SEARCH · Search USGS

Results for “Geological Society of America Bulletin, Part I”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

USGS1988

Limestone and chert in tectonic blocks from the Esk Head subterrane, South Island, New Zealand

The Esk Head subterrane is a continuous belt, generally 10-20 km wide, of tectonic mélange and broken formation on the South Island of New Zealand. This subterrane separates older and younger parts of the Torlesse terrane which is an extensive accretionary prism composed mostly of quartzo-feldspathic, submarine-fan deposits ranging from Permian to Early Cretaceous in age. The Torlesse is the most Pacific-ward of several Permian and Mesozoic accreted terranes in New Zealand that record tectonic amalgamation and ultimate accretion against the Pacific-facing Gondwana margin. The Esk Head subterrane of the Torlesse is especially informative because it includes within it conspicuous tectonic blocks of submarine basalt and a variety of basalt-associated seamount and sea-floor limestones and cherty rocks thought to be representative of the subducted plate. Limestones in tectonic blocks are of Late Triassic and probably Jurassic ages and include (1) submarine-cemented, pelagic-bivalve, geopetal packstone-grainstone; (2) brachiopod-bryozoan encrinite; and (3) radiolarian, pelagic lime mudstone. Most of the Triassic blocks have been dated using conodonts which have remarkably low color alteration index (CAI) values (<1.5). An incomplete sampling of cherts in tectonic blocks and from Holocene gravels derived from the Esk Head subterrane yields radiolarian-based ages of Late Triassic, Early Jurassic, Middle Jurassic, and Late Jurassic. Paleogeographic inferences drawn from megafossils, bioclasts, and radiolarians, as well as from carbonate cements, indicate deposition of the oceanic sedimentary rocks at paleolatitudes somewhat lower than that of the New Zealand part of the Gondwana margin, but higher than paleoequatorial latitudes. These oceanic sediments and their basaltic substrates were evidently emplaced in the Torlesse accretionary prism following off-scraping from an extensive subducting oceanic plate, probably the Phoenix plate, which was obliquely convergent with the northwest-trending Gondwana margin during Late Jurassic and/or Early Cretaceous time.

Geological Society of America Bulletin↗

USGS2003

New K-Ar ages and the geologic evidence against rejuvenated-stage volcanism at Haleakalā, East Maui, a postshield-stage volcano of the Hawaiian island chain

The postshield and previously inferred rejuvenated-stage history of Haleakalā volcano is reevaluated on the basis of 52 new K-Ar ages, 42 from the postshield Kula Volcanics and 10 from the overlying Hāna Volcanics. Postshield extrusion was robust from 0.93 to 0.76 Ma. A period of low extrusion rate or volcanic quiescence occurred between 0.76 and 0.65 Ma, well within Kula time. A chemical change to increasingly alkalic lava occurred at this time as the volcano changed from broadly hawaiitic to basanitic in its eruptive products and robust extrusion resumed. A slightly longer period of low extrusion rate or quiescence occurred after ca. 0.4 Ma, but only trifling change in geochemical character is observed. Geochemically, the Hāna Volcanics unit, chiefly basanitic, overlaps greatly with the upper part of the Kula Volcanics; there is a weak tendency to slightly more alkaline character among the Hāna Volcanics. The age of the Kula/Hāna boundary is ca. 0.15–0.12 Ma; thus, volcanic quiescence of only &sim;0.03 m.y. separates the two formations, much shorter than the previously known limit of 0.25–0.30 m.y. The brevity of this hiatus, coupled with coincident vent loci and broadly similar geochemical characteristics for the Hāna and the upper part of the Kula Volcanics, indicates that the Hāna Volcanics unit comprises deposits of postshield-stage volcanism that has waned substantially since ca. 0.4–0.3 Ma. Haleakalā has not yet begun a classically defined rejuvenated stage. Our findings support recent numerical modeling of plume-lithosphere interactions that predict that Haleakalā is near the end of its postshield growth.

