HomeScience

Science

Learn! Blog

Having access to digital geological data, along with access to new platforms and environments, is critical as our world comes together for positive transformation and teamwork. Today, we have a unique opportunity to speak with the leadership of the Deep-Time Digital Earth Project (DDE), who have taken the time to introduce us to its mission and its resources.

American Association of Petroleum Geologists (AAPG)
Asia Pacific Blog

AAPG Asia Pacific is proud to announce two new AAPG Asia Pacific Presents talks, featuring Bruce Ainsworth and Gretchen Gillis. AAPG Asia Pacific Presents is a collection of online presentations being offered free of charge. The 60-90 minute session will be conducted through Zoom, and will be followed by a short Q&A period, handled by a moderator. To register for one or both of these talks, click on the link(s) below. Registrations will be accepted on a first-come basis.

Show more
American Association of Petroleum Geologists (AAPG)
Explorer Article

The AAPG Women’s Network is excited to kick off the new AAPG fiscal year with a new leadership team and some new initiatives. The AAPGWN is currently working hard to roll out new initiatives, events, and partnerships. The goal of these programs is to expand our community of geoscientists, provide career development resources to women and increase knowledge sharing among our global members.

American Association of Petroleum Geologists (AAPG)
Explorer Article

What is “brand”? The London-based Design Council notes that: “Brand is a set of associations that a person (or a group of people) makes with a company, product, service, individual or organization. These associations may be intentional – that is, they may be actively promoted by marketing and/or corporate identity – or they may be outside the control of the business.” For example, the growing belief among younger demographics that the fossil fuel industry represents the fuels of their parents.

Show more
American Association of Petroleum Geologists (AAPG)
Explorer President’s Column

“The only certainty in geology is the unexpected will happen” is a bit of wisdom my friend and mentor John Shelton likes to quote. If anything, in this environment, it’s an understatement. AAPG, our members and industry were hit with the perfect storm: —COVID-19, geopolitics and commodity prices. Of course, I don’t need to tell you about it. We have all adjusted to a new world, which includes quarantines, masks, eating in, ordering out, Zoom, MS Teams, etc. The dogs love it, the cats hate it. It’s been tough on all of us and my thoughts and prayers are with you and your families, especially those who have lost loved ones. So … how does all this impact your society?

Show more
American Association of Petroleum Geologists (AAPG)
Explorer Director’s Corner

I know I’m not alone. Each day, as part of my morning routine, just as reliably as I brush my teeth and brew strong coffee, I check the price that oil is trading for on global markets. How do I know I’m not alone? Because my first calls of the day – usually with AAPG leaders – usually begin or end with a reference to oil prices. We all know that watching the price of oil does nothing to boost demand, but still we watch, ever hopeful that today will be a good day in the markets.

Show more
American Association of Petroleum Geologists (AAPG)
Explorer Geophysical Corner

Exploration of the Brookian-age Nanushuk and Torok formations on the North Slope of Alaska is a hot topic these days. The Nanushuk and Torok formations are Cretaceous progradational clastic deposits in the Colville basin of Alaska. These formations offer new opportunities to the oil and gas community because of their shallow depth, vast spatial extent, publicly available data, scope of development and other appealing features.

American Association of Petroleum Geologists (AAPG)
Explorer Historical Highlights

The German oil industry did not employ geologists until the 1920s. Instead, they relied on geological surveys and other resources from universities, predominantly from Jakob Stoller of the Prussian Geological Survey. After World War I, with the beginning of private motorization and the interest of the military, demand for oil began to increase. This led to the establishment of a separate department of petroleum geology and the employment of a young geologist, Alfred Bentz, as assistant to Stoller.

Show more
American Association of Petroleum Geologists (AAPG)
Explorer Article

Josh Rosenfeld highlighted some perspectives on the Paleogene drawdown hypothesis in the Gulf of Mexico in the April 2020 issue of the EXPLORER, a result of suspected isolation from the world ocean during the Cuban arc-Bahamas collision with implications for Wilcox reservoir deposition. In contrast, John Snedden and authors’ portrayed the Wilcox as a period of normal marine deposition, requiring no such drawdown, in the May 2020 issue. Still another concept was presented by Roger Higgs at the South African 2009 AAPG International Conference and Exhibition, that marine isolation occurred but that fluvial input exceeded evaporation such that the Gulf became brackish, hence the poor development of Wilcox fauna.

