Abstract. We compile, analyse and map all available geothermal heat flow measurements collected in and around Greenland into a new database of 419 sites and generate an accompanying spatial map. This database includes 290 sites previously reported by the International Heat Flow Commission (IHFC), for which we now standardize measurement and metadata quality. This database also includes 129 new sites, which have not been previously reported by the IHFC. These new sites consist of 88 offshore measurements and 41 onshore measurements, of which 24 are subglacial. We employ machine learning to synthesize these in situ measurements into a gridded geothermal heat flow model that is consistent across both continental and marine areas in and around Greenland. This model has a native horizontal resolution of 55 km. In comparison to five existing Greenland geothermal heat flow models, our model has the lowest mean geothermal heat flow for Greenland onshore areas (44 mW m–2). Our model’s most distinctive spatial feature is pronounced low geothermal heat flow (< 40 mW m–2) across the North Atlantic Craton of southern Greenland. Crucially, our model does not show an area of elevated heat flow that might be interpreted as remnant from the Icelandic Plume track. Finally, we discuss the substantial influence of paleoclimatic and other corrections on geothermal heat flow measurements in Greenland. The in-situ measurement database and gridded heat flow model, as well as other supporting materials, are freely available from the GEUS DataVerse (https://doi.org/10.22008/FK2/F9P03L; Colgan and Wansing, 2021).

The stratigraphy and the geological evolution of the West Greenland margin from the Labrador Sea to Baffin Bay in both the onshore and offshore areas are described. The primary data sets include seismic reflection surveys, wells, and outcrops. In addition, seabed samples, seismic refraction and magnetic data, onshore and offshore maps, and stratigraphic compilations were used. The basins of the West Greenland continental margin are described in three regions from the south to the north: southern West Greenland basins, central West Greenland basins, and northern West Greenland basins. Each region includes a description of the stratigraphy and evolution from the Archean to the Quaternary, divided into six phases: pre-rift and early extension, early rift, subsidence and rifting, late rift, drift, and post-drift. Finally, the regions are correlated and described in a tectonostratigraphic context together with analogues from the Canadian conjugate margin.

The tectonic evolution of the Labrador-Baffin Seaway began with Early Cretaceous extension between Greenland and North America, resulting in the development of basins infilled with nonmarine and shallow-marine clastic strata. The Late Cretaceous was a time of continued rifting and local subsidence, with deposition of widespread deeper water marine mud and localized sand deposits. Seafloor spreading began in the south in the Latest Cretaceous and propagated throughout the seaway by the Early Paleocene. Regional seafloor spreading coincided with the onset of significant volcanism in the Davis Strait to central West Greenland region, as well as a regional regression. A change in the spreading direction around the Paleocene- Eocene boundary, was accompanied by strike-slip motion in the Davis Strait and Baffin Bay, deformation and basin inversion, and development of regional unconformities. After seafloor spreading ceased in the late Eocene, the seaway was filled by upper Paleogene to Recent sediments, with clinoform progradation building the modern-day shelves.

Summary A play-based Yet-to-Find resource assessment of conventional hydrocarbons has been carried out for the West Greenland continental shelf that constitutes one of the last huge frontier areas of the World. The basin fill is divided into six main tectono-stratigraphic phases and eight play intervals. Source rock intervals include Ordovician, Albian, Cenomanian-Turonian, Campanian and Paleocene-Eocene. Reservoir rocks are present at virtually all stratigraphic levels. High-quality regional seals are well documented from all play intervals. Volume estimates for more than 152 structural leads have been integrated into the play analysis and the identified prospectivity has been calculated. The Yet-to-Find analysis is based on a feature (lead) density calculation approach for each of the identified play intervals calibrated with data from the most extensively explored areas (analogue areas). Based on these analogue areas the unidentified prospectivity has been calculated for the underexplored areas. Having calculated both identified and unidentified prospectivity, the roll-up of all play intervals provide the Total Mean Case Risked Recoverable MMBOE. The total Mean risked recoverable for AU1 is 5500 MMBOE, for AU2 9100 MMBOE and for AU3 2800 MMBOE. A final portfolio analysis shows which areas of the West Greenland continental margin are the most prospective for future exploration.

