Med

.

Fine

V. F

ine

Silt

Cla

y

1

2

3

4

5

6

10

9

8

7

15

14

13

12

11

18

19

17

16

20

1

6

2

3

5

9

8

7

11

17

15

14

21

19

18

Med

.

Fine

V. F

ine

Silt

Cla

y

1

2

3

4

5

6

10

9

8

7

15

14

13

12

11

18

19

17

16

20

1

6

2

3

5

9

8

7

11

17

15

14

21

19

18

Metlars M

ember

Livingston Mem

ber

Trough Crossbeds / Laminations

Carbonate Nodules

M

Tabular Crossbeds/laminations

Massive BeddingClimbing Current RipplesScour

Desiccation Cracks

Horizontal BurrowsVertical BurrowsRoot CastsPlanar Laminations

Surface Ripples

Soft Sediment Deformation

Mud Chips

Wavy Bedding

Fluvial Depositional Styles and Fluvial Lacustrine Transition Zones of the Passaic Formation, Newark Basin. Joshua H. Long, Dr. S.J. Friedmann

Med

.

Fine

V. F

ine

Silt

Cla

y

1

2

3

4

5

6

10

9

8

7

15

14

13

12

11

18

19

17

16

24

23

22

21

20

26

25

27

1

6

7

2

4

3

5

8

13

10

9

12

11

14

15

18

17

16

19

21

20

2223

24

26

25

2728

2930313233

34

35

3736

3839

41 40

42

43441 4444

4

6

5

7

8

91011

12

14

13

15

Roadside Q

uarry

M

M

M

M

Depth (m)

Med

.

Fine

V. F

ine

Silt

Cla

y

1

2

3

4

5

6

10

9

8

7

15

14

13

12

11

18

19

17

16

24

23

22

21

20

26

25

27

1

6

7

2

4

3

5

8

13

10

9

12

11

14

15

18

17

16

19

21

20

2223

24

26

25

2728

2930313233

34

35

3736

3839

41 40

42

43441 4444

4

6

5

7

8

91011

12

14

13

15

Roadside Q

uarry

M

M

M

M

Depth (m) Roadside Q

uarry (2)R

ailroad Cut (1)

Railroad Cut (Upper), Location #1

a) b) c)

a) Mud draped tabular sandbeds. b) Climbing current ripples, planar laminations. c) Thin intervening mud beds.

Pebbles Bluff, Location #4

Grain Size Trends

0

200

400

600

800

1000

1200

1400

1600

1800

Mud Silt VeryFine

Lower

VeryFine

Upper

FineLower

Fineupper

MediumLower

Grain SIze

Cum

ulat

ive

Thic

knes

s (c

m)

Railroad cutRaodside quarryTrap RockPebbles BluffSomerset Core

Grain Size

Cum

ulative Thickness (cm)

Abstract The sediments within the Newark Basin contain a record of cyclic deposition at multiple frequencies. Due to their pronounced cyclicity and climatic sensitivity the lacustrine deposits within the basin have been the focus of many basin studies. While the lake deposits are well documented, relatively little is known about the fluvial systems that carried water and sediments to these ancient lakes. Locally, fluvial sediments can be coarse- grained and channelized, and are believed to represent deposition in coarse-grained braided systems, notably in the Stockton and Passaic. Such deposits can be limited to areas proximal to the main border fault system and were noted for this project in the Pebbles Bluff exposure of the LM Member of the Passaic Formation. However, there are many relatively fine-grained, thin-bedded sandy fluvial deposits that show little evidence for channeling and amalgamation. The system evolves through nodal avulsion and the construction of crevasse and terminal splays. Outcrop observations of the Metlars and Livingston Members of the Passaic Formation show that the non-lacustrine, relatively coarser grained facies are dominated by extensive tabular sandsheets whose geometries, structures and range of grain sizes are consistent with deposition in anastomosed fluvial networks, similar to those of the Okavango Delta in Botswana. The Okavango lies within a half-graben in the southernmost extension of the East African Rift system. Paleogeographic reconstructions, using paleomagnetic and paleoclimatic data taken from lacustrine deposits, have placed the Newark Basin at roughly 20°north latitude during the late Triassic and early Jurassic, which is similar in climate to the 20°south latitude position of the present-day Okavango. As such, the Okavango may serve as a general analog for the fluvial members of the Passaic Formation in terms of hydrology and architectural evolution.