Hawaii↗

USGS1953

Limestone walls of Okinawa

Wall-like ridges of limestone that stand well above the surrounding terrain are an interesting phenomenon on the island of Okinawa. These ridges rim a variety of topographic features, but all are believed to represent the same formative processes. Rimming ridges or walls occur along the banks of streams crossing areas of limestone, along the upthrown sides of faults, around a sink hole, and along terrace edges. The limestone walls of Okinawa are believed to have formed by the cementation, or casehardening, of steep exposures of poorly consolidated limestone, followed by differential erosion which brings the cemented zones into relief. Cementation occurs wherever poorly consolidated limestone is exposed to alternate wetting and drying. It is best developed, however, on steeply sloping exposures where no soil accumulates to hinder drying. Differential erosion results in part from slower solution of cemented limestone, due to its greater density, and in part from accelerated solution in the surrounding soil-covered areas. Rampart walls along the seaward edges of terraces have been described from many Pacific islands and are present on many others. They are believed to be comparable to the walls of Okinawa and all are believed to have been formed under similar conditions.

Geological Society of America Bulletin↗

USGS1967

Rocks of eocene age on fippennies ledge, Gulf of Maine

In August 1965, a scallop dredge from R/V Albatross brought up many pieces of fossiliferous opaline chert or porcellanite of Eocene age from Fippennies Ledge , a bank 70 m deep in the central Gulf of Maine . Their presence in this area supports the idea that part of the Gulf is underlain by sedimentary rocks of Tertiary age . Occurrence in the porcellanite of two identifiable species of Bryozoa (ascophoran Cheilostomata), Kleidionella lobata Canu and Bassler and "Ocheto-sella" robusta Canu and Bassler, suggests (1) correlation with the Castle Hayne Limestone of Claiborne to Jackson age ; (2) a temperate zone, distinctly American biogeographic provenance; and (3) accumulation in quiet water.

Maine↗

USGS1969

Alkalic and tholeiitic basaltic volcanism related to the Rio Grande depression, southern Colorado and northern New Mexico

Upper Cenozoic basaltic rocks in and near the northern Rio Grande depression, a major intracontinental tension-rift structure, vary systematically in petrology and chemistry with distance from the depression. Basalts and basaltic andesites of alkalic affinities, commonly showing evidence of crustal contamination, were erupted east and west of the depression concurrently with its formation, whereas little-contaminated tholeiitic basalts filled parts of the depression late in its history. Eruption of the contrasting basalt types was in part concurrent. The lateral change from alkalic to tholeiitic basaltic volcanism may reflect different conditions of magma generation in the mantle that are related to changes in crustal thickness and thermal gradient across the rift. Recent experimental studies suggest that the variations in magma composition may be due to differing depths of magma fractionation, the tholeiitic basalts originating at shallower depths than the alkalic basalts.

Colorado, New Mexico↗

USGS1998

Coseismic temporal changes of slip direction: The effect of absolute stress on dynamic rupture

We investigate the dynamics of rupture at low-stress level. We show that one main difference between the dynamics of high- and low-stress events is the amount of coseismic temporal rake rotation occurring at given points on the fault. Curved striations on exposed fault surfaces and earthquake dislocation models derived from ground-motion inversion indicate that the slip direction may change with time at a point on the fault during dynamic rupture. We use a 3D boundary integral method to model temporal rake variations during dynamic rupture propagation assuming a slip-weakening friction law and isotropic friction. The points at which the slip rotates most are characterized by an initial shear stress direction substantially different from the average stress direction over the fault plane. We show that for a given value of stress drop, the level of initial shear stress (i.e., the fractional stress drop) determines the amount of rotation in slip direction. We infer that seismic events that show evidence of temporal rake rotations are characterized by a low initial shear-stress level with spatially variable direction on the fault (possibly due to changes in fault surface geometry) and an almost complete stress drop. Our models motivate a new interpretation of curved and cross-cutting striations and put new constraints on their analysis. The initial rake is in general collinear with the initial stress at the hypocentral zone, supporting the assumptions made in stress-tensor inversion from first-motion analysis. At other points on the fault, especially away from the hypocenter, the initial slip rake may not be collinear with the initial shear stress, contradicting a common assumption of structural geology. On the other hand, the later part of slip in our models is systematically more aligned with the average stress direction than the early slip. Our modeling suggests that the length of the straight part of curved striations is usually an upper bound of the slip-weakening distance if this parameter is uniform over the fault plane, and the direction of the late part of slip of curved striations should have more weight in the estimate of initial stress direction.