Show more
American Association of Petroleum Geologists (AAPG)
Explorer Article

Super basins around the world offer plentiful opportunities for exploration and development, even with the temporarily reduced financial outlook of the oil industry. Ask explorationists to pick a favorite in today’s environment and the popular choice is almost a cheat. The Gulf of Mexico isn’t just a super basin. It’s a huge expanse of prospects and possibilities, of proven resources and potential reserves. An onshore, near-shore, offshore and deepwater exploration province that is really a vast collection of basins and geological features.

Show more
American Association of Petroleum Geologists (AAPG)
Field Seminar
Palermo, Italy
Thursday, 25 April 2024, 8:00 a.m.–5:00 p.m.

Time: TBC Attendee Limit: Minimum 15 - Maximum 50 People Fee: TBC Registration Deadline: TBC Field Trip Rendezvous Point Hotel nH Palermo This one-day field trip will provide an introduction to a Miocene-Pliocene succession of southern Sicily, which includes outcrops of the Messinian Salinity Crisis (MSC), as well as the Messinian-Zanclean GSSP (Global Boundary Stratotype Sections and Point) and Zanclean stratotype. The MSC sedimentary record consists of an evaporitic-carbonate unit at the base (the Basal Limestone), overlain the Lower Gypsum unit, in turn overlain by the Upper Gypsum unit, and sealed by transgressive chalk deposits of the Trubi Fm. The Lower Gypsum unit (massive gypsum with cm-sized selenite crystals) will be visited along the beach of Siculiana Marina (about 15 km NW of Agrigento). Next, we will visit near Capo Rossello (about 10 km NW of Agrigento) an outcrop of the Upper Gypsum unit consisting of clay-gypsum cycles and overlain by the Trubi Fm. The latter, at Scala dei Turchi beach, consists of chalk deposits arranged in a spectacular thick succession (~120 m thick) interpreted as astronomically-controlled depositional cycles. The uppermost interval of the MSC sedimentary record, including the Messinian-Zanclean GSSP, will be observed along the beach of Eraclea Minoa located about 20 km NW of Capo Rossello. Field Trip Leaders Antonio Caruso University of Palermo Attilio Sulli University of Palermo

Show more
American Association of Petroleum Geologists (AAPG)
Field Seminar
Palermo, Italy
Sunday, 21 April 2024, 8:00 a.m.–5:00 p.m.

Time: TBC Attendee Limit: Minimum 15 - Maximum 45 People Fee: TBC Registration Deadline: TBC This one-day field trip will focus on Mesozoic (Jurassic to Cretaceous) carbonates outcropping in the fold and thrust belt of western Sicily and equivalent to the aquifer complex of the Sciacca Geothermal Field located in the southwestern part of the island. Participants will have the opportunity to visit in the first stop a spectacular “drowned” carbonate-platform succession at Mt. Maranfusa located in an inactive quarry about 50 km SW of Palermo. The succession consists of Lower Jurassic peritidal cycles overlain by Middle Jurassic to Cretaceous pelagic limestone (e.g. ammonitic limestone, “chalk”) and marked by an unconformity with locally hardground. Syn-depositional Mesozoic tectonic is characterized by neptunian dykes and normal faults, whereas reverse faults, strike-slip faults, and joints are related to subsequent Cenozoic deformation. In the second stop, at Mt. San Calogero, adjacent to the picturesque coastal town of Sciacca (about 100 km south of Palermo), we will visit the surface expression of an extensive karst system linked to uprising geothermal fluids. Furthermore, we will discuss main characteristics of the Sciacca Geothermal Field and its connection to deep mantle-derived fluids. Outcrop data will be integrated with both 2D seismic lines and exploration well logs showing the stratigraphy and structure of the deep aquifer. Another topic, given the presence of faults and joints in the outcrops, this field trip can provide the participants with valuable insights into naturally fractured reservoirs at the sub-seismic scale. Field Trip Leaders Gianni Mallarino MOL Group Attilio Sulli University of Palermo

Show more
American Association of Petroleum Geologists (AAPG)
Field Seminar
Banff, Canada
Saturday, 11 May 2024, 8:00 a.m.–3:00 p.m.