Methods

•Data collected in the field compiled in the form of measured sections.

•Photopan analyses.

•Core observations

Hypotheses

Coarse grained facies within the Passaic Formation are:

•Dominated by braided streams

•Dominated by anastomosed streams

•Exhibit characteristics of both braided and anastomosed streams

Conclusions

•Fluvial deposits within the Passaic exhibit structures, geometries and characteristics of meandering, braided and anastomosed fluvial depositional systems.

Interpretations

•Locations 1 &2: Proximal & Distal Lacustrine Deltaic Deep, Perennial Lacustrine Missing Interval (?) Anastomosed Crevasse Splay Deposits Shallow, Ephemeral Lacustrine Lacustrine Deltaic Deep,Perrenial Lacustrine.

•Location 4: Meandering Fluvial Shallow, Ephemeral Lacustrine Lacustrine Deltaic

Somerset #1 Core

Six sub environments of anastomosed systems (Smith &Putnam, 1980):1. Backswamp: Organic silty mud. 2. Peat Bog: Variable amounts of organic debris.3. Ephemeral Floodpond: Very fine grained laminated and wave rippled lacustrine sediments with

Mudcracked exposure surfaces.4. Channel: Shallow, low relief sand lenses. Often contain climbing ripples and planar-crossbeds.5. Levee systems: Variable amounts of organic material.6. Crevasse: Laterally extensive, tabular sand sheets up to 1 meter thick. Constitute the bulk of

the silt sand size component of anastomosed systems. Structures include, climbing current ripples, planar bedding/laminations and wave rippled mud surfaces indicating submergence in shallow water after deposition in deccelerative flow (Naydon, 1994)..

-Nadon 1994

Okavango River, Botswana

Channel

Crevasse Splay Sands

Flood Pond

Epsilon Crossbeds

Med

.

Fine

V. F

ine

Silt

Cla

y

1

2

3

4

5

6

10

9

8

7

14

13

12

11

10

1

3

2

4

M

M

11

14

1213

18

15

17

19

20

2223

21

31

2524

M

M

M

Med

.

Fine

V. F

ine

Silt

Cla

y

1

2

3

4

5

6

10

9

8

7

14

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11

10

1

3

2

4

M

M

11

14

1213

18

15

17

1919

2020

2223

21

31

2524

MM

M

MM

Pebbles Bluff (4)Red Strata

Gray Strata

Purple Strata

Field Locations 1, 2, 3

Pebbles Bluff Location

Somerset Core

-Olsen et al., 1996

Deltaic TurbiditesCurrent Ripples

Planar Bedding

Massive bedding Shallow Lacustrine Muds

Roadside Quarry, Location #2

a) b)

a) Tabular crossbeds overlain by planar laminations

b) Polygonal desiccation cracks.

Railroad Cut (Middle), Location #1

a) b) c)

a) Desiccation cracks b) Soft sediment deformation c) Root casts

References

Nadon, G.C. The Genesis and Recognition of Anastomosed Fluvial Deposits:Data From the St. Mary’s River Formation, South Western Alberta, Canada. Journal of Sedimentary Research. Vol.B64, No. 4

Olsen, P.E., Kent, D.V., Cornet, B., Witte, W.K., Schlische, R.W., High-Resolution Stratigraphy of the Newark Basin. Geological Society of America Bulletin: January 1996; Vol. 108; no. 1;p. 40-77.

Smith, D.G., Putnam, P.E. Anastomosed River Deposits; Modern and Ancient Examples in Alberta, Canada. National Research Council of Canada. 008-4077/80/101396

Acknowledgements

Dr. S. J. Friedmann for his support and guidance.

Dr. Jim Browning, Dr. Roy Schlische and their graduate students at Rutgers University for their help with the Newark Basin cores.

Dr. Phil Candela and Dr. John Merck

Laura Gilbert for her help in the field.

Field Locations 1, 2, 3

Pebbles Bluff Location

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