Bulletin of the Seismological Society of America↗

USGS2025

Seismic response of rock towers at the Trona Pinnacles (U.S.A.) to the 2019 Ridgecrest earthquake sequence: Theory, observations, and models

We analyze the seismic response of a class of fragile geologic features (FGFs), referred to as rock towers (RTs) at the Trona Pinnacles, a group of RTs in southern California that suffered strong shaking during the 2019 Ridgecrest earthquake sequence. FGFs, including RTs, may provide maximum constraints on past earthquake shaking intensity, and thereby support probabilistic seismic hazard assessments (PSHAs). In a rare case study, we explore the hypothesis that RT structural integrity is time dependent, as damage accumulates progressively. We develop finite‐element method (FEM) models of the RTs using photogrammetric shape models. We validate the models by comparing numerical simulations of their response to broadband ground shaking with low‐intensity seismic recordings obtained at the Pinnacles. Results of our simulations are in good agreement with the seismic recordings of actual earthquake aftershocks. We next use the results of the FEM models to analyze the response and evolution of RTs. Our analyses elucidate the influence of geometry over their seismic response, providing a rationale that may explain the rarity of slender RTs at Trona: high‐aspect‐ratio structures that respond in bending develop detrimental tensile stresses that crack the rock, whereas low‐aspect‐ratio ones’ response also includes shearing, which does not compromise material integrity as much as tension. Field measurements with a rebound hammer support this finding, suggesting that the material around the base of slender rocks has been weakened relative to other parts of the RT. We also study how to define simplified mechanical models (“archetypes”) to predict the natural frequencies of RTs. Results from our work illuminate the fundamental mechanisms of seismic response and progressive failure of RTs, and open new avenues of research to potentially incorporate these geologic features as long‐return period constraints on PSHA, in ways analogous to those of the widely used precariously balanced rocks.

California↗

USGS1957

Military geology in the United States sector of the European theater of operations during World War II

Geology, which was of far-reaching importance on the Western Front of World War I, played a less spectacular role during World War II in so far as the United States armies in Europe were concerned. The U. S. Army in the European Theater of Operations (ETO) used geologists in two capacities: (1) to make staff studies at the level of Theater Headquarters, and (2) as officer personnel in a water-supply unit. In the first category, only one group of seven geologists was employed, forming part of the Information Section, Intelligence Division, Office of the Chief Engineer, ETO. The products of this group consisted largely of regional and localized terrain (trafficability) studies that ranged geographically from the Normandy invasion beaches to Czechoslovakia. Problems of water supply, sources of road material, and many other questions of a geologic nature also arose. French geologists collaborated closely with the work of the section. As the campaign progressed, the Military Geology Unit of the U. S. Geological Survey made important contributions to the geologic intelligence of Germany.

Geological Society of America Bulletin↗

USGS1971

Tertiary igneous chronology of the Great Basin of western United States — Implications for tectonic models

The chronology of igneous activity in the Great Basin of western United States is used as a time framework for a simple plate model. This chronology suggests that a plate (Farallon plate) became underthrust to sufficient depth by the middle Tertiary to trigger the eruption of volcanic rocks of andesitic to rhyolitic composition in the central part of the Great Basin, 40 m.y. ago. This plate continued to be underthrust until about 19 m.y. ago, at which time it was completely consumed and volcanic activity ceased. When the oceanic ridge reached a certain point under the Great Basin about 16 m.y. ago, this resulted in the widespread eruption of olivine basalt and the main initial phase of Basin and Range faulting.

Arizona, California, Idaho, Nevada, Oregon, Utah↗

USGS1998

Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada Basin, and the geometry and timing of rifting in the Amerasia Basin, Arctic Ocean

