Genesis of Clastic Dykes and Soft-Sediment Deformation Structures in the Mamfe Basin, South-West Region, Cameroon: Field Geology Approach

Eric, Bokanda Ekoko; Ekomane, Emile; Takem, Eyong John; Konfor, Njilah Isaac; Nkongho, Ashukem Ethel; Ndige, Bisong Rita; Bertrant, Bisse Salomon

doi:10.1155/2018/3749725

Cited by 6 publications

(1 citation statement)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phylogenies are a key mean in biogeographic and molecular evolutionary studies (Avise, 2009;Avise et al, 2000) and increasingly recognized as being essential to research that aim to reconcile biological and geological information to reconstruct Earth surface processes such as mountain building (Hoorn et al, 2013;Mulch & Chamberlain, 2018). In fact, organismal evolution offers an independent line of evidence for the emplacement of major topographical features, which have been proved valid in refining the timing of events substantiated by geologic record (Donoghue & Benton, 2007;Richardson et al, 2018). Specifically, several studies have demonstrated the suitability of phylogenetic data for addressing the timing and complexity of orogenic events, e.g., the Andean uplift and the formation of the Qinghai-Tibetan region (Antonelli et al, 2009;Luebert & Muller, 2015).…”

Section: Introductionmentioning

confidence: 99%

Relict groups of spiny frogs indicate Late Paleogene-Early Neogene trans-Tibet dispersal of thermophile faunal elements

Hofmann

Jablonski

Litvinchuk

et al. 2021

PeerJ

View full text Add to dashboard Cite

Background The Himalaya-Tibet orogen (HTO) presents an outstanding geologically active formation that contributed to, and fostered, modern Asian biodiversity. However, our concepts of the historical biogeography of its biota are far from conclusive, as are uplift scenarios for the different parts of the HTO. Here, we revisited our previously published data set of the tribe Paini extending it with sequence data from the most western Himalayan spiny frogs Allopaa and Chrysopaa and using them as an indirect indicator for the potential paleoecological development of Tibet. Methods We obtained sequence data of two mitochondrial loci (16S rRNA, COI) and one nuclear marker (Rag1) from Allopaa samples from Kashmir Himalaya as well as Chrysopaa sequence data from the Hindu Kush available from GenBank to complement our previous data set. A Maximum likelihood and dated Bayesian gene tree were generated based on the concatenated data set. To resolve the inconsistent placement of Allopaa, we performed different topology tests. Results Consistent with previous results, the Southeast Asian genus Quasipaa is sister to all other spiny frogs. The results further reveal a basal placement of Chrysopaa relative to Allopaa and Nanorana with an estimated age of ca. 26 Mya. Based on the topology tests, the phylogenetic position of Allopaa as a sister clade to Chaparana seems to be most likely, resulting in a paraphyletic genus Nanorana and a separation from the latter clade around 20 Mya, although a basal position of Allopaa to the genus Nanorana cannot be entirely excluded. Both, the placements of Chrysopaa and Allopaa support the presence of basal Paini lineages in the far northwestern part of the HTO, which is diametrically opposite end of the HTO with respect to the ancestral area of spiny frogs in Southeast Asia. These striking distributional patterns can be most parsimoniously explained by trans-Tibet dispersal during the late Oligocene (subtropical Chrysopaa) respectively early Miocene (warm temperate Allopaa). Within spiny frogs, only members of the monophyletic Nanorana+Paa clade are adapted to the colder temperate climates, indicating that high-altitude environments did not dominate in the HTO before ca. 15 Mya. Our results are consistent with fossil records suggesting that large parts of Tibet were characterized by subtropical to warm temperate climates at least until the early Miocene. They contradict prevalent geological models of a highly uplifted late Paleogene proto-Plateau.

show abstract

Section: Introductionmentioning

confidence: 99%

Relict groups of spiny frogs indicate Late Paleogene-Early Neogene trans-Tibet dispersal of thermophile faunal elements

