Citation:

2007PA001473

Name: (Table S1) FMR and rock magnetic parameters for upper Paleocene to lower Eocene strata, Site Ancora
Published: 2007
License: https://creativecommons.org/licenses/by/3.0/

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Published: 2007 (exact date unknown) • DOI registered: 2014-06-16

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Abstract:

Previous workers identified a magnetically anomalous clay layer deposited on the northern United States Atlantic Coastal Plain during the Paleocene-Eocene thermal maximum (PETM). The finding inspired the highly controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR), isothermal and anhysteretic remanent magnetization, first-order reversal curve, and transmission electron microscopy analyses of late Paleocene and early Eocene sediments in drill core from Ancora, New Jersey. A novel paleogeographic analysis applying a recent paleomagnetic pole from the Faeroe Islands indicates that New Jersey during the initial Eocene had a ~6°-9° lower paleolatitude (~27.3° for Ancora) and a more zonal shoreline trace than in conventional reconstructions. Our investigations of the PETM clay from Ancora reveal abundant magnetite nanoparticles bearing signature traits of crystals produced by magnetotactic bacteria. This result, the first identification of ancient biogenic magnetite using FMR, argues that the anomalous magnetic properties of the PETM sediments are not produced by an impact. They instead reflect environmental changes along the eastern margin of North America during the PETM that led to enhanced production and/or preservation of magnetofossils.

Project(s):

Ocean Drilling Program (ODP)

Coverage:

Latitude: 39.692220 * Longitude: -74.849020

Date/Time Start: 1998-07-08T00:00:00 * Date/Time End: 1998-07-08T00:00:00

Minimum DEPTH, sediment/rock: 164.33 m * Maximum DEPTH, sediment/rock: 172.46 m

Event(s):

Ancora * Latitude: 39.692220 * Longitude: -74.849020 * Date/Time: 1998-07-08T00:00:00 * Elevation: 31.6 m * Location: New Jersey * Campaign: * Method/Device: Drilling/drill rig (DRILL)

Comment:

DEPTH, sediment/rock [m] is given in mbsf.

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator	Comment
1	DEPTH, sediment/rock	Depth sed	m		Geocode
2	Description	Description		Kopp, Robert E
3	Absorption	Absorp	arbitrary units	Kopp, Robert E	total ferromagnetic resonance absorption
4	Factor	Factor		Kopp, Robert E	effective g factor of absorption peak
5	Ratio	Ratio		Kopp, Robert E	ferromagnetic resonance asymmetry ratio A (Delta B(low)/Delta B(high))
6	-	-		Kopp, Robert E	Delta B(FWHM) = full width at half maximum (Delta B(low) + Delta B(high)) [mT]
7	Factor	Factor		Kopp, Robert E	empirical discriminant factor alpha (= 0.17A + 9.8
8	Saturation isothermal remanent magnetization	SIRM	10^-6 A m²/kg	Kopp, Robert E	determined after 350 mT pulse
9	Coercivity of remanence	Bcr	mT	Kopp, Robert E	determined from the intersection of the IRM acquisition and demagnetization curves
10	ARM/IRM	ARM/IRM		Kopp, Robert E	ARM assessed in 100 mT AF field and 0.1 mT DC biasing field, IRM acquired in 100 mT field

License:

Creative Commons Attribution 3.0 Unported (CC-BY-3.0)

Size:

219 data points

Data

Download dataset as tab-delimited text — use the following character encoding:

1 Depth sed [m]	2 Description	3 Absorp [arbitrary units] (total ferromagnetic resonance...)	4 Factor (effective g factor of absorpt...)	5 Ratio (ferromagnetic resonance asymm...)	6 - (Delta B(FWHM) = full width at...)	7 Factor (empirical discriminant factor...)	8 SIRM [10^-6 A m²/kg] (determined after 350 mT pulse)	9 Bcr [mT] (determined from the intersect...)	10 ARM/IRM (ARM assessed in 100 mT AF fie...)
164.33	Eocene silt	47	2.062	0.90	250	0.40
165.20	Eocene silt	39	2.059	0.89	255	0.40	82	77.5	0.0008
165.41	Eocene silt	44	2.065	0.91	248	0.40
165.55	late PETM transitional clay	64	1.970	0.69	193	0.31	82	65.3	0.0028
165.81	late PETM transitional sand lens	97	2.030	0.73	212	0.33
165.81	late PETM transitional clay	101	2.030	0.72	215	0.33
166.08	late PETM transitional clay	123	2.000	0.68	201	0.31	82	68.7	0.0027
167.70	PETM clay	189	1.993	0.69	178	0.29
168.17	PETM clay	212	2.000	0.70	183	0.30	82	54.9	0.0027
168.23	PETM clay	74	1.993	0.70	170	0.28
168.54	PETM clay	205	2.020	0.71	182	0.30
168.81	PETM clay	156	2.012	0.69	185	0.30	82	61.4	0.0027
168.82	PETM clay	171	2.010	0.70	190	0.30
169.11	PETM clay	206	1.997	0.69	182	0.30	82	53.0	0.0027
169.53	PETM clay	167	2.027	0.74	179	0.30
169.89	PETM clay	124	1.993	0.67	179	0.29
170.03	PETM clay	196	2.031	0.75	170	0.29
170.11	PETM clay	182	2.004	0.71	181	0.30
170.41	PETM clay	195	2.014	0.70	176	0.29
170.56	PETM clay	176	2.000	0.68	181	0.29
170.79	PETM clay	141	2.004	0.69	188	0.30
170.91	PETM clay	162	2.017	0.74	164	0.29	82	64.4	0.0032
171.06	early PETM transitional clay	142	2.024	0.73	205	0.33	82	?62.2	0.0021
171.22	early PETM transitional clay	135	2.044	0.75	215	0.34
171.25	early PETM transitional clay	147	2.031	0.75	210	0.33
171.36	Paleocene silt	128	2.062	0.92	233	0.38
171.53	Paleocene silt	102	2.120	1.06	237	0.41
171.62	Paleocene silt	112	2.071	0.99	232	0.40
171.87	Paleocene silt	88	2.055	0.95	234	0.39
171.95	Paleocene silt	105	2.055	0.95	238	0.40
172.22	Paleocene silt	94	2.084	0.98	223	0.39
172.46	Paleocene silt	110	2.084	1.04	235	0.41	82	72.3	0.0006