Cores from Northwind Ridge, a high-standing continental fragment in the Chukchi borderland of the oceanic Amerasia basin, Arctic Ocean, contain representatives of every Phanerozoic system except the Silurian and Devonian systems. Cambrian and Ordovician shallow-water marine carbonates in Northwind Ridge are similar to basement rocks beneath the Sverdrup basin of the Canadian Arctic Archipelago. Upper Mississippian(?) to Permian shelf carbonate and spicularite and Triassic turbidite and shelf lutite resemble coeval strata in the Sverdrup basin and the western Arctic Alaska basin (Hanna trough). These resemblances indicate that Triassic and older strata in southern Northwind Ridge were attached to both Arctic Canada and Arctic Alaska prior to the rifting that created the Amerasia basin. Late Jurassic marine lutite in Northwind Ridge was structurally isolated from coeval strata in the Sverdrup and Arctic Alaska basins by rift shoulders and grabens, and is interpreted to be a riftogenic deposit. This lutite may be the oldest deposit in the Canada basin. A cap of late Cenomanian or Turonian rhyodacite air-fall ash that lacks terrigenous material shows that Northwind Ridge was structurally isolated from the adjacent continental margins by earliest Late Cretaceous time. Closing Amerasia basin by conjoining sea-floor magnetic anomalies beneath the Canada basin or by uniting the pre-Jurassic strata of Northwind Ridge with kindred sections in the Sverdrup basin and Hanna trough yield similar tectonic reconstructions. Together with the orientation and age of rift-margin structures, these data suggest that (1) prior to opening of the Amerasia basin, both northern Alaska and the continental ridges of the Chukchi borderland were part of North America, (2) the extension that created the Amerasia basin formed rift-margin grabens beginning in Early Jurassic time and new oceanic crust probably beginning in Late Jurassic or early Neocomian time.

Geological Society of America Bulletin↗

USGS1981

Rates and possible causes of neotectonic vertical crustal movements of the emerged southeastern United States Atlantic coastal plain

Emerged Pliocene and Pleistocene shorelines and associated marine deposits were used to determine the magnitude and rate of vertical crustal movement during the past 3 m.y. in the United States Atlantic Coastal Plain of South and North Carolina. On the basis of a new regional ostracode assemblage zonation, planktic biostratigraphic data, and radiometric data, emerged marine deposits were determined to be primarily interglacial and can tentatively be correlated with hemispheric warm intervals in evidence from deep-sea data. The paleontologic evidence indicates a primary glacio-eustatic component to the local sea-level record and a secondary tectonic component. Net vertical uplift rates averaging 1 to 3 cm/1,000 yr, but perhaps as high as 5 to 10 cm/1,000 yr, are in evidence for the emerged Coastal Plain. Although details of the timing of regional rheological events remain obscure, the trend of net uplift contrasts with general subsidence rates of about 2 to 4 cm/1,000 yr since the Cretaceous in submerged parts of the continental margin near subsiding sedimentary troughs. Hydro-isostatic crustal response to multiple deglaciation events may have periodically uplifted the coast, but long-term lithospheric flexural upwarping in response to sediment loading offshore is a more plausible mechanism to explain the present positions of shorelines above present mean sea level. A eustatic sea-level model is proposed for interglacial high stands of the past 3.0 m.y.

Geological Society of America Bulletin↗

USGS1989

Diapiric transfer of melt in Kilauea Iki lava lake, Hawaii: A quick, efficient process of igneous differentiation

Kilauea Iki lava lake, formed in 1959, is a large pond of picritic basalt (average MgO content = 15.34% by weight), which has cooled and crystallized as a small, self-roofed magma chamber. Repeated drilling of the upper crust of the lake, down to its molten core, and more recent (1981) drilling, through the thermal maximum and part way through the lower crust, have made it possible to monitor the differentiation processes in the lake in detail. Differentiation processes recognized as active in the lake include rather inefficient settling of the larger (2-10 mm) olivine phenocrysts, formation of segregation veins, and formation of diapir-like vertical olivine-rich bodies, all processes which occur in one or more of the other Kilauean lava lakes as well. In addition, most of the central part of Kilauea Iki has been affected by diapiric melt transfer. In this process, relatively low-density liquid, present at 1145-1160 °C, rose from within the loose crystal mush at the base of the lens of melt and intruded the equivalent thermal horizon at the top of the lens of melt, passing through the hotter but denser melt in the core of the lake without mixing. The source volume from which the low-density liquid was extracted is depleted in TiO 2 and other incompatible elements and enriched in FeO and CaO. The upper part of the lake shows the opposite effects. The crystalline assemblage present was olivine + augite + minor plagioclase. The crystallinity of both the source and receiving layers was low enough that no obvious textural imprint was left by the transfer process; the principal evidence for its occurrence is the chemical zonation of the lake seen in core from depths of 13 to 80 m. Diapiric melt transfer was active from 1960 to 1971 and has affected most of the central part of the lake from 13 m to at least 80 m. The process ran simultaneously with the other three main differentia tion processes but started and stopped independently of the others. Calculations suggest that between 21 and 42 wt % liquid has been extracted from the depleted zone at 56-78 m in the center of the lake, making this a very efficient process of chemical differentiation.