Hofmann

Jablonski

Litvinchuk

et al. 2021

PeerJ

View full text Add to dashboard Cite

show abstract

Temporal and spatial variability of cross-fault groundwater-level differences: the impact of fault-induced permeability reduction, precipitation and evapotranspiration

Lapperre¹,

Bense

Kasse³

et al. 2022

Hydrogeol J

View full text Add to dashboard Cite

Faults in the Roer Valley Rift System (Netherlands, Belgium, and Germany) act as barriers to lateral groundwater flow in unconsolidated sedimentary aquifers. This causes a cross-fault groundwater-level step of up to several metres. Using a dataset obtained through 5 years of high-frequency monitoring, the effect of fault-zone permeability, precipitation and evapotranspiration on cross-fault groundwater-level steps is studied at two sites situated across the Peel Boundary Fault. Hydraulic conductivity values at the fault are 1–3 orders of magnitude lower than that of similar lithologies away from the fault, indicating that fault displacement has a significant impact on groundwater flow. The influence of precipitation and evapotranspiration on fault-zone hydrology is inferred from water-table fluctuations over short distances across the fault. On the foot wall, the water table is nearer to the surface and displays a shorter level range with a spiky temporal variability. On the hanging wall, a deeper water table is sloping away from the fault and shows a wider level range with a smoother temporal variability. The observed groundwater level fluctuations are attributed mainly to precipitation and evapotranspiration dynamics. At a larger spatial scale, the 5-year-average cross-fault groundwater-level steps at the two sites are 1.59 and 1.39 m. At a smaller scale, the cross-fault groundwater-level step is much less because of the rising water table towards the fault on the hanging wall. At the smallest scale, just across the fault zone, the groundwater level step is around 0.2 m, indicating that the fault is semi-impermeable.

show abstract

Earthquake-induced clastic dyke and fluid inflow at the Miguel Burnier manganese-ore deposit, Quadrilátero Ferrífero of Minas Gerais, Brazil

2021

View full text Add to dashboard Cite

A clastic dyke has been recognised within manganese (Mn)-rich Cenozoic sediments near a historical Mn-ore deposit in the Miguel Burnier district, Quadrilátero Ferrífero, in the southern São Francisco craton, Brazil. Here, we describe the clastic dyke, a subvertical fissure that is filled with friable arenaceous fragments, and characterise it as seismite. An overprint by stockwork-like Mn-oxide veinlets and Mn-oxide dissemination, mineralogically expressed as birnessite, lithiophorite and jianshuiite, and geochemically represented by metalliferous enrichments, particularly mercury (Hg), occurs in the clastic dyke and its immediate vicinity. Such an overprint also contains illite, which forms a mineral association with birnessite, lithiophorite and jianshuiite, and constrains the temperature of hydrothermal alteration to less than 300 °C. The recognition of seismite and its Hg enrichment indicate that the Cenozoic history of the Quadrilátero Ferrífero cratonic terrane has been affected by seismic episodes, which were not only conducive to local enrichment in Mn at Miguel Burnier, but also to recent seismic-related phenomena such as a dam failure (Agurto-Detzel et al. in GRL 43: 4929–4936, 2016).

show abstract

Genesis of Clastic Dykes and Soft-Sediment Deformation Structures in the Mamfe Basin, South-West Region, Cameroon: Field Geology Approach

Cited by 6 publications

References 13 publications

Relict groups of spiny frogs indicate Late Paleogene-Early Neogene trans-Tibet dispersal of thermophile faunal elements

Relict groups of spiny frogs indicate Late Paleogene-Early Neogene trans-Tibet dispersal of thermophile faunal elements

Temporal and spatial variability of cross-fault groundwater-level differences: the impact of fault-induced permeability reduction, precipitation and evapotranspiration

Earthquake-induced clastic dyke and fluid inflow at the Miguel Burnier manganese-ore deposit, Quadrilátero Ferrífero of Minas Gerais, Brazil

Contact Info

Product

Resources

About