Burial and exhumation history of the Labrador- Newfoundland margin. - PowerPoint PPT Presentation

2719231 Burial and exhumation history of the Labrador- Newfoundland margin. Implications for hydrocarbon exploration on the Grand Banks and on the Labrador Shelf Peter Japsen 1 , Paul F . Green 2 Johan M. Bonow 3 , Alana M. Hinchey 5 & Derek H.C. Wilton 6 1 Geol. Surv. Denmark, Greenland (GEUS), 2 Geotrack International, 3 Geovisiona, 4 Geol. Surv. Labrador, Newfoundland, 5 Memorial University of Newfoundland Geological Survey of Denmark and Greenland Danish Ministry of Climate, Energy and Building 15-18 October 2017 » AAPG London

BACKGROUND

Elevated, passive continental margins (EPCMs): Common features. Common origin? Japsen et al. 2012; Green et al. 2013

Studies of uplift and erosion along EPCMs 2006 2014 2007,16 2012 2016 Publication Unpublished

Permanent vs episodic uplift Japsen et al. 2012

PRE-CRETACEOUS AND CENOZOIC UPLIFT AND EROSION OF LABRADOR

Labrador and Newfoundland margin Moderate elevations Max. 1700 m asl

Similar landscapes on the conjugate margins across the Labrador Sea Torngat Mountains, Labrador: Disko, West Greenland: Elevated plain cut by a deep valley Elevated plain across Paleocene basalt. Result of mid-Cenozoic planation followed by late Neogene uplift (Japsen et al. 2006)

Labrador and Newfoundland Pre-Mesozoic rocks Seismic line dominate onshore Paleogene Paleogene and Cretaceous Precambrian strata truncated towards the landmass Cretaceous

Post-Eocene tiling and truncation towards Labrador 5 : late Eocene. 4 : base Eocene. 3 : mid-Paleocene. 2’ : Late Cretaceous. 2 : mid-Cretaceous. 1 : top basement. Sand-prone units: Gold and yellow colours. Dickie et al. 2011, Mar. Petrol. Geol.

Cretaceous outlier ⇒ pre-Cretaceous denudation Schefferville Albian, Cenomanian Dorf 1967, Psyche

Cooling history of rocks on the coast of northern Labrador from AFTA Pilot study sponsored by the Geological Survey of Newfoundland and Labrador: Apatite Fission-Track Analysis 11 basement samples 1 latest Precambrian sediment samles

MIOCENE EXHUMATION OF THE LABRADOR SHELF

Miocene hiatus across much of the Labrador shelf Ainsworth et al. 2014 Nalcor report

Lithostratigraphic chart Labrador Shelf (Nalcor 2016)

Lithostratigraphic chart Labrador Shelf Beaufort unc. (Nalcor 2016) Miocene hiatus Avalon unc. Mid-Cretaceous hiatus Labrador unc. Base-Cretaceous hiatus

Hopedale E-33 & S. Hopedale L-39 wells ~750 m Miocene section removed? DTH - Default thermal history: Maturity profile predicted if all units are at maximum post-depositional temperatures

Hopedale E-33 & S. Hopedale L-39 wells ~750 m Miocene section removed? -dZ B , Burial anomaly = 500 m B E, Post-Mokami reburial = 200 m Japsen et al. 2007, Geoph. Prosp. dZ B Missing section = 700 m

Hopedale E-33 Possible burial reconstruction Burial History Reconstruction based on the assumption that maximum burial occurred in the late Miocene • Deposition of 750 m Miocene sediments • Removal of these sediments in the late? Miocene Max temps pre-Neogene section

Chronostratigraphic chart Labrador Shelf (Balkwill et al. 1990)

Onset of Upper Saglek progradation Hiatus Late? Miocene exhumation Onset of Lower Saglek progradation “Coarse grained quartz and igneous clasts, which first appeared in the mid-Tertiary in the upper Mokami member, are evidence of the first phase of the uplift of coastal Labrador Chronostratigraphic chart in the late Oligocene to early Miocene ” Labrador Shelf (Balkwill et al. 1990)

Sketch of the Neogene development of Labrador and the Labrador Shelf 1. Uplift of Labrador near base Miocene Onset of lower Saglek progradation • Up to 1 km burial of the shelf • 2. Exhumation in the late? Miocene Removal of up to 1 km thick cover , ~lower Saglek/ upper Mokami • (all the Miocene) in many wells Shelf-wide erosion • 3. Uplift of Labrador near base Pliocene Onset of upper Saglek progradation • Burial of the shelf (up to 1 km) •

BASE-TERTIARY EXHUMATION IN THE GRAND BANKS REGION?

Lithostratigraphic chart Jeanne d’Arc Basin Husky 2015 West Flying Foam L-23

Burial history and VR data. Grand Banks well West Flying Foam L-23 Default thermal history for 25C/km Burial history produced from the lithostratigraphic Default thermal history: Maturity profile predicted if all breakdown obtained from the ‘BASIN Database’. units are at maximum post-depositional temperatures

Burial history and VR data Grand Banks well West Flying Foam L-23 Profile involving 2 periods of deeper burial Default thermal history for 25C/km Max temps pre-Cret. section Burial history reconstruction required to explain Maturity profile (red line) predicted by the burial the GSC VR data history reconstruction

Conclusions Evidence for vertical movements both prior to and after break- up along the margin of Labrador and Newfoundland  Pre-Cretaceous denudation, onshore and offshore  Early Miocene uplift and erosion of Labrador; prograding wedges offshore  Late? Miocene exhumation offshore Labrador  Pliocene uplift and erosion of Labrador; prograding wedges offshore  Possibly base-Tertiary exhumation, Grand Banks