Time: 8:00am - 5:00pm Fee: $300 AAPG members $350 Nonmembers $200 Academic/AAPG Emeritus Members $50 discount for workshop registrants Fee Includes: Transportation Insurance Field guide Entrance fee to Banff National Park Registration available during workshop registration This field trip will focus on the structural geology of the foothills and Front Ranges of Banff. Participants will be able to view excellent field examples of structures very similar to the producing oil and gas fields in the foothills to the west of Calgary and to learn about the complexities of sub-seismic-scale deformation. The field trip starts with an introduction to the interaction between thrust front with foreland basins and the interaction of basement trends with thrust belt geometries and (conventional) hydrocarbon fields. During the 1-day trip participants will follow a dip transect from the undeformed foreland basin, the eastern edge of the foothills marked by the triangle zone, the Front Ranges boundary and end at the Main Ranges west of Banff. Field Trip Itinerary Depart from Calgary – 8:00 a.m. Stop 1: Cochrane Retreat Road Overlook Trip overview and introduction; safety and logistics comments; interaction of thrust front with foreland basin; interaction of basement trends with thrust belt geometry and (conventional) hydrocarbon field distribution; appreciation of scale for subsurface play fairway. Stop 2: Scott Lake Stop 3: The Stony Nakoda Tim’s Classic stop, with historical importance for understanding the thrust belt and thrust geometry. Part 1 of displacement gradient on a large thrust. Most importantly, toilet stop after all the Tim’s coffee and driving. Review of Mt Yamnuska from a different perspective; preview of drive through McConnell damage zone and change in HW stratigraphy.. Stop 4: Lac des Arcs Imbricate thrust sheets in the Front Ranges and Banff Formation. Stop 5: Canmore T-junction Observe complexities of sub-seismic-scale deformation in mechanically layered rocks in the footwall of a large thrust Stop 6: Canmore strike view of the Rundle thrust Exposed strike view analogous to a cut-away of a giant conventional Foothills hydrocarbon field such as Turner Valley. Cross faults within the thrust sheet offset potential reservoir units at sub-seismic scale. Cross faults are arguably part of a regional trend associated with deeper, basement-rooted NE-SW structures. Stop 7: Mt Norquay Overlook Stop 8: Bow Falls Fracture systems in the Vega Siltstone Mbr of the Triassic Sulphur Mtn Fm. This outcrop of Vega Member siltstone of the Sulphur Mtn Fm is considered equivalent to upper Montney Fm. We will focus on the outcrop adjacent to the steps up to the Falls overlook.

Show more
American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Tuesday, 26 March 2024, 12:00 p.m.–1:00 p.m.

Presenting ExCaliber, a novel approach for fast iterations on basin / earth models so that more time can be spent on the final technical & economic integration. ExCaliber is based on an interactive thermal framework, powered at its core by a ML-based basin simulator which can compute in seconds high-resolution basin-scale temperature and Standard Thermal Stress results.

American Association of Petroleum Geologists (AAPG)
Short Course
Houston, Texas
Thursday, 14 March 2024, 8:30 a.m.–5:00 p.m.

This course course will explore the design of new plays, optimized for the goals and constraints of CO2 sequestration, and to develop the tools to de-risk and sell those plays to investors and regulators. It will be of particular interest to subsurface geoscientists and engineers with an interest in CO2 storage in saline reservoirs.

American Association of Petroleum Geologists (AAPG)
Short Course
Houston, Texas
Thursday, 14 March 2024, 8:30 a.m.–5:00 p.m.

The development and application of a fit-for-purpose CO2 injection model is presented in the context of a front-end engineering design for a new Carbon Capture Storage (CCS) project targeting a depleted gas reservoir in the North Sea. This course will provide an understanding of the impact of CO2 impurities on casing and tubing load cases. The course provides the background and results of the Fit-for-Purpose Casing and Tubing Analysis Program that was developed in collaboration with Harbour Energy for the UK Viking CCS Project.

Show more
American Association of Petroleum Geologists (AAPG)
Short Course
Houston, Texas
Thursday, 14 March 2024, 8:00 a.m.–12:00 p.m.