has incised valley, submarine canyon and turbidite sandstones as reservoirs, and Campanian and Paleocene mudstones as seal and source. The Break-up and Drift Play is subdivided into three sub-plays, including: a Lacustrine Sub-play, an Intra-basaltic Siliciclastic Sub-play and a Fractured Volcanic Sub-play. The Lacustrine Sub-play has fluvio-deltaic sandstones as reservoir and intra-formational lacustrine and delta-plain mudstones as seal. The Intra-basaltic Siliciclastic Sub-play comprise fluvial and lacustrine sandstones as reservoir and volcaniclastic or siliciclastic mudstones as seal. The Fractured Volcanic Sub-play comprises fractured, porous volcanic rocks as reservoir and intra-basaltic mudstones or tight fine-grained volcanic rocks as seal. All three sub-plays require vertical or long-distance migration of hydrocarbons from deeper-seated Cretaceous - Lower Paleocene kitchens. Because the tectonostratigraphic phases recognised in the Nuussuaq Basin can also be applied to the regional seismic mapping offshore Greenland the implications of the Nuussuaq Basin plays can be applied to the The onshore Nuussuaq Basin in central West Greenland comprises a complete Albian-Paleocene succession and as such represents the only complete rift succession outcrop analogue for the Cretaceous-Palaeogene offshore frontier basins in West Greenland. The basin fill reflects five tectonostratigraphic phases: 1) Pre-rift, 2) Albian - Early Cenomanian Early Rift, 3) Early Cenomanian - Early Campanian Thermal Subsidence, 4) Early Campanian - Early Paleocene Late Rift, and 5) Early Paleocene - Late Eocene Break-up and Drift. In addition, the succession is divided into nine tectonostratigraphic sequences (TSSs), each representing a specific configuration of depositional elements resulting mainly from tectonic events, which caused major palaeogeographic reconstruction of the basin and therefore critical to the petroleum systems. The sequences are bounded by unconformities or, in one case, by a major flooding phase. The Early Rift Phase in the Nuussuaq Basin was initiated in the Albian with development of half-grabens along N-S directed extensional faults. This phase was characterised by continued growth along extensional faults and embraces three TSSs (TSS1-3). They are characterised by alluvial fan, fandelta and lacustrine sedimentation, wave- and tidal-dominated deltaic deposition, followed by a major fall in relative sea level and canyon incision. Oil seeps indicate presence of a lacustrine/brackish-water source rock at depth. During the following Late Cenomanian - Early Campanian Thermal Subsidence Phase a regional marine drowning of the basin took place with deposition of organic-rich mudstones, followed by re-establishment of deltaic deposition in the Coniacian-Santonian (TSS4). The Early Campanian - Early Paleocene Late Rift Phase was associated with a change in stress regime, formation of NW-SE directed extensional faults, uplift of highs and a major change in depositional environments from deltaic deposition to deposition from gravity flows in a confined system of slope channels and canyons. During the initial phase, structurally-controlled turbidite channels were established in a NW-SE trending graben-like structure that acted as conduits for sediment transport into the offshore areas (TSS5). This was followed by several phases of major uplift resulting from the rise of the Proto-Icelandic Mantle Plume prior to continental break-up eventually leading to the deposition of two structurally controlled TSSs (TSS6-7) characterised by the formation of submarine and subaerial canyons that acted as conduits for huge amounts of sediments transported into the offshore areas. The Nuussuaq Basin experienced significant subsidence during the initial phase of break-up volcanism with deposition of organic-rich Lower Paleocene marine mudstones blanketing the basin followed by a thick succession of Paleocene-Eocene volcanic rocks referred to as the West Greenland Basalt Province (TSS8-9). Volcanism gradually spread eastwards eventually blocking the connection to the sea stemming up a large lake between the prograding volcanic front and the cratonic mainland to the east. Finally, when the volcanic rocks covered the entire basin, rivers were redirected, and sediments were deposited in the offshore Sisimiut Basin to the south and the Melville Bay Basin to the north. During this latest rifting and break-up phase, the Nuussuaq Basin was aborted and terminated as a failed rift basin. Four main plays have been defined based on the tectonostratigraphic subdivision: An Early Rift Play, a Thermal Subsidence Play, a Late Rift Play and a Break-up and Drift Play. The Early Rift Play has alluvial and estuarine sandstones as reservoir, Albian lacustrine/brackish-water mudstones as source rock and Cenomanian-Turonian mudstones as seal. The Thermal Subsidence Play has deltaic and shallow marine sandstones as reservoirs, Cenomanian-Turonian mudstones as source and Campanian mudstones as seal. The Late Rift Play

