and regressions (rise and fall of sea level) related to the waning and waxing of ice sheets at the South Pole.

Why are cyclothems important?

Cyclothems are significant because they can be used to date rocks and identify petroleum deposits. Wanless had a hypothesis in 1926 that the Pennsylvanian beds were compiled and consisted of repeated series of beds later termed cyclothems which are composed of a similar succession of units.

What are cyclothems and when are they common in the rock record?

Cyclothems are repetitious sequences that occur repeatedly in the Permo-Pennsylvanian (Absaroka). The classic cyclothem records a single advance and retreat of the sea in an area, giving rise to a symmetrical rock cycle of non-marine to marine to non-marine sediments; however, the ideal seldom occurs.

What is Walther’s law of succession of facies?

Walther’s Law states that any vertical progression of facies is the result of a succession of depositional environments that are laterally juxtaposed to each other.

What is progradation in geology?

Progradation is the diagnostic depositional trend for regressions, and is defined as the building forward or outward toward the sea of a shoreline or coastline (as of a beach, delta, or fan) by nearshore deposition of river-borne sediments or by continuous accumulation of beach material thrown up by waves or moved by …

What is Chrono correlation?

Chronostratigraphy is the branch of geology that studies the age of rock strata in relation to time. The basic idea is to correlate which rocks around the world formed at the same time in an effort to reconstruct past events and determine depositional environments in Earth history.

What is law of original horizontality?

The Principle of Original Horizontality states: Layers of rocks deposited from above, such as sediments and lava flows, are originally laid down horizontally.

What is the oldest rock layer?

bottom layer

Over time, the sediments pile up to form horizontal layers of sedimentary rocks. The bottom layer of rock forms first, which means it is oldest. Each layer above that is younger, and the top layer is youngest of all.

What does the Law of cross cutting state?

Described by Scotsman James Hutton (1726 – 1997), the Law of Crosscutting Relationships stated that if a fault or other body of rock cuts through another body of rock then it must be younger in age than the rock through which it cuts and displaces.