This half-day short course will familiarize attendees with the planning and execution of a whole core project. It's intended for those who plan to take core on CCUS projects including Geologists and drilling engineers.

American Association of Petroleum Geologists (AAPG)
Short Course
Houston, Texas
Sunday, 10 March 2024, 8:00 a.m.–5:00 p.m.

As part of the international effort to combat global warming, significant attention is being given to ways to sequester (store for the long-term) carbon dioxide, which is a major contributor to the greenhouse effect. This one-day course will look at some of the ways in which carbon dioxide can be stored and provide a detailed review of the SRMS framework prepared by the Society of Petroleum Engineers to classify and categorize the storage quantities.

Show more
American Association of Petroleum Geologists (AAPG)
Field Seminar
Khobar, Saudi Arabia
Monday, 4 March 2024, 8:00 a.m.–5:00 p.m.

Trip Leader Saeed Tofaif, Saudi Aramco Pre-Workshop Field Trip Date: 4 March Registration Deadline: 4 February Attendee Limit: 12-Min. / 25-Max. --> Fee: $200 Note:To register for the field trip please select the field trip option while completing your registration for the workshop The Hadrukh Formation of eastern Saudi Arabia was deposited in early Miocene in tidal, restricted lagoon and sabkha settings with fresh water incursions. Deposition in these non-marine, semi-arid coastal plains resulted deposition of varying lithologies in short lateral extent. This field trip to Hadrukh Formation outcrops in Eastern Province of Saudi Arabia offers observation of internal stratigraphy of the Hadrukh Formation and lithological changes in the lateral extent, which is a key component in defining stratigraphic traps in the subsurface.

Show more
American Association of Petroleum Geologists (AAPG)
Short Course
Pittsburgh, Pennsylvania
Thursday, 29 February 2024, 7:30 a.m.–8:30 a.m.

American Association of Petroleum Geologists (AAPG)
Workshop
Palermo, Italy
Monday, 22 April Wednesday, 24 April 2024, 8:00 a.m.–5:00 p.m.

This Symposium marks a collaborative event that brings together AAPG Europe and AAPG Middle East, with a central focus on carbonates and mixed carbonate systems worldwide, while highlighting their significance within these two regions. The primary objectives are an overview of controls that govern the evolution of these systems in time and space and the characterization and prediction of their properties across scales.

American Association of Petroleum Geologists (AAPG)
Workshop
Abu Dhabi, UAE
Monday, 27 May Wednesday, 29 May 2024, 8:00 a.m.–5:00 p.m.

In order to support the energy transition, optimizing exploration and production from complex stratigraphic-diagenetic conventional and unconventional plays remains highly important. At the same time, Carbon Capture and Storage (CCS) poses new technological challenges that will impact both the industry and academia for decades to come. This 2nd edition will present reviews and discuss technology developments in geological process-based forward modeling achieved during the last 2 years. New perspectives for future technology developments and implementation in industry workflows will be discussed and with the additional focus on CO₂ storage and other sustainability-related applications, the scope of the workshop will be considerably extended.

Show more
American Association of Petroleum Geologists (AAPG)
Workshop
Khobar, Saudi Arabia
Tuesday, 5 March Thursday, 7 March 2024, 8:00 a.m.–5:00 p.m.

Join us for the 4th Edition of: "Stratigraphic Traps of the Middle East" workshop. The workshop will be hosted by AAPG in Al Khobar, Saudi Arabia 5-7 March 2024.

American Association of Petroleum Geologists (AAPG)
DL Abstract

Why H₂ is generated in subsurface? Which are the reactions and the promising geological setting? Example in countries where H₂ have already been found: Australia, Brazil. Kinetic reactions: i.e., Is the natural H₂ renewable? What we don't know yet about this resource and about the H₂ systems (generation/transport/accumulation). Overview of the current landscape (subsurface law, permitting, E&P activity)

Request a visit from Isabelle Moretti!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Climate change is not only happening in the atmosphere but also in the anthroposphere; in some ways the former could drive or exacerbate the latter, with extreme weather excursions and extreme excursions from societal norms occurring all over the earth. Accomplishing geoscience for a common goal – whether that is for successful business activities, resource assessment for public planning, mitigating the impacts of geological hazards, or for the sheer love of furthering knowledge and understanding – can and should be done by a workforce that is equitably developed and supported. Difficulty arises when the value of institutional programs to increase equity and diversity is not realized.