The East Greenland Rift Basin comprises a series of Jurassic subbasins with different crustal configurations, and somewhat different tectonic histories and styles. The roughly N–S elongated basin is exposed in central and northern East Greenland over a length of more than 600 km and a width of up to 250 km. The southernmost exposures are found in the largest subbasin in Jameson Land, while the northernmost exposures are on Store Koldewey and in Germania Land. The focus of the present revision is on the Jurassic, but the uppermost Triassic and lowermost Cretaceous successions are included as they are genetically related to the Jurassic succession. The whole succession forms an overall transgressive–regressive megacycle with the highest sea level and maximum transgression in the Kimmeridgian. The latest Triassic – Early Jurassic was a time of tectonic quiescence in East Greenland. Lower Jurassic deposits are up to about 950 m thick and are restricted to Jameson Land and a small down-faulted outlier in southernmost Liverpool Land. The Lower Jurassic succession forms an overall stratigraphic layer-cake package that records a shift from Rhaetian–Sinemurian fluvio-lacustrine to Pliensbachian – early Bajocian mainly shallow marine sedimentation. Onset of rifting in the late Bajocian resulted in complete reorganisation of basin configuration and drainage patterns, and the depositional basin expanded far towards the north. Post-lower Bajocian early-rift deposits are up to about 500–600 m thick and are exposed in Jameson Land, Liverpool Land, Milne Land, Traill Ø, Geographical Society Ø, Hold with Hope, Clavering Ø, Wollaston Forland, Kuhn Ø, Th. Thomsen Land, Hochstetter Forland, Store Koldewey and Germania Land. Upper Jurassic rift-climax strata reach thicknesses of several kilometres and are exposed in the same areas with the exception of Liverpool Land and Germania Land. In the southern part of the basin, the upper Bajocian – Kimmeridgian succession consists of stepwise backstepping units starting with shallow marine sandstones and ending with relatively deep marine mudstones in some places with sandy gravity-flow deposits and injectites. In the Jameson Land and Milne Land Subbasins, the uppermost Jurassic – lowermost Cretaceous (Volgian–Ryazanian) succession consists of forestepping stacked shelf-margin sandstone bodies with associated slope and basinal mudstones and mass-flow sandstones. North of Jameson Land, block-faulting and tilting began in the late Bajocian and culminated in the middle Volgian with formation of strongly tilted fault blocks, and the succession records continued stepwise deepening. In the Wollaston Forland – Kuhn Ø area, the Volgian is represented by a thick wedge of deep-water conglomerates and pebbly sandstones passing basinwards into mudstones deposited in fault-attached slope aprons and coalescent submarine fans. The lithostratigraphic scheme established mainly in the 1970s and early 1980s is here revised on the basis of work undertaken over subsequent years. The entire Jurassic succession, including the uppermost Triassic (Rhaetian) and lowermost Cretaceous (Ryazanian–Hauterivian), forms the Jameson Land Supergroup. The supergroup is subdivided into the Kap Stewart, Neill Klinter, Vardekløft, Hall Bredning, and Wollaston Forland Groups, which are subdivided into 25 formations and 48 members. Many of these are revised, and 3 new formations and 14 new members are introduced.

Studies of basement‐bounded canyons in West Greenland show that these were long‐lasting features that extended inland for several hundreds of kilometres, acting as prominent sediment conduits sourcing the Albian–Palaeocene Nuussuaq Basin during several phases of basin evolution. The Ilulissat Icefjord canyon was the major conduit for sediment into the basin and provenance data indicate that it had a huge catchment area that extended to East Greenland. The Uparuaqqusuitsut canyon was also an important conduit for sediment in the northern part of the basin. It is suggested that the initial canyon formation occurred during uplift events in the Late Triassic and Late Jurassic when the deeply weathered basement surface formed during Early–Middle Triassic time was eroded. The recognition of these canyons as long‐lasting sediment conduits have huge implications for understanding the sediment distribution, source‐to‐sink studies and the palaeogeography of the North Atlantic basins.