Hawaii↗

USGS1963

Matureland of northern Chile and its relationship to ore deposits

The old surface that extends over a long north-striking belt in northern Chile probably reached the mature stage of erosion by middle Tertiary time. Low areas are mantled by the piedmont deposits of the pampa, and the higher parts exhibit rock decay, oxidation, leaching, and super-gene enrichment of sulfide mineral deposits as a result of deep weathering. The surface and its deposits are deeply eroded south of the main pampa by the Río Copiapó and its tributaries. Numerous ore deposits in the thick secondary zones have not been eroded, but ore deposits are few in the youthful valleys where the primary zones extend to the surface.

northern Chile↗

USGS1991

Anomalous folds associated with the east-central part of the Garlock Fault, southeast California

The east-central part of the left-lateral Garlock fault, in southeast California, is associated with three broad folds that trend and plunge northeast. The folds, which lie north, south, and astride the fault, postdate deposition of alluvial gravels that at one time formed a continuous northwest-sloping fan; the gravels rest conformably on lake beds that contain the Lava Creek B ash bed (0.62 Ma). The anticline, named after Christmas Canyon, has vertical relief of as much as 100 m. Topographic profiles suggest that the gravels exposed along the synclinal troughs to its southeast (Pilot Knob Valley syncline) and northwest (Teagle Wash syncline) lie at about the same elevations as they did when part of the originally active fan, implying that the synclines are passive results of the anticline development. If so, the original slope of the middle Pleistocene alluvial sediment sheet was about 0.6° northwest. The age and dimensional controls allow calculation of the rates of tilting and horizontal shortening. Corrected tilting rates vary from about 2.5° to 4.7°/m.y.; the total shortening of about 7.5 m developed at a minimum rate of 12.5 m/m.y.

California↗

USGS1969

A geophysical study of North Park and the surrounding ranges, Colorado

A geophysical study in the North Park basin and surrounding mountains, Colorado illustrates the structural relationship of various sedimentary, metamorphic, and igneous rock units. Bouguer anomalies from 1330 gravity stations range from −210 mgal over Precambrian metamorphic rocks in the mountains to −260 mgal in the Walden syncline and —280 mgal in the North Park syncline. Steep gradients delineate a fault which strikes west-northwest along the north flank of the North Park syncline. Two models fitted to the gravity data show 1 to 2 km relief on this steeply dipping fault. Density contrasts between Precambrian metamorphic and igneous rocks produce anomalies of as much as 25-mgal amplitudes in the Park and Medicine Bow Ranges. A 30-km-long seismic refraction profile, parallel to the most negative Bouguer anomaly values in the North Park basin, shows velocities increasing from 2.5 to 3.4 km/sec within Tertiary rocks at depths ranging from 1.2 to 2.0 km. Mesozoic sedimentary rocks have a velocity of 4.0 to 4.5 km/sec, a very high velocity in view of the predominance of Upper Cretaceous rocks. Precambrian basement with a velocity of 6.25 km/sec underlies the profile at depths ranging from 3.5 to 4.5 km. Strong second arrivals across the profile, observed at distances of more than 14 km from the shotpoints and interpreted as SP reflections, verified the refraction model. An aeromagnetic survey shows numerous anomalies ranging from 100 to 200γ in the Park and Rabbit Ears Ranges and in the Never Summer Mountains, to 400γ in the Front Range, and to 1200γ over the Medicine Bow Range. Positive anomalies in the Park, Medicine Bow, and Front ranges overlie metamorphic rocks. Magnetic and gravity data suggest that the Never Summer Mountains are separated from the Front Range by a north-trending, steeply east-dipping reverse fault, extending beneath the Front Range along the Colorado River valley. The magnetic data indicate that this fault may connect with a possible fault that is parallel to the Laramie River valley. In the Rabbit Ears Range, a series of magnetic anomalies show that igneous rocks are present in the eastern part of the range. A northeast-trending positive magnetic anomaly, which is parallel to foliation trends reported in Precambrian rocks, extends from the Park Range across the North Park basin to the Medicine Bow Range. On the basis of this anomaly, the high seismic velocity of the Precambrian basement, and computed profiles fitted to the gravity and magnetic data, we infer that much of the basin is underlain by high-density metamorphic rock. As shown by gravity data, the deepest part of the basin is 2.7 km below sea level, resulting in a maximum relief of 6.7 km on the basement, relative to the Medicine Bow Range. A 25-mgal negative gravity anomaly and a zone of negative magnetic anomalies outline a large granitic intrusion in the Park Range, which probably extends northeast beneath the North Park basin and connects with granitic rocks in the Medicine Bow Range.