Show more

Request a visit from Sherilyn Williams-Stroud!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Three-dimensional (3D) seismic-reflection surveys provide one of the most important data types for understanding subsurface depositional systems. Quantitative analysis is commonly restricted to geophysical interpretation of elastic properties of rocks in the subsurface. Wide availability of 3D seismic-reflection data and integration provide opportunities for quantitative analysis of subsurface stratigraphic sequences. Here, we integrate traditional seismic-stratigraphic interpretation with quantitative geomorphologic analysis and numerical modeling to explore new insights into submarine-channel evolution.

Show more

Request a visit from Jacob Covault!

American Association of Petroleum Geologists (AAPG)
DL Abstract

President Biden has laid out a bold and ambitious goal of achieving net-zero carbon emissions in the United States by 2050.  The pathway to that target includes cutting total greenhouse gas emissions in half by 2030 and eliminating them entirely from the nation’s electricity sector by 2035. The Office of Fossil Energy and Carbon Management will play an important role in the transition to net-zero carbon emissions by reducing the environmental impacts of fossil energy production and use – and helping decarbonize other hard-to abate sectors.

Show more

Request a visit from Jennifer Wilcox!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Paleozoic North America has experienced multiple mountain building events, from Ordovician to Permian, on all margins of the continent. These have had a profound effect on the resulting complex basins and their associated petroleum systems. Subsequent uplift, erosion and overprinting of these ancient systems impedes the direct observation of their tectonic history. However, the basin sedimentary records are more complete, and provide additional insights into the timing and style of the mountain building events. In this study, we employ ~90 1D basin models, ~30 inverse flexural models, isopachs, and paleogeographic maps to better understand the Paleozoic history of North America.

Show more

Request a visit from Kurt W. Rudolph!

American Association of Petroleum Geologists (AAPG)
VG Abstract

The carbonate sequences that were deposited in the now exhumed Tethyan Ocean influence many aspects of our lives today, either by supplying the energy that warms our homes and the fuel that powers our cars or providing the stunning landscapes for both winter and summer vacations. They also represent some of the most intensely studied rock formations in the world and have provided geoscientists with a fascinating insight into the turbulent nature of 250 Million years of Earth’s history. By combining studies from the full range of geoscience disciplines this presentation will trace the development of these carbonate sequences from their initial formation on the margins of large ancient continental masses to their present day locations in and around the Greater Mediterranean and Near East region. The first order control on growth patterns and carbonate platform development by the regional plate-tectonic setting, underlying basin architecture and fluctuations in sea level will be illustrated. The organisms that contribute to sequence development will be revealed to be treasure troves of forensic information. Finally, these rock sequences will be shown to contain all the ingredients necessary to form and retain hydrocarbons and the manner in which major post-depositional tectonic events led to the formation of some of the largest hydrocarbon accumulations in the world will be demonstrated.

Show more

Request a visit from Keith Gerdes!

American Association of Petroleum Geologists (AAPG)
DL Abstract

For well over a century there have been conflicting indications of the strength of the crust and of faults and what controls them.  Much of our ignorance comes quite naturally from the general inaccessibility of the crust to measurement--in contrast with our understanding of the atmosphere, which is much more accessible to observation as well as more rapidly changing.  Crustal strength is best understood in deforming sedimentary basins where the petroleum industry has made great contributions, particularly in deforming petroleum basins because of the practical need to predict. In this talk we take a broad look at key issues in crustal strength and deformation and what we can learn from boreholes, earthquakes, active fault systems, and toy models.

Show more

Request a visit from John Suppe!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Around 170 million years ago, the Gulf of Mexico basin flooded catastrophically, and the pre-existing landscape, which had been a very rugged, arid, semi-desert world, was drowned beneath an inland sea of salt water. The drowned landscape was then buried under kilometers of salt, perfectly preserving the older topography. Now, with high-quality 3D seismic data, the salt appears as a transparent layer, and the details of the drowned world can be seen in exquisite detail, providing a unique snapshot of the world on the eve of the flooding event. We can map out hills and valleys, and a system of river gullies and a large, meandering river system. These rivers in turn fed into a deep central lake, whose surface was about 750m below global sea level. This new knowledge also reveals how the Louann Salt was deposited. In contrast to published models, the salt was deposited in a deep water, hypersaline sea. We can estimate the rate of deposition, and it was very fast; we believe that the entire thickness of several kilometers of salt was laid down in a few tens of thousands of years, making it possibly the fastest sustained deposition seen so far in the geological record.

