Abstract Cadalene, isocadalene and a series of norcadalenes were identified in black shales of the Permian Irati Formation in the northeastern and central eastern Parana Basin (Brazil). The origin of their α-isomers with an isopropyl substituent is potentially related to higher plants, and likely reflects the spreading of pteridophytes and gymnosperms after the glaciation of southern Gondwana. A general increase in the relative abundance of isocadalene (1,6-dimethyl-3-isopropylnaphthalene, the β-isomer) co-occurs in with increasing thermal maturity at the base of the Amaral Machado Quarry (northeastern basin), and refers to the acid-catalyzed rearrangement of cadalene (1,6-dimethyl-4-isopropylnaphthalene, the α-isomer) due to the presence of montmorillonite, via an organic-inorganic interaction. This localized and incipient maturation can be related to diabase sills of the Serra Geral Formation. Similar maturation due to heating also affected the distribution of the norcadalenes by thermally stabilizing their α-isomers with an isopropyl substituent, in addition to the formation of related compounds with an ethyl substituent. Based on this, a norcadalene ratio is proposed, which is the sum of the 1,6-dimethyl-4-ethylnaphthalene and 1,6-dimethyl-3-ethylnaphthalene over the sum of the 1-isopropyl-4-methylnaphthalene and 1-isopropyl-7-methylnaphthalene. The results of this ratio and the established cadalene ratio resemble each other whereas samples from the Sao Mateus do Sul Quarry (central eastern basin) were not affected by thermal maturation and are characterized by a uniform distribution of the cadalenes and norcadalenes.

中文翻译：

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二叠纪伊拉蒂组（巴西巴拉那盆地）富含有机质页岩中的 Cadalenes 和 Norcadalenes：陆地输入的示踪剂或温度控制的有机-无机相互作用的指标？

摘要 在巴西巴拉那盆地东北部和中东部的二叠纪伊拉蒂组黑色页岩中发现了卡达林、异卡达林和一系列正卡达林。它们带有异丙基取代基的 α-异构体的起源可能与高等植物有关，并且可能反映了冈瓦纳大陆南部冰川作用后蕨类植物和裸子植物的传播。随着 Amaral Machado 采石场（东北盆地）底部热成熟度的增加，异卡达烯（1,6-二甲基-3-异丙基萘，β-异构体）的相对丰度普遍增加，并指由于蒙脱石的存在，通过有机-无机相互作用，酸催化的cadalene（1,6-二甲基-4-异丙基萘，α-异构体）重排。这种局部和初期的成熟可能与 Serra Geral 地层的辉绿岩基岩有关。除了形成具有乙基取代基的相关化合物之外，由于加热引起的类似成熟还通过热稳定具有异丙基取代基的α-异构体来影响降卡达烯的分布。在此基础上，提出了降卡达林比率，即 1,6-二甲基-4-乙基萘和 1,6-二甲基-3-乙基萘的总和与 1-异丙基-4-甲基萘和 1-异丙基-7-甲基萘。该比率的结果与既定的 cadalene 比率相似，而来自 Sao Mateus do Sul 采石场（中东部盆地）的样品不受热成熟的影响，其特征是 cadalenes 和 norcadalenes 的均匀分布。