Colorado↗

USGS1991

The neotectonic setting of Puerto Rico

The island of Puerto Rico, in the northeast Caribbean, lies within a broad deformation zone between the Caribbean and North American plates. The simplest model for the tectonic setting of Puerto Rico has major strike-slip movement on nearly east-west lines in the vicinity of the Puerto Rico Trench coupled to a small counterclockwise rotation of a Puerto Rico block within the broader plate boundary zone. This simple model is attractive because it predicts the tectonic regime south of Puerto Rico, and provides an explanation for a possible component of extension across the Puerto Rico Trench west of 65.5°W. GLORIA long-range sidescan sonar data and seismic reflection profiles have been used to test this model by mapping the major tectonic features across the plate boundary north and south of Puerto Rico. To the north, the new data help to resolve between conflicting models, of underthrusting or strike-slip motion at the Puerto Rico Trench. No direct evidence of compression is seen, although evidence for normal and strike-slip movement is abundant. This, combined with regional considerations, leads us to conclude that the main east-west-trending part of the Puerto Rico Trench between 65.5°W and 68°W lies within a strike-slip regime, although oblique convergence occurs both to the east and west where the plate boundary trends east-southeast. To the south of Puerto Rico, underthrusting of the Caribbean plate beneath the island decreases from west to east, and it is ultimately replaced by extension in the Virgin Islands Basin east of 65°W.

Puerto Rico↗

USGS2008

Miocene extension in the East Range, Nevada: A two-stage history of normal faulting in the northern basin and range

The East Range in northwestern Nevada is a large, east-tilted crustal block bounded by west-dipping normal faults. Detailed mapping of Tertiary stratigraphic units demonstrates a two-phase history of faulting and extension. The oldest sedimentary and volcanic rocks in the area record cumulative tilting of -30??-45??E, whereas younger olivine basalt flows indicate only a 15??-20??E tilt since ca. 17-13 Ma. Cumulative fault slip during these two episodes caused a minimum of 40% extensional strain across the East Range, and Quaternary fault scarps and seismic activity indicate that fault motion has continued to the present day. Apatite fission track and (U-Th)/He data presented here show that faulting began in the East Range ca. 17-15 Ma, coeval with middle Miocene extension that occurred across much of the Basin and Range. This phase of extension occurred contemporaneously with middle Miocene volcanism related to the nearby northern Nevada rifts, suggesting a link between magmatism and extensional stresses in the crust that facilitated normal faulting in the East Range. Younger fault slip, although less well constrained, began after 10 Ma and is synchronous with the onset of low-magnitude extension in many parts of northwestern Nevada and eastern California. These findings imply that, rather than migrating west across a discrete boundary, late Miocene extension in western Nevada is a distinct, younger period of faulting that is superimposed on the older, middle Miocene distribution of extended and unextended domains. The partitioning of such middle Miocene deformation may reflect the influence of localized heterogeneities in crustal structure, whereas the more broadly distributed late Miocene extension may reflect a stronger influence from regional plate boundary processes that began in the late Miocene. ?? 2008 Geological Society of America.

Geological Society of America Bulletin↗

USGS1999

Paleohydrogeology of the San Joaquin basin, California

Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration.

California↗