The Nuussuaq Basin in West Greenland has an obvious exploration potential. Most of the critical elements are well documented, including structures that could form traps, reservoir rocks, seals and oil and gas seepage that documents petroleum generation. And yet, we still lack a full understanding of the petroleum systems, especially the distribution of mature source rocks in the subsurface and the vertical and lateral migration of petroleum into traps. A recently proposed anticlinal structural model could be very interesting for exploration if evidence of source rocks and migration pathways can be found. In this paper, we review all existing, mostly unpublished, data on gas observations from Nuussuaq. Furthermore, we present new oil and gas seepage data from the vicinity of the anticline. Occurrence of gas within a few kilometres on both sides of the mapped anticline has a strong thermogenic fingerprint, suggesting an origin from oil-prone source rocks with a relatively low thermal maturity. Petroleum was extracted from an oil-stained hyaloclastite sample collected in the Aaffarsuaq valley in 2019, close to the anticline. Biomarker analyses revealed the oil to be a variety of the previously characterised “Niaqornaarsuk type,” reported to be formed from Campanian-age source rocks. Our new analysis places the “Niaqornaarsuk type” 10 km from previously documented occurrences and further supports the existence of Campanian age deposits developed in source rock facies in the region.

Summary Good analogues are keys for better understanding petroleum systems in frontier basins and new plays in proven basins. Recent discoveries have proven Permian carbonate plays (e.g. 7120/1–3 and 7220/11-1) in the Norwegian Barents Sea and Triassic siliciclastic plays (e.g. Goliat, Tornerose and Alke Sør) in the North Atlantic. Permian and Triassic plays have been unsuccessfully tested on the Mid-Norwegian continental shelf (M-NCS), but these plays have recently attracted renewed attention. However, the lack of offshore core data from this interval provides a major obstacle in developing valid play models. On the conjugate East and Northeast Greenland margin, excellent outcrops and a large number of shallow fully cored boreholes document the syn- to post-rift Permian–Triassic interval. Data from this interval in East and Northeast Greenland thus provide important constrains on key elements for new play models on the M-NCS. The presentation will provide observations from East and Northeast Greenland that may help to assist the definition of play models for the Permian–Triassic succession in the M-NCS and place them in a tectono-stratigraphic context.

The Glenlivet gas discovery made by DONG E&P and partners (Faroe Petroleum and First Oil) in 2009 is one of the most recent discoveries in the offshore West of Shetland region. The exploration target was an amplitude-supported stratigraphic prospect, and the discovery well 214/30a-2 proved the pre-drill model by finding gas-bearing Late Palaeocene sandstones of excellent quality in the Vaila Formation. The exploration success challenged the exploration history of the Faroe-Shetland Basin, where a number of amplitude-driven stratigraphic prospects led to exploration failures in the 1990s. The prospect was identified by means of high quality 3D seismic data and improved petrophysical and seismic understanding combined with regional mapping of the Vaila Formation sandstones. A detailed sedimentological and biostratigraphic understanding of the Palaeocene succession, in conjunction with the above, helped to de-risk the prospect and led to successful drilling.

In 2009 DONG and partners, Faroe Petroleum and First Oil, made a gas discovery at the Glenlivet prospect in block 214/30a West of Shetland. The discovery well found excellent gas bearing sandstone in the Upper Paleocene Vaila Formation. The exploration success challenged the exploration history of the Faroe-Shetland basin where a number of amplitude driven stratigraphic prospects had led to failures. The Glenlivet prospect was identified by means of high quality 3D data, improved petrophysical and seismic understanding combined with regional mapping of Vaila sandstones. The Glenlivet gas sand is a typical class 3 AVO showing bright amplitudes on all offsets but with increasing amplitude at far offsets. Amplitude response was supported by the depositional model predicting a valid stratigraphic trap with turbidite sandstones pinching-out towards an underlying mud-dominated slope. High quality Vaila sandstone encountered in the nearby well 214/29-1 was used as analogue and petrophysical analysis, fluid substitution and AVO modelling of this sand aided the maturation of the Glenlivet prospect.

