Liassic

The first insect from the Lower Toarcian Posidonienschiefer (“Posidonia Shale”) of Holzmaden (Württemberg, SW Germany), a fore wing of Heterophlebia buckmani (BRODIE 1845)
(Odonata: “Anisozygoptera”), is described from the “Unterer Stein” (“Lower Stone”), a concretion-like carbonate layer. The holotypes of the Upper Liassic Heterophlebia dobbertinensis
HANDLIRSCH 1939, Heterophlebia gracilis HANDLIRSCH 1939, Systellothemis reticulata HANDLIRSCH 1939 from Dobbertin (Mecklenburg) and Heterophlebia proxima BODE 1905
from the Brunsvick area (Lower Saxony) are revised and considered younger synonyms of H. buckmani. Besides a collecting bias, the rarity of insects in the Posidonia Shale of Holzmaden probably results from a larger distance of the sedimentation area to the Vindelician mainland.

Prosepididontus calopteryx HANDLIRSCH 1920, from the upper Lower Jurassic of Germ a ny, is transferred from Trichoptera to Grylloblattida: Geinitziidae. The anal loop like structure of P rosepididontus calopteryx is built of the concave CuP and two anal veins. Prosepididontidae HANDLIRSCH, 1920 is synonymised under Geinitziidae HANDLIRSCH, 1906.

This study analyzes the fracture network at different scales in the
Lower Jurassic limestones outcropping in the Agourai plateau, Middle
Atlas, and their relationship with karst structures. This zone belongs to
the Sub-Tabular Middle Atlas belt, called “Causses Moyen-Atlasiques”.
This area underwent a polyphased tectonic evolution, involving karst
depressions aligned NE-SW parallel to the main faults. The approach is
based on the fracturing analysis and the determination of relationships
between tectonic events and the main karstic structures development,
corresponding to aligned dolines forming important uvala systems. We
analyze the karst distribution along the main faults affecting Liassic carbonates and we describe some karst sedimentary fill.

We investigate the Triassic-Liassic sequence in ten diapirs from the Saharan Atlas (Algeria). Based on detailed mapping, two episodes are identified. The first one consists of a volcano-sedimentary sequence in which three volcanic units were identified (lower, intermediate and upper units). They are interlayered and sometimes imbricated with siliciclastic to evaporitic levels which record syn-sedimentary tectonics. This sequence was deposited in a lagoonal-continental environment and is assigned to the Triassic magmatic rifting stage. The second episode, lacking lava flows (post magmatic rifting stage), consists of carbonate levels deposited in a lagoonal to marine environment during the Rhaetian-Hettangian. The volcanic units consist of several thin basaltic flows, each 0.5 to 1m thick, with a total thickness of 10–15m. The basalts are low-Ti continental tholeiites, displaying enrichment in large ion lithophile elements and light rare earth elements [(La/Yb)n= 2.5-6] with a negative Nb anomaly. Upwards decrease of light-rare-earth-elements enrichment (e.g. La/Yb) is modelled through increasing melting rate of a spinel-bearing lherzolite source from the lower (6–10wt.%) to the upper (15–20wt.%) unit. The lava flows from the Saharan Atlas share the same geochemical characteristics and evolution as those from the Moroccan Atlas assigned to the Central Atlantic magmatic province. They represent the easternmost witness of this large igneous province so far known.

We investigate the Triassic-Liassic sequence in ten diapirs from the Saharan Atlas (Algeria). Based on detailed mapping, two episodes are identified. The first one consists of a volcano-sedimentary sequence in which three volcanic units were identified (lower, intermediate and upper units). They are interlayered and sometimes imbricated with siliciclastic to evaporitic levels which record syn-sedimentary tectonics. This sequence was deposited in a lagoonal-continental environment and is assigned to the Triassic magmatic rifting stage. The second episode, lacking lava flows (post magmatic rifting stage), consists of carbonate levels deposited in a lagoonal to marine environment during the Rhaetian-Hettangian. The volcanic units consist of several thin basaltic flows, each 0.5 to 1m thick, with a total thickness of 10–15m. The basalts are low-Ti continental tholeiites, displaying enrichment in large ion lithophile elements and light rare earth elements [(La/Yb)n= 2.5-6] with a negativ...

We investigate the Triassic-Liassic sequence in ten diapirs from the Saharan Atlas (Algeria). Based on detailed mapping, two episodes are identified. The first one consists of a volcano-sedimentary sequence in which three volcanic units were identified (lower, intermediate and upper units). They are interlayered and sometimes imbricated with siliciclastic to evaporitic levels which record syn-sedimentary tectonics. This sequence was deposited in a lagoonal-continental environment and is assigned to the Triassic magmatic rifting stage. The second episode, lacking lava flows (post magmatic rifting stage), consists of carbonate levels deposited in a lagoonal to marine environment during the Rhaetian-Hettangian. The volcanic units consist of several thin basaltic flows, each 0.5 to 1m thick, with a total thickness of 10–15m. The basalts are low-Ti continental tholeiites, displaying enrichment in large ion lithophile elements and light rare earth elements [(La/Yb)n= 2.5-6] with a negativ...

Metatrichopteridium confusum HANDLIRSCH, 1939 from the Upper Liassic of Dobbertin (Mecklenburg, Germany) is revised and recognized as a representative of the Hennigmatidae. Hennigma SHCHERBAKOV, 1995, with its type species H. cladistorum from the lowermost Cretaceous of Mongolia, is a junior synonym of Metatrichopteridium. The family Hennigmatidae seems to be an offshoot of early radiation of Diptera in the Triassic, which survived unchanged at least until the Lower Cretaceous.