Changes

==Fossil assemblages in the systems tract==

==Fossil assemblages in the systems tract==

In addition to the lithological features, systems tracts can possess distinctive fossil assemblages, although the composition of the population varies, depending on the sample location relative to the ST profile. The vertical succession of STs can be delineated by trends in the distribution, abundance, and diversity of fossil taxa and morphologic groups. Environmental changes within and between systems tracts may reflect changes in sea level, sedimentation, and tectonics. The general paleontological characteristics of systems tracts are as follows.

In addition to the lithological features, systems tracts can possess distinctive [[fossil assemblage]]s, although the composition of the population varies, depending on the sample location relative to the ST profile. The vertical succession of STs can be delineated by trends in the distribution, abundance, and diversity of fossil taxa and morphologic groups. Environmental changes within and between systems tracts may reflect changes in sea level, sedimentation, and [[tectonics]]. The general paleontological characteristics of systems tracts are as follows.

{| class = "wikitable"

{| class = "wikitable"

|-

|-

| Lowstand fan (basin floor fan)

| Lowstand fan (basin floor fan)

| Basin to slope, with a strong component of terrigenous input; fossils commonly include specimens that have been reworked or redeposited from upslope, with pelagic forms typically in shales between stacked lobes

| Basin to [http://www.thefreedictionary.com/continental+slope slope], with a strong component of [http://www.thefreedictionary.com/terrigenous terrigenous] input; fossils commonly include specimens that have been reworked or redeposited from upslope, with [http://www.merriam-webster.com/dictionary/pelagic pelagic] forms typically in shales between stacked lobes

|-

|-

| Lowstand wedge (slope fan and [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograding]] complex)

| Lowstand wedge (slope fan and [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograding]] complex)

| Shallow environment compared to underlying strata; upward shoaling and increasing terrestrial input, with reworked and redeposited fossils

| Shallow environment compared to underlying strata; upward shoaling and increasing terrestrial input, with reworked and redeposited fossils

|-

|-

| Shelf-margin wedge

| [http://education.nationalgeographic.com/education/encyclopedia/continental-shelf/?ar_a=1

Shelf]-margin wedge

| Shallower environment than underlying strata with little vertical environmental change within the systems tract

| Shallower environment than underlying strata with little vertical environmental change within the systems tract

|-

|-