Show more

Request a visit from Frank Peel!

American Association of Petroleum Geologists (AAPG)
DL Abstract

As oil and gas exploration and production occur in deeper basins and more complex geologic settings, accurate characterization and modeling of reservoirs to improve estimated ultimate recovery (EUR) prediction, optimize well placement and maximize recovery become paramount. Existing technologies for reservoir characterization and modeling have proven inadequate for delivering detailed 3D predictions of reservoir architecture, connectivity and rock quality at scales that impact subsurface flow patterns and reservoir performance. Because of the gap between the geophysical and geologic data available (seismic, well logs, cores) and the data needed to model rock heterogeneities at the reservoir scale, constraints from external analog systems are needed. Existing stratigraphic concepts and deposition models are mostly empirical and seldom provide quantitative constraints on fine-scale reservoir heterogeneity. Current reservoir modeling tools are challenged to accurately replicate complex, nonstationary, rock heterogeneity patterns that control connectivity, such as shale layers that serve as flow baffles and barriers.

Show more

Request a visit from Tao Sun!

American Association of Petroleum Geologists (AAPG)
VG Abstract

Production from unconventional petroleum reservoirs includes petroleum from shale, coal, tight-sand and oil-sand. These reservoirs contain enormous quantities of oil and natural gas but pose a technology challenge to both geoscientists and engineers to produce economically on a commercial scale. These reservoirs store large volumes and are widely distributed at different stratigraphic levels and basin types, offering long-term potential for energy supply. Most of these reservoirs are low permeability and porosity that need enhancement with hydraulic fracture stimulation to maximize fluid drainage. Production from these reservoirs is increasing with continued advancement in geological characterization techniques and technology for well drilling, logging, and completion with drainage enhancement. Currently, Australia, Argentina, Canada, Egypt, USA, and Venezuela are producing natural gas from low permeability reservoirs: tight-sand, shale, and coal (CBM). Canada, Russia, USA, and Venezuela are producing heavy oil from oilsand. USA is leading the development of techniques for exploring, and technology for exploiting unconventional gas resources, which can help to develop potential gas-bearing shales of Thailand. The main focus is on source-reservoir-seal shale petroleum plays. In these tight rocks petroleum resides in the micro-pores as well as adsorbed on and in the organics. Shale has very low matrix permeability (nano-darcies) and has highly layered formations with differences in vertical and horizontal properties, vertically non-homogeneous and horizontally anisotropic with complicate natural fractures. Understanding the rocks is critical in selecting fluid drainage enhancement mechanisms; rock properties such as where shale is clay or silica rich, clay types and maturation , kerogen type and maturation, permeability, porosity, and saturation. Most of these plays require horizontal development with large numbers of wells that require an understanding of formation structure, setting and reservoir character and its lateral extension. The quality of shale-gas resources depend on thickness of net pay (>100 m), adequate porosity (>2%), high reservoir pressure (ideally overpressure), high thermal maturity (>1.5% Ro), high organic richness (>2% TOC), low in clay (<50%), high in brittle minerals (quartz, carbonates, feldspars), and favourable in-situ stress. During the past decade, unconventional shale and tight-sand gas plays have become an important supply of natural gas in the US, and now in shale oil as well. As a consequence, interest to assess and explore these plays is rapidly spreading worldwide. The high production potential of shale petroleum resources has contributed to a comparably favourable outlook for increased future petroleum supplies globally. Application of 2D and 3D seismic for defining reservoirs and micro seismic for monitoring fracturing, measuring rock properties downhole (borehole imaging) and in laboratory (mineralogy, porosity, permeability), horizontal drilling (downhole GPS), and hydraulic fracture stimulation (cross-linked gel, slick-water, nitrogen or nitrogen foam) is key in improving production from these huge resources with low productivity factors.

Show more

Request a visit from Ameed Ghori!

American Association of Petroleum Geologists (AAPG)

Related Interests