The Nuussuaq Basin is the only exposed Cretaceous–Paleocene sedimentary basin in West Greenland and is one of a complex of linked rift basins stretching from the Labrador Sea to northern Baffin Bay. These basins developed along West Greenland as a result of the opening of the Labrador Sea in Late Mesozoic to Early Cenozoic times. The Nuussuaq Basin is exposed in West Greenland between 69°N and 72°N on Disko, Nuussuaq, Upernivik Ø, Qeqertarsuaq, Itsaku and Svartenhuk Halvø and has also been recorded in a number of shallow and deep wells in the region. The sediments are assigned to the more than 6 km thick Nuussuaq Group (new) which underlies the Palaeogene plateau basalts of the West Greenland Basalt Group. The sediment thickness is best estimated from seismic data; in the western part of the area, seismic and magnetic data suggest that the succession is at least 6 km and possibly as much as 10 km thick. The exposed Albian–Paleocene part of the succession testifies to two main episodes of regional rifting and basin development: an Early Cretaceous and a Late Cretaceous – Early Paleocene episode prior to the start of sea-floor spreading in mid-Paleocene time. This exposed section includes fan delta, fluviodeltaic, shelfal and deep marine deposits. The Nuussuaq Group is divided into ten formations, most of which have previously been only briefly described, with the exception of their macrofossil content. In ascending stratigraphic order, the formations are: the Kome Formation, the Slibestensfjeldet Formation (new), the Upernivik Næs Formation, the Atane Formation (including four new members – the Skansen, Ravn Kløft, Kingittoq and Qilakitsoq Members – and one new bed, the Itivnera Bed), the Itilli Formation (new, including four new members, the Anariartorfik, Umiivik, Kussinerujuk and Aaffarsuaq Members), the Kangilia Formation (including the redefined Annertuneq Conglomerate Member and the new Oyster–Ammonite Conglomerate Bed), the Quikavsak Formation (including three new members: the Tupaasat, Nuuk Qiterleq and Paatuutkløften Members), the Agatdal Formation, the Eqalulik Formation (new, including the Abraham Member), and the Atanikerluk Formation (including five members: the Naujât, Akunneq (new), Pingu (new), Umiussat and Assoq (new) Members).

As a result of a lithological, sedimentological and biostratigraphic study of well sections from the Danish sector of the North Sea, including some recently drilled exploration wells on the Ringkøbing–Fyn High, the lithostratigraphic framework for the siliciclastic Palaeogene to Lower Neogene sediments of the Danish sector of the North Sea is revised. The sediment package from the top of the Chalk Group to the base of the Nordland Group is subdivided into seven formations containing eleven new members. The existing Våle, Lista, Sele, Fur, Balder, Horda and Lark Formations of previously published lithostratigraphic schemes are adequate for a subdivision of the Danish sector at formation level. Bor is a new sandstone member of the Våle Formation. The Lista Formation is subdivided into three new mudstone members: Vile, Ve and Bue, and three new sandstone members: Tyr, Idun and Rind. Kolga is a new sandstone member of the Sele Formation. Hefring is a new sandstone member of the Horda Formation. Freja and Dufa are two new sandstone members of the Lark Formation. Danish reference sections are established for the formations, and the descriptions of their lithology, biostratigraphy, age and palaeoenvironmental setting are updated.

As a result of a lithological, sedimentological and biostratigraphic study of well sections from the Danish sector of the North Sea, including some recently drilled exploration wells on the Ringkøbing–Fyn High, the lithostratigraphic framework for the siliciclastic Palaeogene to Lower Neogene sediments of the Danish sector of the North Sea is revised. The sediment package from the top of the Chalk Group to the base of the Nordland Group is subdivided into seven formations containing eleven new members. The existing Våle, Lista, Sele, Fur, Balder, Horda and Lark Formations of previously published lithostratigraphic schemes are adequate for a subdivision of the Danish sector at formation level. Bor is a new sandstone member of the Våle Formation. The Lista Formation is subdivided into three new mudstone members: Vile, Ve and Bue, and three new sandstone members: Tyr, Idun and Rind. Kolga is a new sandstone member of the Sele Formation. Hefring is a new sandstone member of the Horda Formation. Freja and Dufa are two new sandstone members of the Lark Formation. Danish reference sections are established for the formations, and the descriptions of their lithology, biostratigraphy, age and palaeoenvironmental setting are updated.